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专英一教案1、2章Ch.1 Low speed aerodynamicsDivision of AerodynamicSubsonic aerodynamics 亚音速空气动力学M<0.8 Transonic aerodynamics 跨音速空气动力学0.8<M<1.2 Supersonic aerodynamics 超音速空气动力学1.2<M<5 Hypersonic aerodynamics 高超音速空气动力学M>5 1.1 The atmosphereComposition of air （See tab.）Layer of atmosphereTroposphere 对流层Stratosphere 同温层Mesosphere 散逸层Thermosphere 热电离层Ionosphere 离子层，电离层Ozone layer 臭氧层专业名词ISA International Standard Atmosphere 国际标准大气pressure 压强Ptemperature 温度Tdensity 密度ρaltitude 高度H，hspeed，velocity 速度vattitude 姿态viscosity 粘度μcompressibility 压缩性compressible 可压缩的，可压的（density changes with pressure）incompressible 不可压缩的，不可压的（density does not changewith pressure）English system（英制）：Fundamental units 基本单位force（力）pounds（lb）磅distance（距离）feet（ft）英尺time（时间）seconds（sec）秒Derived units 导出单位速度：velocity（distance/time）V，ft/sec（fps），knots=1.69（fps），节=1海里/小时面积：area（distance squared）S or A，squared ft（ft2）压强：pressure（force/unit area）P，lb/ft2加速度：acceleration（change in velocity）a，ft/sec/sec（fps2），ft/sec2质量：mass（weight/ acceleration of gravity）m，lb-sec2/ft（slug）m=w/g=lb/ft/sec2位能：potential energy（force× height）p，ft-lb功：work（force ×distance）W，ft-lb海里：nautical miles，（nmi），浬nmi=6076ft=1853.2m英里：statute miles，mile，（stmi），法定里，stmi=5280ft=1609m每分钟转速：revolution per minute，RPM，密度：density（mass/unit volume）ρ，slug/ft3，（lb-sec2/ft4）温度：temperature 。
初中八年级英语——Flying Donuts说课稿Good morning,everyone!It’s a pleasure for me to stand here and I’m very glad to have such an opportunity to share some of my teaching ideas with you.My topic today is taken from Lesson 37 of Unit 5 in Student Book 4. The main content of this unit is “Go With Transportation”,and the topic of Lesson 37 is “Flying Donuts”.I decide to present the lesson from six parts.Part One—Analysis of the Teaching MaterialFirst:Status and FunctionThis unit tells us the improvement of traffic transportation and the related stories. I will lead the students to use their imagination and encourage them to be creative. I will encourage them to say something about what they think the future transportation will be like. In this way,students’learning interest will be aroused and their oral English can be improved.Second:Teaching Objectives and Dema nds1. Knowledge objectives(1)Students can master the new words“fuel”,“oil”and “coal”.(2)Students can understand and know how to use thephrases“think of,on the way to. . . ,have fun”,etc.2. Ability objectives.(1)Students can develop their abilities of listening,speaking,reading and writing.(2)Students can improve the ability of working in pairs.(3)Students can develop their abilities of communication by learning the useful structures.3.Emotion objectives(1)Students’interest in study can be developed.（2）Students can know more about transportation and dare to express their opinions in English.(3)Students can improve their creative awareness.Third:Teaching Key and Difficult Points1. Key points:(1)Students can master the new words,phrases and sentences in this lesson.(2)Students can know about the improvement of transportation and Danny’s invention.2.Difficult points:Students are able to talk about their imaginary future transportation in oral English.Part Two—Teaching Methods1. Communicative teaching method;2. Audio? visual teaching method;3. Task? based teaching method;4. Classified teaching method.As we all know, the main instructional aim of learning English in Middle School is to cultivate students’ abilities of listening,speaking,reading,writing and their good sense of English language. So in this lesson I’ll mainly use communicative teaching method, audio? visual teaching method, task? based teaching method and classified teaching method. I’ll let the students get a better understanding of the key structures. I’ll also give the students some tasks and arrange some kinds of activities,like talking,watching CAI,and reading in roles.Part Three—Learning Methods1. Teach the students how to be successful language learners.2. Make genuine situations and provide meaningful duty, encourage the students to study the text by themselves.Part Four—TeachingStepsStep 1 Warm up and Lead InShow the students some pictures of common transplantation,like car,bike,train and so on. Ask the students:What can you see in the pictures? Is there another kind of transportation around us?Purpose of my designing:In this part,the students will say something about what they see or what they don't see in thepictures. In this way,their interest in this lesson will be aroused.Step 2 Presentation1.Learn New Words in GroupsThe new words in this lesson are fuel,oil and coal. Show students pictures of these things and teach them these new words.Purpose of my designing:After seeing the pictures,students will have a clear knowledge about these words and can learn them quickly and easily.2.Play the Tape RecorderLet the students listen to and imitate the text,pay attention to the pronunciation and intonation,and then finish the exercises on the computer.Purpose of my designing:This step is aimed at making the students get the general idea of the text. At the same time,let the students have a chance to practise their listening and speaking abilities.3.Text Learning and a QuizI’ll use CAI to present the whole text. And I’ll write the key points on the blackboard. After writing,I’ll teach them to read the words and sentences on the blackboard. Make sure they can read them correctly.After teaching them the whole text,including the meanings of new words,the use of similar expressions and soon,I’ll ask the students to try and speak out some phrases on the screen,like Idon’ t think so,have fun,a new kind of,on the way to school,and so on.Purpose of my designing:To present the text by CAI is much easier for the students to learn and grasp them meaning. CAI can provide a real situation with sound and picture and it makes the relationships between the4students better.4.Key Structures and Difficult Points LearningFirst,I will divide the students into three groups and tell them to have a discussion about what they have learn in this lesson. Then encourage them to try to understand the whole text,know what the difficult points are,and soon. At last,I will help them to master them all.For example,I teach the students to know about the differences among phrases “think of”,“think out”and“think over”. I will show them some sentences and get them to know the use of these phrases. Then encourage them to do some exercises about these phrases.Purpose of my designing:By doing exercises,the students will know how to use these similar phrases correctly.5. Read and SayI’ll give the students two or three minutes to prepare,and then get them to read the text together in three groups. Tell them to read aloud.Then I will encourage the students to say something aboutthe future transportation or their imaginary transportation. Encourage them to say more.Purpose of my designing:By reading the text and describing their opinions,the students can practise theirreading and speaking abilities again.Part Five—Summarize and HomeworkAsk the students such questions:What have we learned in this lesson? What does Danny say about his new kind / type of transportation? Do you like his idea? What new phrases have we learned today? Do you have enough confidence to finish these exercises?Now,let’s try! Then show them some exercises and help them to finish. At last,tell the students what today’s homework is.Part Six—Blackboard DesignLesson 37 Flying Donuts Language points:1.think of 认为,想起; think over 仔细考虑; think out 想出2.at / in the front of 在……前面(部) / in front of 在……前面3.on the way to school 在上学的路上/ on one’s way home 在回家路上4.with 用……Purpose of my designing:Presenting the key contentsclearly on the blackboard is beneficial to students’ knowledge grasping.5.OK. That’s all. Thanks for your listening.。
Unit 6 Lesson 34 Flying Donuts 教案Ⅰ. Teaching ContentOral words and expressions: fuel, imagination.Ⅱ. Teaching Aims1. Stimulate students’ learning interests.2. Cultivate students’ listening by catching the useful information in the listening process.Ⅲ. Teaching Important Points1. Encourage students’ to increase creative ability.2. Why is the invention called “flying donuts”.Ⅳ. Teaching Difficult PointsW hat’s the theory of an invention?Ⅴ. Teaching PreparationPictures.Ⅵ. Teaching AidsAudiotape, flashcards, pictures.Ⅶ. Type of lessonNew lesson.Ⅷ. Teaching ProceduresStep1. Play a game:Let some students explain it in English, while the others guess what it is. You must say the transportation. For example:A transporter is very long. It can hold many people in it. It can also take goods. What is it?Step2. Listen to the tape and answer the following questions:1. What is Danny’s invention made of?2. Why is it called “Flying Donuts”?3. Will Danny’s invention really work?Step3. Read the text and check the answers. Then listen to the tape again and read after it for several times.Step4. Ask the students to read the text in roles. Then act the dialogue in front of the class.Step5. Make sentences with the following language points: on the way to school, turn on, at the front of.Step6. Let’s come to “PROJECT”.Divide the class into small groups of three of four students. Each group chooses a type of transportation for the students. Instruct students to begin collecting information about that type of transportation. They will prepare a comic strip or timetable of important dates in its development. Groups present their work to the class. Depending on class size and the length of presentations, you may wish to divide up the class. Groups would then present their projects to one portion of the class.If the project cannot be finished in one class, it can be continued in the next lesson.Ⅸ. Homework1. Finish off the activity book.2. Go on the next reading in the student book.。
Module 4 Planes, ships and trains一、学习目标:A.单词和短语：road, accident, except, far, far away, crowded, choice, classmate, all the time, journey, book, outside, close, park, however, costB.交际用语：1. What happened?2. Don’t worry.3. —Who lives the closest to school?— Lingling lives closest.4. — What is the most comfortable way to go to school for Betty?— By taxi.5. —What’s the most expensive way to go to school?— Going by taxi is the most expensive.6. How do you get there?7. What’s the cheapest way?8. What’s the best way to get there?9. —What’s the cheapest way to travel from London to Paris?— The cheapest way is by coach.10. It’s the most comfortable way, but it’s the most expensive.11. He lives farthest from school.12. It is the fastest and the second cheapest.13. The more information, the better.二. 教学目标1. Function: Describing and comparing modes of transportation.2. Structure: Superlative adjectives and adverbs (-est, most); irregular superlatives.3. Skills: 1) Listening and understanding familiar topics (transportation)2) Comparing modes of transportation.3) Reading and finding specific transportation4) Writing a short passage comparing modes of transportation.4. Around the world: The longest railway5. Task: Making a holiday plan for a family trip to a city in China.三、重点及难点:Superlative adjectives and adverbs (-est, most); irregular superlatives.四、教学设计:Unit 1 He lives the farthest from school.ⅠTeaching modelListening and speakingⅡTeaching methodPWP approachⅢTeaching aims1. Key vocabulary: road, accident, except, far, far away, crowded, choice,classmate, close, all the time2. Key structures: superlative adjectives and adverbs (-est, most); irregularsuperlatives.3. Key sentences:1) What happened?2) Don’t worry.3) — Who lives the closest to school?— Lingling lives closest.4) — What is the most comfortable way to go to school for Betty?— By taxi.5) —What’s the most expensive way to go to school?— Going by taxi is the most expensive.ⅣTeaching aidsTape recorder, OHP, videoⅤTeaching StepsStep 1 Warming-up1. Work in pairs. Show some pictures and ask “How do you often go to school?”2. Look and say something about the pictures.3. Introduce the new words.4. Learn the new words.5. Read the new words.Step 2 Look and match.1. Ask the students to read the words in Activity 1.2. Look at the pictures in Activity 1 carefully.3. Now match the words with the pictures.5. Check the answers with the students.Keys: 1. train 2. ship 3. taxi 4. underground 5. busStep 3 Look, listen and match.1. Ask the students to read the words in Activity2.2. Play the recording and ask the students to listen to the recording carefully. T: Listen and match the words in the box with the pictures in Activity 1. You need to use one word more than once.3. Check the answers with the students.Step 4 Listen and read.1. Show some pictures, and ask the students to talk about them.2. Ask the students to read the conversation silently.3. Play the recording and ask the students to listen the conversation, and then answer the questions.1) How does Lingling go to school? Why?2) How do you think Betty will go to school?4. Read the conversation.5. Act it out.Step 5 Complete the table.1. Ask the students to read the conversation again.2. Now complete the table.3. Check the answers.Keys: by bus (by bike) by underground walks / on foot by bus Step 6 Complete the sentences.1. Ask the students to read the words in the box in Activity 4.2. Read the sentences.1) The _________________ way to go to school is by taxi.2) Tony lives the __________ from school.3) Lingling’s home is the _________ to school, so she always walks.4) For Betty, going to school by bike is the ______ choice.3. Complete the sentences with the correct words from the box.4. Check the answers:Keys: 1. most comfortable 2. farthest 3. closest 4. bestStep 7 Complete the sentences.1. Ask the students to read the words or expression in the box in Activity 5.2. Read through the sentences.1) All the students take the bus to school ___________ Sam.2) The ___________ train in the world is the Shanghai airport train.3) I saw a(n) __________ on the way to school yesterday.4) I do not take the bus to school because it is usually very ___________.3. Complete the sentences with the correct words from the box.4. Check the answers:Keys: 1. except 2. most modern 3. accident 4. crowdedStep 8 Pronunciation and speaking.1. Play the recording once without stopping.2. Play the recording again and ask the whole class to repeat.1) —Who lives the closest to school?— Lingling lives closest.2) — What is the most comfortable way to go to school for Betty?— By taxi.3. Ask the students to listen and mark the intonation.4. Now listen again and repeat.Step 9 Work in pairs.1. Ask the students to read the words or expression in the box in Activity 7.2. Read the example with the class.—What’s the most expensive way to go to school?— Going by taxi is the most expensive.3. Work in pairs.Step 10 Language points1. Maybe I should go to school by taxi. 或许我应该坐出租车去上学。
教学对象：四年级学生教学目标：1. 知识目标：让学生掌握与航空航天相关的英语单词和短语，如：plane, rocket, astronaut, space, launch等。
2. 能力目标：培养学生运用英语进行简单交流的能力，如询问某人职业、介绍航天知识等。
3. 情感目标：激发学生对航空航天知识的兴趣，培养学生热爱科学、探索未知的品质。
教学重点：1. 掌握与航空航天相关的英语单词和短语。
2. 学会运用英语进行简单交流。
教学难点：1. 灵活运用所学词汇和短语进行表达。
2. 正确发音和语调。
教学准备：1. 教学课件（包含航空航天图片、视频等）。
2. 单词卡片、句子卡片。
3. 小组活动材料。
教学过程：一、导入1. 教师展示航空航天图片，引导学生观察并说出图片内容。
2. 引导学生思考：你们知道这些图片中的东西叫什么名字吗？它们有什么作用？二、新授1. 教师出示单词卡片，带领学生认读并学习以下单词：plane, rocket, astronaut, space, launch。
2. 教师出示句子卡片，引导学生模仿并跟读以下句子：- What is this?- It's a plane/rocket/ astronaut/ space/launch.- Who is this?- He/She is an astronaut.3. 教师通过课件展示航天器的发射过程，引导学生学习以下短语：launch, take off, orbit, land。
三、巩固练习1. 小组活动：每组选出一个代表，展示自己小组的航空航天知识卡片，其他组员猜测卡片内容。
2. 游戏环节：教师播放一段关于航天的视频，学生观看后回答视频中提到的单词和短语。
四、拓展延伸1. 教师引导学生思考：如果你们是国家的一名宇航员，你们最想探索哪个星球？为什么？2. 学生分组讨论，每组派代表分享自己的观点。
五、总结1. 教师带领学生回顾本节课所学内容，强调重点单词和短语。
牛津教材flying high 教案教学目标：1. 通过本课学习，学生能够掌握本单元中一些重要单词和句子的运用。
2. 学生能够了解并掌握一些关于飞行的知识和技巧，提高对航空知识的兴趣。
3. 通过小组合作学习和实践活动，培养学生的团队协作精神和动手能力。
教学内容和步骤：一、导入（5分钟）1. 教师出示一些关于飞行和航空的图片或视频，引起学生的兴趣。
2. 教师引导学生进入本单元的主题“flying high”，并简单介绍本课的学习内容。
3. 学生自由讨论关于飞行的各种话题，为接下来的学习做好准备。
二、新授（20分钟）1. 教师出示本课的重要单词和短语，并进行讲解和发音示范。
* airplane 飞机* take off 起飞* land 降落* jet lag 时差不适应* control 操纵杆* altitude 高度2. 学生跟读并理解这些单词和短语的含义，通过游戏和小组合作活动进行操练。
3. 教师出示一些句子范例，引导学生学习并掌握有关飞行的句式表达。
4. 学生分小组进行角色扮演或对话练习，运用新学的单词和句子进行交流和表达。
教师进行巡回指导。
5. 教师出示一些问题和思考题，引导学生进行讨论和思考，加深对新知识的理解和运用。
三、拓展（10分钟）1. 教师出示一些航空知识的相关阅读材料或视频片段，引导学生进行阅读或观看，扩展学生的知识面和兴趣点。
2. 学生分小组进行讨论和交流，分享自己的理解和感受，深化对航空知识的认识和理解。
3. 教师进行总结和评价，鼓励学生继续关注和学习航空知识，培养自己的兴趣爱好。
四、结束（5分钟）1. 教师总结本课的主要内容和知识点，强调重点和难点。
2. 学生回顾本课的学习过程和收获，教师给予鼓励和评价。
3. 学生自愿进行课堂小结展示，分享自己的学习成果和感受。
五、作业（课后布置）1. 抄写本课单词和短语。
2. 完成相关练习题和作业题。
3. 搜集一些有关飞行的图片或视频，与同学分享。
幼儿园飞机英语课堂教案1. 教学目标•能够认识和理解单词Airplane，wing，propeller等。
•能够模拟飞机的飞行动作，掌握英语表达方式，比如Fly high，Fly low等。
•培养幼儿的英语学习兴趣和口语表达能力。
2. 教学准备•飞机图片或模型。
•设备音响和播放器。
•用于展示教案的屏幕或黑板。
•一些玩具，如小飞机。
3. 教学内容3.1 Warm-up（5分钟）1.通过播放音乐和跟随动作的形式，引导幼儿做一些热身运动，比如合拢双脚，伸展双臂，转头等。
3.2 Presentation（10分钟）1.展示飞机的图片或模型，让幼儿认识并学习相关单词2.引导幼儿比较两种不同的飞机，问他们有什么不同之处，比如大小、形状和颜色等。
3.3 Practice（20分钟）1.引导幼儿通过模拟飞机飞行的姿势，学习英语表达方式，如Fly high，Fly low等。
2.捉迷藏游戏，把一些小飞机藏在房间各处，让幼儿用英语表达它们的位置，例如“the airplane is under the table”等。
3.呈现图片，通过浏览和回答问题的形式，巩固幼儿对英语单词和短语的认识和记忆。
3.4 Extension（20分钟）1.让幼儿自己制作一架简单的飞机模型，给学生提供画纸、剪刀、粘性物品和其他必要的工具。
2.让幼儿自己绘制飞机并写下一些与飞机相关的单词和英语短语。
让学生分享自己的作品，并互相交流。
3.5 Summary（5分钟）1.让每个学生分享今天的学习体验，分享他们记住了什么单词和短语等。
2.适当总结今天的教学内容。
4. Homework（5分钟）1.关于飞机的活动，老师可以要求学生在家中绘制自己最喜欢的飞机并且写下几个关于飞机的英语单词。
以上是本次课堂的教案，希望能够对教学有所帮助。
《Airplane Flight》幼儿园小班英语教案一、引言1.1 背景介绍：介绍飞机的历史和发展，以及它在现代社会中的重要性。
1.2 课程导入：通过展示飞机模型或图片，激发幼儿对飞机的兴趣。
1.3 课程目标：明确本节课的教学目标和预期效果，让幼儿能够理解和运用与飞机飞行相关的英语词汇和表达。
二、教学目的2.1 语言能力：培养幼儿的英语听说能力，让他们能够用英语描述飞机的外形、功能和飞行过程。
2.2 认知能力：让幼儿了解飞机的基本构造和飞行原理，培养他们的观察力和思维能力。
2.3 情感态度：培养幼儿对英语学习的兴趣和积极性，让他们在轻松愉快的氛围中学习。
三、教学重、难点3.1 教学重点：教授与飞机飞行相关的英语词汇和表达，如wing、tail、propeller等。
3.2 教学难点：让幼儿理解和掌握飞机的飞行原理，如lift、thrust、drag等。
3.3 教学策略：通过实物展示、图片、视频等多种教学手段，帮助幼儿理解和记忆英语词汇和表达，以及飞机的飞行原理。
四、教学设想4.1 教学方法：采用情景教学法，创设飞机飞行的场景，让幼儿在真实情境中学习和运用英语。
4.2 教学步骤：先通过实物展示和图片，让幼儿认识和了解飞机的基本构造和功能，然后通过视频和动画，让幼儿了解飞机的飞行原理，通过角色扮演和游戏，让幼儿运用所学的英语词汇和表达，描述飞机的飞行过程。
4.3 教学评价：通过观察幼儿的参与程度、语言表达能力和对飞机飞行原理的理解程度，评估教学效果，并根据评估结果调整教学策略和方法。
五、教学准备1. 准备飞机模型或图片，用于展示和教学。
2. 准备与飞机飞行相关的英语词汇卡片，如wing、tail、propeller等。
3. 准备飞机飞行的视频或动画，用于讲解飞机的飞行原理。
4. 准备角色扮演和游戏的道具，如飞机模型、飞行员服装等。
六、教学过程1. 导入：通过展示飞机模型或图片，激发幼儿对飞机的兴趣。
一、教学目标1. 知识目标：使学生了解航空英语的基本概念、用途和重要性。
2. 能力目标：培养学生阅读航空英语资料的能力，提高学生的英语听说能力。
3. 情感目标：激发学生对航空英语的兴趣，培养学生对航空事业的热爱。
二、教学重难点1. 教学重点：航空英语的基本概念、用途和重要性。
2. 教学难点：阅读航空英语资料，提高英语听说能力。
三、教学准备1. 教师准备：教材、PPT、相关航空英语资料、图片等。
2. 学生准备：预习教材，了解航空英语的基本概念。
四、教学过程1. 导入新课（1）教师展示航空图片，引导学生谈论航空话题。
（2）介绍航空英语的基本概念，如：航空英语、航空术语等。
2. 讲授新课（1）讲解航空英语的用途，如：机场服务、航空安全、航空维修等。
（2）介绍航空英语的重要性，如：提高服务质量、保障航空安全等。
（3）展示航空英语的例子，如：登机牌、航班信息、航空安全须知等。
3. 课堂活动（1）分组讨论：学生分组讨论航空英语在航空行业中的应用。
（2）角色扮演：学生模拟机场服务场景，运用航空英语进行对话。
4. 巩固练习（1）教师提问，检查学生对航空英语的理解程度。
（2）学生阅读相关资料，提高阅读能力。
5. 课堂小结（1）教师总结本节课所学内容，强调航空英语的重要性。
（2）布置课后作业，让学生阅读航空英语资料，提高英语听说能力。
五、教学反思1. 教学效果：通过本节课的学习，学生能够了解航空英语的基本概念、用途和重要性，提高英语听说能力。
2. 教学改进：在今后的教学中，可以增加更多实际案例，让学生在实际操作中提高航空英语水平。
六、教学评价1. 学生评价：通过课堂活动、课后作业等方式，评价学生对航空英语的掌握程度。
2. 教师评价：根据学生的课堂表现、作业完成情况等，评价学生的英语听说能力。
Ch. 4Flight Performancetransport aircraft performance：take-off performance 起飞性能climb performance 爬升性能cruise performance 巡航性能descending performance 下降性能landing performance 着陆性能turning performance 盘旋性能engine-out performance 发动机失效后性能stalling performance 失速性能4.1 take-off performanceConsider an airplane standing motionless at the end of a runway. The pilot releases the brakes and pushes the throttle to maximum take-off power，and the airplane accelerates down the runway. At some distance from its starting point，the airplane lifts into the air.4.1.1 Forces acting on an aircraft in take-offThe forces acting on an aircraft in take-off are weight W、lift L、thrust T、drag D and a rolling resistance R caused by friction between the tires and the ground. This resistance force is given by the coefficient of rolling friction and the net normal force（W-L）exerted between the tires and the ground.4.1.2 take-off distanceThe sum of S g and S a is the total take-off distance for the airplane.The S g is called the ground roll（or sometimes the ground run）which is covered along the runway before the airplane lifts into the air. The S a is the take-off distance in airborne over the obstacle which is generally defined to be 50ft for military aircraft and 35ft forcommercial aircraft.The ground roll S g is further divided into intermediate segments. These segments are defined by various velocities，as follows：1,V stall stalling speed 失速速度2,V mcg minimum control speed on the ground 地面最小可操纵速度This is the minimum speed at which enough aerodynamic force can be generated on the vertical fin with rudder deflection while the airplane is still rolling along the ground to produce a yawing moment sufficient to counteract that produced when there is an engine failure for a multiengine aircraft.3,V mca minimum control speed in the air空中最小可操纵速度If the airplane were in the air（without the landing gear in contact with the ground）, the minimum speed required for yaw control in case of engine failure is slightly greater than V mcg. For the groundroll shown in Fig.，V mca is essentia1ly a reference speed-the airplane is still on the ground when this speed is reached.4,V1 decision speed 决断速度This is the speed at which the pilot can successfully continue the take-off even though an engine failure（in a multiengine aircraft）would occur at that point. This speed must be equal to or larger than V mcg in order to maintain control of the airplane. If an engine fails before V1is achieved，the take-off must be stopped. If an engine fails after V1is reached，the take-off can be achieved.5,V R take-off rotational speed 起飞抬前轮速度At this velocity, the pilot initiates by elevator deflection a rotation of the airplane in order to increase the angle of attack, hence to increase C L. Clearly, the maximum angle of attack achieved during rotation should not exceed the stalling angle of attack. Actually, all this is needed is an angle of attack high enough to produce a lift at the given velocity larger than the weight, so that the airplane will lift off the ground. However, even this angle of attack may not be achievable because the tail may drag by the ground.（Ground clearance for the tail after rotation is an important design feature for the airplane, imposed by take-off considerations.）6, V mu minimum unstick speed 最小松杆速度If the rotation of the airplane is limited by ground clearance forthe tail, the airplane must continue to accelerate while rolling along the ground after rotation is achieved，until a higher speed is reached where indeed the lift becomes lager than weight. This speed is called the minimum unstick speed.7,V LO liftoff speed 起飞速度，离地速度For increased safety, the angle of attack after rotation is slightly less than the maximum allowable by tail clearance, and the airplane continues to accelerate to a slightly higher velocity, called the liftoff speed, denoted by V LO. This is point at which the airplane actually lifts off the ground. The total distance covered along the ground to this point is the ground roll S g.4.1.3 Factors affecting take-off performanceThe design parameters have an important effect on take-off ground roll. S g depends on wing load W/S, thrust-to-weight T/W and maximum lift coefficient（C L）max, the ambient density ρ∞，wind and ground conditions.S g increases with an increase in W/S.S g decreases with an increase in（C L）max.S g decreases with an increase in T/W.S g increases with a decrease in ρ∞.S g increases with a tailwind，and decreases with a headwind.4.2 Climb performancezooming 急跃升power required 需用功率thrust required 需用推力power available 可用功率thrust available 可用推力excess power 富裕功率excess thrust 富裕推力A climb is an ascending flight path at constant speed.It is usually a straight path but, sometimes, a climbing turn is necessary.● a zoom, which exchanges speed for height.An aircraft flying at high speed /low altitude can rapidly convert the kinetic energy to potential energy by raising the nose and “zooming”.In a normal climb to cruise altitude, such techniques are inefficient. Fuel burnt in the engine is converted into increasing potential or kinetic energy.A zoom is an increase in altitude that exchanging the kinetic energy of motion for potential energy. i.e. by converting excess velocity V to increased altitude. A zoom is only a transient process.● a climb where the aircraft is driven upward by excess thrust fromthe engine and sustains its speed throughout.ceiling 升限absolute ceiling 绝对升限，理论升限service ceiling 实际升限，使用升限A steady climb is achieved by converting propulsive energy （thrust）to give altitude.A climb can be maintained until the reduction in thrust, due to increasing altitude, eventually reduces the rate of climb to zero. Thisis known as the absolute ceiling of the aircraft. The service ceiling is the altitude where the maximum rate of climb is reduced to 100 feet per minute.types of climbThere are three（or four）types of climb：●maximum angle climb●maximum rate climb●normal climb●cruise climb4.2.1 Forces acting on an aircraft in climbIf you maintain a steady climb at a constant indicated airspeed, the engine-propeller must supply sufficient thrust to overcome：●the drag at the climb airspeed; and●the component of the weight that acts negatively along the climb path.In a climb there is no acceleration. The forces are in equilibrium and consequently the resultant force is zero.In a climb thrust is greater than total drag; total lift is slightly less than weight.∵ T= D + W×sinθ, L = W×cosθAs the climb becomes steeper, more and more thrust is required and less and less lift. In a vertical climb, which some fighters can achieve, the thrust balances the drag and all of the weight, there is no lift at all.We normally climb at 50 or less, so the difference between lift and weight is small. （cos 50=0.996）4.2.2 Maximum rate climbVertical speed is called rate of climb. Rate of climb is shown in the cockpit on the vertical speed indicator（VSI）.Power =work done/ per second=force ×distance/ per second = force ×velocity=thrust ×TASV sinθ =V y=V（T－D）／W=（P a-P r）/W=富裕功率/WP a power available（P a＝T×V）,P r power required （P r＝D×V）P a-P r excess powerIf W=const.，（V y）max=（P a-P r）max /WClimbing for maximum rate is achieved at a speed where there is maximum excess power.The greater the excess power，the lower the weight, the lower the drag，and the greater rate of climb.4.2.3 Maximum angle climb∵sinθ = （T-D）/W T-D：excess thrust 富裕推力∴ The angle of climb depends directly on the amount of excess thrust and the weight.●the lower the weight, the greater the angle of climb.●the greater the thrust, the greater the angle of climb.●the lower the drag, the greater the angle of climb.For maximum climb gradient, the aeroplane should generally be kept in a low-drag configuration.The speed for the maximum rate of climb（V y）usually occurs at a speed somewhere near that for the best lift/drag ratio, and is therefore faster than the speed for the maximum angle of climb.dh = V y dt = V ×sinθ dtdL = V ×cosθ dt4.2.4 Factors affecting climb performancePerformance in the climb, either angle or rate of climb, will reduce due to●reduced thrust and power;●increased weight or drag;●low air density due to high temperature or higher altitude;●inaccurate airspeed（either too fast or too slow）.1，temperatureHigh ambient temperatures decrease climb performance. If the temperature is high, then the air density（ρ）is less. The engine-propeller and the airframe will both be less efficient, so the performance capability of the aeroplane is less on a hot day.2，altitudeIncreasing altitude decreases climb performance. Power available from the engine/propeller decreases with altitude. The climb performance, both the rate and the angle of climb, will decrease at altitude.（mixture leaned 贫油）3，airspeed1）flying too fastIf you fly faster than the recommended speed, there is less excess thrust and less excess power.2）flying too slowIf you fly slower than the recommended speed, the excess power is reduced and, therefore, the rate of climb is directly reduced.4，the effect of wind on climb performanceWhen air moves, the aircraft will travel a lesser or greater horizontal distance（headwind and tailwind respectively）in that time. The angle of climb relative to the terrain, is steeper in a headwind and is reduced by a tailwind.4.3 Cruise performance4.3.1 Forces acting on an aircraft in cruiselift produced by the main plane（wing）CPweight of the total aircraft CGdrag which acts rearward opposite to the flight paththrust produced by the enginesIn steady（unaccelerated）, straight and level flight the aircraft is traveling in a straight line at a constant altitude and at a constant airspeed，total lift equals total weight, and thrust equals total drag. The aircraft is in equilibrium. thrust= drag, lift= weight.This means that all forces and moments are in balance there is no resultant force to accelerate or decelerate it- nor resultant moment to change its attitude in pitch, roll, or yaw.1, pitching moments of the four forcescouple 力偶（thrust/ drag, lift/ weight）Where the CP is behind the CG, the lift- weight pair produces a nose-down pitching moment.The thrust- drag pair produces a nose-up or nose-down pitchingmoment. The size of this moment is significantly less than the lift- weight moment because of a small moment arm and small force.nose-down pitching moment 低头俯仰力矩（-）nose-up pitching moment 抬头俯仰力矩（+）2, balancing moment-the tailplanehow balancing the four forces to achieve pitching equilibriumThe conventional aircraft is fitted with a tailplane that provides a means of balancing the results of the four main forces.The large distance of the tailplane from the centre of gravity （large tail moment arm）allows the use of relatively small tailplaneforces to achieve the necessary restoring moments.The tailplane may be fixed or varied.Most large aircrafts have a variable-incidence tailplane with an attached elevator which provides a much wider range of trim capability and greater control power.Variable-incidence tailplane are commonly found on aircrafts that have a large CG range, a large speed range and varying pitch moments.variable-incidence 变安装角, trim 配平3, variation in the balance of forces and moments1）variation of speed in the cruiseA reduction in cruise speed will require an increase in angle of attack to maintain lift equal to weight, which will result in a forward movement of the CP.A forward movement of CP position for a constant lift will reduce the magnitude of the nose-down pitching moment. Since the drag that results from a lower speed will also change, then the total balance of forces will change, requiring a new balancing moment from the tailplane.The result of changing speed in the cruise is to vary the magnitude of the tailplane force.2）variation of weight in the cruiseIn a normal flight, the weight gradually reduces as fuel is burned-off. If the aeroplane is to fly level, the lift produced must gradually decrease as the weight decreases. If there is a sudden decrease in weight，say，by half a dozen parachutists leaping out, then to maintain straight and level flight, the lift must reduce by a corresponding amount. The C L（angle of attack）or the airspeed must be reduced so that less lift is generated.Suppose that the aeroplane is cruising at a particular angle of attack, say, for the best L/D ratio. To maintain this most efficientangle of attack as the weight reduces, the airspeed must be reduced to reduce the lift so that is still balance the weight. So, if the height and the angle of attack are to be keep constant, then the airspeed will have to be reduced. The power（thrust）will be adjust to balance the reduced drag.a dozen 一打,12亇parachutist 降落伞leaping out 放出If you wish to keep the power constant and you want to maintain height as the weight decreases, the lift must be decreased by reducing the angle of attack（decreasing the C L）. Therefore the speed will increase.If you want to keep the speed constant and maintain height, then as the weight reduces you must reduce the lift produced, and you do this decreasing the angle of attack.H=const. W↓→L↓ ∵W=L=（1/2）ρV2SC Lρ＝const.α=const.→C L=const.→V↓（→D↓→T↓∵D=T）T=const.→α↓（C L↓）→V↑（D=T）V=const. →α↓（C L↓）Sometimes the weight increases in flight by, for instance, the formation of ice on the structure. An increased weight will mean that increased lift is required to maintain level flight- and once again the above discussion applies, but in reverse.Ice on the wings, especially on the upper surface near the leading edge will cause a drastic（急剧的）decrease in the efficiency（C L）of the wing and a significant increase in drag.To maintain the recommended angle of attack for the required cruise mode, a lower speed must be flown for the lower weight-alternatively, the aircraft may be allowed to slowly climb （cruise climb）.3）variation of centre of gravity positionDifferent CG position will result in variation to the balance of moments about the CG.A change in CG position results a different tailplane force.4）attitude in level flightTo obtain the required lift at low speed, a high angle of attack （high C L）is required, while at high speed, only a small angle of attack（low C L）is needed.4.3.2 Performance in level flightThe thrust required for steady, straight and level flight is equal to the drag（D=T）,and so the thrust- required curve is identical to the drag curve.High thrust is required at high speeds to overcome mainly parasite drag（low angle of attack, low induced drag）.●Minimum thrust is required at minimum drag speed（which is alsothe best L/D ratio speed, since L is constant in straight and level flight and D is at its minimum）.●Increased thrust is required at low speeds（high angle of attack）to overcome mainly induced drag.Power= thrust ×true airspeedWe can develop a power required curve from thrust required curve by multiplying the thrust required, at any point on the curve, by TAS any that point and then plotting the result against the same speed scale. This will give us the power required to maintain level flight at that speed.1，what does the graph show ？●maximum level flight speedMaximum level flight speed occurs when the power available from the engine-propeller matches the power required to produce enough thrust to balance the drag at the high speed.●minimum level flight speedThe minimum level flight speed is usually not determined by the power capability of the powerplant, but the aerodynamic capability of the aeroplane.In steady straight and level flight, the lift must balance the weight.W = L = 1/2ρV2SC LAs altitude is increased, air density（ρ）decreases.One way to generate the required lift and compensate for the decreased density （ρ）is for the pilot to increase the true airspeed V so that the value of 1/2ρV2 remains the same as before.2, speed stability and the drag curve1) higher speedsAbove minimum drag speed, any minor speed fluctuation is self correcting. This is called speed stability.In the regime, an increase in airspeed increases the total drag, due to an increase in parasite drag causing the aircraft to slow down. A decrease in airspeed decreases the total drag, due mainly to an decrease in parasite drag causing the aeroplane to accelerate back to its original speed.In the normal airspeed regime, above the minimum drag speed, the pilot does not have to be active with the throttle since the aeroplane is speed stable and, following any disturbance, will tend to return to its original trimmed airspeed without pilot action. 2) lower speedsAt lower speeds（below minimum drag speed）it is a different matter. If a gust causes airspeed to decrease, the total drag increases.Total drag now exceeds thrust, causing the aeroplane to slow down further.If a gust causes airspeed to increase, the total drag decreases. Drag is now less than thrust, causing the aeroplane to accelerate further away from the original speed. This is called instability.4.3.3 Maximum range cruiseMaximum range is the greatest distance that can be achieved from the fuel available. It shows how far the aircraft can travel irrespective of the time taken.irrespective 与…无关比航程specific air range （SAR）Specific air range（SAR）is a ratio of distance to fuel consumption.SAR = distance/ fuel used=（distance/time）/（fuel used/time）= TAS/ fuel flow耗油率specific fuel consumption（SFC）Specific fuel consumption（SFC）is a ratio of fuel flow to thrust.SFC= fuel flow/ thrust ∴fuel flow=SFC ×thrust∴ SAR= TAS/ (thrust× SFC）（SAR）max= （TAS/drag）max/（SFC）minSAR of an aircraft is dependent on two separate factors, an airframe consideration and a separate engine consideration.1, airframe consideration（max. TAS/ drag）TAS/ drag=（TAS/IAS）×（IAS/drag）For maximum value of TAS/ drag, we need a maximum value of TAS/ IAS, together with the maximum value of IAS/drag.The maximum IAS/ drag ratio is achieved, when a line from the origin in drawn at a tangent to the drag ∽IAS curve，this IAS being 1.32 times the IAS for minimum drag（V IMD）. This speed is valid at all altitude.（for the jet aircraft）Power required=thrust required ×TASPower required/ TAS= thrust required=drag∴（Power required/ TAS）min=（drag）min2, engine consideration（minimum SFC）For minimum SFC, we want the engine to use the least fuel for a given amount of thrust produced.One of the main factor that has reduced SFC is a change in engine design and configuration.Of the variable that effects SFC, and controllable by the pilot, engine RPM has the most affect.Engines are designed to have a band of rpms over which SFC does not change significantly. Within this operating band there will be one specific setting that provides the lowest SFC. This is called the design rpm.cruise climb：Once aircraft weight has reduced from the initial cruise figure, the aircraft is climbed with design rpm such that IAS reduces to maintain best range angle of attack.step climb：As weight is reduced, the aircraft is climbed to the next suitable level where best speed and design rpm can be used. A flight may consist of number of steps, where the cruise is commenced（开始）with optimum figures.4.3.4 Maximum endurance cruiseMaximum endurance（续航时间）is the greatest time from the available fuel and taken no account of distance traveled.Time in flight is inversely proportional to the fuel flow.The lower the fuel curve, the greater the endurance.SFC= fuel flow/ thrust∴fuel flow=SFC ×thrust= SFC ×dragWhen SFC=const.（fuel flow）min= SFC×（drag）minThe minimum fuel flow occurs at minimum thrust required, this is （L/D）max（for a jet engine）Since fuel flow for an engine-propeller combination depends on power set，minimum fuel flow（maximum endurance）will occur at the speed where minimum power is required.The designers will have recommended a particular angle of attack that will achieve the necessary operating economies（for maximum range or for a compromise between range and a reasonably short flight time）.4.4 Descending performance下降特性descend v. 下降，descent n.下降，descending a.下降的There are several types of descent：● a glide where the engine is idling（空转,空载）and effectivelyproducing zero thrust.● a powered descent where the engine is providing some thrust.● a dive（俯冲）where the altitude is exchanged for airspeed（thereverse of the zoom）.There are two measures of a descent：●the angle of descent●the rate of descent（ROD）.4.4.1 Forces in descending1, the glide 下滑If an aeroplane is descending at constant airspeed, with no thrust being produced by the engine-propeller, it is called a glide. Only three of the four main forces will be acting on the aeroplane – weight, lift and drag.In a steady glide three forces will be in equilibrium as the resultant is zero.L = W×cosθ ∵cosθ≈1 ∴L ≈ WD = W×sinθ L/ D = 1/ sinθ→sinθ= D/L = 1/K∴ K = K maxθ =θmin下滑的水平距离l = V×cosθ×tThe maximum gliding distance（minimum glide angle）is obtained if the aeroplane is flown at the speed for best L/D ratio（minimum drag）.The greater the drag, the steeper the glide because a greater component of weight is needed along the flight path and the only way to achieve this is to steeper the angle of glide.The shallowest glide angle is exactly the best L/D ratio.A high performance sailplane may have a best glide ratio of 60：1.2，the powered descentIf the engine-propeller is producing thrust, it will help overcome part of the drag force.D = T+W sinθ sinθ= （D-T）/Wrate of descent 下降率（V y=V sinθ）Less of the weight component is required to overcome the drag and so the angle of descent is made shallower at the same airspeed.A shallower descent angle at the same airspeed, gives a lower rate of descent than in the power off glide.As thrust is increased, a point is reached where no component of the weight is need to maintain the airspeed and the descent angle is reduced to zero, the aircraft is back to straight and level flight.1）Increasing power flattens the descent and reduces the rate of descent.2）controlling the descentThe pilot decides which（rate of descent, angle of descent, airspeed ）is most important. If the time to destination（目的地）is important, then airspeed may be the prime factor. If the passengers are of concern, the rate of descent may be the prime requirement. 3) descent airspeedAirspeed is the prime reference, and attitude and power are adjusted to maintain a descent path or profile.4) descent rate（a rate of 500ft per minute）5) descent path（relative to the ground on final approach or a glide）When the profile has to reach a specific point on the ground and there is need to maintain both a constant path or airspeed.●reduce the power●increase the drag by extending the flaps, the undercarriage,side-slipping4.4.2 Factors affecting glide angle1) airspeedThe wrong airspeed（too fast or too slow for the weight）steepens the glide because it reduces the L/D ratio.2) configurationEven partial flap setting will increase the drag more the lift and consequently reduce the L/D ratio.Extending the undercarriage or speed brakes would increase drag and steeper the descent.3)weightGlide angle is determined by L/D ratio, which is determined by angle of attack. The speed for best L/D ratio changes with weight. If the weight is less, the required lift is less, and so to maintain the same angle of attack, the airspeed must be reduced. At the angle of attack for the best L/D ratio, the airspeed will be lower but the glide angle remains the same.4)effects of wind on the glideThe air is moving during glide the horizontal distance traveled relative to the ground is directly effected by the wind. A headwind reduces glide distance over the ground; a tailwind increases it. Steeper into a headwind and shallower with a tailwind.4.5 Landing performanceThe analysis of the landing performance of an airplane is somewhat similar to that for take-off，only reverse.4.5.1 Forces acting on an aircraft in landing1，The forces acting on an aircraft in landing approach are weight W、lift L、thrust T、drag D.Assuming equilibrium flight conditions：L＝W cosu aD＝T＋W sinu asinu a＝（D－T）／WThe approach angle is usually small for most cases. For transport aircraft u a≤3o. Hence, cosu a≈1 and L≈W.So,sinu a＝（D－T）／W＝D/L－T/W2，The forces acting on an aircraft in landing ground roll is the same as the take-off ground roll. There are thrust, lift, drag, weight and a rolling resistance R，caused by friction between the tires and the ground. This resistance force is given by the coefficient of rolling friction and the net normal force（W-L）exerted between the tires andthe ground. However, normal landing practice assumes that upon touchdown, the engine thrust is reduced to idle（essentially zero）. In this case T＝0.Many jet aircrafts are equipped with thrust reversers which typically produce a negative thrust equal in magnitude to 40％or 50％of the maximum forward thrust. Some reciprocating engine /propeller-driven airplanes are equipped with reversible propellers that can produce a negative thrust equal in magnitude to 40％of the static forward thrust. For turboprops, this increases to 60％.4.5.2 landing distanceThe sum of S a、S f and S g is the total landing distance for the airplane.The S a is the approach distance in airborne over the obstacle which is generally defined to be 50ft for commercial aircraft. At that instant the airplane is following a straight approach path with angle u a. The velocity of the airplane at the instant, denoted by V a, is required to be equal to 1.3 V stall for commercial airplanes and 1.2 V stall for military airplanes.At a distance h f above the ground, the airplane begins the flare, which is the transition from the straight approach path to horizontal ground roll. The flight path for the flare can be considered a circular arc with radius R. The distance measured along the ground from the obstacle to the point of initiation of the flare is the approach distance S a.Touchdown occurs when the wheels touch the ground. The distance over the ground covered during the flare is the flare distance S f. The velocity at the touchdown V TD is 1.15 V stall for commercial airplanes and1.1 V stall for military airplanes.After touchdown, the airplane is in free roll for a few secondsbefore the pilot applies the brakes and/or thrust reverser. The free roll distance is short enough that the velocity over this length is assumed constant, equal to V TD. The distance that the airplane rolls on the ground from touchdown to the point where the velocity goes to zero is called the ground roll S g.4.5.3 Factors affecting landing performanceThe landing ground roll is similar to take-off ground roll. S g depends on wing load W/S, revere thrust-to-weight T rev/W（if used）, maximum lift coefficient（C L）max, the ambient density ρ∞，wind and ground conditions.S g increases with an increase in W/S.S g decreases with an increase in（C L）max.S g decreases with an increase in T rev/W.S g increases with a decrease in ρ∞.S g increases with a tailwind，and decreases with a headwind.4.6 Turning performance4.6.1 Forces in a turn。
Ch.5 Stability and control5.1 Balance and trim1,balance in straight and level flightbalance 平衡see-saw 杠杆bean 梁wooden bean 木梁suspended bean 悬吊梁fulcrum 支点trim 配平equilibrium 平衡control column 操纵杆rudder pedal 方向舵脚蹬align, alignment 成一直线Balance consists of two elements-the total forces acting the aircraft and the alignment of these forces. When the forces are balanced and aligned the aircraft is said to be in equilibrium.There are two types of forces-static forces, dynamic forces.Weight is a static force it can be considered constant at any time. Thrust varies with engine power, propeller rpm and airspeed but can be set at a constant value by the pilot.Lift is aerodynamic force which changes with airspeed and flap extension but which can be controlled directly by the pilot changing the angle of attack.Drag changes with angle of attack, configuration and airspeed.In straight and level flight, lift opposes weight L=W thrust opposes drag T=D.The lift and weight will only decrease gradually as the weight decreases with fuel burn-off. The thrust and drag will vary considerably depending on angle of attack and therefore airspeed. 2, pitching momentUnder most conditions of flight the CP and CG are not coincident, i.e. are not at the one point, causing nose-down pitching moment or a nose-up pitching moment.The different lines of action of the thrust force and drag forceproduce another couple, causing a nose-down pitching moment or a nose-up pitching moment.Ideally the pitching moment from the two couples should neutralize each other in level flight so that there is no resultant moment tending to rotate the aircraft3, the tailplanehorizontal stabilizer 水平安定面function 功能,作用counteract 平衡,中和residual 剩余的, neutralize 抵消coincident 一致The function of tailplane（or horizontal stabilizer）is to counteract these residual pitching moments from the two main couples and to damped any oscillation in pitch, i.e. it has a stabilizing function. The tailplane usually has a symmetrical or a negatively cambered aerofoil.The moment produced by the tailplane can be varied either by moving the elevator or by moving the entire tailplane.The moment arm of tailplane is quite long, and the aerodynamic force provided by the tailplane needs only to be small to have asignificant pitching effect.The area of the tailplane is small compared with the mainplanes （main wings）.5.2 StabilityThere are two elements of stability, static and dynamic, and for an aircraft, it is usual to separate the modes into the three axes of movement.There is longitudinal stability, lateral stability and directional stability.There is an inseparable relationship between lateral and directional stability.5.2.1 Static stability and dynamic stability1,Static stabilityThe static stability of the aeroplane describes its tendency to return its original condition（angle of attack）after being disturbed and without any action being taken by the pilot. The strength of the tendency is the measure of its stability.2, Dynamic stabilityremove 取消,去除dead beat 非周期的,无振荡的indefinitely 无限地divergent 发散short period短周期,long period, phugoid 长周期,Dynamic stability is concerned with the motion of the body after the disturbing force has been removed.It is an oscillation which may stop immediately（well-damped or dead beat），continue but reduce slowly（slightly or lightly damped），continue indefinitely（undamped）or get worse（dynamically unstable or divergent oscillation）.Imagine the aircraft is trimmed in straight and level flight, the aircraft will respond to the vertical gust by pitching down to maintain its trimmed angle of attack.This oscillation is generally well-damped and reduces to zero in 1 or 2 oscillation. The damping is provided by the air on the horizontal area of the aircraft. The pitching oscillation is known as the short period pitching oscillation（SPPO）.The airspeed of the aircraft may also change and this can cause a slower（long period）oscillation where the aircraft leisurely（慢慢地）follows a path where the airspeed and altitude are exchanged. The slow motion is called the phugoid.3,the three reference axesWe refer（归类）the motion of the aircraft to motion about each of three axes-each passing through the centre of gravity and each mutually perpendicular （at 90o to each other）. These are sometimes called body axes.Stability around the longitudinal axis is known as lateral stability. Stability around the lateral axis is known as longitudinal stability. Stability around the normal axis is known as directional stability.Rotation around a point or axis is called angular motion; the number of degrees of rotation is called angular displacement, and the speed with which it occurs, angular velocity.The motion of an aircraft is best considered in each of the planesseparately, although the actual motion of the aircraft is a little more complex. For example ,rolling into a level turn the aircraft will not only roll but also pitch and yaw.We will consider longitudinal stability first, then directional stability and lateral stability. Roll and yaw are closely connected. 5.2.2 Longitudinal stabilityinbuilt 固有的,内在的,dart 飞镖,arrow 箭To be longitudinal stable, an aircraft must have a natural or inbuilt tendency to return to the same angle of attack after any disturbance without any control input by the pilot.If the angle of attack is suddenly increased by a disturbance, then force will be produced that will lower the nose and decrease the angle of attack.1，the tailplane and longitudinal stabilityIf a disturbance, such as a gust, changes the attitude of the aircraft by pitching it nose up, the tailplane will be presented to the relative airflow at a greater angle of attack. This will cause the tailplane to produce upward, or decreased, aerodynamic force, which is different to that before the disturbance. The altered aerodynamic force gives a nose-down pitching moment, tending to return the aeroplane to its original trimmed condition.Example：the tail fin of a dart or an arrow.2，the CG and longitudinal stabilityThe further forward the CG of the aircraft, the greater the moment arm for the tailplane, and therefore the greater the turning effect of the tailplane lift force.A forward CG leads to increased longitudinal stability and aft movement of the CG leads to reduced longitudinal stability.The more stable the airplane, the greater the control force that you must exert to control or move the airplane in manoeuvers, which can become tiring.The tailplane provides static longitudinal stability.3，design considerationTailplane design features also contribute greatly to longitudinal stability- tailplane area, distance from the centre of gravity, aspect ratio, angle of incidence and longitudinal dihedral are considered by the designer.At high angle of attack the mainplane may shield the tailplane or cause the airflow over it to be turbulent. This will decrease longitudinal stability.5.2.3 Directional stabilityDirectional stability of an aeroplane is its natural or inbuilt ability to recover from a disturbance in yawing plane without any control input by the pilotIf the aircraft is disturbed from its straight path by the nose or tail being pushed to one side（i.e. yaw）.The vertical fin（or tail or vertical stabilizer）is simply a symmetrical aerofoil. As it is now experiencing an angle of attack, it will generate a sideways aerodynamic force which tends to take the fin back to its original position.The powerful moment（turning effect）of the vertical fin, due to its large area and the length of its moment arm between it and centre of gravity, is what restores the nose to its original position.The greater the fin area and keel surface area behind the CG, andthe greater the moment arm, the greater the directional stability of the aeroplane.The fin provides directional static stability.As the yaw causes rolling moment so that behavior of the aircraft with yaw and sideslip involves both its directional stability and its lateral stability.5.2.4 Lateral stabilityLateral stability is the natural or inbuilt ability of the aeroplane to recover from a disturbance in the lateral plane, i.e. rolling about the longitudinal axis without any control input by the pilot.A disturbance in roll will cause one wing to drop and the other to rise. When the aeroplane is banked, the lift vector is inclined and produces a sideslip into the turn.As a result of this sideslip, the aeroplane is subjected to a sideways component of relative airflow. This generates forces that produces a rolling moment to restore the aeroplane to its originalwings-level position.1，wing dihedralEach wing is inclined upwards from the fuselage to the wingtip, and adds to the lateral stability characteristics of the aeroplane. Positive wing dihedral increases lateral stability.As the aircraft sideslips, the lower wing, due to its dihedral, will meet the upcoming relative airflow at a greater angle of attack and will produce increased lift.The upper wing will meet the relative airflow at a lower angle of attack and will therefore produce less lift. It may be shielded somewhat by the fuselage, causing an even lower lift to be generated.The rolling moment so produced will tend to return the aircraft to its original wings-level position.Negative dihedral, or anhedral has a destabilizing effect. In some aircraft with a high-mounted sweep wing, anhedral is used to compensate for excessive lateral stability.2，wing sweepbackThe wing can add to lateral stability if it has sweepback. As the aircraft sideslips following a disturbance in roll, the lower sweepback wing generates more lift than the upper wing. This is because in the sideslip the lower wing presents more of its span to the airflow and higher velocity than the upper wing and therefore the lower wing generates more lift and tends to restore the aeroplane to a wing-level position.3，high keel surfaces and low CGIn the sideslip that follows a disturbance in roll, a high sideways drag line caused by high keel surfaces（high fin, a T-tail high on the fin, high wings, etc.）and a low CG will give a restoring moment tending to raise the lower wing and return the aircraft to the original wings-level position.4，high-wing aroplaneIf a gust causes a wing to drop, the lift force is tilted. The resultant forces will cause the aircraft to sideslip. The airflow striking the upper keel surfaces will tend to return the aircraft to the wings-level condition.A high-wing aroplane increases lateral stability, it has less dihedralcompared to a mid- or –low wing design.5，lateral and directional stability together1) roll followed by yaw 滚转引起偏航For lateral stability, it is essential to have the sideslip that the disturbance in roll causes.The sideslip exerts a force on the side or keel surfaces of theaircraft, which, if the aircraft is directionally stable, will cause it to yaw its nose into the relative airflow. The roll has caused a yaw in the direction of the sideslip and the aeroplane will turn further off its original heading in the direction of the lower wing.The lateral stability characteristics of the aeroplane, such as dihedral, cause the lower wing to produce increased lift and to return the aircraft to the wings-level position.There are two effects in conflict here：The directionally stable characteristics（large fin）want to steepen the turn and drop the nose further.The laterally stable characteristics（dihedral）want to level the wing.spiral mode 螺旋模态, Dutch roll 荷兰滚right 矫正,best 极力, wallow 摇摆If the first effect wins out, i.e. strong directional stability and weak lateral stability（large fin and no dihedral）, then the aircraft will tend to bank further into the sideslip, towards the lower wing with nose continuing to drop, until the aeroplane is in a spiral dive. This is called spiral instability, or the spiral mode.If the lateral stability（dihedral）is stronger, the aircraft will right itself to wings-level, and if the directional stability is weak（small fin）the aircraft may show no tendency to turn in the direction ofsideslip, and causing the wallowing effect, Dutch roll, which is best avoided.2）yaw followed by roll 偏航引起滚转If the aircraft is displaced in yaw, it is can cause sideslip. This sideslip will cause the lateral stability characteristics of the aircraft’s wing, such as dihedral, sweepback or high-wing. This causes a rolling moment that will tend to raise the forward wing, resulting in the aircraft rolling towards the trailing wing and away from the sideslip.The aircraft’s inhe rent directional stability（from the fin）will tend to weathercock or yaw the aircraft in the direction of sideslip.3）stability characteristics and aeroplane controlIf the directional stability is poor（small fin）and the lateral stability is good（dihedral）it can cause Dutch roll（rolling/yawingoscillation）. Often the aircraft is fitted with a yaw and/or roll damper（a small control surface driven by a rate gyro）to stop the oscillation. It is uncomfortable for the pilot and passengers.If the directional stability is dominant（large fin）and the lateral stability not so strong, it can cause spiral instability or spiral mode.rate gyro 阻尼陀螺, dominant 占优势,占主导地位6, Stability on the groundtip over 翻倒,taxing 滑行, ground loop 地转skid 空转, brake 刹车, wheel 车轮runway 跑道The centre of gravity（CG）must lie somewhere in the area between the wheels at all times on the ground, otherwise theaeroplne will tip over - forwards or backwards.5.3 ControlThe control surfaces are the means by which the pilot overcome the static stability of the aircraft and causes a change in flight path or a change in trimmed conditions.Usually there are three sets of primary control system and three sets of control surfaces：●the elevator for longitudinal control and balance in pitch, operatedby fore and aft movement of the control wheel or column;●the ailerons for lateral control and balance in roll, operated by rotation of the control wheel or sideways movement of the control column;●the rudder for directional control and balance in yaw，operated bythe rudder pedals.Ideally each set of control surfaces should produce a moment about only one axis but, in practice, moments about other axes are often produced as well, e.g. aileron deflection to start a roll may also cause adverse yaw.The deflection of the control surfaces changes the airflow and the pressure distribution over the whole aerofoil and not just over the control surface itself.The effect is to change the lift produced by the total aerofoil- control surface combination.An aeroplane with too much stability designed into it has limited controllability. The designer must achieve a reasonable balance between stability and controllability.For instance, a passenger aircraft would require more stability,whereas a fighter would benefit from greater controllability and manoeuvrability.5.3.1 Pitch control1，ElevatorThe primary control of angle of attack is the elevator.The pilot moves the elevator by fore-and-aft movement of the control column.When the control column is moved forward, the elevators move downwards, changing the overall shape of the tail plane-elevator aerofoil section so that it provides an altered aerodynamic force. The effect is to create a pitching moment about the CG of the aircraft that moves the nose down.When the control column is pulled back, the elevator moves up and an altered force is produced by tail plane-elevator aerofoil, causing the nose of the aircraft to pitch up.The strength of the tail moment depends on the force it producesand the length of the arm between it and the CG. The force generated by the tailplane-elevator combination depends on their relative size and shape, the tailplane basically contributing to stability and the elevator to control.The larger the relative size of the elevator, the more the control.To retain satisfactory handling characteristics and elevator effectiveness throughout the desired speed range ,the position of the CG must be kept within the prescribed range.The forward allowable limit of the CG is determined by the amount of pitch control available from the elevator.The aft limit of the CG is determined by the requirement of adequate longitudinal stability.Steady flight at a low speed and a high angle of attack will require significant up - elevator, and backward pressure on the control column, to keep the nose up.At a high cruise speed there will need to be a steady down deflection of the elevator to keep the nose down and maintain a low angle of attack, hence a steady forward pressure on the control column.2，The stabilator or all-flying tailSome designers choose to combine the tailplane and elevator into the one surface and have the whole tail-plane movable- known as the all moving tail, the flying tail or the slab tail.When the control column is moved the entire ‘slab’ moves.5.3.2 Roll control1，AileronsThe primary control in roll is the ailerons. The ailerons are usually positioned on the outboard trailing edge of the mainplanes. The ailerons act in opposing senses, one goes up as the other goes down, so that the lift generated by one wing increases and the lift generated by the other wing decreases.A resultant rolling moment is exerted on the aeroplane.The magnitude of this rolling moment depends on the moment arm and the magnitude of the differing lift forces.●The downgoing aileron is on the upgoing wing.●The upgoing aileron is on the downgoing wing.2，Adverse aileron yawDeflecting an aileron down causes an effective increase in camber of that wing and an increase in the effective angle of attack. The liftfrom that wing increases, but unfortunately so does the drag. As the other aileron rises, the effective camber of that wing is decreased and its angle of attack is less, therefore lift from that wing decreases, as does the drag.The differing lift force causes the aircraft to bank one way, but the differential aileron drag causes it to yaw the other way.Adverse aileron yaw can be reduced by good design incorporatingdifferential ailerons, Frise ailerons, or coupling the rudder to the ailerons.●Differential ailerons（差动）are designed to minimize adverse aileron yaw by increasing the drag on the downgoing wing on the inside of the turn. This is achieved by deflecting the upward aileron through a greater angle than the downward aileron.●Frise ailerons increase the drag of the descending wing on the inside of the turn. As the aileron goes up, its nose protrudes into the airstream beneath the wing causing increased drag on the downgoing wing.On the other way, the wing is rising, the nose of the downgoing aileron does not protrude into the airstream, so cause no extra drag. Frise-type ailerons may also be designed to operate differentially, to incorporate the benefit of differential ailerons.●Coupled ailerons and rudder cause the rudder to move automatically and yaw the aeroplane into bank, opposing the adverse yaw from the ailerons.The primary effect of rudder is to yaw the aeroplane, and the secondary effect is to roll it. The primary effect of ailerons is to roll the aeroplane, and the secondary effect is to yaw it.3，Roll is followed by yaw 滚转引起偏航The secondary effect of ailerons is to cause yaw.When the aeroplane is banked using the ailerons, the aeroplane will slip. As a result of the sideslip, the airflow will strike the side of the aeroplane and the large keel surface（rear fuselage and fin）, which are mainly behind the CG, cause the nose of the aeroplane to yaw in the direction of bank.5.3.3 Yaw control1，RudderThe primary control in the yawing is the rudder. The rudder is hinged to the rear of the fin（or vertical stabilizer). It is controlled from the cockpit by the rudder pedals to the rudder bar.By pushing the left pedal, the rudder will move left. This alters the fin- rudder aerofoil section, and sideways lift is created that sends the tail to the right and yaws the aeroplane to the left about thenormal axis. With left rudder applied, the aeroplane yaws left. hinge 铰接, cockpit 座舱2，Yaw is followed by roll 偏航引起滚转The secondary effect of rudder is roll. The primary effect of rudder is to yaw the aeroplane. Having yawed the aeroplane, the further effect of rudder is to cause a roll.3，Slipstream effectAs the slipstream corkscrews（螺旋形前进）around the fuselage, it strikes one side of the fin/rudder at a different angle to the other.If the slipstream over the fin and rudder changes, then the rudderdeflection must be changed to balance it.4，Rudder in crosswind take-off and landing 带侧风起飞、着陆中的方向舵take-off 起飞, landing 着陆, approach 进近,crab 偏航, crab-wise 偏航方向, touchdown 接地,触地crosswind 侧风In ground operation, any crosswind will hit the side of fin and tend to weathercock the aircraft into wind.The rudder must be used to stop the aircraft yawing into wind and keep it tracking straight along the runway.On approach to land, the most common technique is to crab the aircraft into wind so that it is flying in balance（i.e. directly into the relative wind and with the rudder ball centered）and tracking somewhat ‘crab-wise’ along extended centerline of the runway.Just prior to touchdown the aircraft is yawed with the rudder, so that when the wheels touch, they are aligned in the direction of the runway.Another technique in a crosswind landing is the sideslipping approach.Near the ground, you would yaw the aeroplane straight（with the rudder）so that it is aligned with the centerline. Unless the wheels touch almost immediately, the wind will cause the aeroplane to drift towards the side of the runway. To avoid this, you would lower（using the ailerons）the into-wind wing sufficiently to stop the aircraft drifting off the centerline prior to touchdown.The aeroplane is now sideslipping and fly a litter bit out of balance.5，Rudder powerWhile the rudder must be sufficiently powerful to handle the above requirements satisfactorily, it must not be too powerful. Given maximum deflection by the pilot it should not cause structural damage.5.4 Other control devicesOthers control devices include：●modified aileron design 副翼修型设计●spoilers 扰流片,阻力板●slots 缝● leading edge strips 前缘条●speed brakes 减速板●vortex generators 涡流发生器● strakes 侧板●tabs 调整片1，Modified aileron design and spoilersTo reduce adverse aileron yaw, there are several techniques employed：● differential ailerons● Frise ailerons● spoilers, which are plate-like surface that are raised from the uppersurface of the wing to increase drag on the side. They may be used in conjunction with the raised aileron or instead of it. Thus the aileron goes down on one side and the spoiler is raised on the other.● aileron/rudder interconnect● manual rudder input2，SlotsThey are usually incorporated within the wing leading edge ahead of the aileron to retain aileron effectiveness even at the point of stall Most are fixed and exposed to the airflow at high angle of attack. Some are created by a movable plate which pops out（突出）at high angle of attack due to the reduced state pressure.3，Leading edge strips/slatsStrips and other shapes, including rope（钢索）, are add to the leading edge of the wing to encourage attachment of the airflow at high angle of attack. In this way, the ailerons remain effective.4，Speed brakesSpeed brakes are flat plate surface which slide out or hinge upward from the upper surface of the wing.Some aircrafts have combined spoilers and speed brakes.5，V ortex generatorsV ortex generators（VGs）are finger-like protrusions on the upper surface of the wing. They are small plates set at an angle to the flow which generate a small vortex. They may even be aerofoil shaped.The intent is to use the vortex to stir the boundary layer and promote an earlier transition to turbulent mixed flow. Turbulent flow remains attached for a greater distance over the aerofoil, andturbulent attached flow is better than turbulent separated flow.The VGs stir the boundary layer and effectively reduce the high drag of separated flow.6，StrakesQuite common on aircraft are extensions to lower leading edge of fin to increase the chord and strength of the fin（dorsal fin）, under the fuselage（ventral fin）.All of these design adjustments are made to improve the control and stability at various parts of the flight envelope.dorsal 脊dorsal fin 背鳍, ventral fin 腹鳍7，Wingtip shaping, fences, end plates and winglets 翼梢形状，翼刀，端板和翼梢小翼These devices improve lift and reduce induced drag by reducing the spanwise flow of the air.8，Tabs1) fixed tab 固定调整片A fixed tab is a small metal tab that can bend to a set position on the ground only. It is fixed in flight.It is usual on the ailerons and rudders of small aircraft.2) trim tabs 配平调整片An aircraft is in trim in pitch, roll or yaw, when it maintains a steady attitude without the pilot having to exert any pressure on the control column.The function of the trim tab is to reduce the control surface force to zero for that condition of flight, so that the aeroplane will maintain it ‘hands-off’.In most light aircraft trim system are mechanically operated by a trim wheel.3) balance tab 补偿调整片On conventional tailplane it is quite common to have a balance tab incorporated as part of the elevator.If the pilot exerts back pressure on the control column, the elevator is raised and the balance tab goes down. The elevator balance tab unit generates a small upward aerodynamic force that acts to hold the elevator up, thereby reducing the control load required of the pilot.The balance tab acts automatically as the elevator moves.4) anti- balance tab 反补偿调整片The anti- balance tab moves in the same direction as the tailplane but moves further. The deflection at the trailing edge of the surface increases the stick force.The increased load, that the pilot has to apply, to manoeurve the aircraft, prevents overstressing the structure.5) servo tab 伺服调整片A servo tab is variation of the balance tab where the pilot control is connected, not to the main control surface, but to the tab. As the control input moves the servo tab into the airflow, the aerodynamic forces generated drive the main control surface in the opposite direction, causing the desired manoeurve.Servo tabs were used on large transport aircraft as the force required to move the surface was beyond the reasonable strength of the pilot.5.5 Stability versus controlversus ［拉丁语］…对…trade-off 折衷,权衡hand-off 松手,请勿动手,不许动手1，Stability versus controlDo not confuse stability with controllabilityStability is the tendency of the aeroplane to return its original condition after being disturbed and without any action being taken by the pilot.Controllability refers to the ease with which the pilot can manoeuvre the aircraft and hence overcome the stability.There is a significant trade-off between stability and controllability. A high degree of stability makes the aircraft resistant to change and thereby tends to reduce the controllability i.e. good stability makes it harder for the pilot to control and manoeuvre the aeroplane.An aeroplane is in a state of equilibrium when the sum of all the forces on it is zero and the sum of all the turning moments on it is zero.The aircraft is in trim if all the moments in pitch, roll and yaw are zero.An unstable aircraft is difficult to fly because the pilot must continually interfere by applying control forces. A stable aircraft can almost fly “hand-off” and require only guidance（制导）rather than second-to- second（時時刻刻）control inputs.2, Control response 操纵响应The size and shape of the control surface and its moment about the centre of gravity are of great importance in its effectiveness. Since the size and shape are fixed by the designer and CG only moves small distances, these can be considered constant. The variables in control effectiveness are airspeed and control surface。
英语飞机教案教案标题：英语飞机教案教学目标：1. 学习并掌握与飞机相关的英语词汇和表达方式。
2. 提高学生的听说读写能力，以及对英语语音和语调的理解和运用能力。
3. 培养学生的合作学习和解决问题的能力。
教学重点：1. 飞机相关的英语词汇和表达方式。
2. 听说读写能力的提升。
3. 合作学习和解决问题的能力的培养。
教学准备：1. 飞机模型或图片。
2. 飞机相关的词汇卡片。
3. 录音设备或多媒体设备。
教学过程：引入活动：1. 展示飞机模型或图片，引起学生对飞机的兴趣。
2. 使用图片和简单的英语词汇，引导学生猜测飞机的英文单词。
主体活动：1. 听力训练：a. 播放一段关于飞机的录音，让学生听并回答相关问题。
b. 给学生发放飞机相关的词汇卡片，播放录音，让学生根据听到的内容找出对应的词汇卡片。
2. 口语练习：a. 学生分组，每组选择一个角色扮演飞机上的乘客和空乘人员，进行简单的对话练习。
b. 学生自由发挥，模拟乘坐飞机的情景，进行对话练习。
3. 阅读理解：a. 分发一篇关于飞机的短文，让学生阅读并回答相关问题。
b. 学生分组，互相交流自己阅读的内容，并互相提问。
4. 写作练习：a. 让学生根据自己的想象，写一篇关于乘坐飞机的短文。
b. 学生互相交换作文，进行修改和改进。
总结活动：1. 学生展示自己的口头表达和写作成果。
2. 教师进行总结和反馈，鼓励学生的努力和进步。
拓展活动：1. 学生可以自行查找关于飞机的资料，并进行小组展示。
2. 学生可以利用多媒体设备制作关于飞机的简短视频，展示给全班。
评估方式：1. 听力训练和口语练习中的回答问题和对话表现。
2. 阅读理解和写作练习中的答案和作文质量。
3. 学生展示和互动表现。
教学延伸：1. 鼓励学生参加英语角或其他英语活动，提高英语口语表达能力。
2. 推荐相关英语学习资源，如英语学习网站、应用程序等，供学生自主学习和练习。
教学反思：在教案撰写过程中，要充分考虑学生的实际情况和学习需求，设计多样化的活动，既注重听说读写能力的培养，又注重学生的兴趣和合作学习能力的培养。
课时：2课时教学目标：1. 让学生掌握民航专业英语的基本词汇和常用句型。
2. 培养学生运用民航专业英语进行日常交流的能力。
3. 提高学生的听说读写综合运用能力。
教学重点：1. 民航专业英语词汇的积累。
2. 常用句型的掌握。
3. 实际情景对话的应用。
教学难点：1. 民航专业英语词汇的记忆和应用。
2. 在实际交流中灵活运用所学知识。
教学过程：一、导入（5分钟）1. 教师用英语介绍民航专业英语的重要性，激发学生的学习兴趣。
2. 引导学生回顾已学过的英语知识，为接下来的学习做好铺垫。
二、新课讲解（40分钟）1. 词汇讲解：- 介绍民航专业英语的基本词汇，如：机场（airport）、航班（flight）、登机牌（boarding pass）、行李（luggage）等。
- 通过图片、实物等教学手段，让学生直观地了解词汇的含义。
2. 句型讲解：- 介绍民航专业英语的常用句型，如：How may I help you?、What's your flight number?、Could you please show me your boarding pass?等。
- 结合实际情景，让学生模仿并练习这些句型。
3. 情景对话：- 设计一段关于机场安检的情景对话，让学生分组练习。
- 教师巡回指导，纠正学生的发音和语法错误。
三、课堂练习（15分钟）1. 词汇练习：- 让学生用学过的词汇造句，巩固所学知识。
- 教师选取优秀句子进行展示，并给予点评。
2. 句型练习：- 让学生根据所给情景，运用所学句型进行对话。
- 教师随机抽查学生的对话，并给予评价。
四、总结与作业（5分钟）1. 教师对本节课所学内容进行总结，强调重点和难点。
2. 布置课后作业：- 让学生收集更多民航专业英语词汇，整理成笔记。
- 让学生根据所学知识，编写一段关于机场安检的情景对话。
教学反思：本节课通过词汇讲解、句型讲解、情景对话和课堂练习等多种教学手段，让学生在轻松愉快的氛围中学习民航专业英语。
飞机军事英语教案
教案标题：Exploring Aviation and Military English through Airplanes
教案目标：
1. 通过学习与飞机和军事相关的英语词汇和表达，提高学生的英语听说能力。
2. 培养学生对航空和军事领域的兴趣和了解。
3. 通过小组合作和互动活动，提高学生的团队合作和沟通能力。
教案步骤：
引入活动：
1. 利用一段视频或图片展示不同类型的飞机和军事飞行器，引起学生对飞机和军事的兴趣。
2. 引导学生进行简短的讨论，询问他们对飞机和军事的了解程度，并激发他们对这个话题的好奇心。
词汇学习：
1. 提供与飞机和军事相关的词汇表，包括飞机部件、军事行动、空军等。
2. 通过图片和示范，教授学生如何正确发音和使用这些词汇。
3. 组织学生进行小组活动，让他们在情景中使用这些词汇，例如描述飞机的不同部分或讨论军事行动。
听力训练：
1. 播放一段关于飞机或军事的录音，要求学生仔细听并回答相关问题。
2. 组织学生进行角色扮演，模拟飞行员和空军指挥官之间的对话，让他们运用所学的词汇和表达进行交流。
口语练习：
1. 分发相关的对话和问题卡片，让学生进行小组对话练习。
2. 安排学生进行小组讨论，讨论飞机和军事对国家安全的重要性，并提出自己
的观点和理由。
拓展活动：
1. 邀请一位军事专家或飞行员来校进行讲座，让学生有机会与专业人士交流和
提问。
2. 组织学生进行模拟军事行动的角色扮演，让他们运用所学的英语词汇和表达，展示团队合作和决策能力。
总结：
1. 回顾本节课所学的飞机和军事相关词汇和表达。
2. 鼓励学生分享他们在本节课中的收获和体会。
3. 提供相关的学习资源和阅读材料，鼓励学生继续深入了解飞机和军事领域。
评估：
1. 观察学生在小组活动和角色扮演中的参与程度和表现。
2. 收集学生完成的练习和对话卡片，评估他们对词汇和表达的掌握程度。
3. 通过口头提问和回答的方式，评估学生对飞机和军事话题的理解和表达能力。
这个教案旨在通过引入飞机和军事话题，激发学生的兴趣，并通过相关的词汇
学习、听力训练和口语练习，提高他们的英语能力。
通过拓展活动和评估，学
生将有机会与专业人士交流和展示他们的团队合作能力。
