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Debunking Lift Theories Still Taught


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Well Complete, your statement that " the plane is moving and the air is not".. is at best irrelevant and at worst means you have an incorrect understanding of the physics of motion. I could continue like this but have a better idea...How about this to settle the argument about my Jabiru...we can be real scientists and run an experiment.

I will run a tube from the rear of my fuselage to the door and put in a sensitive pressure meter or a flow-meter. ( I can make use of a variometer which is a very sensitive flow-meter and is already in my panel).

 

If the pressure is MORE at the door or the flow is AWAY from the door then I will donate $100 on your behalf to the site. But if, as I say from my understanding of Bernoulli, the pressure is LESS at the door or the flow is TOWARDS the door then you will make the donation for me.

 

Be aware that the fuselage at the doors is over 100cm in diameter, and the fuselage near the tail is about 25cm in diameter. Slipstream from the propeller adds to the speed of the airflow over both points. You can see a bit of the actual fuselage in my photo.

 

Lots of details to work out, like how to agree on a trusted observer, and who will hold the money, but are you game?...I am.

Hi Bruce - any progress yet?

 

 

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No I have started at the start and my point was that although the material may or may not be correct, the way that it has been put forward has been in my opinion, dismal. If you were trying to prove that people get their back up because of confirmation bias, you have not, what you have proven is that people get their back up when called stupid, or told bluntly that what they believe (because that's what they were taught) is nonsense. No one asked the question, you essentially just marched on in and told everybody that if they didn't believe you that they were stupid.I would personally rethink your satisfaction scores, many students I have been on courses with, just tell the instructor what they want to hear, because they don't want to be pinned down and grilled by someone who is just going to tell them how stupid they are. No it's not how course critiques are supposed to work, but frequently it's what happens.

On that note, you appear to have some confirmation bias of your own, inasmuch as you believe that it's your student's fault that they don't believe you, not your own instructional technique or condescending attitude.

 

A good instructor will find a way to help all of the students understand, not beat them into submission.

 

No captive audiences? Yes they are, their boss decides that in order to comply with their legally required SMS, that they should receive regular lectures about such stuff, he picks out something he thinks will comply, and there you are talking to a bunch of people who would rather just be out doing their job. Been there many times, enjoyed it once ( a well spoken funny doctor about DAMP).

________________________________

Mr M61-

 

 

 

If you were trying to prove that people get their back up because of confirmation bias, you have not, what you have proven is that people get their back up when called stupid, or told bluntly that what they believe (because that's what they were taught) is nonsense. No one asked the question, you essentially just marched on in and told everybody that if they didn't believe you that they were stupid.

 

A lot of emotion in your statement there M61.

 

Firstly, I started the post to offer correct information. That I did and there is no doubt that it is correct. It is not my information. it is from unimpeachable sources.. No-one was obliged to comment. So why di you suppose I was abused or belittled on the basis of offering information?

 

At no time did I say that if they didn't accept the information they were stupid. Why would you feel the need to make such a statement?

 

I did not respond impolitely to anyone who behaved in the same way. The escalating response was only to those who initiated hostility.

 

So one may well ask, why the hostility to correct information? if people are not mature enough to re-evaluate what they believe in the light of new evidence I wonder if they should be behind the controls of an aircraft.

 

On that note, you appear to have some confirmation bias of your own, inasmuch as you believe that it's your student's fault that they don't believe you, not your own instructional technique or condescending attitude. A good instructor will find a way to help all of the students understand, not beat them into submission.

 

Confirmation bias is subconsciously selecting only that information that fits your perception and then altering your behaviour comply with it.

 

A good facilitator offers information to people and leaves it up to them to evaluate. If they disagree then the conversation is expanded looking for perceptual flaws that can be identified so that they can then understand the information. If it involves a conceptual debate then that is a good thing to increase understanding.

 

You cannot force listeners to participate but interestingly all the insults that have been initiated have come from people telling me I was 'full of crap' or more specifically 'horseshit' instead of questioning the validity of the various concepts I was explaining or asking for clarification. Perhaps you should review some of the commenters here and ask them why they attacked me so rudely?

 

No captive audiences? Yes they are, their boss decides that in order to comply with their legally required SMS

 

 

Ahhh no. No I am talking about corporate audiences at conferences and workshops. People who pay to come voluntarily. You won't last long in business if you suck and I have been doing this successfully for over a decade so..

 

I would personally rethink your satisfaction scores, many students I have been on courses with, just tell the instructor what they want to hear, because they don't want to be pinned down and grilled by someone who is just going to tell them how stupid they are.

 

 

I don't think you understand how tertiary scores are evaluated. They are anonymous and I can assure you that students have no problem eviscerating an lecturer they do not like.

 

And again, if that is how you run a lecture, your students don't turn up. My classes were always exceptionally well attended.

 

Perhaps students understand that they are there to learn and have open minds... Something in that for all of us I think...

 

 

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Would you please specify why giving information that some clearly do not understand was arrogant?

I'm not criticising the information you're handing out, but if you really require an explanation of how you come across while handing it out, then it's clearly something you wouldn't understand. Perhaps you should re-read your own posts from the beginning, as you are constantly reminding others to do.

 

rgmwa

 

 

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Hi Complete, I didn't think you had accepted my challenge, and in fact I felt a bit of a heel for making it.

 

I quite enjoy your posts and I think you mean them in fun, so I felt bad about demolishing you. You might even be playing us all for April fools in jest.

 

Also, I didn't know until Daffyd Llewellyn pointed it out that my "discovery" about flow from the tail to the doors was well known to people in the industry.

 

 

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Dear Mr. Completeaerogeek, thanks for your words, keep them coming, you understand the difference between objectivity and subjectivity very clearly. Aviation definitely needs more people like yourself, de bunking ridiculous theories that have no place in aviation classrooms. You remind me of a friend of mine, a mathematician, very smart, objective and clever with words. Keep it up.

 

 

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Ahh a retrospective qualification. How is providing information a negative experience? Making a correct statement and then having people abuse you for it is part of public discourse.I don't mind it as long as the overall information and discussion of benefit.If your ego isn't in the way you can learn many new concepts. I have no problem being wrong. it is how we all learn. But if you care going to criticise me then you need to support it with facts and objective assessment. Otherwisse it is just your ego talking.

 

So my question to you is this: Is your statement and that of M61 an objective one?

 

Read my first post with all of the valid information and then see the hostile response it got from some. No-one was coerced into responding or commenting.

 

Their egos led them to lash out and insult me despite the fact that what I was saying was 100% correct.

 

This has been happening from time immemorial when anyone dismantled cultural myths. it is called shooting the messenger and it comes from insecurity and lack of intellectual courage.

 

If one person on this site now better understand basic aerodynamics then I have succeeded in my intent.

Yes, mr geek, I believe that I'm being objective, no complaint about the material, just the attitude in which it's delivered. This argument, if you could call it that, is not new, and I would hazard a guess, that most people in the industry are aware of what you are saying.

The point is, that with a less "holier than thou" attitude, your audience may be much broader. Engage them in a less hostile manner. If you really understand your human factors, you will be aware of how people react to different personalities. Terms like "silly", and "nonsense", while possibly correct, immediately get people offside.

 

 

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Well some of complete's material is ok, but some is so far off that its almost comical, like thinking it made a difference that the Jabiru was moving and the air was still. My bet is still on the table, but I do feel a bit bad about demolishing such an easy target.

 

 

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Well some of complete's material is ok, but some is so far off that its almost comical, like thinking it made a difference that the Jabiru was moving and the air was still. My bet is still on the table, but I do feel a bit bad about demolishing such an easy target.

I am focusing solely on the delivery.

 

 

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In post #163 Guernsey made an attempt at humour using an aviation termIn post #164 Eightyknots joined in with another one

In post #165 I joined in with another one

 

I just want to reassure you that were were feeding off each other's jokes rather than baiting you to keep up your dialogue.

 

Having done some checking, I already knew from the 'repetitive' tag that it was going to be continuing regardless of what I said, probably until the last man standing was disposed of.

 

I'm happy to summarise my comments by recommending people buy the book "Aerodynamics for Naval Aviators" NAVWEPS 00-80T-80, Naval Air Systems Command, United States Navy - available now on www.amazon.com for $20.67

 

Ahhh M61. I see you have twigged. Thanks for your comments.The first part of my purpose was to explain clearly that what may people think is correct is in fact nonsense and hopefully be of help. The second part was to see what sort of response I got.

 

The vociferous arguments based on fallacies are exactly what we in the industry need to fix. An authority figure (instructor or captain) using the cockpit or classroom power gradient consciously or unconsciously can teach new pilots or F/Os all kinds of bad habits or suppress their correct views and the junior pilot will often accept this just to 'get along'.

 

This is the 'Authority from Eminence' logical fallacy I mentioned earlier. (I am currently writing a book on this)

I have no doubt that you have many worthwhile things to say about the half venturi theory and other lift theories still being taught in Aviation Principles. However, with all due respect, completeaerogeek, I am afraid your style comes across as Authoritarian by belittling other Forumites. No one here is silly! On the contrary, people here are eager to share ideas and learn from others. I am afraid that in a Down Under setting and culture, this Authoritarian method is highly problematic and a number of listeners simply won't buy the message.

 

See Mr Turboplanner' comments. He is comprehensively wrong but will not see it.

In defence of "Mr" Turboplanner:

 

1. I have never met him and I only "know" him from the posts I read from him in this forum.

 

2. Nevertheless, it is clear to me that not only has he demonstrated that he is of a teachable spirit but he has also consistently made many valuable contributions over the years that I have seen his posts. I don't always agree with everything he says but I don't feel that denigration is the appropriate response if anyone doesn't agree with him.

 

3. If you feel that a person is not convinced about an issue or you feel that "he is comprehensively wrong" the onus falls on you to make your argument more intelligible, palatable, understandable or convincing ...that is the correct approach. Belittling is definitely the wrong methodology.

 

Let's keep the forum the way it was intended: a friendly place where ideas can be interchanged freely without anyone feeling bad for disagreeing with another person.

 

Kind regards,

 

eightyknots

 

 

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I always refer pilots to the FAA Handbook of Aeronautical Knowledge for theory stuff. Free online. Chapter 3 is relevant here.

 

Yet we still get http://learntoflyblog.com/2014/09/29/ground-school-aerodynamics-answers-and-explanations/ contrary to the FAA so perhaps it is time that the theory providers get together.

 

 

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Lift characteristics of a "thick" aerofoil like on a Tri-motor were well illustrated by showing manometers from all parts of the surface. Positive and negative pressures are featured. Do you have access to anything like that djp?. low speed sections probably have more low pressure generated lift (on the top surface) than increased pressure on the bottom. Close to sonic sections which have featured a lot in this discussion are not what we use. nor do we need laminar flow type wing sections either. Our speed range is from 30 knots to about 130 knots and the stall speed requirement affects a lot of the design logic.. Nev

 

 

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