Constant Speed Props

[RRAM]

Originally posted by Straiga
RRAM,
 Its what is taught to stundents pilot obtaining a pilot certificate and what I had to discuss as parts of my check ride for becaming a newly FAA designator examiner and check pilot for the company I fly for, now I give the check rides for the company pilots to pass a 135, 121 and ATP check rides.

Interesting. However it's also interesting that you can't explain correctly which forces are involved in a piston engined plane's takeoff, and how to counter them (at least, how and why to correctly counter them).

Tell us all of the extent of your flying experiences please, so we have a bases for your knowledge, and be more direct on the things that Im wrong on.  So I can give you an appropriate responce.

 Later!

Oh, my flight log doesn't go further than 5 or so hours, with 4 takeoffs and landings aboard an idiot-proof plane. And no, I ain't got a pilot licence. It isn't cheap (at least not where I live) and for now I can't pay for one. Each time I've flown I've done it with an instructor or pilot on my side, and as a personal favor...but I'm going to solve it after I get my studies completed and as soon as I can pay for the classes and licence.


However, I've spent thousands of hours reading about phisics (mostly because I studied Phisic science in the past), planes (mostly WWII-vintage), planes manuals, hundreds of web pages, and literally thousands of quite comprehensive threads on the internet about flying, why does a plane fly, how does a plane work, etc etc etc.

To know about a topic you don't necessarily need to be actively involved in the professional activity related to that topic. You just need to know. And admittedly, I know just a fraction of a fraction of a fraction of what someone as Hitech (someone with some hours of flight in P51s in his log, and aerial mock dogfights, something I guess you don't have) knows. But that's enough to know that what he has said in this thread is quite right. And enought to know that quite a lot of what you said isn't.


BTW, I can re-read the thread and find out each of your errors to make a list here, but I guess there isn't the need to do it. Others have already pointed out those errors...and they explained,too, WHY you were wrong. I can explain that myself but why to do if it's already done?. Even more because I have serious trouble explaining technical stuff in english because, as you might have noticed, my english, while good enough to read and understand almost 99% of what it comes in front of my eyes, is not good when it's time to write or speak, much less when it involves technical expressions I may have problems to translate from my native language.

So to lose time to do some copy&paste of what other, or others, have already told you won't solve a thing. As I said before, re-read the whole thread, read what others know, and have told you, while "forgetting" what you know...and then find out if it makes more sense that what you say.

It's as simple as that

[gripen]

Straiga,
It does not matter what kind of experience you or me have with airplanes; we can't change laws of physics. The torque from the propeller does just rolling moment. It's a very common error to mix the yawing moments caused by slipstream and/or asymmetrical shape of the plane to the torque effects.

The Bf 109 is a good example how different forces affect in the take off. In the beginning of the take off it had a very strong tendency to turn right. This was caused by slipstream of the clock wise turning propeller (if viewed from the cockpit); slipstream causes more force to the left side of the fuselage forcing plane to turn right.  

After speed had increased in the take off and tail was raised, it had a tendency to turn left. This was caused  by tourque; more moment to the left wheel. Naturally at this moment the rudder could be used to keep direction.

Once the plane came airborne it had a strong tendency to drop left wing due to tourque,  if it was pulled to the air at too slow speed even the full deflection of the ailerons (to the right) was not enough to prevent rolling motion to left..  

gripen

[Straiga]

RRAM,
 
 Unlike Hitech I do have an LOA in the P-51 thats means I have a license unlike hitech to fly solo in a P-51 and to carry one  passanger. With over 500s logged time inthe mustang.
 Im sure Hitech experience in a p-51 was taken off and landed by the pilot in the plane with him due to insurance restraints. If you comparing my flight experience to Hitechs, LOL, I stop logging flight time after about 14,000 hrs. I think I have over 23,000 hrs actually. I probably have more flight instruction time than Hitechs total flying time. As an ex-military and commercial airline pilot I think if after I log off I going to laugh my head off about this.
 Oh and get about another couple thousands hours of reading and youll have about .1 percent of the total knowledge that I have forgotten, and 0 percent of actual experience. Good luck with the third grade. Get the point!

 Hey Hohun,
 
 I know you want get this right but If the prop slip stream hits the left side of the vertical stabilizer from the clock wise rotation of the prop, the nose will turn to the left needing right rudder to correct. Thats Physics.

 And tourgue is spelled (torgue).

 I usually get paid for this.

[RRAM]

Originally posted by Straiga
Get the point!

what I get is that you can't even describe in a correct way the forces involved in a piston engined plane's take off. Thus, I seriously doubt what you say you are.

in any case what I'm sure is that you're underrating what I may know. Heh, I'm not sure if you will get this example, but to know how to build houses you don't need to be an architect. To actually build a house you need to...but to know how to do it, not.

You just need to know how to do it. How to do it without being an architect?...well, you could very well understand how to do it by reading the reasons why houses are built the way they are, the phisics involved, the materials chosen and why, etc. A perfect way to reach that is to read books about the topic, and talking to architects and engineers, for instance.


In a similar way: to understand why a plane flies, and how it acts and reacts while it's flying you don't need to be a pilot, nor a mechanic, nor an engineer. You can understand almost everything of it by understanding the phisics involved (and I used to study just that at the university, you know. and BTW, I passed my 3rd grade a long way in the past. I'm currently studying my 2nd career), and reading about aeronautical engineering (which I have done extensively), or discussing matters with actual pilots and engineers (which I ALSO have done, also extensively).


and reading your "facts" posted in this thread, bassically I think you're not what you claim to be. And if you are (of course I may be completely wrong), then I won't want to fly in the back seat of your P51 when you are taking off .


in any case, everything I've read, everything I've talked about with professionals of flight, etc, tells me that the one who's giving the correct info in this thread is hitech, gripen, Hohun, or Pyro (his example of the  driving screws as an analogy is quite good, BTW).


I just entered this thread simply to give you an advice, so you could open your ears to what others were telling you instead of sticking to your own point of view, not to discuss who has the most hours logged in a P51. Now do as you want to; I'm not giving valuable info to the main topic of this thread,  so I'll leave you alone so you can go on pointing  (I assume will be that way) wrong facts so hitech or others can correct them. Reading the thread, later, I may learn a bit more from those who I really believe that actually know what they are talking about .

[Straiga]

Give me a fax number and I well fax you my certificates. As soon as I can copy my certificates I will fax them to you.
 If hitech and pyro were to build a real airplane you can be the test pilot orval. But its your funeral.
 See I told you that computer pilots make the worst airplane students, what they know you have to download, its the wrong info its like trash in and trash out, teach them the right information because the plane teaches the pilot the right way to fly not the written way. You need a 609 check ride dude.

 Heres one that you cant figure out, if you take a DHC-6-300 Twin Otter and if you have an extream amount of ICE on the tail plain and stalled the tail plane, what should you do to recover from the stall.
   1. Push forward on the controll yoke
   2. Pull back on the control yoke
   3. Use left rudder
   4. Use left rudder and aileron

[straffo]

Originally posted by Straiga
And tourgue is spelled (torgue).

 I usually get paid for this.

what ?

[gripen]

Straiga,
I quess you mean me instead Hohun?

In the case ofthe Bf 109 there is not much  slipstream effect to the vertical tail due to asymmetrical shape of the tail.

And while english is not my native language, it's tourque not tourgue AFAIK.

gripen

[TimRas]

Originally posted by gripen

And while english is not my native language, it's tourque not tourgue AFAIK.

gripen

English is not my native language either, but i think the word you two are so desperately to spell right is "torque".

Gripen, the helical propwash and precession in takeoff of 109 (and most planes) work in the same direction, in this case left, see
http://www.jiop.fi/ksimuseo/faq_mtkierto.html#engl

http://www.djaerotech.com/dj_askjd/dj_questions/propeffects.html

[gripen]

TimRas,
You can easily verify from the Kokko's report that when the Bf 109 was operated from the hard surface (as in the case of the winter time Malmi), there was no large yawing moments after tail was raised. (in the beginning, before tail was raised, there was a strong tendency to turn right as noted above). If the surface was soft then there was a  tendency to turn left after tail was raised (as noted above) and this was caused by tourque (asymmetrical loading to wheels in the soft surface). The vertical tail of the Bf 109 had built in compensation for propeller slipstream effect.

gripen

[flakbait]

Originally posted by RRAM
P.D. Amazing thread, very informative. There should be a link in the main page with the best and most informative messages written in the forums about the mechanics of flying. Should help people a lot to better understand what's flying about.

and I'm serious, I think it's worth a thought   [/B]

Ask and yee shall recieve! I should have most of the info contained in this thread along with a slew of other stuff posted on my site by Friday. An Engineering section is something I've always wanted to add, but with a lack of interest I didn't see much point in it. On a side note, I should also have a few more AC added to Ground School (like 6 or so). Keep an eyeball on the Help forum over the next few days, cause that's where I'll post a note when it's up.



-----------------------
Flakbait [Delta6]
Delta Six's Flight School
Put the P-61B in Aces High

[Straiga]

Gripen,
 When the plane, pitches forward and to lift the tail your bringing in gyroscopic precession at that point. A force applied in that direction meanning  nose pitch down, the resultant force acks 90 degrees later which is to the left. Every prop plane I have flown, had the vertical stabilizer set to counter prop slip stream but this is more for cruise not as much on takeoff, right rudder is still used also.
 Torgue is spelled torgue not tourgue.

[Batz]

Torgue is spelled torgue not tourgue.

You need to invest in a dictionary.  

The word is torque with q not a g.  

Main Entry: torque
Function: transitive verb
Inflected Form(s): torqued; torqu·ing
: to impart torque to : cause to twist (as about an axis)
- torqu·er noun

[moot]

tonque broplem

[gripen]

Straiga,
In the case of the Bf 109 most slipstream effects could be avoided by keeping  tail down until the tail started to "bite". Note that when the tail was down, it had no or very little leverage (depending on surface) to move right in slipstream (to cause left side yawing moment) . Basicly TimRas's first links tells us what happened when tail was raised too early before tail started to counter yawing.

FAF test pilot Pekka Kokko made quite comprehensive tests on the Bf 109G-2 and found out that by using correct take off technique, yawing effects (caused by slipstream) were minimal when the throttle was advanced slowly in the beginning of the take off (to avoid right side yawing when the tail was down) and the tail was keeped  down until tail started to work (to avoid left side yawing when the tail was up). In fact I'm quoting pretty much directly his text.

And you should read carefully TimRas another link because it explains to(u)rque pretty well; moment to the other wheel in take off and also use of ailerons to counter torque in air. Kokko's report also tells us how the the Bf 109 dropped left wing (due to torque) if the plane was pulled to air at too slow speed.

gripen

[RRAM]

Originally posted by flakbait
Ask and yee shall recieve! I should have most of the info contained in this thread along with a slew of other stuff posted on my site by Friday. An Engineering section is something I've always wanted to add, but with a lack of interest I didn't see much point in it. On a side note, I should also have a few more AC added to Ground School (like 6 or so). Keep an eyeball on the Help forum over the next few days, cause that's where I'll post a note when it's up.

WTG, Flakbait