Author Topic: Trim!  (Read 2292 times)

Offline Straiga

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Trim!
« on: December 07, 2004, 05:08:11 AM »
Im not understanding the trim in AHII.

 Here I take a plane up and trim it at a set power setting for a given altitude, trim the ball center, trim aileron (I still dont Know WHY), and trim elevator. Then do some turns and bring the airplane back to the same airspeed and altitude, then plane should be trimmed but its not, I still have to trim the plane. The plane should already be trimmed, for the airspeed and altitude.

 The plane should show some right rudder trim and some nose down trim, and nuetral aileron trim, for a single engine airplane in straight and level unaccelerated flight. But all the trims are centered, except the airleron trim, it shows right airleron, I guess this is for Torque (wrong). This I dont understand. If you think you trim in aileron because of torque this is wrong, you use rudder to counter torque.
 So show me some written documents that prove me wrong about the torque. You guys know I have P-51 time and you dont counter torque with aileron. And please dont show me a picture of a helicopter again theres a big difference when you have a 80 ft. rotor span compared to a 11 ft prop disks, when talking about torque. You ought to know the diference between the way a helicopters flys compared to an airplane. Its like day and night, if you think its the same, start reading some more.

I have a lot of airplane sims, and why is this the only sim that uses aileron trim the way it does. When you trim the ailerons in a real airplane its because of a possible fuel embalance, or have a bomb still hanging on one side, or trim because in a multi-engine airplane you lost one engine. Trim the dead engine into the good one about five degrees up.

 With the autopilot set for best climb, the elavator trim, it shows full up. Theres no trim left. In a real plane, you trim for a climb and theres a lot of trim wheel left. You should also see right rudder being used, with nuetral aileron. This I dont understand.

 When my dad and brother were flying AHII over Thanksgiving, they couldnt stop laughing and picking the sim apart, because they never had to trim so much in there life, just to keep the plane flying true. Although they were impressed with the planes skins and terrain.
My dad said if a fighter pilot had to trim so much as in AHII, he would not have time to line up someone to shoot at. Trimming an airplane in 3D and having to use throttle, stick and rudder constantly in combat good luck. Its to busy, just point the plane and shoot.
 He said trim for cruise and use the stick and rudder pedals, and some elavator trim if needed and leave the airlerons in nuetral trim. Thats all you need to do.

 My dads A retired General USAF
 36 mission in Korea (P-51, F-86)
 112 missions over N. Vietnam (F-105, F-111)

 Later Straiga

Offline stantond

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Trim!
« Reply #1 on: December 07, 2004, 08:31:37 AM »
Hi,

Torque is not modeled in AH.  The trim is not 'completely realistic'.  The trim used is an abstraction of what is really used in an aircraft.  

Trim modeling *is* incorporated, however.  That added level of detail is a further step towards realism.  But, it is not perfect.  Lepturns web site (in the AH links) has a useful discussion on trim used in AH.

Combat trim allows pilots to fly around without constantly 'fiddling' with the trim.  Manual trim is useful in the flight envelope edge when flying certain planes and landing.  The AH flight models are not perfect, but they are the best I have found.  If you know of any better, myself and many others would be interested (including HiTech I bet).

I recommend similar posts be placed in the 'Help and Training' forum.   Also,  you would be wise to spend some time in the training arena.  Posting here just sounds like a rant... which I don't believe was your intention.


Have fun,

Malta

Offline Straiga

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Trim!
« Reply #2 on: December 07, 2004, 08:58:36 AM »
No it was not my intention to rant, but I have no prob with flying in AHII. But its just a major hassle to constantly trim, trim, trim, trim.
Just put the ailerons to nuetral and lets just trim elavator and use the rudder with a little trim. This would be closer to the real thing.

Straiga

Offline hitech

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Trim!
« Reply #3 on: December 07, 2004, 08:59:47 AM »
Torque Is completely modeled in AH.

As far as how trim is modled it is very representative of triming an aircraft. We have some trims that the real counter part didn't have, but in the real counter parts you had to maintain stick input to typicly fly level.

As far as Straiga's question, depends if you had combat trim on or off.

HiTech

Offline Straiga

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Trim!
« Reply #4 on: December 07, 2004, 09:02:32 AM »
Combat trim off

Offline Schutt

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Trim!
« Reply #5 on: December 07, 2004, 09:29:03 AM »
And ah trimm changes the amount of elevator authority you have.

Trimming aircraft for lvl flight at 400mph and pulling full up yields less g turn than trimming nose up and pulling up.
Is that authentic?
That also gives a great disadvantage flying in combat trim than in manual trim.

ciao schutt

Offline hitech

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« Reply #6 on: December 07, 2004, 09:55:21 AM »
Yes it is authentic schutt. At fast speeds you can not pull hard enough on the stick to reach it's full defelection. Adjusting trim moves the zero for point of the stick. And you get the same amount of stick force from the zero point, hence you call pull more g's.

At slower speeds adjust trim does not effect turn performance at all. Because no matter where the trim is set, you can pull the stick to the stops.

HiTech

Offline stantond

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« Reply #7 on: December 07, 2004, 11:26:13 AM »
What I meant to say was that In AH, low speed torque induced flight characteristics can not be found as described in articles such as:

http://home.att.net/~ww2aviation/Bentwings.html

I have not seen the 'ensign eliminator' effect in any of the F4U's.  Not having the tail wheel locked on landing can cause a crash, but that is not what I consider a flight characteristic.  Fwiw, I don't remember ever seeing low speed torque effects modeled in any flight sim.  



Regards,

Malta

Offline Straiga

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« Reply #8 on: December 07, 2004, 11:10:56 PM »
Its nice to be able to trim the plane in all axises.
 But the point I trying to make is that trimming the aileron as much as we have to do, it is not nessasary. WWII and todays airplanes set the aileron trim to nuetral and leave it alone, now is this hard to understand.
 In 30 years of flying I may have only trimmed a hand full of airplanes with the aileron trim. Once was a DC-10 because it had a very bad bios in that the way it flew.
 The big war birds use a lot of right rudder trim and even more rudder on takeoff while the aileron trim is set to nuetral. Hmm. It make you wonder doesnt it.

 When you trim an airplane say for cruise speed and at a set altitude you should be able to do loops, turns, climbs and desents then put the plane back at that altitude and speed and it should be trimmed already. Do you see my point.

Straiga
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Offline Widewing

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Trim!
« Reply #9 on: December 08, 2004, 12:08:36 AM »
Quote
Originally posted by Straiga

 The big war birds use a lot of right rudder trim and even more rudder on takeoff while the aileron trim is set to nuetral. Hmm. It make you wonder doesnt it.


That depends upon the airplane and the circumstances.

For example: For takeoff, all tabs are set at neutral for the P-40. Not so for the F4U-4

According to one F4U-4 pilot:

" I checked various settings. Full flaps. Cowl flaps open. Hook up. Trim 6 degrees nose right, 1 degree nose up, 6 degrees right wing down. Tailwheel locked. Cockpit canopy open and locked. Shoulder straps and seat belt tight. Prop control full forward for maximum revolutions per minute (rpm). Mixture auto rich. Supercharger neutral. Wings locked. Controls move freely."

This is just one example and it applies to carrier deck runs, but it seems to establish that there are no absolutes.

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline Straiga

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« Reply #10 on: December 08, 2004, 02:37:56 AM »
I dont buy it.

                           US NAVY
                 
              Flight opperations manual

         F-4U-5/ F-4u-5N/F-4U-5NL/F4U-5Px

Emergencey Takeoff

A. Shoulder harness and safty belts secure and locked
B. Canopy open
C.Tail wheel lock
D. Fuel selector ON
E. Fuel transfer switch ON
F. Aux (Boost) fuel pump switch HIGH check fuel pressure
G. Rudder tab 6 degrees NOSE RIGHT
H. Elevator tab 1 degree nose up
I.  Aileron tab Nuetral

 Same for carrier takeoffs (catapult or non catapult Takeoffs)
 Full flaps required

2-50 Tabs settings

 The rudder force required maintain a straight run will be high unless the rudder tab has been set to at approximately 6 degrees nose right prior to takeoff run. (nothing said about ailerons or aileron trim)

1-7 Tabs

 The tabs on the control surface consist of the balance tabs on each airleron. A trim tab on the left aileron, and combonation spring and trim tabs on the rudder and elevators.
 The airleron balance tabs are deflected automatically in a direction opposite to that of the ailerons when the ailerons are deflected. This reduces the stick force to opperate the ailerons. Same as in previous F-4U models.

 P-51D Mustang

Takeoff

Rudder 61/2 degrees nose right
Elevator 2 degrees nose down
Aileron nuetral

B-17G

 Takeoff

 Rudder 5 1/2 dgrees nose right
 Elevator 2 degrees nose up
 Airleron Nuetral

 Straiga
« Last Edit: December 08, 2004, 02:41:47 AM by Straiga »

Offline straffo

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« Reply #11 on: December 08, 2004, 03:00:48 AM »
Quote
Originally posted by Straiga
I dont buy it.

                           US NAVY
                 
              Flight opperations manual

         F-4U-5/ F-4u-5N/F-4U-5NL/F4U-5Px
 


I don't know if it's important but Widewing wrote about the F4U-4 not the F4U-5

Offline Straiga

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« Reply #12 on: December 08, 2004, 03:56:27 AM »
The F-4U-4 and F-4U-5 have the same airframe but the 5 has a bigger engine. If you dont need airleron trim in the 5 you dont need it in the 4. LOL

 Trim: P-51D same as P-51C, F-14A same as F-14D, P-38L same as P-38J.  DC-10-10 same as DC-10-30    LOL

 B-24D

 Takeoff
 Elevators 1 degree nose up
 Rudder 2- 2 1/2 nose right
 Aileron nuetral

 Straiga
« Last Edit: December 08, 2004, 04:01:35 AM by Straiga »

Offline straffo

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« Reply #13 on: December 08, 2004, 04:05:01 AM »
no need to be ironic , I was just makiing a point.

Offline Straiga

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« Reply #14 on: December 08, 2004, 04:16:12 AM »
So my point is if you dont need aileron trim on takeoff which is the highest torque producing range and at the point for the most amount of rudder application is needed to counter torque, you dont need aileron trim in the air, it should be nuetral.

 King Air E90, B200, B300, B350

 Takeoff
 
 Elevator trim 2 up
 Rudder trim nuetral
 Aileron trim nuetral

 At cruise

 Elevator trim 5 down
 Rudder trim 2 nose right
 Airleron trim nuetral  

 Straiga