realistic trim reponse

[gyrene81]

Actually the 109 had trim tabs on the horizontal stab that had to be adjusted on the ground. Can't remember exactly how the 190 trim worked.

Anyone know what the OP is going on about anyway? Trim settings work pretty well in the game.

[Motherland]

ALL WW II acft had trim tabs,

I think that many/most WWII aircraft had no inflight adjustable trim at all, though I may be mistaken.

[Motherland]

The point I'm trying to illustrate is this; Trim tabs could not conceivably overcome the several tons of force required to move a fabric covered control surface on ANY acft experiencing the effects of the sonic wave build up (compression) at high speed.
 In some cases the aircraft the compression effects are more pronounced at lower speed due to the wing planform and/or the control surface area, a good example is the A6M series, lightly built, large ailerons, thicker planform. These features allowed zeros to perform very well at low to medium speeds 250 mph and lower, above 250 mph testing revealed the inability to roll to the right and a limited ability to roll left assisted only via engine torque (only at 1/2 throttle and above). Many zeros were shot down by taking advantage of this controls issue.

ME-109s compressed earlier than P-47's or P51's and U.S. pilots took advantage of that as well, TRIM did not affect the onset of compression nor did it add any amount of effective control input during the effects of compression. In nearly all cases the trim tabs were MANUALLY adjusted via trim wheels in the cockpit.  MY wish....( insert drum roll here) ...is for the trim to be diminished at higher speed and eliminated during the effects of compression. keep it real   

A) The 109 series did not suffer from compression, rather from control stiffness at high speeds. These are two different things.
B) 'Trimming' out of a dive was use by 109 pilots in real life. So if you'd like to 'keep it real'...

[gyrene81]

I think that many/most WWII aircraft had no inflight adjustable trim at all, though I may be mistaken.

Motherland...uhhhh...that's in direct contradiction to your statement about the 109 pilots trimming out of a dive...how could they do that if there was no "inflight adjustable trim"?

[Ack-Ack]

A) The 109 series did not suffer from compression, rather from control stiffness at high speeds. These are two different things.

A lot of people seem to confuse control stiffness due to high speeds and compression/compressability.  Most players in game experience control stiffness at high speeds rather compressability.  Of course, obvious exceptions are planes like the P-38 and P-47 that did suffer from compressability in high speed dives depending at the start altitude of the dive.


ack-ack

[Soulyss]

Actually the 109 had trim tabs on the horizontal stab that had to be adjusted on the ground. Can't remember exactly how the 190 trim worked.

Anyone know what the OP is going on about anyway? Trim settings work pretty well in the game.

The 109 had elevator and aileron trim controls in the cockpit, two wheels located to the left of the pilots seat.  What it was lacking was rudder trim if I recall correctly.

In Alfred Price's book on the 190 he has the following to say on the 190 trim system.

A fighter pilot did not want to have to re-trim the aircraft each time he moved the throttle.  The team were so successful in this that they found that movable trim tabs were unnecessary.  Small fixed trimming tabs were fitted to the ailerons, the elevators, and the rudder.  They were adjusted on the ground after the initial flight, to compensate for the wide tolerances that occur with a mass produced aircraft.  The only system of trimming the aircraft in flight was in the elevator sense, and that was achieved using an all moving tailplane.

[Motherland]

Motherland...uhhhh...that's in direct contradiction to your statement about the 109 pilots trimming out of a dive...how could they do that if there was no "inflight adjustable trim"?

Even the majority of 109 models had only two axises (pitch/roll) that could be trimmed in flight. The rudder trim had to be adjusted on the ground (on versions that had it- this was not the majority).

[Karnak]

That is all moot.  catdaddy's mistake is to interpret all control stiffness in AH as compression when in fact very little of it is compression and is instead control stiffness due to excessive airflow over the control surfaces.

Prominent examples in AH are the Bf109's or Ki-84's difficulty pulling out of a fast dive, the Spitfire's poor roll rate at high speeds and the A6M's poor roll rate and poor elevator response at high speed.  None of those are compression effects.

[Anaxogoras]

A lot of people seem to confuse control stiffness due to high speeds and compression/compressability.  Most players in game experience control stiffness at high speeds rather compressability.  Of course, obvious exceptions are planes like the P-38 and P-47 that did suffer from compressability in high speed dives depending at the start altitude of the dive.


ack-ack

Nonsense.

[Ack-Ack]

Nonsense.

Is that all you got? 


ack-ack

[BnZs]

Actually the 109 had trim tabs on the horizontal stab that had to be adjusted on the ground. Can't remember exactly how the 190 trim worked.

Anyone know what the OP is going on about anyway? Trim settings work pretty well in the game.

Both aircraft changed the incidence of the horizontal stab for trim in the longitudinal axis. The OP apparently did not bother to find this out when he stated that "there was not one single WW II acft that was equipped with with an all flying tail (entire horizontal stabilizer moves to trim acft)"

[Motherland]

Also I thought the P38L was the first model to have boosted ailerons?

[Soulyss]

Also I thought the P38L was the first model to have boosted ailerons?

I need to confirm, but I believe that the boosted ailerons and dive flaps first appeared on the P-38J-25-LO. 

[gyrene81]

I like trim...trim is good...not real bushy trim but then...trim is trim ya know? Fast action trim can be a lot of fun...but most of the time I like the slower casual trim use...I don't turn down the chance to get trim unless the rest of the frame looks like it belongs in a dog food bag...or if the trim itself looks like it's been chewed up by a dog. I like trim in all sizes too.


I like trim...

             






Hopefully skuzzy doesn't give me the old "see rule #" action...

[FLS]

The AAF Manual 51-127-1 on the  P-38, under the section titled Compressibility Recovery Procedure, states: "Use only a few degrees of elevator trim tab". This is also listed under Normal Dive Recovery as well as being part of the procedure for recovering from compressibility in a dive.