Could trim control become obsolete?

[bowler_man]

Hello everyone. I was thinking today about the concept of trim adjustments on aircrafts. Would it be possible to get rid of trim if yokes on planes didn't return to it's original position after being moved? For example, let's say you've reached your flight level, and you pushed the stick forward to level off. Once you level off, you could let go of the yoke, and it would remain in that position, not snap back. I don't know too much about physics or exactly what trim is, but it seems to me like that could be a solution to planes drifting off once pressure on the controls is released. Thoughts?

[BFMF]

I don't know, I kinda like controllers returning to neutral when released

[Brett_Henderson]

What you're talking about would be getting into the,  "fly by wire"  arena.. and without a computer to monitor it all, you'd have to have some sort of friction arrangement to "hold" the controls wherever it is put them.. taking away all "feel" for the pilot.

All that tradiational trim does, is to change the aerodynamically neutral state of a control surface, to match a desired attitude.

[Hagar]

Not sure why it would be be necessary to do away with trim controls. Your idea would probably make the aircraft very difficult to fly. In fact, unless it was a fly-by-wire system I don't think it would be mechanically possible.

[Fozzer]

Pre-Selecting the Altitude and Heading, followed by switching on the Radio Autopilot (if fitted) should achieve a stable hands-off flight controlled automatically by the servo-motors....

...otherwise the Manual Trim will always be necessary to ease the pressure on the controls...

Paul...G-BPLF.... 8-)

[DaveSims]

Hello everyone. I was thinking today about the concept of trim adjustments on aircrafts. Would it be possible to get rid of trim if yokes on planes didn't return to it's original position after being moved? For example, let's say you've reached your flight level, and you pushed the stick forward to level off. Once you level off, you could let go of the yoke, and it would remain in that position, not snap back. I don't know too much about physics or exactly what trim is, but it seems to me like that could be a solution to planes drifting off once pressure on the controls is released. Thoughts?

The thing is, it is the aerodynamic forces on the control surfaces that cause the yoke to return to "neutral".  The trim just acts as a balance of those forces, to cause neutral pressure on the yoke in whatever position you desire.  If these forces were removed, there would be no feel to the aircraft, which would make it very hard, and sometimes dangerous, to fly.  Many aircraft are rigged to actually increase the control forces more than what they would normally be, to prevent pilots from accidentally over controlling the aircraft. 

[beaky]

What you are describing is, in effect, a "fly by wire" system, where the pilot lets the autopilot fly while pretending he's flying by using yoke and rudder pedals to tell the AP what he wants to do, instead of pushing buttons and turning knobs.

I get the idea- eliminate the need for the pilot to make trim adjustments- but heck, that's what autopliots are for. Why not just engage the AP and tell it what heading and altitude you want?

  If you are operating the trim system correctly- regardless of what type it is- the stick or yoke should not move from its new position anyway. Why make it more complicated?
 



The idea with trim, particulary with airplanes that have some sort of mechanical connection between controls and flight surfaces, and moving trim tabs, is not to "fly with trim", but to put the controls where they need to be, then trim until you can let go and they will stay where you left them. Works fine without any additional machinery moving the controls. When you add servos to move the yoke, etc. what you have is an autopilot.

[olderndirt]

the concept of trim adjustments on aircraft.

A concept ignored, more or less, on FS products.

[-Crossfire-]

Has everyone forgot about the new Dassault Falcon 7X?

[DaveSims]

[quote]Has everyone forgot about the new Dassault Falcon 7X?

[beaky]

[quote]Has everyone forgot about the new Dassault Falcon 7X?

[DaveSims]

[quote][quote]Has everyone forgot about the new Dassault Falcon 7X?

[captanish]

its a real bad idea.. namely because many aircraft including jets have a trim system that moves the entire horizontal stabilizer instead of just a tab on the tip of the elevator/ aileron and in these aircraft if u dont trim your plane correctely and end up with excessive drag from the deflected elevator u could end up with real marginal performance esp on a single engine! we actually use this technique to bleed speed in real dornier 228s on landings or even in the air.. as far as i know even fly by wire systems have a force feedback system on the stick.. u cant really go eliminating the trim .. it can be automated - like a trim coupling system whhen u raise or retract flaps but overall its a senseless idea - it doesnt really hurt anyways.. many aircraft have trim operated by an up down switch so no big deal anyways! hope it answers the question.

[snippyfsxer]

Have any of you guys used the PMDG MD-11?  The LSAS (that is Longitudinal Stability Augmentation System) provides automatic trim input within a certain attitude and altitude envelope.  So sometimes it is a matter of pointing the nose where you want it to be, and sometimes it isn't.  I have the plane in my virtual Hangar because I'm lazy, but I have found it is rather easy to get into the situation where you are fighting the aircraft;  You are trying to trim it to a certain attitude and it wants to either trim you right back or physically take control of the elevators themselves.  It is my understanding that this is exactly one of the criticisms of the real life aircraft.  And boy does that thing land hard and fast.  Thank God its just a sim;