Is there a specified trim setting for any aircraft? For the 787 if I’m >MLW my trim is usually between 40%-50%, someone said I’m doing it wrongly. But then when I cap my trim at a certain percentage I still see the pink bar telling me that I should trim the excess pitch up forces more.
For the A380 I trim at 80% if I’m near MTOW, sometimes 100% trim isn’t enough if I’m doing an ultra long haul flight and it’s heavy.
for all aircraft i do 60 to 70
The aircrafts are in trim, when the magenta line is gone.
So I should continue to trim if it’s still there? There’s no said limit for any aircraft right.
I’d have a look here. There’s some great info that will help you :)
I think I should change my question: Am I wrong to keep my trim at a certain level even when there’s still pink bar shown?
I know the consequences of not trimming properly, my aircraft won’t be fuel efficient.
You can keep your trim however you feel comfortable especially during takeoff and landing. I prefer a lot of trim in most aircraft because that’s what I’ve been accustomed too but others may like less trim. During cruise I do prefer to adjust until there is no more magenta visible.
Have you ever encountered trimming 100% and still see magenta?
I can keep my aircraft at 0% trim. It doesn’t have any effect during takeoff and landing but I found out that trimming extends my aircraft’s range.
I can’t say I have but with the CRJs and DC/MD aircraft I’ve found that those are aircraft I have more positive trim input when compared to other aircraft. I don’t believe I’ve ever trimmed any aircraft over 70% positive trim.
Is it wrong to trim negatively? Especially for narrow-bodied aircraft like A320 I found that if I exceed 250 kts I see the magenta going up telling me to trim the downward force.
Trimming is all relative to your profile and aircraft. During cruise I have found the use of negative trim but not too often.
This should help it should change for each phase of flight.
I use 30% at most for a heavy aircraft, if you’re cruising with negative trim you likely have the fpv over the pitch, which means your airspeed is too high. Trim is a setting for speed, it is basically auto-speed that changes your pitch to maintain speed. If you set a trim and add throttle it will maintain that speed whether it points you up or down to do so; granted it will have to level out by porpoising a bit. For example, takeoff trim on the C172 is trim for 80kts which is the climbout speed, so theoretically if you stabilize the aircraft it will climb out at the right speed by itself. It’s pretty interesting, I recently learned it while preparing for the FAA knowledge test. I suggest you check it out.
I was at M 0.73 on an A320 without the need for a negative trim. If I was at M 0.78 which is the cruising speed for the A320, I need to trim negative as the fpv is over the pitch, isn’t that odd?
I don’t really get how trim links with maintaining speed because when I takeoff 99.9% I’m not at the correct trim setting. To correct my trim setting when hand-flying my aircraft during climbout is something which I rarely do because it’s very difficult to hold my device stable with two hands and setting trim with my thumb, I may accidentally activate A/P or gear down. I’d love to trim on a real aircraft but sadly I’m unable to.
If you were at a low altitude, it would require more airspeed to reach that mach setting. Up at FL380 it should be fine at .78.
If you’re doing a short haul, look at you aircraft’s cruising speed in KIAS for reference.
The link between trim and airspeed is an extremely complicated aerodynamic system, takes a while to understand.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.