How to handfly the B777
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How to handfly the B777
Hi
I'm a A320 enthusiastic.
My favorite Boeing is the B777, so i started reading the FCOM, FCTM....
i also purchased PMDG 777. never flew a GA aircraft directly on A320 ( virtually with Qpac A320: most realistic C* law simulated so far)
But I really having a hardtime maintaining the desired flight plath with the PMDG 777
i use to fly the PMDG 737 NG ( NGX) from PMDG, PMDG always does top notch add on :
With the NGX, when i want to change the flight path, I just pitch up or down until i get the flight path I wanted, then adjust thrust to maintain the desired speed and trim to remove the force on the work, the NGX then maintain the FP provided the speed is not changing and the config too.
What i understood from the b777 is that it has an autotrimming feature like the A320 but only for config change, thrust, turbulence, bank, gear , so if you want to change speed you need to do it with the trim on the yoke which will change the trim speed reference, the aircraft will then target the trim reference speed with phugoid phenomenon.
But how do you maintain the flight path with a such feature.
for example I was flying level at 3000 feets, LOC captured. 2 NM from FAP, I select flaps 20, when the GS is captured, I select gear down and then I disconnect the AP and AT. selct then flaps 30, the autotrim will compensate for the flaps change, but speed will decrease toward VREF30+5 KTS (assuming no wind) and I haven't yet change the Trim reference speed which is still at Vref 20 (when AP disconnected), so if no input are given, the AC will pitch down to accelerate and target the VREF25 speed.
So when I select flaps 30 after disconnecting both AP and AT, i trim up as long as the speed is decreasing in order to maintain the Flight path, need also to move the yoke too tough, but i'm not trimming for releasing the force on the yoke but I'm ordering a new trim reference speed, so,when i release the yoke, the flight path is not maintain as te AC will pitch up to maintain the new trim reference speed. PMDG add a trim reference speed indicator on the speed tape so that we simmer can know where the trim reference is currently until we get used to how the trim reference system work.
So after disconnecting the AP and AT, i select flaps 30 and I trim so that the TRS is at VREF30+ 5kts, when the AC speed is within 5 kts of the TRS, i trim once so that the blip trim enters in action and set the trs to the current AC airspeed but even when I'm perfectly trimmed, the AC doesn't maintain the flight path, the aircraft is always pitching down and I can't trim up because of the Blip trim function.
flying a A320 is mush more efficient to maintain the fligh path, but that's only my opinion.
i could post avideo in a couple of hours.
I hope that some 777 pilots can sheld some light on this topic
Regards
CMB
I'm a A320 enthusiastic.
My favorite Boeing is the B777, so i started reading the FCOM, FCTM....
i also purchased PMDG 777. never flew a GA aircraft directly on A320 ( virtually with Qpac A320: most realistic C* law simulated so far)
But I really having a hardtime maintaining the desired flight plath with the PMDG 777
i use to fly the PMDG 737 NG ( NGX) from PMDG, PMDG always does top notch add on :
With the NGX, when i want to change the flight path, I just pitch up or down until i get the flight path I wanted, then adjust thrust to maintain the desired speed and trim to remove the force on the work, the NGX then maintain the FP provided the speed is not changing and the config too.
What i understood from the b777 is that it has an autotrimming feature like the A320 but only for config change, thrust, turbulence, bank, gear , so if you want to change speed you need to do it with the trim on the yoke which will change the trim speed reference, the aircraft will then target the trim reference speed with phugoid phenomenon.
But how do you maintain the flight path with a such feature.
for example I was flying level at 3000 feets, LOC captured. 2 NM from FAP, I select flaps 20, when the GS is captured, I select gear down and then I disconnect the AP and AT. selct then flaps 30, the autotrim will compensate for the flaps change, but speed will decrease toward VREF30+5 KTS (assuming no wind) and I haven't yet change the Trim reference speed which is still at Vref 20 (when AP disconnected), so if no input are given, the AC will pitch down to accelerate and target the VREF25 speed.
So when I select flaps 30 after disconnecting both AP and AT, i trim up as long as the speed is decreasing in order to maintain the Flight path, need also to move the yoke too tough, but i'm not trimming for releasing the force on the yoke but I'm ordering a new trim reference speed, so,when i release the yoke, the flight path is not maintain as te AC will pitch up to maintain the new trim reference speed. PMDG add a trim reference speed indicator on the speed tape so that we simmer can know where the trim reference is currently until we get used to how the trim reference system work.
So after disconnecting the AP and AT, i select flaps 30 and I trim so that the TRS is at VREF30+ 5kts, when the AC speed is within 5 kts of the TRS, i trim once so that the blip trim enters in action and set the trs to the current AC airspeed but even when I'm perfectly trimmed, the AC doesn't maintain the flight path, the aircraft is always pitching down and I can't trim up because of the Blip trim function.
flying a A320 is mush more efficient to maintain the fligh path, but that's only my opinion.
i could post avideo in a couple of hours.
I hope that some 777 pilots can sheld some light on this topic
Regards
CMB
Yikes.....where do you begin? Firstly I have no idea if you have any "real" flying experience so forgive me if you you know the following, and I may be a bit rusty since I last taught Straight and Level 2 over 25 years ago....( Power+Attitude+ Trim = Trimmed performance.....but of course that only worked if the whiteboard briefing was done using the correct combination of colours..
), but I'll give it a go.
Correct, the aircraft needs to be trimmed for speed changes in the same way as the likes of C172, an F4, even a 747.
If you want to think about it in that way, yes, but I reckon you're overcomplicating the process.
If you've never flown a conventional aircraft you need to do what the real newbies do, which is not rush into IF approaches. You need to spend time mastering the basics, in this case learn to trim. Forget the ILS at the moment, take your "sim" up to medium altitude, and take time accelerating and then decelerating the aircraft, whilst at the same time trying to hold and trim to a fixed attitude (i.e. ignore any height changes - just hold the attitude). Once you've got the hang of that then try trimming as you change attitude to try and hold straight and level ( as the speed changes you need to be changing the pitch attitude and trim- once you've done that you'll be in a better position to trim out changes on the approach and elsewhere. Just a FWIW - you mention the Trim reference Speed (TRS) a lot but don't get hung up on that - on our aircraft we don't get a readout of the TRS ( we can in the sim, for training purposes), trimming is all done by feel ( is there a residual stick force?) and by eye (is the attitude I selected changing?)....if the answer to either of those is yes then you're not in trim.
On the basis that a picture paints a thousand words anyone know of an S&L 2 or similar video/youtube link?
Well maybe the hard earned art of manually trimming is regarded as old fashioned by some in Toulouse but IMHO there's "flight path maintenance" and then there's flying ........in any event bonne chance!!
), but I'll give it a go.
What i understood from the b777 is that it has an autotrimming feature like the A320 but only for config change, thrust, turbulence, bank, gear , so if you want to change speed you need to do it with the trim on the yoke which will change the trim speed reference
the aircraft will then target the trim reference speed with phugoid phenomenon.
If you've never flown a conventional aircraft you need to do what the real newbies do, which is not rush into IF approaches. You need to spend time mastering the basics, in this case learn to trim. Forget the ILS at the moment, take your "sim" up to medium altitude, and take time accelerating and then decelerating the aircraft, whilst at the same time trying to hold and trim to a fixed attitude (i.e. ignore any height changes - just hold the attitude). Once you've got the hang of that then try trimming as you change attitude to try and hold straight and level ( as the speed changes you need to be changing the pitch attitude and trim- once you've done that you'll be in a better position to trim out changes on the approach and elsewhere. Just a FWIW - you mention the Trim reference Speed (TRS) a lot but don't get hung up on that - on our aircraft we don't get a readout of the TRS ( we can in the sim, for training purposes), trimming is all done by feel ( is there a residual stick force?) and by eye (is the attitude I selected changing?)....if the answer to either of those is yes then you're not in trim.
On the basis that a picture paints a thousand words anyone know of an S&L 2 or similar video/youtube link?
flying a A320 is mush more efficient to maintain the fligh path, but that's only my opinion.
Last edited by wiggy; 28th Jul 2014 at 16:38.
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My 2 cents, as a "real" (PPL) pilot and as a flight sim guy:
Don't fly the big airplanes with lots of sophistication. Fly something small, single engine piston, until you fully understand the relationship between power, pitch, speed, trim, etc. (The secret is, for any particular configuration, trim sets your speed. When you let go, the airplane will change pitch until it finds the same speed again.)
From your description about speed changes, you don't fully understand the need to adjust pitch/power when you change your configuration. This is something small airplanes can teach you better than big airplanes.
Once you fully, 100% understand that, then fly the big stuff. I don't fly 777, but based on your description, you just need to FLY THE AIRPLANE. If you're on G/S and stable, when you change config, don't mess with the trim. Adjust power and pitch to get the airspeed you want while still on the G/S. Only after that, trim to remove the stick-force. (If you knew how much you need to trim before that, you can do it at the same time, but only when you have the experience.) The trim is not a primary flight control, it is there to neutralize the stick in stable flight. Don't try to fly the airplane with the trim as a primary flight control.
Don't fly the big airplanes with lots of sophistication. Fly something small, single engine piston, until you fully understand the relationship between power, pitch, speed, trim, etc. (The secret is, for any particular configuration, trim sets your speed. When you let go, the airplane will change pitch until it finds the same speed again.)
From your description about speed changes, you don't fully understand the need to adjust pitch/power when you change your configuration. This is something small airplanes can teach you better than big airplanes.
Once you fully, 100% understand that, then fly the big stuff. I don't fly 777, but based on your description, you just need to FLY THE AIRPLANE. If you're on G/S and stable, when you change config, don't mess with the trim. Adjust power and pitch to get the airspeed you want while still on the G/S. Only after that, trim to remove the stick-force. (If you knew how much you need to trim before that, you can do it at the same time, but only when you have the experience.) The trim is not a primary flight control, it is there to neutralize the stick in stable flight. Don't try to fly the airplane with the trim as a primary flight control.
