the blip trim is annoying

[cmbaviator 5]

Hi,

 

I found that it's quite hard to trim the T7 because of the blip trim trigger :

 

 

* at initial climb after flaps retraction, target speed is 250 KIAS, so i often add +5 tks to the trim speed reference(TSR), but as the speed is increasing and is within 5kts of the TSR, each time I trim, the blip trim enters into action , so the the pitch attitude suddently goes up, then i increase the TSR and re increase that the blip trim tale over ...... I don't know how the pilots deals with this in real life, but for me it will be more easy and intuitive to like doudle tap quicky the trim swithces if the PF wants the blip trim to enter in action.  of course lets say the speed is 200 kts and i want 250, i can gradually set 210, 220, then 230...... but i found that even a 10 kts difference is too much as the plane will pitch up severly, thus needing lots of deflection to maintain level for example.

 

Hope to hear some suggesitons

 

regards

 

CMB

[Gavin 99]

I mean this as a genuine question and not a criticism, but what does the verb 'to like doudle tap' mean please?  Thanks.

[scandinavian13 5,192]

 

 

I don't know how the pilots deals with this in real life, but for me it will be more easy and intuitive to like doudle tap quicky the trim swithces if the PF wants the blip trim to enter in action

 

Pilots "single tap" the trim switches briefly when within 5 knots of the trim reference speed.  It's programmed just like the real plane, so pilots handle it in real life just as they would here.

 

I think because there's a lack of force feedback in the sim, I usually trim the plane to be a little nose heavy, which allows me to adjust my "pressure" on the yoke without pushing it forward.  With the 777, I had to train myself out of that and just trim it like I would when I fly any plane in real life: neutral trim.

[cmbaviator 5]

I mean this as a genuine question and not a criticism, but what does the verb 'to like doudle tap' mean please?  Thanks.

 

 

Sorry I meant double

Pilots "single tap" the trim switches briefly when within 5 knots of the trim reference speed.  It's programmed just like the real plane, so pilots handle it in real life just as they would here.

 

I think because there's a lack of force feedback in the sim, I usually trim the plane to be a little nose heavy, which allows me to adjust my "pressure" on the yoke without pushing it forward.  With the 777, I had to train myself out of that and just trim it like I would when I fly any plane in real life: neutral trim.

 

I'm not blamming PMDG, but the way the blip trim enters in action, because it seems that you can trim 10 kts by ten kts, because if less, the blip trim enters in action, changing suddenly the attitude

[scandinavian13 5,192]

 

 

because it seems that you can trim 10 kts by ten kts, because if less, the blip trim enters in action, changing suddenly the attitude

 

If it's suddenly changing altitude, you're not flying the plane correctly.  And the limit is 5 knots.  It won't trigger outside of that.  My bet is either a misconfigured trim command on your hardware, or you're doing something very odd.

[Driverab330 74]

I too experience the same problem which I reckon I have mentioned it somewhere before, in FSX it seems really hard to trim the PMDG777 just by the feel of it. I use a Saitek Yoke and normally I always try to hold the attitude and press the trim button until the time when I can let go of the control and airplane flies at a stable attitude. And 9 out of 10, the airplane will either pitch up or down with short 1 sec time delay after I let go of the control column. The easiest way is to switch on the AP then disconnect again after attitude had stabilised. Even with the correct trim reference speed set, it is still have some level of pitch oscillation which is not very ideal. I have calibrated the yoke and followed the guidance to setup the yoke. 

 

And I wonder does anyone have similar experience? 

 

This is particular annoying when I do touch and go circuits with the 777 because the trim is always all over the place on downwind. If this is a pure hardware problem, I wonder if this behaviour will disappear by using a better quality Yoke? This also brings out another question as to what type of Yoke PMDG used when during development phase of the 777 so that if I use the same yoke, I should be able to get a better flying experience with it.    

 

I personally don't think getting a force feedback yoke will help, because the real 777 yoke to my understanding is also spring loaded to the center. What the PFC did was to change the spring force at different airspeed and configuration so that it gives a certain level of feedback to the pilots and this applies to pitch only, the force to roll the airplane is the same all the time. Its not like a cessna where the yoke stays at different position at different pitch trim levels.

 

Real world 777 pilots blip trim all the time when accelerating or slowing down to trim out the force. and I can tell you its much easier to fly than FSX. I blip the trim the airplane usually for every 5kts of speed change so that i dont really have to hold the control column with much force this is very useful when accelerating at low altitude as the rate of acceleration can be quite high. 

 

I really hope theres solution to this problem, either I buy a new yoke or a software update. because I really enjoy flying the 777. 

[scandinavian13 5,192]

 

 

Real world 777 pilots blip trim all the time when accelerating or slowing down to trim out the force. and I can tell you its much easier to fly than FSX. I blip the trim the airplane usually for every 5kts of speed change so that i dont really have to hold the control column with much force this is very useful when accelerating at low altitude as the rate of acceleration can be quite high. 

 

If you believe it's a problem on the developer's end, submit a ticket - particularly if you have verifiable evidence that you can back your statements up here.

 

Also - you need to sign your posts here.

[vr-pilot 11]

This is particular annoying when I do touch and go circuits with the 777 because the trim is always all over the place on downwind. If this is a pure hardware problem, I wonder if this behaviour will disappear by using a better quality Yoke?

I use a Mad Catz V.1 Stick. It is spring loaded and works great for the T7 IMO. "Blip trim" and "1 sec trim for 10 kts of speed change" are functioning as they should.

The only thing to consider is the residual voltage tendency of its potentiometers. This results in noisy flashing axis values and can influence the pitch and nose trim behaviour significantly. But by unplugging and replugging the USB connector the residual voltage gets discharged and the noise vanishes. 

At PC startup I first run the Mad Catz V.1 Stick control tab to ensure that the potentiometers are unloaded, then I run the TrackIR software (for calibration). After that I launch FSX, FSPS FA, ASN and I am ready to go... B)

[MarkW 1,479]

Pilots "single tap" the trim switches briefly when within 5 knots of the trim reference speed.  It's programmed just like the real plane, so pilots handle it in real life just as they would here.

 

I think because there's a lack of force feedback in the sim, I usually trim the plane to be a little nose heavy, which allows me to adjust my "pressure" on the yoke without pushing it forward.  With the 777, I had to train myself out of that and just trim it like I would when I fly any plane in real life: neutral trim.

 

I have to admit I have problems trimming the 777 as well.  Not extreme issues but I find that I need to put too much pressure on the yoke (so presumably I am slightly out of trim).  Kyle, is there any way you would consider a 10 minute video with the blue trim bug on to show us what you do to trim correctly on takeoff and hand flying the landing, say from 5 miles out.?  I think seeing it will help more than reading about it.

[777simmer 117]

Pilots "single tap" the trim switches briefly when within 5 knots of the trim reference speed.  It's programmed just like the real plane, so pilots handle it in real life just as they would here.

 

I know you probably did not mean it that way.....so just to clarify to others:

 

Pilots are nit aware of being within 5kt of the trim ref speed.

 

This is after all not displayed in the real aircraft.

 

All you do is trim untill you feel no more push/pull force on the yoke.

You do this with short bursts of trim usually. like 1-2 sec bursts.

 

At some point you feel the force is pretty much gone.

If you then after a few seconds see.....hey the nose is going up /down slightly and it tends to gain/loose 1-2-3kt again slowly, then you would just give a short quick gentle push/pull on the yoke so the nose goes where you need it again and then quickly tab the trim switch in the direction of trim needed.

 

And then the aircraft is suddenly perfectly in trim.

As a pilot you then think you did a great job where in fact I guess the blib trim just got activated.

 

I say I guess, because the real 777 pilot is not aware of a blib trim function.

I do not think this is anywhere in the manuals.

 

With that said......in the real 777 the blib trim does not seem to fight me.

A single quick tab of the trim usually gets that final trim in there.

As if the system knows what speed I want to set the trim for.

 

In the PMDG777 and with the FBW trim ref speed displayed, the blib feature is fighting me sometimes and does not allways help me.

On the contrary, i have a feeling that sometimes it blibs to the actual speed and at other times it blibs to the speed bug.

 

An option to turn blib on/off in the FMC would be great.

[Vim Fuego 1]

 

 

An option to turn blib on/off in the FMC would be great.

 

An attractive idea, I find it alternately very to quite frustrating myself.  However, so it seems do at least one of your fellow 777 pilots in the real world.  I stumbled across this archived post from 2003 on pprune where a 777 pilot (no.2 post) lists his likes and dislikes of the then fairly new 777.  Guess which feature he posted as no.1 on his list of dislikes??

 

http://www.pprune.org/archive/index.php/t-107512.html

 

Seems as though PMDG may have got this undocumented feature exactly right after all!   

[scandinavian13 5,192]

 

 

 Kyle, is there any way you would consider a 10 minute video with the blue trim bug on to show us what you do to trim correctly on takeoff and hand flying the landing, say from 5 miles out.?  I think seeing it will help more than reading about it.

 

I'll see what I can work up.

[Driverab330 74]

With that said......in the real 777 the blib trim does not seem to fight me.

A single quick tab of the trim usually gets that final trim in there.

As if the system knows what speed I want to set the trim for.

 

In the PMDG777 and with the FBW trim ref speed displayed, the blib feature is fighting me sometimes and does not allways help me.

On the contrary, i have a feeling that sometimes it blibs to the actual speed and at other times it blibs to the speed bug.

 

 

Thats exactly what I am trying to say. I will see if I can shoot a video in the sim or in actual flying compared with PMDG trimming function. But like 777simmer mentioned, we dont need to fight the trim, it is supposed to be working intuitively all the time. Because its not a requirement for pilots to know exactly how the trim works behind the scene in a flight crew training course. Coming from the small airbus, the speed trim function only took me 2 hours of sim time to get used to and of course once flying the real thing is much easier.

 

Normally the PMDG 777 works ok for the initial take off, however, the auto trim  and the Yaw damper does not seem to react very well when the departure consists of multiple turns, intermediate level off and climbs even if the airspeed is maintained and the trim ref speed is correct, it takes a bit long for the attitude to settle.  

 

I understand the quality of control input signal from a normal gaming yoke is no comparison to what the actual sim or the airplane. Thats why I would like what kind of Yoke most beta testers or PMDG developers used so that the airplane behaves a bit more closer to what the real one does. Because the replies on this  forum  regarding to this issue gives me the impression that the PMDG reckon the flying quality of the airplane is already quite close to how the airplane would behave, so if I use a similar yoke, I should be able to get a similar result, because I know there are some slightly better built Flight sim flight control columns out there on the market than the popular Saitek flight pro Yoke.

 

I am not trying to criticise the effort PMDG put in on developing this brilliant 777 add-on, I really love it. To me they have done a great job already on simulating this very complicated modern airliner. Having studied relevant subject in university I understand how hard it is to program a simulator of an airplane from the ground up. However, because the product is already so bloody good. If some how this little glitch (could be hardware problem which hopefully can be solved by getting a better yoke or software issue) can be ironed out, I would say it is  very very close to a level D simulator experience.  

 

it is just my opinion here. I reckon sometimes, may be it is better to tune the PMDG 777 to how it actually flies in term of hand flying quality, than trying to follow every single wordings as to what the engineering design book says. I understand initially the book provides a frame work to build the programming code. The problem being that we don't have a very sophisticated flight control column at home compared to the official Boeing training devices or the real airplane. So by following the book, we may not get the desire result as how it suppose to work. Its a bit more like when BMW/Mercedes/Porsche/Audi develops their car, they always tune the car's software and various chasis/suspension setup through numerous driving test in order to make the car to have a particular handling quality or characteristic. I believe at times, how the pmdg777 flies like compared to the real one is to me more important than how it actually work behind the scene. 

 

I am trying express my humble opinion here so that hopefully PMDG can further improve the already terrific product. Because to be honest, I reckon it is a great game. Again I will try to do a video comparison and then I will submit a ticket once I have time to sort those out.

 

Happy Flying everyone, cheers. 

[MarkW 1,479]

I'll see what I can work up.

 

Great, thanks.

[vr-pilot 11]

 

 

I believe at times, how the pmdg777 flies like compared to the real one is to me more important than how it actually work behind the scene.

I follow the blue FBW speed bug quite much because it is very useful as an orientation, nevertheless its use is "unrealistic" as it is not displayed in the RW T7. I ask myself why it is actually not depicted on the RW speed tape. Could be helpful for manual flight in general or even more during abnormal flight conditions.

BTW: I like the T7's stabilizer auto trim restriction to flap and gear configuration changes quite much. IMO it is superior to the Airbus philosophy in terms of man-machine-interface.