Jump to content

Sign in to follow this  
Guest

test flight report / some possible bugs

Recommended Posts

Guest

Hello,before I watch the Grand Prix, I would like to publish the results of thefirst flight I made with the new 757 which is a great product!I found these possible bugs:============================- Take Off: Weight was 223.0, Flaps 15, Temp. 12. VR was set to 147 kts, but I could not get the nose up at this speed- !!! SPD-mode: at low speeds it works great, but at higher speeds...uh oh! When I switched (during climb) from VNAV to V/S, Speed set to 315, actual speed was 300, the plane did not accelerate!!! The A/P set the thrust to 75% N1 which was way too low to maintain the desired 315 knots. So the speed went down and I had to set thrust to manual in order not to stall.- When having passed the Top Of Climb, the distance to TOC is showed as a negative value. Is that also the case in the real 757?- FMC shows repeated messages "Insufficient Fuel", ALTHOUGH it is just a short flight from EDDH to EHAM and there was more than 50% of max.fuel on board. The FMC also indicated (CRZ Page) that the remaining fuel at EHAM is 30.8- I tried to tune the ADF to 388.50, but I did not manage to set the last digit to "5". Isn't it possible to set the digits after the "." ?These things could be improved:===============================- realistic engine start behaviour (not running 1 sec. after turning the knob to GND)- the reverse thrust sound is interrupted each second or so. i don't know if this has to do with my SB Live Player card, but all other sounds workI would be glad if someone at PMDG could have a list at these items and see if they are really bugs.This plane is absolutely great and I hope that it will be improved even more.regardsMalte

Share this post


Link to post

Malte,I'll take a crack at a couple of these1) When you were trying to take off at 233,000lbs, where was your C.G. on the graph, Normally with the A/C maxed out the C.G is way forward and the A/C requires additional nose up trim to get airborne. ussually around 9 units on the indicator.2) V/S mode does not follow Speed Window commands, it is strictly trying to maintain a specific V/S dialed into the V/S window regardless of Airspeed. Try FL CH mode if you would prefer to keep your speed up while climbing and descending. FL CH mode will obey the speed dialed into the window at the expense of Pitch Attitude.3) Never seen the TOC go negative so can't help with that4) Insufficient Fuel msg is a shortcoming of the Honeywell 200K FMC system and used to show up on the real 757 before the upgrade to Pegasus. So for the PMDG A/C which uses the 200K system, this message may appear any time during climb. The FMC expects the A/C to continue to burn fuel at the current rate shown in climb and is advising you at current burn rate, you will not make your destination. Message can be cleared at top of climb and should not return if you have enough fuel on board. :-)5) Haven't tried the ADF so will have to pass on this.6) I believe the Engine Start was a FLY II limitation related to the way it models turbine engines. It was brought up in testing and apparently cannot be corrected inside of FLY at this time7) Never had any problems with Reverse Thrust Sounds, Just the surging engines at idle which is also FLY II related. Hope this helpsRegardsPaul:-cool

Share this post


Link to post

>2) V/S mode does not follow Speed Window commands, it is >strictly trying to maintain a specific V/S dialed into the >V/S window regardless of Airspeed. I am afraid I can't agree with this. This goes against the very basis how 767/757 AP operates. In the V/S mode (and A/T was clearly armed in Malte's scenario) the A/T should engage in the SPD mode and keep the speed dialed in the speed window. The V/S mode is a double whammy since both V/S and SPD must be obeyed whereas in the FLCH mode only the speed must be obeyed.Michael J.

Share this post


Link to post
Guest

I beg to differ on this one. V/S on Boeing aircraft does not guarantee speed protection. FLCH does. When you engage V/S, the system basically commands a set vertical speed, and uses whatever IAS results from this. In some (maybe even most) cases, it will be able to obey the speed entered in the MCP. FLCH, on the other hand, specifies a thrust setting, and uses the vertical speed that results from it.In short: if you have to maintain a certain airspeed, use FLCH. If you need to maintain a specific vertical speed, use V/S.Jon (KSEA)

Share this post


Link to post

Ok then how about if I restate it: in V/S first priority is maintaining the V/S but if it can it will also maintain the speed. In fact if you dial in a reasonable speed it will be obeyed. We are clearly talking here about the nominal flight envelope.Michael J.

Share this post


Link to post
Guest

2) Of course V/S doesn't maintain a set speed. I forgot to say that I also had the SPD mode activated.So I had V/S _AND_ SPD engaged, but the throttles went to 75% which was way too little power for maintaining 315 kts.But the plane _COULD_ have reached 315 kts if the A/P had set power to 90% or so, that would have already been enough.regards malte

Share this post


Link to post

Malte-I am missing a critical piece of info here:What altitude is all this happening at? (OAT would be nice too)

Share this post


Link to post
Guest

Hello,You wrote "- Take Off: Weight was 223.0, Flaps 15, Temp. 12.VR was set to 147 kts, but I could not get the nose up at this speed"I got the same problem, at various weights... I looked at the CG in the menus, et I adjusted trim for takeoff according to the specifications in the manual... and I'm not able to rotate the aicraft at Vr !!!Anyone else got this problem ?ThanksMarcVarlamoff

Share this post


Link to post
Guest

Malte,about the SPEED mode thing: Could it possibly be that you used any reduced climb thrust setting? For example CLB1 or CLB2. I don't really know if this could caused the "reduced" N1 values, but I can imagine, since CLB1 and CLB2 results in lower EPR settings and EPR is related to N1 values.Hope I could help a bit.Best regards

Share this post


Link to post

When you say 75% power, What EPR was the engine indicating and what was the Thrust Limit Mode selected on the TMSP. If CLB thrust was active, then EPR limit for climb should be around 1.2X EPR depending on temp. The A/T system should always obey the Thrust Limit selected on the TMSP, however the PMDG model is not perfect in this aspect. It does obey thrust limits in most modes of operation.Paul:-cool

Share this post


Link to post

Marc,If you are setting the Trim in the Green Band as per the manual, you will have to have arms like the Terminator to get this puppy airborn. There is a minor bug in the way the Stab Trim Indicator was drawn from what I can tell. With the Stab at neutral, the indicator shows 8 units. The actual stab neutral setting should be 4 units. I'm sure you can see how this can be become a problem. This was a very late find in the Beta so I don't think it has been addressed yet. What I do is assume that 8 units is neutral and trim to about 9 units for take-off. Luckily the T/O Configuration Warning system doesn't appear to monitor the Stab Setring on this model so you can operate this way until the visual is corrected.RegardsPaul:-cool

Share this post


Link to post
Guest

no, the problem is not caused by a thrust limit.regardsmalte

Share this post


Link to post
Guest

hi -even when i selected G/A thrust limit, the thrust would not increase. the green thr limit indicator was showing a much higher limit than the actual epr setting that that was set by the a/thr system.regardsmalte

Share this post


Link to post
Guest

Lefteris -I'm going to try to reproduce the situation and give you more detailed information on it.regardsmalte

Share this post


Link to post
Guest

Hi Lefteris,I just took two screenshots in order to show you the problem with the SPD mode.Both pics show similar situations:- Speed set to value X- Speed mode engaged- V/S mode engaged- Thrust limit not reached- problem: A/P does NOT apply enough power in order to maintain selected speed --> speed falls until i switch off a/thr and set thrust manually- My Joystick throttle was _NOT_ activated so that can't be the problem.- My System is a 850MHz Celeron, ATI Rage Fury Pro, 256 MB RAM. Since I get good frame rates, it can't be too slow or something.Speed set to 249, Actual Speed 219 and falling, Thrust increasing VERY slowly.http://stud.fh-wedel.de/~wi3557/tmp/spd_error.jpgAnother Situation:Speed set to 315, Actual Speed 257 and falling, Thrust increasing VERY slowly.http://stud.fh-wedel.de/~wi3557/tmp/spd_error2.jpgI hope that we can find a solution for this problem!regardsMalteEDDH

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  
×
×
  • Create New...