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Post by r22s7 on Nov 29, 2015 11:48:17 GMT
Hi everyone, I am having trouble with the Boeing 707. When I climb using the autopilot, after a while it will stop and descend. Not just descend, but pretty much completely nose down, as in all you can see from the cockpit window is the ground. I have lowered the fuel quantity to make a light takeoff from the (relatively) short runway at YSNF, apart from that, I don't know where the problem may lie. I like using the 707 to fly to smaller airports, where the runways are shorter, so to takeoff again, I need to carry less fuel and refuel en-route. I have attached some screenshots, with more information. Climbing out of YSNF, everything seems fine. Until, we start descending... ...Despite a positive rate of climb... ...And then, completely out of control I don't know what I am doing wrong. This is using the 707-138. Any help is greatly appreciated. Thanks
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Post by Herman on Nov 29, 2015 16:11:06 GMT
Hmmm....very strange behaviour. Looking at your images a few things strike me that are indeed a bit baffling. Firstly I do not think that you are using the right Panel for that aircraft. The 707-138 used engine water injection and has some indicating lights to show that on the Panel. Your engine power instruments ( N1, N2 and EET) are all petty well at Max. yet the engine EPR is very low. Very strange. Your Auto Pilot appears to be engaged and the TT is showing a 1800ft\min climb yet your VSI is showing a high rate of decent of 3000ft\min. Your air speeds are extremely high for your altitude. I have not been able to figure out what your problem was but I will try to simulate this flight and report back a bit later. Herman
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Post by Herman on Nov 29, 2015 17:01:43 GMT
After doing a test run from YSNF RW29 at same fuel load with the Boeing 707-138 I did not experience any problems whatsoever. All functions including AP functions worked just fine.
So I am at a loss why you had any difficulty unless it was something self induced???
Herman
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Post by Mike Monce - HJG on Nov 29, 2015 17:18:10 GMT
Is this a new installation of the HJG 707, or one you've been using for awhile and the behavior just now showed up? If it's a new install, I would suggest you might want to re-download all the files for the plane and do a complete reinstall. Sometimes in downloads files can get some bits out of place. If it happened with the air, cfg or panel files, then things can go screwy. Mike
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Post by Herman on Nov 29, 2015 17:25:02 GMT
Also, did you follow the special install procedure for FSX regarding the aircraft cfg and Panel cfg.
Herman
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Post by aerofoto - HJG Admin on Nov 29, 2015 18:36:01 GMT
This is "A VERY RARE EVENT" .... but .... I have heard of its occurrence previously .... the last time being some several years ago though. Different files can behave differently on differnt systems .... of course. It has been recorded (as I hinted above) .... that the trim can slip/run away during AP controlled flight (for whatever reason). It shouldn't .... obviosly .... and doesn't in 99.999 % of cases though. One detail I note in your panel image is that the AP ALT HLD switch appears to be selected "OFF". Did your uncomanded descent/dive start in the cruise .... whilst the AP ALT HLD mode was engaged (suggesting its somehow disengaged of its own accord, or possibly been inadavertantly disengaged per keyboard or other action), or possibly not selected "ON" at all to start with) ? .... or .... did the phenominon start at some point during your climb toward cruising altitude and before the AP ALT HLD mode would have been engaged ? Also .... and again according to yotr panel image3 .... I note the YD switch is "OFF" resulting in both YD lamps being illuminated. This might not contribute to your issue, but, the YD should be selected "ON" from around 230-250KTS .... almost from clean-up/retracting the last increment of flap after departure. Additionally .... had you set any degree of manual Elevator Trim setting prior to T/O .... and if so .... then how much setting ? It does, however, look, to me, to be a runway trim issue though. I don't think you've one anything wromg or even installed anything incorrectly either, but, there is "one thing" you can try in order to resolve this .... Go to SCHIRATTI.COM .... and download Pete DOWSON's FSUIPC module. If you're a FSX user then make sure you download the/an "FSX SPECIFIC" version. PLEASE NOTE .... in the case of what I'm about to suggest you "do not" need to pay for a fully licenced version of FSUIPC. An unlicienced "MINIMUM DEFAULTS" installtion is all that's necessary. ANYWAY .... Download and intall this module. Start to FS .... and sselect it's "MINIMUM DEFAULT" (I think it is) option only .... in the case of an unlicensed FSUIPC version this option i all one wil be able to activate anyway, but, should be sufficient to resolve this issue. Shutdown and then restart FS "after" installing and activation the MINIMUM FSUIPC defaults option .... and try flying again. This action should be sufficient to cure the issue. It "did" so in the case of each of the very few examples of "this very rare issue" that have been reported several years ago. Report back .... please Mark C AKL/NZ
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Post by r22s7 on Nov 29, 2015 22:39:23 GMT
There is no minimum default option; I am assuming you mean normal default? I tried it, and it has made no difference.
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Post by aerofoto - HJG Admin on Nov 29, 2015 22:56:45 GMT
Yes .... "NORMAL" defaults .... is the one I meant. Pitty it hasn't resolved your issue though .... because I know it has in each of the very few previously reported issues .... of several years ago. Something, on your system (not necessarily another product because it could even even come down to someting as mundane as a specific Service Pack/Update of something of that description), is likely influencing the elevator trim setting .... causing it to kick-off/runaway .... I suspect .... BUT .... I don't have a solution to offer beyond what I've mentioned that didn't, apparently, work for you Are all your B707's/B720's/C135's similarly affected .... or just the QF -138's/-138B's ? Mark C AKL/NZ
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Post by Herman on Nov 29, 2015 23:35:52 GMT
When I look at the second image, which already shows the aircraft in a descending attitude, the position of the horizontal stabilizer indicates that the aircraft should be assuming a pitch up attitude. If it were the case of a runaway stabilizer I would think that it would be travelling in the other direction. Judging by the high speed the aircraft is travelling (over 500knts)at a low altitude, I think it has reached the point where it has entered a high speed stall due to the shock waves. Air fliow over the wings going supersonic. . Herman
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Post by aerofoto - HJG Admin on Nov 30, 2015 0:29:52 GMT
Ordinarily I'd agree with you Herman .... but .... that H-stab axis could just be its deflection (caught at the time that image was made) through attempting to try'n "manually trim" out of the situation.
Something's defnitely affecting the trim/elevator position "during AP controlled flight" though .... and may be still impacting it after a disengage too and during manual flight control afterward.
Such could, as I hinted above, be caused through a WINDOWS related update (we all saw evidence of that .... some 9 years ago/back in 2006 and which forced an AP code change around that same period also) .... BUT .... having thought about this a bit more .... any such imposition would likely affect the AP, and auto-flight stability, from a much earlier point .... and possibly from the moment the AP was first engaged.
He mentions he was climbing on AP (he looks to have been at around 2,500 FT) and apparently without any issues at first .... when the problem occurred quite suddenly.
It seems, in that case, it could be be the result of some form of spurrious signal or event within FS !!!!
"R22S7" .... have you tried checking (rechecking if necessary) the trim function associated with your joystick .... or whatever controller device you use ?
Like Herman .... I can't replicate any such control difficulties either .... at either MGW or at reduced loadings.
Mark C AKL/NZ
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Post by aerofoto - HJG Admin on Nov 30, 2015 1:37:02 GMT
WELL .... I just performed another quick test flight (using the same B707-138) .... and which is a test I casually term being "A SILLY SORTIE" during which I purposely do "STUPID THINGS" to try'n cause problems .... BUT .... the simulation passed these tests with absolutely flying colours. It remained stable under AP controlled flight during the climb, cruise, and descent .... and the same again also during manual flight control during each of these 3 flight phases .... since I occasionally changed back'n'forth between both AP and manual flight control during each phase. I can only say .... the simulation appears to be "in the clear" .... but .... we did know that beforehand anyway. If FSUIPC "NORMAL" defaults hasn't resolved this particular issue, then, "R22S7's" experience must come down to something going on within his own system .... or possibly associated with his controller device (perhaps) .... I suspect .... but which is also beyond the scope of my expertise and being able to advise regarding Mark C AKL/NZ
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Post by Herman on Nov 30, 2015 3:29:10 GMT
I am still pondering over those engine instrument indications.
How is it possible that all are indicating a high power setting,except for the EPR's??
r22s7 is really not giving us enough information and he is not providing any reply to some of the questions and scenario's posed.
Herman
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Post by aerofoto - HJG Admin on Nov 30, 2015 9:37:39 GMT
I wouldn't worry about any of the engine indications because they're not a contributing factor to his problem. I agree though that we do need more information in regard to what's been asked as well as what we've suggested be checked. Trying to understand these sorts of (very rare) issue and (hopefully) arriving at a resolution is depenadant on bi-lateral communication Mark C AKL/NZ
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Post by r22s7 on Nov 30, 2015 10:38:05 GMT
Sorry, I have also tried the 128B and the 320C, and the result is the same. I was going to try the 720, but it wouldn't show up in the selection menu.
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Post by Herman on Nov 30, 2015 16:45:37 GMT
All I can say is.....I have tried all the above mentioned HJG Jetliners and have found no problems whatsoever.
If you follow the Install Instruction to the letter there should be no problem. You are going astray somewhere and as I mentioned before, your replies are not giving sufficient details for the process of elimination.
Herman
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