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T/O Problems

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Hi all.Just wondering if anyone can offer me any assistance and or advice on a small problem I have with 767 PIC. A typical scenario was a flight I completed earlier on today from EGCC to LEPA. I loaded a total of 25839 Lbs of fuel onboard the aircraft (Roughly 12919 Lbs in each wing tank - Nothing in the centre) which gave me a TOW of 270539 Lbs. Once I began the T/O roll, everything was fine until I reached approximately 80 Kts, then the nose started pitching up by itself even though I hadnt applied any backward pressure on the joystick. I attempted to keep the nose down by applying forward pressure until the aircraft accelerated to the V1 speed of 119 Kts, but to no avail. The aircraft left the ground and I couldnt get the nose to manually lower for nothing (not until I centred the joystick & engaged the AP anyway.)This has happened on several occasions with varying weights etc. The above is just an example of what seems to happen.I initially thought it was the elevator out of trim, but after checking the gauge on the centre pedestal, it was in the range of the green bar so I knew it wasnt anything to do with that. I use a Microsoft Sidewinder FF2 and run FS2002 Pro with FSUIPC version 2.85.I only seem to have this problem when I use 767 PIC, as I also run both Dreamfleets 737-400 & PSS's A320 with no problems at all.If anyone could offer me any sort of assistance or advice regarding this, I would be grateful as this is the only issue I have with PIC.Thanks in advance & happy flying

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Guest Mark McG

Couple of things:1. Are you using a POSKY model with POSKY flight dynamics?2. Fuel Load seems slightly on the light side. A 757 doing the same route would take approx 13500kgs or 28000lbs of fuel. I reckon a 767 would need about 35000lbs.Mark

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What was your trim setting? Try a setting of about 4.5 to 5 nose up with a gross weights of 270,000-290,000. If you have a high nose up trim (like the 'old' PIC needed), it will rotate prematurely.Rob.

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Thanks for the prompt reply guysI'll answer both your questions in this one post.* Mark, I am using the POSKY Boeing 767-300 ER version 3.0 Aircraft, but with the PIC flight dynamics. I used Lee Hethrington's PIC/POSKY Merge to accomplish this.I tend to use the 767-300 Fuel Calculator created by Tarek Sharkway to plan my fuel loads for my flights - How accurate this is, I dont really know.I used to use Rob Van Leest's Excel spreadsheet, but he doesnt seem to have updated it as of late, so I thought maybe the one created by Tarek would be a bit more realistic so to speak now PIC is FS2002 compatible.* Rob, all I can say is that im using the "default" trim setting for take-off. I never really had to adjust it at all for FS2000, thats why I didnt see any need to adjust it now before takeoff. I will however try your recommendation and I'll let you know how I get on with it.Thinking about it you know, when I fly 767 PIC with a full load of fuel directly from the aircraft selection menu, it doesnt do it, so your recommendation definately sounds viable.Thanks again guys !!!

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Lee,I had the same problem, but I don't think it's related to fuel or trim. There are several posts in this forum about the control surfaces (elevators in this case) going to max deflection on their own. I recommend calling up the "status" view on the lower EICAS screen. Take a look at the control surface positions. Is the elevator in its fullest up position? If it is, this is the cause of your "automatic rotation" on the take-off roll. Note that if you re-load your flight session, these deflections will be reset, but as soon as you pull your elevator to the furthest up or down position, the elevators will stay in the furthest up or down position. Give this a try - pull your control stick to the max up position on your next flight and then check the status screen - your elevator will most likely be in the furthest up position and as soon as you begin your t/o roll, your aircraft will start climbing on its own. Not sure why this happens, but I don't think you're alone with this problem.Happy landings.Jay

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Guest ilh

I sometimes find the default trim has run all the way full up, but this may be due to a bad saved flight or resetting a flight. Anyways, I always make sure I have it pretty much in the middle of the green and I never get rotation before I want it at Vr with my PIC/POSKY merge, so I don't think the merge is the cause.Lee Hetherington (KBOS)

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just curious what is meant by the "old" PIC? Does it mean the product out of the box without the fs2002 patch? Or is there two versions of the product?? Would hate to have the "old" pic if there's indeed one better.michael

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Thanks again for the replies you guys* Jay, I will try your recommendation tonight to see if that is the cause of the problem. It definately seems viable. However, it only seems to happen when I setup a "proper" flight with a realistic fuel load etc. If I fly the aircraft directly after selecting it from the selection menu with a full load of fuel, it seems to be fine.* Lee, Im not blaming the PIC/POSKY merge at all - I didnt think for a second it would be anything to do with that. Sorry if you thought I was stating that as the cause of my problem.I do however have a small query relating to your merge file for the 767-200. The merge itself seems to be fine, but when I look back towards the wing from inside the cockpit, I can see the aircraft's navigation lights shining in mid air. I'll provide a screen shot when I get home from work to show you exactly what I mean. This only seems to happen with the 767-200 aircraft - The 300 series seems fine.Thanks for the replies again guys !!Happy flying.

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Guest ilh

I didn't mean to appear defensive. I meant more to have you make sure your trim was where you thought it was.Never noticed that about the 762 merge. Maybe I'll take a peek some time, but I doubt there is much I can do. Is this on the ground? That would explain it.Lee Hetherington (KBOS)

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Thanks for the reply Lee.This is what seems to happen, both on the ground and in the air. Its not a problem at all, so im no way demanding a fix for it or anything - Just to make you aware thats all.

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Guest ilh

It is possible to fix this by making the offending FS2002 light effects invisible from within the cockpit. Is it only the solid white nav light that is showing up (and not strobes)?If so, you could edit (make a copy first) your FS2002effectsfx_navwhih.fx file by adding the following section to it (generally the second section):&l;Properties&r;Cockpit=0VirtualCockpit=0Spot=1Tower=1Map=1Basically, this makes this effect invisible from the 2D and virtual cockpits.If you do not want this change to happen to all aircraft that use this (shared) effect, make a copy with a different name and then change the name in the PIC/POSKY aircraft.cfg.Clear as mud?Lee Hetherington (KBOS)PS: The reason this does not happen in the 763 is the cockpit is further forward and this light is blocked.

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The early rotation problem could be related to a Weight and Balance issue... I think the problem is either the reference datum position or too much weight in the back.. i'll test tonight when I have more time. I use AC Loader (latest version) and my empty weight variable is set within the 767-300ER specs.

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Guest ilh

If you're still having trouble, move the main gear contact points (.1 and .2) back 2.5 feet and see how that feels.Lee Hetherington (KBOS)

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Lee, are you suggesting that for me? or the person that initially opened this thread?

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Guest ilh

Anyone who is having problems, particularly those using some load manager that is distributing weights throughout the aircraft. If their weight is that far back, then it is likely affecting flight too to some extent.Lee Hetherington (KBOS)

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>Anyone who is having problems, particularly those using some >load manager that is distributing weights throughout the >aircraft. If their weight is that far back, then it is >likely affecting flight too to some extent. >>Lee Hetherington (KBOS) Either way your suggestion (moving the main gear contact points back) sounds like a very good one (at least for early rotation problems) it will make the plane rotation a little harder because of the effect of having the wheels further back... but your point proves the point of too much weight in the back :) ACLoader bug? Scott are you reading this?

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Fixed... the load manager (ACLoader) has a cabin lenght for the 767-300ER of 150 ft.. I changed it to 175 and now the early rotation problem is GONE!!

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This topic has proven to be a major hit for views & posts from all you guys - Thanks a lot - Didnt mean to cause a stir, lol !!Sorry i've not been able to keep intouch the last couple of days, but i'll try and answer all your posts in this reply.* Jay, I completed a take-off lastnight with your recommendations re looking at the lower eicas status page to check positioning of the elevators and they move fine and return to centre with the respective joystick movements on the T/O run. I also checked from spot view again to see if the elavators were behaving properly and they were. Everything seems fine - Still got the early rotation though.Any other thoughts regarding this anybody ??* Lee, I have worked through your recommendation and the lights seen from within the cockpit have now disappeared. Thanks a lot.F.Y.I - It was only the static nav lights that I could see before - Not the flashing strobes.* Bojote, I think I might have to try out this ACLoader program myself to see if it cures my early rotation problems. Would it be possible for you to point me in the right direction of this program please. Also, is it freeware or payware. Considering this is my only problem with PIC, im not that keen on having to pay out for a piece of software just to cure a take-off problem. Not meaning to sound fussy or anything. If there are more benefits with this software than just curing an early rotation (Like better weight & fuel load distribution etc.) then i'll look into it.Thanks again for all your replies guys.Happy flying !!

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Lee,ACLoader is Freeware, you can find it in the AVSIM library

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I sometimes find the default trim has run all the way full up, but this may be due to a bad saved flight or resetting a flight. Anyways, I always make sure I have it pretty much in the middle of the green and I never get rotation before I want it at Vr with my PIC/POSKY merge, so I don't think the merge is the cause.Lee Hetherington (KBOS) It's the stablizer trim. When you take off with a PIC plane it doesn't normally require any adjustment. However if you are taking off in a PIC-POSKY Merge plane set the stablizer to 4 or else you gonna ride a wheelie down the runway. I've seen a lot of posts on the subject but from experience it appears that some how the PIC 767 Version is heavier than the POSKY Version even if you have both setup in the same exact configuration. Ive done both many times. The Posky plane is definately handles lighter.

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Guest ilh

I think the issue is the placement of the main wheel contact points in my merge. Yes, it does feel "lighter" during rotation, but I've come to like it, especially on touchdown how the nose slowly floats down.I could probably "fix" this behavior and make it exactly PIC-like, but I haven't felt it is worth the effort (screwing around with reference point and probably a number of other parameters) since a different trim setting, say 4, does the trick.You could also move the main wheel contact points (points 1 and 2) back a few feet and it would have the same effect. Then again, the animation in the visual model might not match up quite the same, but I doubt it matters much.Lee Hetherington (KBOS)

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