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Post by volkerboehme on Dec 28, 2008 15:12:11 GMT -5
Hi,
one more discovery during a long haul flight: Unlike the FsDzign L-49, the L-1649A does not have an automatic fuel management. In the L-49, one could just leave the fuel switches as they are, and FS drains all tanks unless you change anything.
In the L-1649A, I was happily cruising through the night, when suddenly engine #1 MAP dropped to zero. What the heck? Diversion airports are rare off the Greenland coast, and ditching at 5:00 a.m. in December certainly is not an option. I had nailed fuel exhaustion quite soon, and figured out how to activate #5 to 7 tanks without any loss of altitude and hardly any airspeed, but still...
By the way, would I really see a MAP drop? The prop is windmilling and the engines are still sucking air, after all. I first thought it might be carburettor icing because of that.
Best regards, Volker
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Post by sunny9850 on Dec 28, 2008 16:12:22 GMT -5
Hi Volker,
that's what the fuel tank charts are there to assist for. Of course with a 1 man crew flying a 3 man crew airplane that can be a bit of a challenge. But Manfred and team have created a model that truly strives to be as real as it get's. That does make a few things a bit tougher...but also more rewarding when you do get them right.
As for the MAP drop I would suspect that you would indeed see that..despite the windmilling prop. You are not driving the superchargers anymore like you did when there was combustion. How much drop would be real I don't know.
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Post by emfrat on Dec 28, 2008 16:58:41 GMT -5
Hi Volker - I managed to organise my own drama yesterday. I was out of Heathrow for Geneva and Rome, with 50% fuel. Once established in the climb (thanks to sunny9850) I attempted to set up a complete crossfeed, working only from memory. This quickly stopped 1&2 with 3&4 shutting down a few seconds later. I got them going again by reversing what I had done, and continued the climb to FL195. After about 30 mins at cruise, I began to wonder why the AP was still trimming up, when if anything it should have been trimming down. MAP and RPM looked fine, but when I went to the FE panel, BMEP for #1 was way down, and the Status Panel showed I had effectively lost 1&2. I am pretty sure this was because I must have over-revved them when I got the fuel supply back on, giving me the restart. So I decided to turn away from the Alps, and put down somewhere more level. The point is, it was only after I feathered props 1&2 that the MAP dropped. All in all, I thought it was a very realistic experience - and lots of fun too, even if it did end in a smoking heap somewhere near Nancy-Metz With my skill level, I should probably have tried an unpowered landing rather than a full asymmetric one. Cheers MikeW
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Post by ashaman on Dec 28, 2008 21:39:27 GMT -5
I've noticed an odd behavior of the Starliner's instrument's panel. I was ( and I'm still) there trying to crack the tough nut of the the fuel management, and I stress to add with all engines still off, when the pointer, transiting over the cylinders heads temperature register ( and is still registering) an ever increasing temperature that seems to reach a max off 55° C with OAT of 15°, and it doesn't drop until I open the cowl flaps. Is it normal this odd behaviour?
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Post by Deleted on Dec 29, 2008 4:57:45 GMT -5
I've only flown aircraft with mechanically driven superchargers and can confirm that the boost pressure will stay steady if the fuel supply to the engine is cut off. I'm only guesing that on a turbocharged engine the MAP will fall drastically if the supply of hot pressurised exhaust gasses to the turbine is stopped. I would also guess that the turbine would go wild if the fuel supply is turned back on while the throttle is still open.
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Post by bernardo on Dec 29, 2008 8:11:51 GMT -5
Oscillating? Is it normal that the l1649 at cruise alt. beggins to oscillate, nose up and down, trim changes between 1.11 and 0.8 (Shown by the numbers on the trim panel?) What causes this up and down movement? Am I out of trim?. But I'm flying straight. I feel like a Butterfly swimmer when this happens, gasping for air...Ok I'm not in great shape...
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Post by Tom/CalClassic on Dec 29, 2008 11:11:47 GMT -5
I would assume that the power recovery turbines would lose power when the fuel supply is cut off. They provide 3 x 450 HP to the engine. But two things - FS2004 doesn't model either PRT's or mechanically driven superchargers...
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Post by volkerboehme on Dec 29, 2008 12:09:15 GMT -5
Hi,
thanks for the clarification, Tom. That's probably the point - FS thinks that the R-3350 has turbochargers.
It does have a mechanically driven (geared) supercharger, so MAP shoudn't change. The loss of the PRT power shouldn't result in a MAP change either, just the loss of torque. It certainly should register on the BMEP gauge.
Anyway, I was luck that MAP dropped, or I might not have noticed that for a while, since I was only watching the pilot's instruments at that time.
Best regards, Volker
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Post by Johan Dees on Dec 30, 2008 15:57:07 GMT -5
Hi,
It is a fantastic job, dont know how I missed the release of 2.1. Great work and for free!
However, some questions and remarks from me..
1. Can the color of the flap, throttle handle and such be changed to a less vivid color? I find it not only distracting, but it looks not proffesional to me.
2. Reading thru the documentation can anyone comment on the consequences of some actions, i.e. overheating CHT.. does it do anything ? wil one loose an engine ? There are more of these warnings in the checklist file.
3. Climb seems indeed a bit optimistic, but cant tell for sure yet, need further testing.
4. Trim... this feels a bit soft and strange. Setting level with trim, adding a bit power should make her climb, or lessen power, and she should descend, but feels soft.. hard to explain. Almost if trim creeps up or down.
As a jet 'boy' I have a lot to learn, already read the propliner tutorial, but the basics remain the same.
Johan
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Post by riogrande on Jan 1, 2009 14:14:34 GMT -5
Whooohoo! Great job guys! I had to practice landing a few times until I realized it no longer "liked" landing below 100 knots...and burrowed into the ocean cliffs at LAX. They are still looking for all the pieces! Now I'm checking out how it does flying against the prevailing winds from London to SFO. What a lot of work for a freebee...it is most welcome. Thanks a lot!
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Post by Randy_Cain on Jan 1, 2009 14:36:40 GMT -5
Hi, I love the Starliner. I finally got it loaded to fly online with Tom and Edd last Saturday. I have a question. I had a bit of trouble switching between engines for ground handling and taxi. I remember this was an issue in early versions of the L-049. With the 049, a big contributor to the problem was there were duplicate/seperate gauge files for RPM and MAN press for the main panel and again for the FE panel...so 8 gauges in all. I checked the panel.cfg for the 1649 to see if they did the same thing here, but it appears to all ready be the FE panel and the main panel pulling the RPM and MAN data from the same 4 gauges. Any ideas as to what else might result in controls getting locked to one engine? Yours,
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Post by volkerboehme on Jan 1, 2009 16:03:23 GMT -5
Hi,
I finally completed my long-range flight from San Francisco to Heathrow - sucessfuly, on top of that. Here are some observations I'd like to share:
- I already mentioned that Supercharger settings have to be re-set after loading a saved flight. The same applies to fuel tank settings. I noticed a AP lockup when reloading, briefly switching off the AP solves the problem.
- Things get busy at top of descent. While you'd try to reduce MAP slowly, MAP will also rise while you descent due to rising atmospheric pressure. This kept my quite occupied until I was below critical altitude, the matter resolves below that.
- Does anybody know what effect this is in particular? I was drifting off course northward while I was cruising westbound at high latitudes between Baffin Island and Scotland. The gyro compass was slowly rotating, and pressing 'd' to adjust gyro drift re-set the compass. Gyro drift was disabled though. Is that gyro precession or due to the proximity to the magnetic north pole? Fairly strong wind from west might have been contributing as well.
Best regards, Volker
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Post by sunny9850 on Jan 1, 2009 17:21:59 GMT -5
Both the rise in MAP and the Gyro precession are normal and part of the realistic simulation. As for the reloading "issues" they are simply effects of how FS deals with parameters in saved flights, and your mechanical control settings to some degree. Since they are MS's code there is probably nothing any design can do to "fix" it.
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Post by volkerboehme on Jan 2, 2009 1:11:33 GMT -5
Hi Sunny,
thanks for your reply.
Yes, I am aware that the reloading issues are not gauge faults, just the inevitable result of gauges theat go above and beyond the usual FS code. I just wanted to point it out to others. The same applies to the MAP rise. This probably would habe been handled by the FE in real life, though.
Back to the gyro: So it is precession, after all? I have never experienced it, at least not so markedly, but I wasn't flying a flight so far north before, either.
Again, thanks for the reply.
Best regards, Volker
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Post by capflyer on Jan 2, 2009 23:59:08 GMT -5
One must also remember that FS does not simulate the poles in 2004 and thus there are some wierd things that happen near the limits of the "flat earth". If you fly in FSX, the problem is non-existant, but in FS2004, you will find many problems with accelerated drift and inaccurate directional gyros that should not be occuring.
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