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Gryphon

So how do you start the engines in cold weather?

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Here's a new one on me.Parked on the Ramp at PANC with a 300ER. Baro is 2957mb, air temp -11degC and it's 0800. External power and air on, APU running.Select normal engine start and N1 will not rise above 23.9% - result no engine start on either side.Had to change the weather to get the engines to ignite.Anyone know the right way of doing it as I can't believe you can'tstart a T7 just coz it's cold.PuzzledRick

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Did you have the auto start switch OFF. I tried this with the same weather conditions and started OK. Also, I guess you meant baro was 29.57 inches.Ron


Ron Service

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What about the 757 in the same situation! Tried to start engines at -12 deg, There doesn't seem to be an autostart feature on this aircraft!!

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Guest rneaves

I had the same problem at -14C.In the real world you get a faster spin-up at lower temperatures but the reverse happens in FS9 (and previous sims).Perhaps PSS Support could reply to this.Roger Neaves

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Guest rneaves

Is there anyone at home?

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Guest Andybancroft

Try setting the ignition to 'Both' not '1' or '2'Does that work?:-walksmile

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Guest rneaves

Doesn't make any difference. It's a question of N2rpm.PSS have programmed it so that you need 24% to get a light up. At ambients lower than around 8deg C you never reach 24%

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Guest rneaves

Should have been "ambients lower than around MINUS 8 deg C"Apologies.

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Guest Victor Sussman

Hehe, yup, encountered the same thing last night -- temperature was exactly -8. Oh well, I'll just add 'AUTOSTART --> OFF' to my prestart checklist for cold weather starts. :)

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Guest rneaves

Unfortunately my problem was in the 757. Interesting though to see that the 777 can have the same problem.PSS support please?

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Guest Victor Sussman

I wasn't aware that the 757 had autostart.

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Hi,For what you say I assume it's the 757 RR version?RR engines should start with N3 rpm as low as 15%, however any number below 20% will give very slow acceleration and mostly result in a hot start. In very cold weather it is normal that lightup would happen quite a while after fuel switch was turned to ON. Besides, switch must first be put in RICH position and left there as long as EGT shows 0 on EICAS. Once value rises from 0, it must be turned to ON.Is any of these things simulated in PSS?Tom

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PSS have not modelled the RICH fuel switch position used on RR powered 757s. The PSS 757 pedestal is identical for both PW and RR versions. Not that it's terribly important for such an add-on, but it would be nice to see some PW and RR differences in the flight deck, other than the not quite realistic lower EICAS display (N3 should have the magenta start cue on RR, not N2).This problem is typical of the "simulation by flight manual" found on most PC add-ons. The manual says wait until such and such RPM before turning on fuel, so the engine is modelled so that it won't light if fuel is introduced before that. The manual is telling the pilot how to achieve a good start, not how the engine actually functions if mishandled.They should enable the simulated engine to start at much lower RPM, although as has been said the start might not be as good and may be too hot and slow. 15% would be a much better figure to base the model on. That would allow starts like this in cold temperatures and also be more true to life (even if automatic hot start simulation is beyond MSFS).To be fair, not many MSFS add-ons have attempted to simulate engine start problems due to mishandling. PSS have chosen not to modify the poor basic MSFS jet engine start simulation, so after light up the engine spool up is far too fast (almost instantaneous).Kevin


ki9cAAb.jpg

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So what you're saying is you can't start the PSS 757 in cold weather!!Would PSS Support please confirm or deny this?Thanks.

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Guest rneaves

Exactly. I use real world weather and its been a pain during the recent low temperatures in central USA to have to go out of it, reset the OAT, start the engines and then go back to real world.Maybe after the splendid news we're all expecting by next weekend, PSS might turn their attention to this problem.

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