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HS748 Engine Failures

Posted: 13 Sep 2013, 14:34
by tonyc
Hi guys

Its me again! :lol:

Having now conquered my start problems I have 2 further problems that I cannot seem to overcome.

The first and biggest one is that on a flight from Glasgow to the Scottish Islands at a height of 14000ft (air temp -10C) I applied engine deice as a precautionary measure but even so I am getting a double engine failure after around 30 mins. I am sure that I am doing something wrong but can't see what.

The other problem is that I start engines after push back the taxy out to the runway but when I apply full power we don't move, not an inch! If I end the flight then start the engines on the runway there is no problem. I have a feeling it is to do with my power settings? I am using a joystick with integral throttle, I haven't used my Saitek throttle quadrant would this make a difference?

All help most gratefully received!

Tony

Re: HS748 Engine Failures

Posted: 13 Sep 2013, 14:58
by TSR2
Hi Tony,

Two levels of De Ice on the 748, fast and slow. Fast up to -6, sow at -6 or below. The other thing to check is the fuel heating (can't remember the settings off the top of my head)

Re the power, Gust locks are still engaged?

Re: HS748 Engine Failures

Posted: 13 Sep 2013, 15:37
by tonyc
I will check the deice Ben. Do you mean slow between 0 and -6 then fast from -6 and beyond?

Didn't use the gust locks at all when taxying.

Re: HS748 Engine Failures

Posted: 13 Sep 2013, 15:48
by TSR2
Gust locks are on by default, so you need to take them off.

other way round on the de ice, fast down to -6, -6 and below use slow.

Re: HS748 Engine Failures

Posted: 13 Sep 2013, 17:02
by tonyc
Ok I actually managed my first full flight from Glasgow to Benbecula at 14000ft without mishap! :)

I think it was a matter of getting the fuel trim correct, deice, fuel heating and I put the fuel cross feed on. It worked!

Re: HS748 Engine Failures

Posted: 13 Sep 2013, 19:19
by J0hn
Heh heh, funny that happened to you - that was exactly what happened to me the first time I flew across the Cairngorms (from Greenland to Glasgow that time), quite a few years ago now.

I was so pleased to have made it on my first proper flight with the 748 - we were beta testing Air Hauler at the time - just about 10 minutes from the circuit and it just suddenly started losing altitude - then plummeted whilst I was desperately pressing everything in the cockpit! :lol:

Good times.

Re: HS748 Engine Failures

Posted: 13 Sep 2013, 19:54
by TSR2
Best thing to do guys is follow the in cockpit checklist, you really can't go wrong if you follow that, and keep an eye out for the warning lamps and make sure you have enough fuel. ;)

Re: HS748 Engine Failures

Posted: 14 Sep 2013, 08:04
by Viscount Cornbank
Tony,

The only programmed conditions which can cause an engine to fail are excessive TGT for a prolonged period, power unit icing and fuel filter icing. The temperatures at which icing can happen are randomly programmed so it won't always be the same. The checklist calls for the correct settings for all of these conditions.

[EDIT]

The lack of take off power could be the result of the autofeather system tripping if the throttles are advanced too quickly. The propeller will autofeather if the throttle is advanced beyond about two thirds or circa 13000 RPM and the associated engine torque is less than 50 psi, provided the other propeller isn't feathered. By the nature of FS hardware throttle controls this could occur at exactly the same time on both engines, resulting in double autofeather.

This is all in the manual by the way.

cheers
Fraser

Re: HS748 Engine Failures

Posted: 18 Sep 2013, 20:10
by Nigel H-J
Must be something to do with the air up in Scotland that does it!! :hide: I was coming back from the Scottish Islands at F/L 150 inbound for Glasgow a few months ago and cruising quite happily when, with no warning, the No2 Engine failed followed shortly by No1 :-O after much scratching about going through the emergency checklist (Thanks to Fraser) I managed to get them re-started and arrived Glasgow very much the wiser!! ;)

Nigel.