Double Engine Flameout

[AvA757Pilot 6]

I am experiencing a new problem...so far with the -700 and the -800. On climb to cruise both engines will simultaneously and unexpectedly fail. Aircraft setup at the time is LNAV/VNAV engaged and fuel set to main tanks- which are full.The first time it happened I was unable to get either restarted at FL300 and the long glide began. The second time I was passing FL190. I was able to restart both engines and re-engage LNAV but the autothrottle would not re-engage and after a brief 3000' climb the engines quit again and could not be re-started.Most baffling and frustrating to say the least so any assistance would be appreciated.Roger Curtiss

[Qavion 19]

Were your wing tank pumps switched on at the time? Engines will work (up to a point) without the tank fuel pumps switched on. However, high altitude/high thrust situations may put a strain on the engine pumps.I'm not sure if icing is modelled, but if you are flying through cloud and the temperatures are low, it's best to switch on your Nacelle Anti-Ice.Cheers.Q>

[AvA757Pilot 6]

Your points are well taken but not relevant in this instance. Fuel pumps were on and no icing present in either situation.

[Guest]

never heard of this issue before but it would be helpful for some screenshots of the overhead and main panel when this happens

[AvA757Pilot 6]

I will see what I can do about that. I have also received the advice from someone that it might be a CH yoke quirk. I am using CH Yoke and TQ but certainly do not have this problem with any other aircraft- so I am wondering how accurate that idea might be.

[tunnelcat 1]

When the engines fail, are both fuel cutoff switches turned off? I have both the Ch Yoke and Throttle Quad and I've only had that happen when I accidentally moved the mixture control on the yoke, which then closed both fuel cutoff switches and shut down the engines. Unfortunately, moving the mixture control lever on the yoke will shut off fuel with PMDG aircraft. I don't know if this can be unmapped.Kim

[AvA757Pilot 6]

I am aware of that anomaly and I am virtually positive such was not the case. I was not actively touching the controls at the time- aircraft was on autopilot and in VNAV climb both times. I will fly the plane again and be watching for the flameout since I now know to expect it and see if there are any hints just prior to the failure.