Starting the engines

[stevenp 1]

Hi everybody. I've done I think 12-14 longhaul flights with the jet since I bought it and I was think I found something. I can start all engines at the same time. Is this correct or is this a bug? The lds 763 and the pmdg 744x can not start all engines at the same time with the 763 only able to start one and the 744 only able to start two at a time. So is this a bug or is this a cool feature on the plane?

[Guest Susan27]

Powerful APU?

[caxico08 0]

HiI know for a fact you can start 2 engines at the same time on the real Boeing 747-400, due to the powerful APU. I do not know about the MD11Kim

[Guest hangar744]

Sometimes we start all four at once on the 744.regards,delcom

[stevenp 1]

So it can obviously be done. Delcom are you a real life pilot? ATP rated.

[Guest hangar744]

Engineering, maintenance...so I fix them.EDIT: 744 heavy maintenance...to be more accurate.regards,delcom

[stevenp 1]

Ahh I see. So do you think the md-11 can be started at the same time. It probably has a apu similar to the 744 or t7.

[Guest hangar744]

Hi Steven,sorry I can't tell. I don't know anything about the MD-11 APU. The MD-11 GE engine config is pretty close to the 744 GE so the demand during engine start should be also approximately the same. If the MD-11 APU performance is as good as on the old lady plus no tricks in the logic preventing more than two engine start simultaneously...then it is possible. How it really goes in practice, that's another question.It all comes down to APU performance (and QNH, OAT...etc). No problem for the 744...obviously we don't do "four at once" every day just for fun. We are really careful...a lot of things can go wrong.I just checked my records I took during tests. Four engines at once with all packs off...no problem at all. However the 1 pack on scenario exceeded the performance of the APU resulting 4 failed autostarts. An other test shows 1 ADP on with packs off...four engines started with no problems with autostart.I would not even think about trying this in Dubai or La Paz.Any MD-11 cowboys here? For sure they know the answer.Now I'm off to make my PMDG APU work hard...really hard.happy (amber) duct press readoutsregards,delcom