757/767

[ComplexHiAv8r]

"Overpowered"? No such animal!

Maybe "De-rated?"

The -1900 had derated engines, but if you overtorqued them while you're single-engine, you're pretty much going to die.

I did the old 'recip' thing in the 1900 sim once and jammed the power to the firewall... I had a nice inverted view of the hangar right before the "CLAP!" and the screen went red.

Did it come up and say GAME OVER???

 

[derg]

Did it come up and say GAME OVER???

Oh, you knew you were dead. Crashing a sim is pretty nasty... and bad for the equipment!

The very first leg, the guy gives me a V1-go, I jam the power levers to the firewall and that thing rolled about 220 degrees.

A turboprrop is a man's airplane! None of this sissy turbojet stuff!

"Oh I do declare..."

"Yes, Winthrop?"

"I believe we have umm, how do the bourgeoise say, uhh 'chugged' an engine?"

"My word! I do believe so. Let's casually do the immediate action items... but first..."

"Yes Milton?"

"Hand me a bottle of that delightful bottled water!"

 

[ComplexHiAv8r]

In another thread there was a comment about a compressor stall when you firewall an aircraft (turboprop/turbojet). Is this common on all aircraft?

 

[derg]

Nope. Probably depends a lot on the FCU - Fuel Control Unit.

The only jet I have experience with that had a compressor stall problem was the 727. On the #2 engine, with a crosswind or something, if you weren't careful, you'd get the occasional "thwap!" but it wasn't too serious.

 

[casey]

In another thread there was a comment about a compressor stall when you firewall an aircraft (turboprop/turbojet). Is this common on all aircraft?

not on all engines. On our engines (allison 3007A(1|1P|1/3|1E)) have variable pitch stators on the first couple stages of the compressor (CVG's), auto re-ignite from the FADEC's and FADEC controlled thrust advancement to keep the compressor from stalling. If you firewalled the thrust levers in this setup, no matter how quickly you firewalled them the FADEC advances the thrust at the proper rate and if the flow starts to disrupt the CVG's and ignitors do thier thing to keep the engine lit. All the while the FADEC monitors everything and doenst let you exceed ITT limits.

On some engines though it is possible to both stall the compressor or burn the engines up with very fast thurst advancement or just firewalling them at any time. I'd say ITT excedence would be a bigger issue that compressor stalls though in any modern engine.

 

[B767Driver]

I have heard that the 757 was way over powered but never heard that the 767 is overpowered. The 757 powerpplants depending on type are rated between 42-45,000 lbs. What are the GE & P&W engines rated at on the 767?

I left the 767 in May...but I think both engines were rated at 60,000#. I flew it at domestic weights and I remember climbing at 4000fpm at FL300. International weights...I hear it's pretty sluggish.

 

[falconvalley]

MTOW for the 767 is around 450,000#. The 757 is around 225,000#. I did all of my sim training in a 757 and then had one ride in a 767ER before the checkride.

I found the power and trim settings to be quite a bit different between the two types. Especially on the level off/acceleration segment after a V1 cut. The 767 has so much power that if you aren't quick on the trim during level off the airplane will no kidding flip over on it's back. After you level off at 1000'...you suspend all action until the trim and power are adjusted. Now, you do this in all airplanes...but I found it so critical in the 767, that when I was flying, I'd ask the captain to hold all checklists until I had it trimmed. Other airplanes I could respond to the checklist while trimming.

That's quite a difference in weight. I have ridden in 767s very few times, but I've always been impressed with the 757's runway takeoff performance. It kinda reminds me of watching a reduced thrust takeoff in a Tanker. I swear the time on runway is shorter than in my 152!