c5load From United States of America, joined Sep 2008, 917 posts, RR: 0 Posted (2 years 3 months 5 days 19 hours ago) and read 1675 times:
The other day I was flying from UAFM-ETAR and was put in a step climb. I noticed when we would level off the pilots would bring back 1 and 4 throttles for a few couple of minutes, then push them up and bring back 2 and 3. When asked, they said when all four throttle handles were in the same position it put the engines in the vibe range. Do civilian four engine airliners do this at lower altitudes?
"But this airplane has 4 engines, it's an entirely different kind of flying! Altogether"
411A From United States of America, joined Nov 2001, 1826 posts, RR: 9 Reply 1, posted (2 years 3 months 5 days 7 hours ago) and read 1485 times:
No, generally not, at least on the specific types that I have flown.
However, on some types with turbocompressors (B707 for example), outboard engines are reduced to idle for descent, and the inboard throttles are left slightly advanced, to ensure enough air is available from the turbocompressors, to allow the cabin altitude to descend, for landing.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 2, posted (2 years 3 months 5 days 5 hours ago) and read 1413 times:
Quoting c5load (Thread starter): When asked, they said when all four throttle handles were in the same position it put the engines in the vibe range. Do civilian four engine airliners do this at lower altitudes?
None that I know of. Some engines do have keep-out zones (speed/altitude combinations) to avoid vibration and resonance, but the FADEC takes care of that and it's not something the crew generally has to deal with.
Airportugal310 From United States of America, joined Apr 2004, 3104 posts, RR: 2 Reply 3, posted (2 years 3 months 4 days 10 hours ago) and read 1248 times:
Quoting c5load (Thread starter): The other day I was flying from UAFM-ETAR and was put in a step climb. I noticed when we would level off the pilots would bring back 1 and 4 throttles for a few couple of minutes, then push them up and bring back 2 and 3. When asked, they said when all four throttle handles were in the same position it put the engines in the vibe range. Do civilian four engine airliners do this at lower altitudes?
That seems like a pain. I didn't think that engines had to be THAT closely monitored. Learn something new everyday