Boeing 757 From , joined Dec 1969, posts, RR: Posted (14 years 4 months 3 weeks 13 hours ago) and read 2850 times:
Do you know any planes that taxi with one engine? I know the 757 does. Do the 727, Md-11, DC-10 only use the engine on top to taxi? BTW, does the 747 land with the two inner engines on and the two outter engines off or does it use all engines?(I'm new to the aviation world)
BostonBeau From United States of America, joined Sep 2000, 471 posts, RR: 0
Reply 2, posted (14 years 4 months 3 weeks 12 hours ago) and read 2768 times:
I remember being on an Eastern B727 where the pilot came on saying that we had been taxying on two engines, and that there might be a "bang" as he started the third engine. I would guess that he had been taxing with the center engine off.
Andman From , joined Dec 1969, posts, RR:
Reply 4, posted (14 years 4 months 3 weeks 12 hours ago) and read 2745 times:
Planes that are used on long hual flights sometimes taxi with some of their engines off in order to save fuel, and extremely tight flights are towed onto the runway. I know that 727s used to be common aircraft that only taxied on engines 1 and 3, and left #2 off until they reached the hold short line.
Iainhol From , joined Dec 1969, posts, RR:
Reply 6, posted (14 years 4 months 3 weeks 12 hours ago) and read 2741 times:
I think many airplanes do, it all depends on the crew and the goings on. I know when I jumpsat a A340 the started all 4 before taxi however I wait to take off was only 5 mins or so, so the probably needed to warm up all of them.
I Like To Fly From United States of America, joined Feb 2001, 1188 posts, RR: 2
Reply 7, posted (14 years 4 months 3 weeks 12 hours ago) and read 2728 times:
Boeing 757, many people only check here once or twice a day, if that. Give (much) more than a half hour before expecting a responce. Sorry I can't help with your question though. I know planes do it, but I am not exactly sure if it procedure or not. Welcome to airliners.net!
Coboeing777 From United States of America, joined Feb 2001, 693 posts, RR: 4
Reply 12, posted (14 years 4 months 3 weeks 12 hours ago) and read 2675 times:
Continental's 737 usually taxi into the gates with only the #1 engine running. However they shut off #2 right before that because a lot of time you will see #2 still spooling down. When pushing out both engines are started but there sometimes when they captain chooses to only start #1 until they are on the taxiways.
The MD80's usually come in with just one engine running too.
Boeing 757, whose 757 have you seen taxiing with only one engine running? CO's ALWAYS come into the gates with both running until they are parked. Same goes for pushing out. I always thought it was because the 757's were kinda hard for the pilots to steer on the ground being that power would be on one side of the plane. Maybe Im wrong. anyone know?
RJ From United States of America, joined Mar 2001, 198 posts, RR: 1
Reply 13, posted (14 years 4 months 3 weeks 11 hours ago) and read 2669 times:
The reason that some airliners taxi on one engine is to conserve fuel. This could either be encouraged by management as a way of helping the bottom line or it may be the Captain's decision because of known delays that may cause a lengthy taxi. At my carrier it is at the Captain's discression wether to taxi on one engine or two. Some of the factors in making this decision are: weather, taxi time, ramp space and parking location, airport procedures. It should also be noted that some engines have limitations placed on them after start up. On the CRJ it is recommended that after start up, a minimum of two minutes at idle be observed prior to operation at max thrust. A two minute cool down also applys when shuting the engine down.
As far as a 747 approaching on two engines, I'm willing to bet my paycheck that this doesn't happen. The reason is that if the airplane had to do a missed approach or go-around for any reason, the airplane would need the thrust produced by the engines. Imagine purposely limiting yourself to two engines for a missed approach in a fully loaded 747!
Yaki1 From , joined Dec 1969, posts, RR:
Reply 14, posted (14 years 4 months 3 weeks 11 hours ago) and read 2641 times:
One would never make an approach with an engine shutdown unless there was a problem. The crew needs to be ready, if necessary, to make a go around. Some crews may shut down some engines after landing while taxing to the gate, usually only on aircraft with three or more engines. It's easier to taxi with symetrical thrust and not as much engine power is required to provide breakaway thrust while manuvering around busy airport ramp areas. During pushback and taxi out, most crews start all engines at the gate, this assures that maintenance is nearby in case of problems. Sometimes, for example, the start valve will not open and a mechanic may manually open the valve. The major exception is when a flight is fuel critical, but many airports have operational towing with those fancy new high speed tugs. Aircraft often can not take-off until they burn some of their taxi fuel, the max. taxi is higher than max. takeoff weight.
AA737-823 From United States of America, joined Mar 2000, 6137 posts, RR: 10
Reply 15, posted (14 years 4 months 3 weeks 10 hours ago) and read 2636 times:
After rereading that subject line, I DON'T advocate banging 727s, it sounds very much unsafe.
NO airplane will LAND without all of it's engines running, unless that engine has experience malfunction or uncontained failure. IT's dangerous, they might need that engine for thrust reverser in case brakes don't perform... as expected.
I don't mean to argue, but this is MY experience. I have NEVER been aware of taxiing in an airplane without all engines spooled up fully. Not once. Back when I was little, I wouldn't have known, but I certainly would now... I think it's a good idea in order to save fuel. Well, now that I consider props, yes the SAABs I was on (American Eagle) did taxi with one prop spinning, but not any of the JET powered aircraft.
By the way, 727 engines bang ALL the time. Especially the number two engine. It's a problem with airflow. That engine frequently starves, bangs (kinda like a backfire in a car but not exactly) and roars back up like normal. Pratt and Whitney JT8D's are nearly indestructible. They deal with this banging, whereas if it happened to a newer 737, the computer would shut down the engine and display "you're screwed" on any one of six LCD displays in the ultra modern cockpit.
Gmonney From Canada, joined Jan 2001, 2160 posts, RR: 18
Reply 16, posted (14 years 4 months 3 weeks 9 hours ago) and read 2613 times:
Thanks a lot everyone, I think this is a great topic, its something that I would never have thought about but now that I have and I have seen the answers, its reasuring that this forum is about quality material.
Kcle From United States of America, joined Feb 2001, 686 posts, RR: 0
Reply 19, posted (14 years 4 months 3 weeks 9 hours ago) and read 2606 times:
Since CLE is a hub for CoEX, many, many Beech 1900s amd ATR 42s can be seen taxiing to the runways with one engine in use. I've always thought that they didn't use both engines because that much power wasn't needed. But, fuel seems more idealistic.
B727 From United States of America, joined Oct 1999, 525 posts, RR: 1
Reply 22, posted (14 years 4 months 2 weeks 5 days 23 hours ago) and read 2546 times:
Most turbo props shut down the No. 1 engine durring taxi, this will let the engine
come to a stop before they reach the gate so passengers can de-plane. When the props taxi out they use the No. 1 engine, this keeps the total hours pretty close to each other on multi-engine aircraft.
The heavies do it to conserve fuel.
ILOVEA340 From United States of America, joined Oct 1999, 2100 posts, RR: 4
Reply 23, posted (14 years 4 months 2 weeks 5 days 20 hours ago) and read 2520 times:
I've never been on a 757 that only taxis w/ one engine. it may depend on the carrier. most of the small prop planes do.
Atr 42 (usually not 72 though)
SAAB 340 and 2000
Shorts 330 and 360
BAe's (includes jetstreams and ATR's)
Cedarjet From United Kingdom, joined May 1999, 8409 posts, RR: 54
Reply 24, posted (14 years 4 months 2 weeks 5 days 20 hours ago) and read 2512 times:
It's pretty common. It's not the greatest thing to bring up as an example but if you look at the cockpit voice recorder transcripts from ValuJet 592 and the Delta 727 that crashed on takeoff at DFW, one of the last things they did before entering the runway was start the other (or third) engine. Both had long taxiway queues to sit in before their ill-fated journey.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
: Leave it to Skippy to post something idiotic...!!!!!!!! I LOVE THAT QUOTE!!!!!!!!!!! IT IS ALL TRUE
26 Boeing 757
: To Skip: LOL! (I totlay agree with Critter592!)
: I have seen lots of Continental 737's that have the #2 engine already stopped by the time they reach the gate.