RB211's on a 757?

[lostmoon 0]

Hi Gang,I took the red eye from KLAX to KEWR this morning on a Continental 757-300. From the boarding area, I noticed that engines on the 757-300 for Conti were RR. Are they they same RB211's that are on 744's on Qantas, BA and Cathay?It was my first time riding on an a/c with Rollerz, and I must say, it was beautifully powerful, and just sounded different. Almost quieter perhaps.If it *IS an RB211, curious to know if these engines are interchangable with the 744 and certain 75's.Tomas

[Guest Clansman]

Hello Tomas,The 757 is known for it's powerful engines and consequent "heavy" callsign due to engine exhaust wake turbulence.A quick look on wikipedia revealed that the 757 has indeed 2 RB211-535 (37000-43100 lbf) and the 747 also has RB211s, but these are 4 RB211-524/G (50000-60600 lbf/58000 lbf). They may be similar on technology, used materials and building process, but the power ratings make them quite different engines. I don't think that Qantas, BA or Cathay (or any other) can/want to switch the 524s by the 535s on their 747s, because of the very different thrust ratings and I doubt that the Boeing engineers would allow that...So my (wikipedia supported) theory to answer your question is that: no, they cannot interchange those engines between the 757s and the 747s.Hope you had a nice trip. I've only flew on a Tristar 500 and on a cessna 172. Really different rides :-)Links:http://en.wikipedia.org/wiki/Boeing_757#757-300http://en.wikipedia.org/wiki/Rolls-Royce_R...B211-535_serieshttp://en.wikipedia.org/wiki/Boeing_747#Powerplantshttp://en.wikipedia.org/wiki/Rolls-Royce_R...B211-524_serieshttp://en.wikipedia.org/wiki/Wake_turbulence[yes, I like wikipedia: it RULEZ!!]Cheers,Pedro Venda.

[mburkhard 23]

>The 757 is known for it's powerful engines and consequent>"heavy" callsign due to engine exhaust wake turbulence.Pedro,just for your information.Whether or not an aircraft is categorised as a "heavy" has nothing to do with the power of its engines or their exhaust.Factors for the strength of wake turbulence is an aircraft's weight and it's aerodynamic configuration (Size of the wings, flaps etc.).Engine exhaust does not have anything to do with it. After all even the A343 is in the "heavy" wake turbulence category even though we all know that it's engines are nothing more than giant hair dryers... ;)Regards,Markus

[Guest flyandive]

As I know the ER models of the 757 are over the 255,000lb mark. I don't know about the non ER However, what he may me refering to is that for ATC purposes (FAA7110.65) the 757 has it's own catagory for wake turbulance seperation standards to the point that it doesn't matter if it's certified as a heavy. ATC still has to seperate it as if it were a heavy or something along those lines. I think it might not have to have as high a standard but it's higher than other medium size airliners. I'll look it up when I get a chance tommarow. As for the engines I'm not sure if they are interchangeable. They are the same engine and I was talking to a BA pilot, retired, who had flown 757/767 and well as the 744 and he said that the engines had different tolorences for vibrations, temps, etc, and he asked a mechanic why these limits were higher on the 757/767. The mechanic told him the limits still existed however they didn't want their pilots to be so willing to shut an engine down halfway across the atlantic when they only have two total. 744 it didn't matter as much. I'll be working for Continental this summer as an intern planning flights, I'm sure I'll learn some useful information.-Chris Mohan

[Guest Clansman]

>>The 757 is known for it's powerful engines and consequent>>"heavy" callsign due to engine exhaust wake turbulence.>>Pedro,>>just for your information.>Whether or not an aircraft is categorised as a "heavy" has>nothing to do with the power of its engines or their exhaust.>Factors for the strength of wake turbulence is an aircraft's>weight and it's aerodynamic configuration (Size of the wings,>flaps etc.).whoops! I apologise for my incorrect explanation. Thanks for the correction: that's the outcome of the community colaboration into the forums :-)>Engine exhaust does not have anything to do with it. After all>even the A343 is in the "heavy" wake turbulence category even>though we all know that it's engines are nothing more than>giant hair dryers... ;)oh yes, I've recently looked into that and WHAT A CHANGE!! from the 340-200/300 to the 500/600 the engine thrust ratings has almost doubled!!Indeed, where I'm working right now, I can see all aircraft departing from rwy 21 of Lisbon LPPT. They all pass right above my building and I seldom miss a departure (when the clouds let me, of course).The LPPT based TAP airline company has about 3 a340-200/300 that cross the building at a much lower altitude than all the others, they seem to barely make it... They really REALLY look like very slow climbers. Also, the TAP a340 and the TAAG 743 are the only ones that I can hear (the building is well isolated). Every other plane passes above the building at a much bigger altitude than the a340; it's quite a difference.As for the noise... well, the TAAG 747-300 passes by at a MUCH higher altitude than the a340, but I can hear it almost as well, so it must be NOISY! :-pCheers,Pedro Venda.

[skyymann 6]

When I worked at DFW TRACON, we hated the A340 that DLH flew to FRA every night. WE called it "Der Sky Pig" (In my best German accent :-) ) Climb rate was so slow as to be scary. Never had that problem with A330s or 777s.Scott

[Tabs 2,790]

>When I worked at DFW TRACON, we hated the A340 that DLH flew>to FRA every night. WE called it "Der Sky Pig" (In my best>German accent :-) ) Climb rate was so slow as to be scary.>Never had that problem with A330s or 777s.>>ScottI've heard the same exact thing from a Phoenix TRACON controller about the LH A340 that goes from PHX to FRA as well...

[lostmoon 0]

Gents,Thanks for the cool replies. Learned something today, as usual! Der Sky Pig! I love that. As for the A340, don't know much about it, nor have I riden in one. But, from what I gather from the comments, it sounds weak and slow! OY VAY!By the way, I really felt like a kid in a candy store seeing all the heavies at KLAX. Saw a Philippines 744, United 744, Air China 744, and an Asiana 744-F at the end of RWY 24L, with it's nose door open, and all it's cargo doors open, with the jack firmly in place at the aft. Was AWESOME.I am in New York. Anyone know if KJFK has a good spotting area?Tomas

[mburkhard 23]

>As for the A340, don't know much about it, nor have I riden in>one. But, from what I gather from the comments, it sounds weak>and slow! OY VAY!Tomas,don't get a wrong impression about the A340-200/300. Yes they are extremely bad climbing aircraft, and on hot days at high altitude airports like Johannesburg you might want to keep a close eye on those performance tables.BUT... no one is going to pay you for a good rate of climb. So, as long as the aircraft can fly in and out of all the airline's destinations the management just won't care. Cruise speed is not THAT bad with Mach .79 to .82 for the A343. It does a nice job after all in flying long hauls, compared to its direct competitor from earlier times (MD-11) fuel consumption really is much better on the A343.But yes, the times of the A342 and A343 are gone now, the design is becoming old... Production of the A342 ended years ago and the A343 production might end next year as there are only less than 10 planes on order. After all, the A342/A343 design is only one year younger than the MD-11...Regards,Markus

[Jeff Nielsen 1,385]

I believe what makes it a "heavy" is the aircraft's gross weight. Wake turbulance can be a byproduct of gross weight amongst other things.Correct me if I'm wrong.

[FlyinIron406 3]

250,000lbs and heavier I believe, and the 757 has the WORST wake turbulence of any aircraft in the world :(

[Guest tomahawk_pa38]

I have just returned to EGLL from NZCH via OMDB on an A340 (NZ- Dubai) and 777 from Dubai to EGLL (Emirates) - I hate to start a fight but no comparison between the two from a comfort point of view. The 340 knocked the socks and everything else off the 777 which was cramped, noisy, plasticy and frankly uncomfortable. Neat trick with overhead lights on the bus - nice effect of stars in the ceiling at night and when they switched the main lights on for breakfast, got a neat 'sunrise' effect over a period of about 15 minutes bringing them up from off to bright. 777 - flick the switch and instant fluorescent tubes - that sure does wake you up ! Didn't notice a particularly slow rate of climb though but I seem to recall not getting that push in the back from acceleration on take off that you get with the smaller buses or Boeings.

[skyymann 6]

I flew from LAX to AKL and back last month on Qantas. They had the same effect on the 744. Very nice. After that trip, I'd recommend Qantas to anyone!!Scott

[Guest wisborg]

>don't get a wrong impression about the A340-200/300. Yes they>are extremely bad climbing aircraft, and on hot days at high>altitude airports like Johannesburg you might want to keep a>close eye on those performance tables.I recall the first time I saw an Airbus A340-300 (Scandinavian Airlines) take off from Copenhagen Airport (sea level) and honestly I got scared. I was out at the end of runway 22R (10800 ft) taking photos, and it just kept coming, and I just had time to think that it wouldn't make it before it managed to get above the fence.Later a couple more A340s took off, and the drill was the same./ Jesper

[Guest Clansman]

>I have just returned to EGLL from NZCH via OMDB on an A340>(NZ- Dubai) and 777 from Dubai to EGLL (Emirates) - I hate to>start a fight but no comparison between the two from a comfort>point of view. The 340 knocked the socks and everything else>off the 777 which was cramped, noisy, plasticy and frankly>uncomfortable. Neat trick with overhead lights on the bus ->nice effect of stars in the ceiling at night and when they>switched the main lights on for breakfast, got a neat>'sunrise' effect over a period of about 15 minutes bringing>them up from off to bright. 777 - flick the switch and instant>fluorescent tubes - that sure does wake you up ! nice report :-) was that an a340-200/300 or a 500/600?>Didn't notice a particularly slow rate of climb though but I>seem to recall not getting that push in the back from>acceleration on take off that you get with the smaller buses>or Boeings.The slow climb/overall low thrust rating appears to have it's upsides, like the reduced accelerations for example, eventually resulting in less material stress and fatigue.Cheers,Pedro Venda.