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#1
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why aren't there three engine airliners?
727s, L-1011s and DC-10/MD-11s are out of service as airliners. Are there flaws inherent to the three engine concept or did the executions just not have staying power?
Sixto 87 300D |
#2
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Since the 60s and 70s when those aircraft were designed and introduced, jet engines have become more fuel efficient and more powerful. Thus, the need for 3 engines dropped when the same flights could be accomplished with 2 engines with less fuel burn to boot. There was also one less engine to maintain and you know how airlines like to save money. Just take a look at what 2 engined jets those tri-jets have been typically replaced with. 727= 737-800/900, 757-200, A320/321 L-1011= 767-400, 777-200, A330 DC-10/MD-11= 767-400, 777-200, A330
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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate Sooner or later every car falls apart, ours does it later! -German Narrator in a MB Promotion Film about the then brand new W123. Last edited by H-townbenzoboy; 02-17-2010 at 03:37 AM. |
#3
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The only real problem with the third engine was that it tended to be in the tail. On the off chance that it blew up, there was a good chance of it taking out the hydraulics for the flight controls. Not good.
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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar. 83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles 08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles 88 Jaguar XJS V12 94,xxx miles. Work in progress. |
#4
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$$$ mostly, in production, maintenance & operation
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#5
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they would like to go to one, but it wont fly with "0" engines in an emergency
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1982 300CD Turbo (Otis, "ups & downs") parts for sale 2003 TJ with Hemi (to go anywhere, quickly) sold 2001 Excursion Powerstroke (to go dependably) 1970 Mustang 428SCJ (to go fast) 1962 Corvette LS1 (to go in style) 2001 Schwinn Grape Krate 10spd (if all else fails) |
#6
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FAA rules used to require > 2 engines for over water flights, incase one failed.
With newer more powerful engines, 2 engine planes are now certified for over water flights. Even older 737s with newer engines are now used over water too.
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KLK, MCSE 1990 500SL I was always taught to respect my elders. I don't have to respect too many people anymore. |
#7
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Damn if an engine fails it fails. I don't give a ***** if it's over water or land.
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You don't need a weatherman to know which way the wind blows - Robert A. Zimmerman |
#8
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Its also pretty noisy back there, from what I remember.
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1985 380SE Blue/Blue - 230,000 miles 2012 Subaru Forester 5-speed 2005 Toyota Sienna 2004 Chrysler Sebring convertible 1999 Toyota Tacoma |
#9
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The B727 was a compromise a/c designed to fill the multiple needs of airlines for short runway capability, high altitude runway capability and ETOPS. Newer engines have been certified for longer ETOPS so an extra engine is redundant nowadays. Engines are significantly more powerful now as well.
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Never a dull moment at Berry Hill Farm. Last edited by R Leo; 02-17-2010 at 09:41 AM. |
#10
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I also believe they do not have the hush kits, or they are less effective for tail mounted engines.
Despite the enormous size of todays engines, the core engine itself hasn't gotten that much bigger (% wise). The increase in size creates bypass air, which is used to increase the engines effiency and decrease it noise.
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KLK, MCSE 1990 500SL I was always taught to respect my elders. I don't have to respect too many people anymore. Last edited by kknudson; 02-17-2010 at 10:51 AM. |
#11
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ETOPS - It's a time and distance thing. Not a water thing. It's not all about the engines either. And then there's crew certification... Odd as this may sound - I have flown Boeing 757s that were ETOPS certified and some that were not. Both with the same RB211 engines. As for the Q - Post #2 from H-Town pretty much answered the OP question.
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1980 300D - Veggie Burner ! |
#12
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1980 300D - Veggie Burner ! |
#13
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FWIW, see attached great circle mapper with 60 and 120 min ETOPS on rte to SYD from LGA via SFO...light blue is 60min...all of the continental US is within 60min B757 ETOPS. Not so for mid-ocean. That answers why I've seen similar a/c at terminals, some with ETOPS on the nose gear door, some without.
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Never a dull moment at Berry Hill Farm. Last edited by R Leo; 02-17-2010 at 11:59 AM. |
#14
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Isn't it also true that tri-jets were tail heavy which caused some interesting handling characteristics? (I remember seeing some photos from a few inexperienced pilots who managed to scrape the tails on landing)
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1982 300GD Carmine Red (DB3535) Cabriolet Parting Out 1990 300SEL Smoke Silver (Parting out) 1991 350SDL Blackberry Metallic (481) "The thing is Bob, its not that I'm lazy...its that I just don't care." |
#15
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That wasnt because the aircraft was tail heavy.
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1980 300D - Veggie Burner ! |
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