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707 Engine Pylons  
User currently offlineHemispheres From United States of America, joined May 2004, 85 posts, RR: 0
Posted (9 years 6 months 1 week 9 hours ago) and read 2623 times:

I've always wondered this but was too dumb to ask. Why is the engine pylon for the #1 engine different than the rest. It's missing the distinctive hump toward the front of the engine. Anyone know the purpose? (enlarge the first pic, you can see what I mean better)

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6 replies: All unread, jump to last
 
User currently offlineBR715-A1-30 From , joined Dec 1969, posts, RR:
Reply 1, posted (9 years 6 months 1 week 8 hours ago) and read 2598 times:

Didn't it have something to do with RAM-AIR or BLEED-AIR or some AIR thing in order to start the engines. 4-3-2-1... In either way, 1 was the last to be started at any given time.

Send an email to John Travolta  Big grin


User currently offlineJetstar From United States of America, joined May 2003, 1640 posts, RR: 10
Reply 2, posted (9 years 6 months 1 week 8 hours ago) and read 2591 times:
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The foward part of the engine pylons for #2, 3 & 4 have the turbo compressors needed for the aircraft cabin pressurization system, Engine #1 did not have the compressor.

In the early jet airplane days, the FAA did not allow engine bleed air to be used for cabin pressurization, they had to use outside air. The turbo compressors used engine bleed air to drive a pump the compressed the outside air and pumped it into the cabin.

Nowadays engine bleed air is now used for direct cabin pressurization.


User currently offlineSATL382G From , joined Dec 1969, posts, RR:
Reply 3, posted (9 years 6 months 1 week 8 hours ago) and read 2585 times:

Ah yes, the weekly what is that thing on top of the 707 pylon thread.

It's a turbocompressor. Essential for aircraft pressurization.

If you look at the entire Boeing/KC135 series you'll see a variety of diffent configurations. Some have 3 turbocompressors, some 2, others 1, etc.

regards


User currently offlineBully707 From Germany, joined Jan 2005, 1035 posts, RR: 0
Reply 4, posted (9 years 6 months 1 week 6 hours ago) and read 2498 times:
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And the TF33 powered AWACS have none....  Big grin

Bully



"That's the good thing about the 707...it can do anything, but read!" Joe Patroni, Airport '70
User currently offlineAndz From South Africa, joined Feb 2004, 8442 posts, RR: 10
Reply 5, posted (9 years 6 months 6 days 20 hours ago) and read 2368 times:
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Ah yes, the weekly what is that thing on top of the 707 pylon thread.

First time I've seen it, the poster learned something and so did I. That's what the forum is for.




After Monday and Tuesday even the calendar says WTF...
User currently offlineBucky707 From United States of America, joined Aug 2000, 1028 posts, RR: 3
Reply 6, posted (9 years 6 months 6 days 17 hours ago) and read 2277 times:

"And the TF33 powered AWACS have none....

Bully"


Are you an AWACS driver?


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