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737 Engines

Sat Jul 29, 2000 3:17 am

How come the engines on many 737s are not perfectly round? They look sort of like an oval and not round like many other jet engines.


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king air
Posts: 103
Joined: Fri May 28, 1999 8:38 am

RE: 737 Engines

Sat Jul 29, 2000 3:45 am

They were flattened on the bottom for ground clearance. This shape was found to actully increase air flow into the engine. If you were to stand next to one on a ramp you would see just how close they come to the ground. If the cowling was round it would scrape the ground on taxi way bumps and some landings.
 
PILOTALLEN
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Joined: Fri Nov 05, 1999 11:01 am

RE: 737 Engines

Sat Jul 29, 2000 5:07 am

I just have one question are the planes still in a circular shape? are they moved back further? cause like the bottom being flat and all, hard to ask this question dont know how to word it
Thats not flying, thats falling with style -Woody
 
PILOTALLEN
Posts: 634
Joined: Fri Nov 05, 1999 11:01 am

RE: 737 Engines

Sat Jul 29, 2000 5:08 am

I just have one question are the planes still in a circular shape? are they moved back further? cause like the bottom being flat and all, hard to ask this question dont know how to word it
Thats not flying, thats falling with style -Woody
 
FDXmech
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Joined: Sun Mar 19, 2000 9:48 pm

RE: 737 Engines

Sat Jul 29, 2000 9:24 am

To increase ground clearance, the engine gearbox is mounted on the left side of the engine rather than the bottom of the engine. With the gearbox on the side of the engine they were able to produce an oval nacelle. The engine itself is round.
You're only as good as your last departure.
 
Southern
Posts: 193
Joined: Sat Jul 01, 2000 3:56 pm

RE: 737 Engines

Sat Jul 29, 2000 5:20 pm

it took me a while to find out too but when i was down on the tarmac the engines were very close to the ground, if they were round it would scrape against the ground when you land or are taxing as the wing would bounce
 
AmericanMD80
Posts: 478
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RE: 737 Engines

Sun Jul 30, 2000 2:47 am

It gives it a unique look!

 

~americanmd80~
do what you like . like what you do . life is good
 
FDXmech
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RE: 737 Engines

Sun Jul 30, 2000 6:06 am

Also, another thing done to the 737-300/400/500 to increase engine clearance was to install a taller nose wheel/tire than the 737-100/200.
You're only as good as your last departure.
 
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RayChuang
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Joined: Sat Jun 24, 2000 7:43 am

RE: 737 Engines

Sun Jul 30, 2000 11:49 am

However, you might want to note that the engine nacelle on the 733/734/735 are unique to that plane because of the gear design, which was almost identical to 731/732's. This was so it could accommodate the much wider fan blade of the CFM56 engine without causing ground clearance problems.

The 736/737NG/738/739 models lack this nacelle design, since the new wing and landing gear design on the Next-Generation 737 no longer requires the flattened bottom on the nacelle itself.
 
flyf15
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RE: 737 Engines

Sun Jul 30, 2000 12:06 pm

Wouldn't it be more of a FOD issue?
 
Guest

RE: 737 Engines

Sun Jul 30, 2000 12:10 pm

Yeah, FOD is all part of the mix. Greater ground clearance equals less damage from both ground scrapes AND sucking in debris.
 
Spaceman
Posts: 525
Joined: Wed Jul 26, 2000 3:28 pm

RE: 737 Engines

Sun Jul 30, 2000 12:15 pm

I think Boeing made a desigh flaw of making the 737 so short. It is litterally half as tall as other airplanes. To make it worst they have to make engines which are not round at the bottom so it won't scrape the ground. It makes look awkward and weird too.
 
runway
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RE: 737 Engines

Tue Aug 01, 2000 1:17 pm

The Boeing 737 has been one of the most sucessful commercial aircraft ever built. The first series were built with a low bypass engine that are by todays standards a little too noisy and less fuel efficient than newer ones.
The best way to solve this (problem), without designing a whole new a/c is to equip them with new engines, like CFM56, or V2500. These are high bypass engines that require a large fan for thrust, which in its self would fit under the wing, however some acc had to be repositioned inside the cowl, and the cowl cut to give it reasonable ground clearance.  
 
akelley728
Posts: 1964
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RE: 737 Engines

Tue Aug 01, 2000 11:00 pm

Spaceman:

There is no 'design flaw' in the 737 being so short. If you would've looked at the history of the 737 before making such a remark you would see that it's short for a reason.

When the 737 was designed it was built with rural airports in mind. Airports that wouldn't have alot of support equipment around. The 737 is short so that most everything is within easy reach of ground operators. I could go on and on, maybe a ramp rat can elaborate further?
 
FDXmech
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Joined: Sun Mar 19, 2000 9:48 pm

RE: 737 Engines

Wed Aug 02, 2000 12:37 am

You would think FOD would be more prevalent in an engine so close to the ground as opposed to one higher up. But it has been my experience that the 737-300 had relatively few incidents of FOD ingestion as opposed to the MD80 which suffered frequently from fan damage. The MD80 is legendary for the main tires kicking FOD into the engine intakes. The 737 with its engines in front of the main gear isn't as susceptable.
You're only as good as your last departure.

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