qantas777
Posts: 390
Joined: Thu Aug 24, 2000 7:52 am

The Spirals On Airplane Engines

Tue Sep 05, 2000 8:48 am

Why are there spirals on engines to begin with? Why does Rolls Royce and IAE have the yellow spiral instead of white and i noticed some 737-300/400/500's without the spiral. Does this mean the engines are older???
Thanks, Padraig
 
D L X
Posts: 11663
Joined: Thu May 27, 1999 3:30 am

RE: The Spirals On Airplane Engines

Tue Sep 05, 2000 8:56 am

The spirals are there so that the necessary people can easily tell if the engine is spinning or not.
 
Delta777-XXX
Posts: 940
Joined: Sun Jun 11, 2000 3:50 am

RE: The Spirals On Airplane Engines

Tue Sep 05, 2000 9:06 am

D L X... you mean like un-easy passengers???  
 
Guest

RE: The Spirals On Airplane Engines

Tue Sep 05, 2000 9:16 am

Actually,they are used to prevent birdstrikes in the engine.In an engine without the spirals,the birds treat it as a dark cave and fly in, only to get killed by the fan blade and the engine loses power.

Engines with the spiral are less prone to birdstrikes as the birds see the stripes and dare not go in as it is bright to them.


Gundu
 
Hepkat
Posts: 2134
Joined: Fri Aug 11, 2000 8:22 am

RE: The Spirals On Airplane Engines

Tue Sep 05, 2000 12:13 pm

All this talk about birds and engines, I have a question. Don't birds actually HEAR the roar of engines? I mean, they ARE quite loud. Or is it that the engines are so powerful, that by the time they hear them, it's too late and they're already being sucked into them? I guess this is also possible since engines are also quite powerful.
 
Guest

RE: The Spirals On Airplane Engines

Tue Sep 05, 2000 12:58 pm

Yeah, but birds are pretty dumb. And at night, sound doesn't help much.
 
JETPILOT
Posts: 3094
Joined: Tue May 18, 1999 6:40 am

RE: The Spirals On Airplane Engines

Tue Sep 05, 2000 1:21 pm

I guess no We're Nuts never had a pet bird.

Birds are extremely intelligent.

The spiral seves two purposes.

The first purpose, and the reason for the spiral shape is so ground personel can tell it's turning while wearing ear protection.

When the engine is running the spirals become solid white cirlces. The theory is that these white circles give the aircraft the illusion of being a large predatory bird.

 
D L X
Posts: 11663
Joined: Thu May 27, 1999 3:30 am

RE: The Spirals On Airplane Engines

Fri Sep 08, 2000 11:35 am

Now, I had heard the "bird theory" many times, and I just can't really believe it.

I mean, planes fly an awful lot faster than birds do, even at their slowest. A bird simply won't see the white stripes on the engines. What they will see is a REALLY BIG FRIGGIN' BIRD that it would be wise not to mess with.
 
dustweek
Posts: 75
Joined: Fri Aug 06, 1999 10:55 am

Birds

Fri Sep 08, 2000 1:24 pm

This topic has been done to death before.
I agree the bird theory makes less sense than the ground crew safety theory.

But ANA did have a press release a few months back where they specifically mentioned bird strikes as the reason for their spirals.

At the same time, workers at other airlines said their spirals are for ground crew safety.

Take your pick.