Engine Question

[Lan Ding Gere]

Firstly, appologies to AlanM for stealing his picture from another post.

I was looking at the following picture and noticed, not only on this plane but pretty much every plane that I can remember. What is the white "comma" like line in the cenrte of the engine fans ? What is it's purpose and why is it there ?

It may sound a little silly, but this is the only thing I could think of. As the centre of the fans have less distance to travel round making it easier to see, this would give you an indication as to which direction the blades are rotating.

Maybe you guys could help me

Ummmm ? (http://www.airliners.net/open.file/172630/L/)

LDG

[AlanM]

LDG....steal away!!

I thought it was simply so you could see that the blades were turning.......something to help the engineers??

[Lan Ding Gere]

Thanks for confirming that Alan.

Looking at your profile and then on your homepage, I realised that you have taken some of the many photographs that I view daily. To be honest, I normally only read the comments, but will look out for some of your great photographs.

Keep up the good work

LDG

[eng1170]

I've always been under the impression that it's to do with putting the wind up birds (of the feathered variety) and as such helps in reducing bird ingestion, as does taking-off with the landing lights on!!

I could be wrong!

[lomapaseo]

Hi Folks

I wrote a paper on this subject for distribution to airlines that wanted to try out these paint schemes some 20 years ago.

It is most definitely not to be thought of as affecting birds in spite of all the ole wifs tales. The comma and other painted features, spin at speeds that make them only a blur to the birds eye. The birds primary behaviour is based on
1. Food
2, predators &
3. reproduction

Ask yourself as the B747 is bearing down on a hapless bird at 155 kts. With a blurred faint white on the engine nose spinner and with 120 Db noise, is the bird thinking

Lunch
or sex?

As someone opinioned above, These paint schemes are very effective at the gate at keeping mehcanics from jumping into engines prematurely before the fan has windmilled down to a speed that can be safely accomodated by a good lean against the spinner (never never a foot in the fan for the big uns.).

[RadarContact]

Funny enough, the (painted) spinner is the one thing that does not blur at high n1. Obviously because its close to the rotation axis.

What might an airborne bird think when flying towards an engine with a a) painted spinner
b) unpainted spinner?

-cave/nest/hiding place (dark!)
-[b]big[7b] problem - let's stay away.

I believe it works...

[JAFCon]

Asked the same Question many years ago to Mister RR Salesman,
- its supposed to scare the birds away, but latest thinking from GE is that it tends to attract them, Our RR Engine's have them and our GE Engines dont.

And I,m still confused as to what it does!!!!!!!!!! :confused: :confused: :confused: :confused: :confused:

[fruitloop]

Possibly to determine directional rotation. (read don't introduce fuel until N1 is turning the right way e.g. tail wind starting can cause high EGT shortening turbine life span !):D