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By: 6th March 2006 at 22:56 Permalink - Edited 1st January 1970 at 01:00
-Suppose to make it more noticeable when its spinning
By: 6th March 2006 at 23:39 Permalink - Edited 1st January 1970 at 01:00
-It's designed to scare birds away to prevent bird strikes.
By: 7th March 2006 at 00:10 Permalink - Edited 1st January 1970 at 01:00
-yer im sure its to show ground staff aswell that it is still turning
By: 7th March 2006 at 01:35 Permalink - Edited 1st January 1970 at 01:00
-It's the two reasons mentioned above. Its primary function (as I understand it at least) is to scare birds away. Birds have a higher vision 'refresh rate' than humans, so although it may just look like a tiny swirl in the middle of the fan to us, for birds it's much more noticable.
And of course it allows ground crews to see when the engine is tuning in low light when it's not easy to see the fan blades.
Paul
By: 7th March 2006 at 05:59 Permalink - Edited 1st January 1970 at 01:00
-To hypnotize the curious onlookers ;)
By: 7th March 2006 at 09:04 Permalink - Edited 1st January 1970 at 01:00
-cheers guys!
By: 7th March 2006 at 09:56 Permalink - Edited 1st January 1970 at 01:00
-How could anyone man or bird see the spiral once the engine has been run up.
Unless they have strobe vision!
By: 7th March 2006 at 10:18 Permalink - Edited 1st January 1970 at 01:00
-How could anyone man or bird see the spiral once the engine has been run up.
Unless they have strobe vision!
Dude.. read all the posts again. Birds have better framing rate than humans. Hence... !
By: 7th March 2006 at 10:34 Permalink - Edited 1st January 1970 at 01:00
-How could anyone man or bird see the spiral once the engine has been run up.
Unless they have strobe vision!
Well, I guess if you can't see it - you know its spinning.
By: 7th March 2006 at 10:38 Permalink - Edited 1st January 1970 at 01:00
-...what's the painted spiral on the cone at the centre of the fan for,...i see it on some engines, but not on others?
Interesting topic, I too have been curious to know why this is the case...and now I know - thanks for the information!
To hypnotize the curious onlookers ;)
LMAO!:D:D:D
By: 7th March 2006 at 11:10 Permalink - Edited 1st January 1970 at 01:00
-While the tips may be going round close to the speed of sound the centre is stationary. As distance from the centre increases as does the speed. It is possible to see the shape (it's not always a spiral) painted on the spinner particularly at idle.
Another use of the shape is to indicate rotation to the pushback crew as some engines require a call to confirm the N1 is rotating before fuel is selected on. I don't know why some engines don't have them though. We have one aircraft that has one engine with the painted spinner and one that doesn't.
By: 8th March 2006 at 10:56 Permalink - Edited 1st January 1970 at 01:00
-They arn't an aircrafts equivalent of go faster stripes :eek: :eek: :eek: :eek: :eek:
By: 8th March 2006 at 11:49 Permalink - Edited 1st January 1970 at 01:00
-A little trick i learnt in pre-gcse HE classes - If you get the paint in its pourable form and spin the nose cone for the fan blades very quickly (like normal idle spinning or maybe just a bit less) then pour the paint from the center in a line directly to the edge of it. This will create the spiral effect :D
Usually used with chocolate or carmel etc
By: 8th March 2006 at 17:50 Permalink - Edited 1st January 1970 at 01:00
-How about painting this type?
Engine damage caused by a heron hit very close to V1!
By: 8th March 2006 at 20:27 Permalink - Edited 1st January 1970 at 01:00
-How about painting this type?Engine damage caused by a heron hit very close to V1!
did the heron make that large white mess on the cone?
seriously now, to raise another question, whats the pipe sticking out of the top of the engine casing in that picture for?
By: 8th March 2006 at 21:05 Permalink - Edited 1st January 1970 at 01:00
-pitot tube?
By: 8th March 2006 at 23:14 Permalink - Edited 1st January 1970 at 01:00
-Pitot tubes are used to measure the air pressure resultant from the forward motion of the aircraft.
This probe measures the pressure of the air immediately prior to entering the fan/compressor stages and amongst other things is used to compute the EPR indication.
By: 9th March 2006 at 00:28 Permalink - Edited 1st January 1970 at 01:00
-So is that a yes?
By: 9th March 2006 at 05:43 Permalink - Edited 1st January 1970 at 01:00
-I think the real reason is, if you use fluoroscent lighting, you will misjudge the fan speed. The spiral will clearly show the actual rotation. That will help maintenance crews. JM2C
By: 9th March 2006 at 22:04 Permalink - Edited 1st January 1970 at 01:00
-So is that a yes?
No. Pitot probes are on the nose. :p
Posts: 1,381
By: adamdowley - 6th March 2006 at 22:50
Hi all
This just occured to me - what's the painted spiral on the cone at the centre of the fan for, as shown in the a.net shot? i see it on some engines, but not on others?
http://www.airliners.net/open.file/0998402/L/
thanks