Anti Collision light/Engine shutdown

[BjornMa]

Hi

Just wondering, at what N2% is it normal to turn the anti collision lights off after shutdown? (Read somewhere around 15%, correct?) Also, is there still a chance that ground personnel could get sucked in moments after shutdown?

Reason I'm asking is because, I've seen personnel walk only a few feet away from the engine after shutdown, and for me it doesn't seem that safe since it's still rotating quite fast.
Don't know how much "suction" it creates once no fuel is powering it.

Thanks

[Tom Stian]

3 hours ago, BjornMa said:

Hi

Just wondering, at what N2% is it normal to turn the anti collision lights off after shutdown? (Read somewhere around 15%, correct?) Also, is there still a chance that ground personnel could get sucked in moments after shutdown?

Reason I'm asking is because, I've seen personnel walk only a few feet away from the engine after shutdown, and for me it doesn't seem that safe since it's still rotating quite fast.
Don't know how much "suction" it creates once no fuel is powering it.

Thanks

Hello

I see that on b737.org.uk says the following:

Anti-Collision: Are the orange rotating beacons above and below the fuselage. They are universally used as a signal that the engines are running or are about to be started. They are typically not switched off until N1 has reduced to below 3.5% (or N2 below 20%) when it is considered safe for ground personnel to approach the aircraft.

http://www.b737.org.uk/aircraft_general.htm#Lights

 

And I see some say N2 15% and some N2 10%

 

The boeing manual says this.

 

So the question is what the definition on "complete stop" is maybe

I switch it off around N2 10%.

 

Edited July 8, 2016 by Tom Stian

[BjornMa]

Ah, perfect, thank you! 

[Tom Stian]

Your welcome

 

[Eddie]

I've always seen 3.5% N1 used as the standard, and is what I use myself (on all aircraft), but I don't have a source to back this up besides apage on the 737 Technical Site or something to that effect.