Re: Airliner lights question

Date:         26 Oct 98 02:59:49 
From:         "Michael Weiss" <mweiss@email.msn.com>
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Jeff Bowen wrote ...
>1.  Is there some point in the checklist that these lights are turned on
>and off and I have just seen a pilot who forgot to turn them off or is it
>left entirely to the discretion of the flight crew?

My understanding based on what I've read is that they are not required by
the FAA for all landings, but they are used for by the airlines for all
landings anyway because it's a cheap way to increase safety.

My personal experience indicates consistent use below 10,000 feet. Lots of
rules change at the 10K level, so it's not surprising to me.

>2.  What about the flashing and non-flashing lights on the exterior of
>airliners?  What lights are placed where and what is their exact function?

There are white strobes at the wingtips, and they are used while in flight.
They serve to differentiate between aircraft and stars, and make the
aircraft visible from far away. There is also a green static light on the
starboard wingtip, and a red static light on the port wingtip. This serves
to identify to others which direction the aircraft is traveling (it's hard
to tell without it whether an airplane is headed toward you or away from
you).

There are also red lights on the top and bottom of many fuselages, and a
white one near the tailcone.

Commercial aircraft also have white lights on the inboard side of each
wingtip, which are used to illuminate the logo painted on the tail. I have
not seen any consistency in their use; I assume, therefore, that it's
entirely at the discretion of the crew whether this pair is used.

Incidentally, I haven't yet observed this with other aircraft, but the MD80
appears to have the wingtip strobes switched by the nosegear. That is, when
the nosegear lifts off the runway at V1 on takeoff, the strobes start
flashing, and when the nosegear contacts the runway upon landing, the
strobes stop. Does anyone know how common this is?