Why do planes have headlights?

[happy_face]

I am one of the 'fortunate' ones who live on the flight path to Heathrow and I've often wondered why planes have headlights? Surely it's not because the pilots need them to see.

[ICEMANSAV]

you need Clanad for that one!

[andy hughes]

I would think it's so the ground crews can see them. Imagine if you are working away on a runway at night, you hear an engine getting closer, and a 747 lands on you. With a light on its nose, you have a fighting chance of seeing it coming! Same applies to planes taxiing, the captain can see any obstructions on the taxi / runway and avoid them.

This answer is based on logical reasoning rather than specific knowledge - if anyone knos better, feel free to contradict.

[Quizmonster]

The following is a quote from someone who appears to know what he's talking about...

"The purpose of a landing light is to illuminate the area ahead of and down from the airplane to enable the pilot to check for obstructions on the runway, check for damage to the runway, and in some instances, to locate the runway."


Click http://www.game-tricks.net/viewtopic-160420.html for more, though more specifically dealing with flashing aircraft headlights which appear to be designed to scare away birds.

[Clanad]

Andy and QM's responses are, how do you British say, "spot on"?  There have been a few... very few, special applications, usually military aircraft, that were equipped with flashing, forward facing, lights.  The standard landing and taxiing lights, however, were not part of such a system.  The landing lights are turned on when the aircraft is cleared for takeoff or cleared for landing (airline useage).  There may be "recognition" lights mounted near the landing lights and face forward to help other aircraft identify you...  These are of less power and size, however.  The landing and taxi lights are all installed, as QM's quote indicates, to focus forward and down.  In fact they are sometimes installed incorrectly and the beam doesn't illuminate as well.  The landing lights are turned off after exiting the runway, either day or night, but the taxi light, which is attached to the nose landing gear, and therefore "swivels" in the direction of the tires, is left on and helps the crew see ground obstacles at night.  It can be selected high or low power on all transport category aircraft... By the way, it's believed, at least by a large number of pilots, that using the radar helps birds avoid the aircraft as well... no real data to prove it, but, who know's, so most use it if approved by the company...

[KebabMeister]

Clanad, which military aircraft used flashing forward lights?  I used to work at a RAF ATC and never came across that?

[Clanad]

KebabM... I've a friend that maintains three older C-130's in civilian useage now.  He said they had to disable the flashing feature on the landing lights.  It may have been a special feature for only those aircraft.  I used to fly  Convair 580's, that had been a Convair 340-440 and had seen life previously as a military aircraft.  Some of the fleet had landing light switches that had a flashinig function marked.  It didn't work by that time, but had been deactivated.  Additionally, I've seen references to the feature in some fighter/interceptor aircraft...

[KebabMeister]

Thanks for the reply Clanad.  The aircraft I was familiar with were Tornado and Harrier aircraft and both had fixed forward landing lights (the latter often switched them off for NVG approaches/circuits/landings).

[captken]

yes its so that pilots can see at night or on foggy days