A320 landing light speed limit

[ahmed88]

whats the speed limit to extend the landing lights ? low speed makes sense, but a study material for the type course says it can be used at ANY speed..

thanks

[The Flying Cokeman]

ie there is no speed limit for the landing lights but having them extended will cause a 3% increase in drag. It makes sense extending them at or below 250 kts where you typically would be below 10.000 ft anyway. Just a thought.

[Max Angle]

Surprisingly there is no restriction in the FCOM, they do however create quite a lot of noise and vibration when extended above 250kts.

[ahmed88]

yeah, i checked the electrical circuit for the landing light and there is no speed input anywhere in the circuit, just a straight forward on off retract function. there goes a couple marks off of my first type exam -.-

[red 5]

There is no speed limit as the aircraft can be despatched with the light stuck in the extended position iaw the MEL. However as previously mentioned an increase in fuel consumption and buffet will occur.

[TopBunk]

ie there is no speed limit for the landing lights but having them extended will cause a 3% increase in drag.

My sources suggest 1% fuel flow increase for each light extended.

[ahmed88]

so why is it allowed to be extended at high speeds, whats the reason behind it ?? maybe certain situations might require the landing lights to be on or something ? :P

[Gas Bags]

ahmed,

Read the answers to your post and all will be revealed. In fact the reply prior to your last post is the answer to the question you are now asking.

If a landing light is U/S in the down position (i.e. stuck in that position) what do you do? ground the aircraft?

No you refer to the MEL which allows the aircraft to depart in that configuration.

GB

[ahmed88]

sorry failed to notice it, yeah i guess that clears it up then.

thank you all for your replies, very helpful !