Saturday, November 26, 2005

AD & AJ - Low Intensity Centre Row Lighting

If you were to duplicate the AA lighting, including the green threshold lighting, except align the yellow lights with the centreline of the runway, you would have AD lighting. The string of yellow lights is supposed to consist of at least twelve lights (i.e. be 2400' long), but at some aerodromes it is shorter, and still called AD, just with a notation showing the actual length of the string of approach lights. AD and its non-standard variants is quite common.

I'll remember the name for this type because in aviation an AD is an Airworthiness Directive, an instruction to modify or inspect something on an aircraft, and the AD lighting is effectively AA lighting modified to be in the middle, where any sane person would have wanted it in the first place.

AJ lighting resembles AD lighting, but 1000 feet from the runway there is an additional bar of white lights, and there may also be sequenced flashing strobe lights (SF) in the outer 2000 feet. I spent a while looking for a picture, or for an example of an airport that has AJ lighting, but I can't remember or find one. I'll try to remember it anyway.


Blake said...

Would this be an example of AJ?

Aviatrix said...

Nope, that's AC. AJ lacks the flanking red bars, and just has the one white bar, 1000' from the threshold.

Nice pic, though.

Greybeard said...

All this chat suddenly about landing/approach lighting systems!
Are you in cahoots with former Defence Minister Hellyer?

Please, please......clue us in on what you're planning to "guide in" with these lights!

Aviatrix said...

Relax, Greybeard. I'm just educating myself as to the fancy names for all the illumination that guides me to the threshold.

The challenge will be to see if I remember it all in a week.