The International Cessna 170 Association

Does anybody out there have any experience sourcing a replacement bulb for a Whelen 70509 beacon?

I'm not talking about the bulb assembly that they sell for 1 aviation unit (approximately $100 with shipping) but rather the bulb itself.

I recently purchased a replacement for the original one in my beacon. The original lasted at least a couple hundred hours till the flasher unit expired during a low voltage situation when my battery was headed South. I replaced the beacon flasher, and the bulb for 2 1/2 aviation units. Back in business again I departed for a very enjoyable flight that lasted approximately 3hrs. On my next preflight I noticed that my beacon was not working again, ensuing investigation revealed that the bulb filament had burned through

Less than pleased with my investment thus far I proceeded to gently remove the light bulb from its housing. The bulb is nothing more sophisticated that a 35W 12v bi pin halogen yard light about the same size as a T4, and in fact experimenting with a $6 replacement bulb yielded excellent results. The problem is the two pins that protrude from the bottom of the bulb, they are nearly an inch long each, splayed out wide, then straight so they plug into the flasher base. So far I've been unable to locate a halogen replacement with pins that long.

If anybody has suggestions on a bi pin replacement bulb with long pins I appreciate the input.

I suspect Whelen will probably stop making replacement bulb assemblies in the near future, and the idea of spending 7 or more aviation units on their LED replacement sets my teeth on edge.

I'd also like to repair my old Grimes rotating beacon to have a spare, but that will require some drive parts that I wasn't able to find when I replaced it with the Whelen flasher.

Aircraft Spruce: Item Number: Part# 11-03251

https://www.aircraftspruce.com/catalog/ ... kkey=14558

Warning: When replacing Halogen lamps... DO NOT TOUCH the lamp with your fingers as the oil from your hand will caue premature failure. If accidentally touched, clean with alcohol. Use a tissue or cloth gloves to handle.

Yep, that's exactly what I ordered the first time. I was very careful not to touch the bulb itself when I installed it, and it blew out on the first flight. For nearly $100 plus shipping I'm darned if I want to buy another one, but I reckon I'll probably have to.
Thanks for the input

Yeah..that’s danged irritating... YOu might contact the people you bought it from (or contact Whelen directly) and maybe they’ll feel sorry for you and replace it. I was surprised when Whelen did that for a strobe on my airplane that lasted less than a week.

Just for the record, an AMU (aviation monetary unit) is $1,000 not $100.

Sheesh, suddenly everything seems so much more affordable

Jr.CubBuilder wrote:

Sheesh, suddenly everything seems so much more affordable

That’s the point; originally conceived to inform spouses of airplane expenses without having their head explode.

Well for what it's worth I did manage to adapt a $6 12V 35W halogen garden bulb into the plastic part of the beacon. It's mounted and has so far been working fine for three to four times as long as its $100 Whelen predecessor.

If I paid myself minimum wage for the time invested I think a new Whelen part would have been cheaper. Perhaps had I bothered to politely request help from Whelen directly they would have replaced my bulb for free or at a discount. However, in the end I am left with a general sense of self congratulatory satisfaction, that in some small way I have engineered a work around and bucked the corporate money gobbling machine.

A few years back I felt the same satisfaction after acquiring a box of PAR36 100W tractor bulbs for my landing/taxi lights at a unit cost of $3............those are all bunt out now and I've replaced them with LEDs because I got really tired of changing them and I'm hoping the LEDs last a bit longer.