Robert,

First, which size lamp does your 172 use, PAR 36 or PAR 46?

As others have already pointed out, you can use a Q4509 in place
of the PAR 36 GE 4509 and get more light and logner life.

My 1976 M model uses a PAR 46 lamp and I found a Halogen
lamp that would replace it, the GE H7635. This is a halogen 12V,
50W PAR 46 lamp that fits into the GE 4537 mount. I found them
at http://www.bulbs.com for $14.95 in you buy a case. I order a couple
of lamps from http:wwww/RockAuto.com for about $18.00 each.

The other idea is to stop the vibration that is causing the shorten lamp
life. The following is from a post back in March that discusses a kit
Cessna made to change the resonant frequency of the cowl with some
fiberglass stiffeners and an idea about mounting the lamp holder on
rubber isolation mounts.

Ronnie


"John_F" wrote in message
...
My 1976 C172M had the same problem. Cessna has or at least had a kit
that stiffened the lower nose bowl and changed the resonant frequency
of the assembly to move it away from the resonance freq of the lamp.
It takes a couple of hours to install the honeycomb and glass cloth
but it has worked for more than 20 years on my plane. Before
installing the kit my landing light would not last more than 3 hours
on or off. Now it lasts for years.
John

On Wed, 01 Mar 2006 19:00:58 GMT, "Ronnie"
wrote:



"Robert Barker" wrote in message
...
We seem to be going thru landing lights more frequently than we should in
our 172's. Are there any STCd alternatives to the standard Cessna part?
Maybe a LED lamp or at least something more durable? I realize it's only
a $40 part, but we're a new club and every little bit helps...

Thanks