First check if there's power to the lamp. If so, you may want to pull
out the parts book and see if all the bushings and grommets for the
entire housing are present and in good shape. Many times vibration
will kill the bulb. Good luck and keep us posted of your findings.

On Fri, 12 Sep 2003 21:08:27 GMT, Chick Urick
wrote:

The landing light in my 1979 Cessna 172N keeps blowing out. I have
replaced it 3 time and rarely use it. The past bulb hasn't been
lighted more than 3 minutes, max. I preflight and it is fine, went to
land - dark, no light. Perhaps a lose connection (I'll) check again
or possible a surge in the electrical system? Any thought would be
appreciated. Thanks C.Urick (VA)