I know that Robinson now offers LED-type landing lights. This question is about the traditional incandescent landing light globes (which in the case of a Raven II would be two 28V, 100W, General Electric GE4591 bulbs).
We feel that these globes fail too often. In all cases, the filament is 'gone', sometimes with, or sometimes without, black charring inside the glass. But never is the glass of the bulb imploded or cracked, nor does the circuit breaker ever trip.
I tried to search this Forum for advise but couldn't find any thread that has dealt with this matter. Hence my question:
What is in your experience the typical failure rate of these globes in a R44? And has anybody identified specific operating conditions that cause those globes blow more often?
Fix wing people indeed report (in this Forum and elsewhere) frequently the same problem. Admittedly, a broken landing light seems to be a much bigger problem for a fix winger, during any night landing. Whereby arguably in a helicopter, landing lights are not needed for safe night operations, provided you operate to and from landing sites that are equipped with "night flying facilities", which again in many legislations is a minimum requirement for any night ops (however, in case of night autos a working landing light would be a great benefit
).
We only started keeping accurate records of this 'routine' replacements recently. Over the past 300 flying hours (engine Hobbs) we had 11 blown bulbs, with any one globe failing between 20 and 120 HRS after its last replacement. This is flying time, and the actual time with lights ON would me much less, although the lights get switched ON once during daily preflight (with engine OFF) and occasionally during flight.
The average life of a given globe therefore is around 60 flying hours. Practically that means (as the a/c has two landing light globes) that in average every 30 HRS either one globe has to be changed. (Only once though we had that both globes were blown at the same time.)
Is that still normal?
