From: ARWING Administrator
Sent: Tuesday, March 09, 2010 8:45 AM
Subject: [AR-Wing] a/c circuit breaker hazards

Hello all,

If you will recall, the FAA issued a Special Airworthiness Information Bulletin in December advising pilots that if a circuit breaker pops during flight, to reset it only once and if it comes back out, to leave it alone for the remainder of the flight because of the potential for electrical fires. In the latest edition of "Light Plane Maintenance", this problem  was discussed about a fatal crash. 

It highlights a December 23 flight in  which, on the day before the accident, a pilot had a weather radar failure and manually pulled the related circuit breaker. The burning smell went away according to the pilot's entry in the airplane's maintenance discrepancy binder. The pilot continued the flight with the circuit breaker pulled  for another hour. 

The next day, it is likely the next pilots reset the weather radar C/B, restoring power to the weather radar system wiring. This is consistent with routine or the "Before Starting Engines" checklist. Then 10 minutes after takeoff, the pilot announced a problem and crashed about two minutes later. 

The NTSB determined that the most likely failure was from the weather radar and its associated wiring, which would be possible only  if that crew reset the weather radar circuit breaker. In the accident airplane, we do not know if the circuit breaker tripped again but, if it did, it was after an uncontrollable fire was started.

Since we have different pilots flying on separate occasions in CAP operations, it would behoove us to caution all pilots in the Arkansas Wing against merely resetting a circuit breaker as part of our preflight checks without a careful examination of the online discrepancy log in WIMRS for that aircraft prior to undertaking the flight. 

Also, if a circuit breaker trips while on a flight, it is vitally important for the pilot in command  to report this occurrence to the aircraft maintenance officer immediately  upon landing so that the problem can be corrected before the next scheduled flight. It could be a matter of life or death for the next crew.

I would ask that all unit safety officers include this subject in their  next safety briefing and ensure that all pilots in the unit are personally made aware of this policy.

Doug Wood