20040816016509I

(-23) Overview: on Monday August 16, 2004, at approximately 1230 EST, a Piper seneca (PA-34), aircraft (N467TC) was in run-up prior to takeoff at Naples airport, Florida. The pilot (sander huertus maar) reported an electrical burn smell and smoke entering the cockpit. Background: a PA-34-200T airplane operated by Florida flight training center from venice Florida, serial number 34-7870006, registered as N467TC was operating as a part 91 operator and preparing for a takeoff at Naples airport, Florida. The crew smelled an electrical burn and the cockpit filled with smoke. Purpose/goal: gather evidence during this investigation to determine cause of smoke in the cockpit, and to determine if general notification is needed to prevent future reoccurrences of this nature. Key attendees/individuals of interest: FAA inspectors: walter r. wheeler and pamela gallina pilot: sander huertus maar second pilot: john andrew kandes jr. political considerations/other dynamics: n/a attachments: n/a expected questions & suggested answers: 1. What was the origin of smoke: troubleshooting revealed that the cause of the problem was a burnt and melted battery, which caught fire and burned the battery case,and the wheel well shroud in the nose compartment and the internal shroud in the nose compartment. Wires attached to the nose compartment light were crystallized and fell apart when touched. 2. What were the findings by FAA inspectors? Investigation revealed that the battery positive post separated from a lead acid battery, the left two cells were burnt, and the battery melted and deformed. Composite covers for the battery case and the wheel housing burnt and melted. Nose cover internal housing in the compartment shows evidence of extreme heat, charred pieces, and deformed shaping. Wire damage around battery is minimal. There are indications of a short in the wiring for the nose compartment light, which was held to the frame by masking tape. Wire shield casings burnt and were crystallized (casings cracked and fell off with touch). Several mounting screws for composite and metal flooring missing and not installed, flooring was loose and movable. Weight scales and medical kit were free and movable, not secured in the compartment. Manual tow bar was free to move around in the compartment also. Possible cause: battery shorted out in the nose area of the compartment and resulted in a fire. 3. Was there investigation to determine origin of the smoke? Yes. 4. What were the findings? Mr. David green, an airframe and powerplant mechanic (A&P) with inspection authorization (IA) number 2809540 and manager of Florida flight maintenance, determined the cause of the fire to be the battery caught on fire due to an overload from the left engine wiring to the solenoid during engine start. Suspected overload will be verified by an electrical load analysis prior to replacing the wires. He performed maintenance by replacing the battery to and return the aircraft to service for a one-time flight for maintenance at home station. Concerns: because of the length of the wire from the engines to the solenoids, older wires internally corrode and have a tendency to overheat and could cause an overload, and future incidents or fires during engine start up. This could be a prevalent problem on this type of aircraft, and others that have long starting wires from the engines to the solenoids and battery.