20220217002049I

Pilot statement:

I was flying back towards the airport (ktmb) just before 2:00PM EST approximately 11 miles from tamiami airport slightly northeast near pinecrest when I smelled fire I called the tower received an echo arrival and then turn off all electrical to troubleshoot the problem I checked all breakers and nothing was popped. I turn the electrical system back on to call the tower and let them know that I had an electrical fire and would be turning off all communications and electronics. I had smoke rolling out of the floor from the center of the instrument panels no flames, as soon as I turned off all power the smoke stopped. I did not declare an emergency and safely landed back on the heli pad.

Received N313JP with report of smoke in the cockpit. Proceeded with apreliminary inspection under the instrument panel using a boroscope. Inspection revealed burns and discoloration at the J9P and P9J connector. It was also revealed that some damage had occurred on protective covering (snake skin) on a nearby wire bundle. It was determined that the instrument panel would need to be partially removed to access this connector as it stubbed up through the floor at the most forward part of the airframe.

The instrument panel structure was partially removed and access was gained and it was determined the connector had somehow shorted to the back shell and grounded out. The connector was disconnected and pulled back on the right side access panel. All restraints were removed from the wire bundle to better determine the extent of the damage to the ship side of the connector. Inspection revealed that no less than 3 inches past the ship side of the connector was damaged. It was determined that pin b wire number K510A20 had burned away inside the connector and had damaged adjacent wiring from heat.

The connector P9J was replaced and the damaged part of all the wiring was removed. New wire was environmentally spliced, and staggered by gauge and terminated with new pins, and inserted into their respected positions referencing MD helicopters, inc. 500 series- basic hmi, wdm, page 20-55, and figure 20-9 rev. 20. Wire bundle was then lace tied, and nomex covering was placed around the wire bundle for vibration protection. The wire bundle was then rerouted through the floor and left for connection to the mating side of the connector I /a/ w section 19-3 as well as 19-4 of the ac mm CSP-H-2 rev. TR12-001 March 2012 . All adjacent wire bundles were inspected for damage, no damage was found, and was chaff protected as needed, and secured.

Connector J9P (instrument panel) was accessed and loosened from its position. The connector and its wiring were cleaned and inspected. Socket b had been burned away, and a hole was noted in the connector. The wire K510E20 was damaged no less than 3 inches back from its termination. This wire was spliced with new 20 gauge wire and terminated with a new socket. The rest of the wire bundle was inspected and it was determined that only discoloration had occurred at the back shell. A new connector was used and the rest of the wiring, was cut at the old connector no more than 1 inch from the original termination. Referenced, MD helicopters, inc. 500 series-basic hm page 20-55, figure 20-9 sheet 1, rev.20, for termination of wires and respected positions. It was noted that the original connector was only zip tied to the instrument panel structure, and had no appropriation for hard mounting that was provided by the manufacturer. The new connector did have the appropriate mounting structure and was hard mounted at the provided position.

The connectors were then mated and preceded with check out of the affected systems. Power was applied to these systems with no discrepancy noted at this time.