Date: 201508
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Texan T6/Harvard (Antique)
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Landing
ATC / advisory: CTAF ZZZ
Aircraft component: Tail Wheel
Component problem: Improperly Operated
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Confusion; Training / Qualification; Troubleshooting; Workload
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Ground Strike - Aircraft; Ground Excursion Runway
Detector: Person Flight Crew; Person Maintenance
When detected: Other Post-Flight
Result: Aircraft Aircraft Damaged; Flight Crew Became Reoriented; Flight Crew Took Evasive Action; General Maintenance Action
Contributing factors: Procedure; Human Factors
Primary problem: Procedure

Narrative: Second flight of the day for formation training following FAST formation practices. Three T-6 aircraft were participating in the training. My T-6 was the number two ship in a flight of three ships. We were landing after performing an overhead 360 approach to landing. I had touched down on the right side of the center line (lead touched down on the left side). I wheeled landed and was keeping the a/c on the main gear until the 2000 foot remaining mark. I then let the tail come down. The airplane felt light on the main gear and started to lift and divert to the right. I added power and left rudder for directional control. The airplane left the runway for the grass on the right side then went right wing high and started to divert left. I closed the throttle and attempted to regain directional control and bleed of speed and energy. During this entire roll out; the tail wheel felt that is was not locked. I initially though the locking pin sheared and I only had rudder for directional control. I managed to get the a/c back onto the runway and stopped after swerving left and right until stopped. Once stopped; I shut down the engine and got out to inspect the tail wheel and the a/c. It was obviously not locked. There was evidence that the aft portion of the left wing tip and aileron came into contact with the grass while the a/c was off of the runway. The airport manager closed the runway until we were clear of the runway. This was about 30 minutes duration. With the help of a mechanic; we removed the fairing and saw the locking pin was intact and we were able to move the tail wheel into the locked position. Started the engine and taxied to the hangar for further inspection. The Tail wheel would lock and unlock without difficulty. Remained locked during the taxiing to parking. It is suspected that I inadvertently unlocked the tail wheel during roll out by applying too much forward pressure and also let the tail settle with too much forward speed. This cause the float and unloading of the main gear. The damage was determined by several mechanics not to an airworthiness issue and the airplane was returned to service and flow back to the airport it is based at without incident.




Synopsis: A T-6 Texan Pilot inadvertently unlocked the tailwheel during landing when he applied too much forward pressure causing the aircraft to leave the runway. During one of the off runway turns a wingtip struck the grass.