The pilot reported that, during the takeoff roll in the tailwheel-equipped Cessna 170, it began to veer to the left.
He applied corrective control inputs, and the flight instructor called for him to abort the takeoff, but the airplane ground looped as it departed the runway at the airport in Missoula, Montana.
The airplane sustained substantial damage to the right wing and aileron.
Both pilots were flight instructors, and the pilot at the controls was receiving instruction for his tailwheel endorsement. The flight instructor providing instruction stated that the event happened too fast for him to correct the diversion.
Neither pilot reported a pre-accident mechanical failure or malfunction with the airplane that would have precluded normal operation.
Probable Cause: The pilot receiving instruction’s failure to maintain directional control during the takeoff roll, which resulted in a runway excursion and ground-loop, and the flight instructor’s failure to adequately monitor the pilot.
This December 2019 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Flew many hours in the C170,180,and the185 and don’t remember needing to ever lift the tail for t/o as one would normally do with the Piper Cub! But maybe I did and just don’t remember doing it but I have to say that flying the 170 was the easiest plane I ever flew even more forgiving than the Cub.
Over the years at a busy flight school, we had many flights done for 141 standardization where the flight crew was two CFI’s. We use to joke that probably the most dangerous crew that there could be in an airplane was two CFI’s. Everyone agreed that there was a slight tendency to let down one’s guard when flying with another CFI, subconsciously thinking the other CFI would make any timely corrections or observations that were necessary, I guess. Maybe that could have happened here? Anyway the important thing is to be aware that with a two CFI crew, vigilance or reaction time doesn’t necessarily double – it may actually take a slight hit.
Interesting read with no root cause identified. Unlikely to have been inadvertent use of left brake. Given the calm conditions, at 50mph, if the tail was up, would it have been possible to rotate?
Maybe a 6th one to add to this article too https://www.boldmethod.com/blog/lists/2017/03/5-times-your-flight-instructor-will-grab-the-controls/
In any case, glad both walked away.