Control was lost of a C-140 flown by two ATP pilots while attempting a wheel landing. Evacuation was made by both uninjured pilots upon coming to rest inverted.

Narrative

The C-140 was being flown by a second pilot; a current CFI; ATP (tail-wheel endorsed; without a current medical) with myself; also a current CFI; ATP (tail-wheel endorsed); in the right seat. The second pilot was making a normal wheel landing. The touchdown and roll-out were proceeding normally. We were landing on Runway 22. The winds were 250 at 5 with no gusts stated on the AWOS. As the aircraft slowed it began to slowly drift right. The first pilot was following through on the rudder pedals and the correction the second pilot was inputting was initially sufficient. Then the aircraft moved more quickly to the right and with full corrective rudder deflection already input the second pilot initiated left brake. This act caused the first pilot and the second pilot to slide forward sufficiently to cause a reflexive response; bracing forward with hands and feet. This caused both pilots to inadvertently depress both sets of brake pedals causing the aircraft to flip over. The speed was sufficiently slow that the aircraft did not slide at all on the runway. Neither the first; nor the second pilot were hurt or injured.