The Rockwell Commander 112TCwas making a series of touch-and-go landings at Cranfield. After touching down on the fourth touch-and-go, with a light crosswind from the left that was well within the limits of the aircraft and the right

The Rockwell Commander 112TCwas making a series of touch-and-go landings at Cranfield.

After touching down on the fourth touch-and-go, with a light crosswind from the left that was well within the limits of the aircraft and the pilot’s experience, the aircraft swung to the left coincident with the flaps being raised and the application of power.

The pilot immediately closed the throttle and applied right rudder, but the Commander continued to veer left, departed the runway and came to rest after crossing a drainage ditch during which the nosewheel was torn off and the propeller dug into the ground.

The group-owned aircraft had recently been repaired after extensive damage caused by a wheels-up landing. Whilst undergoing these repairs, the original two-blade propeller had been replaced with a three-blade unit.

After its return to service, the pilot reported that he and other members of the operating group had experienced an “instability on rolling out” which he attributed to a lack of recency on the aircraft.

On two occasions excursions from the runway occurred, neither causing any damage. The maintenance organisation that both repaired the aircraft following the wheels-up landing and replaced the propeller stated that flight tests were carried out on completion, and these included one flight with a member of the owner group on board who said that the Commander exhibited normal flying and handling qualities throughout.

Specifically, they stated that installation of the three-blade propeller had not resulted in any discernible change in these qualities. The accident pilot acknowledged that a propeller rotating clockwise (viewed from behind) will give rise to a swing to the left as power is applied, due to asymmetric propeller wash over the fin and rudder.

Whilst not thinking it very likely, he considered that the ‘prop wash’ effect from the new three-blade propeller might have differed from that of the original two-blade propeller.