History of Flight
On March 18, 2013, at about 1515 Pacific daylight time, a Piper PA-23-250, registration N318CA, departed the end of the runway following a rejected takeoff at Stark's Twin Oaks Airpark in Hillsboro, Oregon. The airplane was registered to Twin Oaks Airpark, Inc., and operated by the private pilot on a local instructional flight under 14 CFR Part 91. The certified flight instructor and the private pilot receiving instruction were not injured. The airplane sustained substantial damage to both wing spars and the forward fuselage structure. Visual meteorological conditions prevailed, and no flight plan had been filed.
The flight was intended to be the private pilot's first multiengine lesson. Both pilots reported performing an uneventful preflight check, brake check, and engine run-up. They confirmed the door was closed and locked; the flight instructor inflated the door seal and checked that the parking brake was disengaged. The private pilot positioned the airplane at the end of the runway and applied full engine power. Both pilots stated that when the airplane approached a speed of 80 mph, just prior to rotation, the right cabin door opened about 1 inch. They had traveled about one-third of the runway length at that time, and the flight instructor called for an abort. The pilot reduced engine power to idle and applied brake pressure. The flight instructor stated that the airplane began to decelerate, but she became concerned they would not stop on the remaining runway. The private pilot noted brake effectiveness began to dissipate as they neared the runway end. The airplane overran the runway and came to rest in a ditch.
Two witnesses corroborated that during the takeoff roll, both engines went to idle about one-third down the runway. They observed the airplane decelerate but continue, departing the runway end at a walking pace. The airplane was not equipped with foot brakes on the right side, occupied by the flight instructor.
Personnel Information
The flight instructor held an airline transport pilot certificate and reported 9,368 total flight hours, including 5,440 hours in multiengine airplanes and 5.1 hours in the accident make and model. She had 3,551 hours as a flight instructor, 74 of which were in multiengine airplanes.
The pilot undergoing instruction held a private pilot license with single-engine land and instrument ratings. He reported 191.4 total flight hours, all in single-engine airplanes.
Tests and Research
According to the flight instructor, the airplane's gross weight at the time was 4,230 pounds. The flight manual's accelerate-stop distance performance chart, using the weather conditions and weight after reaching 80 mph indicated, with zero flaps on a level dry paved runway, indicated a required distance of about 1,800 feet. The manual did not provide factors for runway slope.
The Emergency Procedures section of the flight manual included a procedure for closing the cabin door in flight: retard throttles, reduce airspeed to 90 mph or less, open the storm window (left of pilot), close the door, then recover power and airspeed. The manual also stated that should the door become unlocked during takeoff, landing approach, or low altitude flight, required action is at the pilot's discretion.
A Federal Aviation Administration (FAA) inspector examined the airplane's brake system after the accident and reported no mechanical failures or anomalies that would have precluded normal operation.
When asked about the abort decision, the flight instructor stated that she had heard anecdotal evidence from other flight instructors that the airplane type was hard to control if the door opened in flight, so she chose to abort rather than risk a flight control problem after departure.