Gilford, NH, USA
N7106Y
Piper PA-30
The Piper PA-30, Twin Comanche departed on a local multi-engine training flight. A few minutes later, it impacted water. Several witnesses observed the airplane and reported different airplane actions prior to impact. Examination of the airplane revealed that when it contacted the water, it was in a near flat attitude, rotating nose left, with the right wing lower than the left wing. Metal distortion was found on the tip tanks and outboard sections of both wings that was consistent with the left wing moving rearward, and the right wing moving forward, at the time of impact. The tip weight on the rudder was bent over to the right. Both engine mounts were deformed to the right. Damage to both propellers was consistent with the propellers in the governing range, at or near the same power setting, and not feathered. There was no evidence of a pre-existing failure or malfunction with the airplane or engines.
HISTORY OF FLIGHT On September 25, 2002, about 1125 eastern daylight time, a Piper PA-30, N7106Y, operated by Alan Emerson Aviation Inc., Gilford, New Hampshire, was destroyed when it impacted Lake Winnipesake, near Gilford, New Hampshire. The certificated flight instructor and private pilot were fatally injured. Visual meteorological conditions prevailed for the instructional flight, that departed from Laconia Municipal Airport (LCI), Gilford. No flight plan had been filed for the local flight that was conducted under 14 CFR Part 91. According to an inspector from the Federal Aviation Administration (FAA), the private pilot was a prospective buyer of the airplane, and was receiving flight instruction for his multi-engine rating. This was the private pilot's second flight in the airplane. The airplane was observed taxiing for departure with the private pilot in the left seat, and the flight instructor in the right seat. The airplane departed from LCI about 1100. Several witnesses observed the accident. The following are excerpts from some of the witness statements: "...I witnessed what appeared to be an all white twin engine plane coming straight down nose first into the water. As it approached, it appeared the pilot tried to bring the nose up. The plane went into the water surface and disappeared out of sight...." "...I saw what looked like a small plane in a vertical dive...there was no sound that I could hear. As the plane approached it gave me the impression of a radio controlled model that someone was trying to pull up out of the dive. My reaction was 'he gonna make it' and then there was a splash and a pop...The angle at impact appeared to be less than 45 degrees and perhaps more like 30 degrees off the horizontal...." "...I looked and spotted the plane over Welch Island and remarked that the plane was flying at a rather low level (approx 200 feet) up the lake. We continued with our fishing until...[another person] shouted to look up the lake where I was able to see the plane twist in a downward spiral, and crash in a vertical fashion into the lake...." The accident occurred during the hours of daylight at 43 degrees, 37.88 minutes north latitude, and 71 degrees, 21.63 minutes west longitude. PERSONNEL INFORMATION The flight instructor held a commercial pilot certificate, with ratings for single and multi-engine land, single engine sea, and instrument airplane. In addition, he held a flight instructor certificate for single and multi-engine land and instrument airplane. His total flight experience was in excess of 20,000 hours. The flight instructor's pilot logbook was not recovered, and his recency of experience was not documented. However, according to records from the FAA, on April 5, 2002, the pilot had successfully passed a checkride under 14 CFR 135.293, in a Piper PA-31-350. Additional FAA records indicated the pilot had 2,000 hours in make and model and had flown 150 hours in the preceding 90 days. The pilot was last issued a second class FAA airman medical certificate on September 3, 2002. The private pilot held ratings for single engine land and instrument airplane. His total flight experience was 811 hours with one previous flight in the accident airplane. His last flight review was conducted on August 30, 2001. The pilot was last issued a third class FAA airman medical certificate on July 21, 1999. AIRCRAFT INFORMATION The airplane was maintained under an annual inspection program. The airplane logbooks and record of recent flights were not recovered. According to maintenance records from the operator, the airplane last received an annual inspection on June 29, 2002, with a tachometer reading of 904 hours. WRECKAGE AND IMPACT INFORMATION The debris field for the airplane was located about 2,000 feet east of Steamboat Island, and ran in a north/south direction. The airplane came to rest in about 80 feet of water. On the day of the accident, the outboard 10 feet of the left wing, with the tip tank attached was recovered from the surface of the lake. Recovery operations were then suspended due to weather and resumed on September 30, 2002. After recovery, the wreckage was moved to the insurance adjustor's facility in Biddeford, Maine, and examined there on October 8 and 9, 2003. The outboard section of the left wing separated from the remainder of the wing, about 3 feet outboard of the left engine. The wing was bent in an upward direction, with dimpled skin observed on the underside. The metal on the bottom of the left wing tip tank was crushed up and was deformed consistent with movement in a rearward direction. On the separated section of left wing, the rear spar was bent forward. Metal on the bottom of the left wing, at the location of the left aileron was compressed forward. The left aileron was separated from the wing, and the trailing edge was compressed toward the leading edge. The right wing was fragmented. The spar was bent rearward. The tip tank was ruptured. Dimpled skin was found on the inboard underside of the right wing. In the cabin, there was no flooring. The seat tracks were fragmented, and bent up. One seat was recovered; however, its pre-impact location, left or right side was not determined. The seat legs on the left side of the recovered seat were compressed vertically. Both sets of seatbelts were found unlatched. No evidence of loading was visible on either set of seatbelts. The empennage was separated at the aft fuselage bulkhead. The rudder weight on top of the rudder was bent to the right. Dimpled skin was observed on the right side of the vertical stabilizer. Leading edge compression was observed on the outboard 28 inches of the right stabilator. Bending at the point of separation of the right side stabilator was up. Stabilator trim was found full nose down. However, the fuselage had been compressed, stretched, and distorted, due to impact and recovery. The rudder trim was handled through a bungee cord system and its pre-impact setting was not determined. Both fuel selectors were found set to the AUX position. However, these were cable actuated, and the pre-impact position was not determined. The fuel filters in the selectors were absent of debris; however, the selectors contained silt. The throttle quadrant was separated from the instrument panel, and the pre-impact settings of the levers was not determined. The turn needle in the turn and bank was stuck full left and the ball full right. The altimeter was set at 30.32 inches of mercury. The landing gear selector was in the up position and damaged. The flap selector was destroyed. The crankshafts on both engines were rotated, and thumb compression was attained in all cylinders. Valve train continuity was confirmed on both engines. The magneto timing was set at 25 degrees before top dead center, except for the left magneto, left engine, which was set at 26 degrees before top dead center. Spark was obtained from all towers on all magnetos. Both engine oil suction screens were absent of debris. The right engine fuel control unit fuel filter was absent of debris. The left engine fuel control unit fuel filter was about 35 percent obscured with debris. The oil filter on the left engine was dated June 21, 2001, with a hour meter reading of 883.2 hours. The oil filter on the right engine did not contain any data. The Piper maintenance manual called for a change of engine oil filters every 50 hours. Both engines mounts were deformed to the right, with the deformation being more pronounced on the right engine. The bolts on the left propeller were safety wired with 0.032 safety wire. The bolts on the right propeller were safety wired with 0.041 safety wire. The Piper maintenance manual called for the use of 0.041 safety wire on the propellers. Both propeller blades on each propeller hub were bent rearward. The bend was more pronounced on one blade from each propeller hub. In addition, the blades were free to rotate within the hub, and one propeller blade in the right hub had rotated about 180 degrees. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies were conducted on the occupants by the Office of the Chief Medical Examiner, Concord, New Hampshire. Toxicological testing was conducted on the occupants by National Medical Services, Willow Grove, Pennsylvania, and was negative for drugs and alcohol. TESTS AND RESEARCH The propellers and fuel control units from each engine were retained for additional testing. According to the report from Hartzell Propellers: "...Both propellers were rotating and not feathered at the time of impact. The amount of power could not be determined." "There were no propeller discrepancies noted that would have precluded normal operation. All damage was consistent with impact damage...." According to the report from Precision Airmotive Corporation, both fuel control units had received impact damage, and dirt was found in them. Flow rates were either within limits or with less than a 5 percent variance from limits. ADDITIONAL INFORMATION According to an aeronautical engineer, and general aviation spin specialists with NASA's Langley Research Center, Hampton, Virginia, when an airplane is in a flat spin, and the outboard wing is down, this is an indication that the spin may not be recoverable. This is due to lack of airflow over the rudder, and in the case of the PA-30, the added inertial from the tip tanks. He further described a flat spin as a stable maneuver, which is difficult to recover from, even with asymmetrical power. The aircraft wreckage was released to the insurance adjustor on October 9, 2002.
The flight instructor's failure to maintain airplane control, which resulted in an uncontrolled collision with water.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
