“Installed ice protection systems are intended to provide protection while departing icing conditions.” – SIMCOM Instructor
At 0700, the pilot of a Socata TBM 700, N731CA, filed an IFR flight plan using DUATS. The personal FAR Part 91 flight with the pilot and four passengers on board would originate at Teterboro (N.J.) Airport and cruise at 292 kt. at FL 260 for its destination of Atlanta. The pilot requested no information during his contacts with Teterboro controllers, nor did the controllers issue weather information. Ground control issued a taxi clearance to Runway 6 at 0943. Five minutes later the pilot reported he was ready for departure.
The TBM lifted off, checked in with departure control and began its climb. While passing 8,000 ft. for 10,000 ft., the pilot was directed to climb and maintain 14,000 ft. The controller then advised the pilot of moderate rime icing from 15,000 ft. through 17,000 ft. with light rime ice at 14,000 ft. The controller asked that the pilot advise him if the icing got worse, and the pilot responded, “We'll let you know what happens when we get in there, and if we could go straight through, it's no problem for us.”
At 0958:24, the controller directed the pilot to climb and maintain 17,000 ft. and to contact New York Center. While climbing between 12,800 and 12,900 ft., at 116 kt. ground speed, the pilot acknowledged and advised that the aircraft was entering IMC.
At 1002:17, the Center controller advised the pilot that he would be cleared to a higher altitude when ATC could provide it, and that light icing would be encountered at 17,000 ft. The pilot responded, “I can confirm that light icing . . .” and stated that, “. . . light icing has been present for a little while and a higher altitude would be great.” The altitude of the airplane at that time was 16,800 ft. and 101 kt. ground speed.
At 1002:34, the pilot reported, “We're getting a little rattle here. Can we ah get ah higher as soon as possible, please.” The Center controller responded with “stand by” and coordinated for a higher altitude with an adjacent sector controller.
At 1002:59, the Center controller directed the pilot to climb and maintain FL 200 and the pilot acknowledged.
At 1004:08, the airplane reached an altitude of 17,800 ft. before suddenly turning 70 deg. to the left and entering a descent.
At 1004:29, while descending through 17,400 ft., and at 90 kt. ground speed, the pilot transmitted, “and N731CA's declaring . . .” No subsequent radio transmissions were heard from the pilot.Numerous witnesses observed the airplane during the descent and accident sequence. A consistent observation was that the airplane descended at a rapid rate and was trailing smoke. At least five witnesses saw pieces of the airplane separate during flight or they observed the airplane descending without a wing attached.
The final radar return at 1005:17 was observed at an altitude of 2,000 ft., about 600 yd. west of the impact site. The previous return, recorded 9 sec. earlier, indicated 6,200 ft.
The airplane impacted the paved surfaces and a wooded median on Interstate 287, about 1 mi. south of Morristown, N.J. The point of initial impact of the main wreckage was in the southbound lanes. The main wreckage debris field was oriented on a heading of about 070 deg. and was about 350 ft. in length. The propeller assembly separated from the engine during impact and came to rest in a wooded area on the east side of the northbound lanes.A post-crash fire was evident on the highway and in the wooded median, where sections of the fuselage, the left wing and the vertical stabilizer came to rest.
Due to the impact damage and fragmentation of the cockpit, cabin and fuselage, the seating positions of the airplane occupants could not be determined.
The outboard section of the right wing and several sections of the empennage, including the horizontal stabilizer, elevator and rudder, were found about 1,200 ft. southwest of the fuselage in a residential area.
Investigators performed a visual inspection of the pneumatic leading edge deice boots and uncovered no preexisting ruptures or cracks. All observable boot fasteners were intact and secure. Impact damage prevented functional testing of the aircraft deice systems. The cockpit deice system panel was found intact.
The airframe deice, propeller deice, pilot heat 1 and 2, and stall warning heater switches were found in the “ON” positions. The ice inspection light, the left and right windshield deice, and the inertial separator switches were found in the “OFF” positions.
Examination of the carry-through structure, where the wings were attached to the fuselage, exhibited twisting and bending distortion at the right wing attachment points in the up and aft direction. The carry-through structure was fragmented. All fracture surfaces exhibited overload signatures. No evidence of preexisting cracks or fatigue was observed.
Examination of the outboard section of the right wing determined that the wingtip, aileron and spoiler remained attached. Examination of the aileron attachment and actuator hardware revealed no evidence of stop-to-stop damage.
During the examination of the airframe structure, the outboard section of the right wing was manually positioned, or “mated,” with the leading edge of the right-hand horizontal stabilizer to explore the possibility of inflight contact. The examination revealed that deformation on the leading edge of the right wing was consistent with an inflight contact with the leading edge of the right-hand horizontal stabilizer. Also, impact signatures and damage observed on the right wing leading edge were consistent with an inflight collision with the right side of the rudder.
The engine displayed contact signatures at the compressor first stage and shroud, compressor turbine, compressor turbine shroud, first-stage power turbine vane ring, first-stage power turbine, first-stage power turbine shroud, second-stage power turbine vane ring, second-stage power turbine and second-stage power turbine shroud. The engine housing exhibited severe radial deformation around the right-hand circumference, resulting in circumferential impact fractures of the compressor turbine blades and the first- and second-stage power turbine blades.
The examination of the propeller revealed that three of the propeller blades remained attached to the propeller hub and a fourth blade separated into two sections. The blades exhibited twisting, chord-wise scratching, “s” bending and blade-tip separations.
In short, said the investigators, the examination of the airframe and engine revealed no evidence of a pre-accident mechanical malfunction or anomaly.