BERLIN, NJ, USA
N9418
Yakovlev YAK-18T
The airplane was on a demonstration flight with a prospective buyer in the left front seat & the co-owners in the right front & a rear seat. A witness said the airplane was above the airport when a puff of white smoke came from the exhaust, & the engine lost power. The gear was extended, & the pilot(s) entered a left turn to circle & descend for a forced landing at the airport. The left seat pilot said the right seat pilot abandoned the controls, saying 'You have it.' He also said that before entering an uncontrolled descent, the right seat pilot yelled, 'We're not going to make it,' then he grabbed the controls, yanked back, and the airplane half snap rolled & dove into trees. However, a ground witness said the airplane descended until it impacted a tree, while still in a left spiral. Exam of the engine revealed 3 broken connecting rods & a shattered #5 piston. The piston had failed in compression & showed polished edges & distress associated with hydraulic lock. Operating instructions required that spark plugs & drain plugs be removed from the #4, #5, & #6 cylinders before turning the propeller to prevent hydraulic lock (if parked more than 3 days). A witness said the owners started the radial engine every couple of weeks without removing anything from the engine. A factory trained engine technician said there was evidence '...the engine was started without the operator having first checked for the presence of oil in the lower cylinders as is described in the aircraft operating instructions.'
HISTORY OF FLIGHT On October 27, 1996, at 1410 eastern standard time, a Yakovlev YAK-18T single-engine airplane, N9418T, was destroyed when it collided with trees during a forced landing near the Camden County Airport (19N) in Berlin, New Jersey. The certificated airline transport pilot received serious injuries. The copilot/owner and the passenger/owner each sustained fatal injuries. Visual meteorological conditions prevailed and no flight plan was filed for the local flight conducted under 14 CFR Part 91. The flight originated at 19N approximately 1400. In a telephone interview, the pilot reported that this was a demonstration flight prior to his purchasing the airplane. He said the owners performed the pre-flight inspection while he performed the pre-purchase inspection. The pilot stated that the owner/copilot checked the engine oil. After the preflight, they performed a 10 minute engine run, inspected the airplane for leaks, and taxied the airplane the length of the field for a fuel purchase of 43.5 gallons which filled the tanks. In the NTSB Form 6120.1/2, the pilot stated that he asked the owner /copilot to perform the takeoff and to circle above the field while he performed operational checks on the various systems and radios on board the airplane. The pilot reported that the airplane climbed to 2000 feet and accelerated to cruise speed. He said: "Aircraft ran normally for 2-5 minutes ... After approximately 2-5 minutes circling the field , the propeller began to wander off the governed speed. After approximately 10 seconds a loud 'Bang' was noted from the engine compartment and power was totally lost. The [copilot] immediately appeared confused and frightened, and abandoned the flight controls saying 'You have it'. Airspeed was maintained at best rate of glide, and the control forces were trimmed away." The pilot stated that he declared an emergency and advised an aircraft preparing for takeoff to clear the runway. The pilot reported: "I lowered the landing gear, as I desired to have some additional drag extended which I might retract should I misjudge the approach and need to stretch the final glide. Flaps were left retracted. Approximately two turns were made above the airport until I was in a good position to make a landing. I entered the base/final turn, quite high but as required for the high sink rate of this aircraft design, and believed that I had the runway made. As I entered the final turn the [copilot] yelled loudly 'We're not going to make it' and grabbed his set of flight controls and sharply yanked the control yoke to the rearmost position. The aircraft immediately performed a half snap roll to the left, and dove inverted into the trees." Witnesses reported that during the take off roll on runway 23 the engine was "...popping [and] missing." The witnesses reported seeing the cargo door open as the airplane climbed above the airport in left climbing turns. One witness reported: "The Yak continued to climb while making a wide left turn and came across the [approach] end of runway 23 at [approximately] 1200 to 1500 feet and made a left turn to parallel runway 5. At that time a puff of white smoke came from the exhaust, the landing gear immediately dropped and the Yak started a left turn toward the airport. I could see the prop windmilling and I was concerned because the gear was down and that would create drag but I was still confident that they would make a successful landing on runway 23. As the Yak circled back across the airport and did not enter downwind for runway 23 I knew they were going to crash and not make the airport. The Yak 18 continued in the left hand spiral back again across the airport ... rapidly descending and impacting the trees still in a left hand spiral." The accident occurred during the hours of daylight, about 39 degrees, 46 minutes north latitude and 74 degrees, 56 minutes west longitude. PERSONNEL INFORMATION The pilot held an Airline Transport certificate with ratings for airplane single and multi-engine land. The pilot also held a Flight Instructor certificate with ratings for airplane single and multi-engine/CFI and instrument airplane/CFI. His most recent Federal Aviation Administration (FAA) First Class Medical Certificate was issued on August 5, 1996. The pilot reported 8000 hours of total flight time with 4050 hours of flight instructor experience. He reported approximately 500 hours in the Yakovlev Model 52, two-thirds of which is flight instructor time, and no experience in the Yakovlev Model 18T. SECOND PERSONNEL INFORMATION The copilot held a private pilot certificate with ratings for airplane single and multi-engine land. A review of the copilot's logbook shows a total fight time of 1102.8 hours of which 1.5 hours were in the Yakovlev Model 18T. METEOROLOGICAL INFORMATION A weather observation taken at the North Philadelphia Airport (PNE), 18 miles to the north of 19N, at 1345 EDT reported: measured ceiling 5000 broken, 7000 overcast, winds variable at 6 knots with 10 statute miles of visibility. The temperature was 67 degrees, dewpoint was 53 degrees. Altimeter setting was 30.25" hg. WRECKAGE The airplane wreckage was examined at the accident site on October 28, 1996. The examination revealed that all major components were accounted for at the scene. The distance from the first broken tree to the wreckage was approximately108 feet. The trunk broke at a point approximately 40 feet above the ground and the corresponding tree top was laying along the scatter path oriented 360 degrees. The broken tree top was approximately 45 feet long. The broken end of the tree top was approximately 85 feet from the base of the tree, with the top branches laying over and beyond the fuselage approximately 130 feet from the tree base. The main fuselage came to rest inverted and nose-down, roughly 45 degrees past vertical. There was no odor of fuel nor evidence of fire. The fuselage displayed a concave dent that ran the length of the roofline. The five-piece windshield/greenhouse assembly was destroyed and the windshield posts were separated from the fuselage at the top of the instrument panel. The left control yoke was broken off of the control column and the right yoke was bent towards the power control quadrant. The control column instrument panel thru bearings on the left and right sides were both broken towards the top of the instrument panel. The cockpit floor in the vicinity of the rudder pedals on both the pilot's and copilot's side was compressed into the cockpit area. The left wing was separated from the fuselage at the wing root and was found 81 feet from the broken tree. The tail section was separated from the fuselage. The vertical fin, rudder, horizontal stabilizers, and elevators were destroyed and wrapped around the broken tree top, connected by control cables. The distance from the base of the first tree to the tail section components was approximately 100 feet. The impact crater was approximately 12 inches deep, three feet in diameter, and located 105 feet down the wreckage path. Control tube and control cable continuity was established from the cockpit to the right wing and to the point of left wing and tail section component separation. The landing gear was found in the extended position. The landing flap was found in the retracted position. Each wooden propeller blade was separated at the hub and the wood splinters that remained in the hub were bent aft. The cowl shutters were crushed aft and wrapped around the face of the radial engine. The engine was forced aft into the firewall on the left side. The engine was transported with the wreckage to Wilmington, Delaware for further examination. AIRCRAFT INFORMATION The YAK-18T was an aircraft of Russian manufacture and was registered with the Federal Aviation Administration as an Experimental Airplane. The aircraft was purchased from the importer, Kolair, Inc., on December 15, 1995. An examination of both the engine and aircraft logs revealed that all entries were made while the airplane was in the possession of the aircraft importer. During the period the airplane was in the possession of the registered owners, neither log book reflected entries for scheduled or unscheduled maintenance nor did they reflect the completion of an inspection due 12/18/95. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies were performed on Mr. Raymond Cella and Mr. Edward Cella by Dr. Robert J. Segal of the Office of the Medical Examiner, Camden County, New Jersey on October 28, 1996. The toxicological testing report from the FAA Toxicology Accident Research Laboratory in Oklahoma City, Oklahoma, for Mr. Ray Cella was negative for drugs and alcohol. TESTS AND RESEARCH An examination of the Vendenyev M-14P nine cylinder radial engine was performed at Dawn Aeronautics in Wilmington, Deleware on November 18, 1996. The examination was conducted by the NTSB IIC, an FAA Aviation Safety Inspector (Airworthiness), an Airframe and Powerplant Mechanic with 4 years experience with the Vendenyev engine and a Vendenyev factory-trained technician. During the disassembly of the engine, very little oil was evident in, on , or around the engine or engine cowlings. The propeller hub spun freely and disassembly of the gear reduction case revealed that the propeller driveshaft had sheared at the thrust bearing. Removal of the #7 cylinder revealed the piston inside with approximately 50% of the #7 connecting rod attached. The remainder of the connecting rod was attached to the crankshaft and appeared to have failed in tension. Further examination revealed the fragments of the #5 piston with approximately 50% of the #5 connecting rod attached which appeared to have failed in compression. The Vendenyev mechanic and the Vendenyev technician each submitted reports describing a failure of the #5 connecting rod due to hydraulic lock. According to the Vendenyev factory trained technician: "At sometime in the past, the engine was started without the operator having first checked for the presence of oil in the lower cylinders as is described in the aircraft operating instructions. (Page 1/2 , para 2.1.3. reproduced below) This caused a partial hydraulic lock in the number 5 cylinder which caused the number 5 connecting rod to bend in such a way that it now came into contact with the cylinder base wall." Subsequently, the "...#5 link rod failed in compression and shear allowing the rod/piston to tangle with the crankshaft floating counter weight. This pulled the piston and rod into the path of #7 piston on its power stroke. That would cause an instant and total engine stoppage. ...The large angular momentum of the speed propeller caused the prop. shaft to fail in torsion thereby disconnecting the prop. from the gearbox and permitting it to freewheel." ADDITIONAL INFORMATION Witnsses reported that the two owners of the airplane had apprehensions about the Yak. One witness said, " [The passenger] was kind of afraid of the airplane." A second witness said the passenger was "...apprehensive about the airplane because of the odd braking system. He was somewhat leery of the airplane because of steering and braking. Once in the air, it was an airplane." A third witness stated, "The passenger was in a fire and his hands were deformed. He didn't feel the Yak was well suited for him because the brakes were air powered. He cut himself on the knobs and levers. He only flew the airplane one time." The third witness said; "...[the owners] ran it up probably every couple of weeks. They'd pull it through several times and then start it. I never saw them take anything off of the airplane. They would pull it through a bunch of times and all of the oil would come out the exhaust." The pilot was the president of Red Star Aviation. He bought, sold, and gave instruction in Yak airplanes. He reported that this was his first flight in the Yak 18 that it "...has the same flight characteristics as the 52." One witness said the pilot was "...explaining to everyone in the office that he had the most experience in Yak airplanes of anyone in the United States." Another witness said, "...he was the authority on Yaks. He knew more about Yaks than anybody in the world." The In-Flight Emergencies section of the Yak 18T flight manual states: "When the forced landing is performed on the aerodrome with the inoperative engine it is necessary during the approach to go into a glide with the retracted LG [landing gear] and plane flap at IAS = 160 - 170km/h. The LG and the plane flap may be extended only when the pilot is quite sure in the correctness of his planned landing maneuvers ... The forced landing off the aerodrome on the unknown (unprepared) landing site can be performed only with the retracted LG. In this case the plane flap may or may not be extended at the pilot's discretion depending on the particular landing conditions." The airplane wreckage was released on November 18, 1996 to Les Sychek, a representative of the owners insurance company.
an inadequate preflight by unknown person(s), sometime before the flight, by failing to avoid a hydraulic lock (from oil seepage) in the #5 cylinder, which resulted in a bent connecting rod, subsequent failure of the #5 piston, and loss of engine power. Also causal was: the flight crew's failure to maintain adequate control of the aircraft and/or clearance from a tree, while maneuvering for an emergency landing.
Source: NTSB Aviation Accident Database
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