PROVO, UT, USA
N600JR
Cessna 320A
The owner and flight instructor were advised by a ramp service agent of a fuel leak coming from the underside of the right engine after starting the left engine. The left engine was shut down and one of the pilots examined the leak and then re-entered the aircraft. The aircraft's left engine was then restarted followed by the right engine, and then the aircraft was taxied out for takeoff. The first takeoff was aborted for undetermined reasons. The aircraft then departed. Approximately 40 minutes later a radio transmission from the aircraft indicated an engine fire. The aircraft was witnessed diving toward the surface of Utah Lake and then skipping over the water before disappearing in a plume of spray. The aircraft crashed approximately two miles northwest of the Provo Municipal airport in 12 feet of water. Postcrash examination revealed an extensive fire in the right engine accessory area and aft into the wing locker area. Metallurgical examination of the right engine exhaust manifold components revealed erosion, oxidization, pitting, cracking and holes in areas of the exhaust tubing.
HISTORY OF FLIGHT On May 15, 1996, approximately 0824 hours mountain daylight time, a Cessna 320A, N600JR, being flown by a certificated flight instructor, accompanied by the owner, a recently multi-engine rated private pilot, was destroyed during collision with water during a descent. The accident site was approximately two miles northwest of the Provo Municipal airport, Provo, Utah, and in Utah Lake. The pilot/owner and flight instructor were both fatally injured. Visual meteorological conditions existed at the time and no flight plan had been filed. The flight, which was reportedly to have been instructional, was to have been operated under 14CFR91, and originated from the Salt Lake City International airport at 0750 hours. A ramp service agent employed by Million Air at the Salt Lake City International airport was interviewed and reported the following circumstances: On the morning of May 15, 1996, he observed N600JR being prepped for flight and stood by to marshal the aircraft as it started up and taxied out. He reported that the left engine was started first and that before the right engine was started he observed fuel "running" out of the right engine cowling (refer to photograph 01). He reported that the fuel was coming from the area between the exhaust pipe shield and the wastegate exhaust dump pipe (refer to photograph 02) and that he motioned for the pilot(s) to shut down and advised them of the condition. He reported that one of the pilots exited the aircraft, looked at the area of the leak and then re-entered the aircraft requesting a fire extinguisher prior to further start attempts. The aircraft was subsequently restarted, left engine first, followed by the right engine. The ramp service agent reported that by the time the aircraft taxied out from its parked location, fuel had pooled on the ramp beneath the right engine and had run into a nearby storm drain (refer to photograph 03). On May 21st, the investigative team was shown the site where the aircraft had been parked on the morning of the accident by the ramp service agent. The team observed a significant, oval area of stained asphalt. The distance between the center of the stain and the west edge of the storm drain was measured to be 55 feet with a slight downhill slope toward the drain. The center of the area displayed degradation and softening of the asphalt with exposed aggregate pebbles. Directly aft of the stained area was an oblate shaped, unstained area consistent with an aircraft tire in contact with the asphalt (refer to photograph 04). A re-recording of communications with N600JR was reviewed by the investigator in charge and related the following events: At 0730, N600JR contacted the Salt Lake City International airport ground control east controller and was instructed to taxi to runway 17. At 0739, N600JR was issued a takeoff clearance on runway 17. At 0740, N600JR advised that he would be clearing (the runway) at taxiway "Kilo seven" (refer to DIAGRAM I) and would be taxiing back to the runup area. At 0745, N600JR requested a change of destination from Tooele to Provo and at 0750, was cleared for takeoff on runway 17. The aircraft was passed off to departure control and the last recorded radio contact was at 0759, when N600JR was instructed to change his transponder to 1200 and advised that radar service was terminated two miles north of "The Point of the Mountain" (approximately 18 nautical miles northwest of the Provo airport). A formal FAA air traffic package was requested but was not provided (refer to ATTACHMENT AT-I). Radar targets believed to be associated with N600JR were recorded by the Salt Lake Air Route Traffic Control Center and showed the aircraft initially at 40 degrees 13.73 minutes north latitude and 111 degrees 48.67 minutes west longitude at 0807:26 hours, and finally at 40 degrees 14.35 minutes north latitude and 111 degrees 49.50 minutes west longitude at 0822:35. A mode "C" altitude readout was received for the last 22 radar hits and showed a relatively consistent -2400 foot per minute rate of descent during the last seven radar targets (last 60 seconds previous to the 0807:35 target). The assistant airport manager at Provo was interviewed and reported hearing a radio call on Unicom whereby a pilot identified his aircraft as 600JR and reported an engine fire (refer to Communications Information below). There were two known witnesses to the accident. The first witness described seeing the aircraft from a distance of 2.5 to 3 miles (refer to attached statement and map) and diving at "about a 70 degree angle." A second witness, who was interviewed but provided no written statement and was located at a campground between the northern boundary of the Provo airport and the boat harbor (refer to CHART I), reported hearing what she thought was a jetski and observed the aircraft wings level and impacting the lake's surface, then skipping several time before disappearing in a large plume of spray. She reported that her view of the aircraft was sideways and that the aircraft was traveling relatively flat above the surface of the lake. She also reported that she thought she saw flames and smoke coming from the aircraft but wasn't certain. She described the impact with the water as "like a loud slap." PERSONNEL INFORMATION First Pilot Information The 32 year old first pilot held both a commercial and flight instructor's (CFI) certificate. His CFI certificate included both single and multi-engine ratings as well airplane instrument. The first pilot's flight time was acquired from a personal flight log opened on December 22, 1994, with 181.5 hours of total flight time carried forward (all single-engine). The log's last entry was recorded May 14, 1996, and the log's tally showed a total of 1253.1 hours of flight time, of which 1197.9 hours were pilot in command, 302.1 hours where instructor, and 201.8 hours were multi-engine. The first pilot's log showed four flights in the Cessna 320A (all in N660JR) during which he logged a total of 4.2 hours (all pilot in command). Second Pilot Information The 29 year old second pilot and owner of the aircraft, held a commercial pilot's certificate. According to records maintained by the FAA, he acquired a multi-engine rating on March 21, 1996. His total flight time, as of his most recent medical, dated October 4, 1994, was 275 hours. The first pilot's logbook showed two logged flight references to the second pilot. Both were remarked as "safety pilot (for the second pilot) and both were conducted in N600JR on 04/30/96 and 05/08/96 respectively. There were no other references to the second pilot noted within the first pilot's logbook. It was not possible to accurately establish which pilot, the owner or the CFI, served as pilot-in-command (PIC) of the accident flight. For the purposes of data retrieval and report consistency, the CFI was designated as the first pilot and the owner as the second pilot. AIRCRAFT INFORMATION According to documentation (the pink copy of FAA Form 8050-1), the aircraft, a 1963 Cessna 320A, was purchased by the owner on April 24, 1996, and flown from Cincinnati, Ohio, to Salt Lake City. The aircraft's most recent airframe logbook showed the aircraft having undergone an annual inspection on November 1, 1994, at a total time of 4432.1 hours. The logbooks showed another annual inspection conducted November 15, 1995, at a total time of 4471.1 hours. The final entry within the logbook showed the aircraft having undergone another annual inspection on April 13, 1996, at a total of 4472.1 hours. All three of these annuals were signed off by the same mechanic, who possessed an IA (inspection authorization). Additionally, an Airworthiness Directive (AD) signoff listing for the aircraft showed that both AD 72-14-08R1 (refer to ATTACHMENT AD-I) and 75-23-08R5C (refer to ATTACHMENT AD-II) had been complied with during the inspection conducted at 4,432.1 hours (November 15, 1994 annual inspection). According to documentation maintained by Keystone Aviation at the Salt Lake City International airport, the aircraft was turned over to their facility for corrective maintenance. A series of four discrepancy action cards were compiled on the aircraft (refer to ATTACHMENT DAC-I). The cards, which were dated 04/25/96, 05/02/96, 05/03/96, and 05/07/96, showed a total of 29 discrepancies on the aircraft, of which at least 13 items remained uncorrected following the 15th of May. None of these discrepancies had been entered in the aircraft's logbooks. The CFI's logbook showed four entries involving N600JR which totaled 4.2* hours as follows: date: from/to: flight time: remarks: 04/30/96 SLC-PVU 1.0 (PIC) flight w/ owner (safety pilot) 05/01/96 PVU-SLC 0.7 (PIC) ferry flight for owner 05/08/96 SLC-TVY-SLC 1.5 (PIC) flight w/ owner (safety pilot) 05/09/96 SLC-TVY-SLC 1.0 (PIC) aircraft into w/ private pilot 4.2 hours total in make/model *This would bring the aircraft's total airframe time to at least 4476.3 hours prior to the accident. The private pilot who flew with the CFI on 05/09/96 was telephonically interviewed and reported that the purpose of the flight was to climb up to 10,500 feet and record engine manifold pressures at different altitudes and temperatures. He reported that the aircraft's left engine was started first and there were no difficulties starting either engine. He also reported recalling that at 10,500 feet and an outside air temperature of 35 degrees a split of 5 inches of manifold pressure existed between the left and right engines at cruise (left: 31 inches & right: 26 inches). The flight terminated at Salt Lake City shortly thereafter. He recalled no odor of fuel during the flight. COMMUNICATIONS INFORMATION The Provo Municipal airport is equipped with a voice activated recording system on its UNICOM frequency (122.80 mega hertz). No time marker is associated with the recording and the recording unit only records whenever it receives a radio transmission, thus the timing of the recording during playback is not time linear. The tape was reviewed during which a radio transmission was recorded as follows: "Provo traffic, six hundred juliet romeo, fire (on) in the engine, fire in the engine." No further communications were received. WRECKAGE AND IMPACT INFORMATION The aircraft crashed into Utah Lake and sank in approximately 12 feet of water. The recovery site was located approximately 12,500 feet northwest of the threshold of runway 13 at the Provo Municipal airport. The elevation of the surface of the lake was approximately 4,485 feet above sea level. The latitude and longitude of the recovery site was 40 degrees 14.46 minutes north and 111 degrees 45.97 minutes west (refer to CHART I). The wreckage scatter covered several thousand feet of the lakebed surface, however, the majority of the aircraft, excluding the left wing outboard of the engine nacelle, was recovered in a small area. The aircraft wreckage was recovered, excluding the outboard left wing, and was transported to the Spanish Fork airport and reassembled in a hangar (refer to photographs 05 through 07). Post crash examination of the single propeller blade recovered separate from the left engine revealed prominent "S" bending deformation (refer to photograph 08). The left turbocharger was recovered and examined and its impeller was observed to display consistent bending deformation of the blades opposite to the direction of rotation (refer to photograph 09). The left propeller governor, which remained attached to its engine, was observed in the "full forward" position. Both propeller blades from the right engine were recovered still attached to the engine crankshaft. One blade was observed to have minimal bending deformation and was oriented in the "feather" position (refer to photograph 10) whereas the opposing blade displayed a smooth aft bending deformation of approximately 70 degrees at a point roughly two-thirds out from the hub (refer to photograph 11). The right turbocharger was recovered and examined and its impeller was observed to be free of any bending deformation of the blades (refer to photograph 12). The control lever of the right propeller governor, which remained attached to its engine, was observed in the "full aft" position. Fuel and oil lines in the accessory sections of both engines were observed to be brittle and worn and there was fire damage to lines in the right engine aft accessory section. During the recovery operation the majority of the right wing including the right main landing gear, and excluding the right engine and wing root area was recovered. During the recovery process extensive fire damage was observed within the right wing locker and trailing edge area (refer to photographs 13). The right main landing gear assembly was observed to be sooted and charred consistent with the aircraft right gear being retracted during the fire (refer to photograph 14). Additionally, spatters of melted aluminum were noted on the leading edge de-ice boot of the right horizontal stabilizer (refer to photograph 15) and soot streaking was observed from the stabilizer's leading edge and aft along the underside of the stabilizer (refer to photograph 16). All but the forward outboard (right) section of the right engine exhaust manifold assembly was recovered (refer to photograph 17). Several separation surfaces displayed oxidation, jagged edges, cracking and wearing (refer to photograph 18). MEDICAL AND PATHOLOGICAL INFORMATION Post mortem examination of both occupants was conducted by Maureen J. Frikke, M.D., and Jennifer J. Rulon, M.D., at the Utah Office of the Medical Examiner, 48 N. Medical Drive, Salt Lake City, Utah, 84113, on May 16th and 20th, 1996 (reference Autopsy case numbers 96-0570 and 96-0571). Toxicological examination was not accomplished. TESTS AND RESEARCH The recovered portions of the right engine exhaust manifold assembly (photograph 15) were shipped to the NTSB's Materials Laboratory for metallurgical examination. The exhaust assembly was broken into four sections by separations between LEFT BANK BELLOWS 1) the left bank (inboard forward (#6) and middle (#4) cylinder) exhaust ducts and bellows and, the bellows connecting the left bank (inboard aft (#2) cylinder) exhaust and inboard manifold, and INBOARD MANIFOLD 2) the bellows connecting the left bank (inboard aft (#2) cylinder) exhaust and inboard manifold, and 3) the flange connecting the aft manifold (turbo charger attach bracket) and aft right bellows, and RIGHT BELLOWS 3) the flange connecting the aft manifold (turbo charger attach bracket) and aft right bellows, and 4) the forward portion of the right bellows (refer to Metallurgist's Factual Report, Figure 2) LEFT BANK BELLOWS Examination of the separation surfaces revealed several small areas of clean and shiny tensile shear overstress fracture. The majority of the fracture faces were darkly discolored and many areas along the separation fracture edges appeared to have been thinned, in some instances to a knife edge. The interior surface of the bellows displayed many deep pits as well as small perforations and cracks. Energy dispersive x-ray spectra from the fracture surface was consistent with an oxidized 300 series stainless steel. INBOARD MANIFOLD Examination of the separation surfaces revealed oxidization and light brown surface deposits as well as thick, high temperature scale and oxidation on the exterior and interior surfaces. In many areas in the interior of the manifold, the scale was cracked and flaked off leaving deeply pitted surfaces. Energy dispersive x-ray spectra from the fracture surface was consistent with an oxidized 300 series stainless steel. RIGHT BELLOWS Examination of the bellows revealed a large number of small holes at the fracture and in the surrounding area. In some localized areas the holes accounted for more than 50%
A fuel leak most probably ignited by hot exhaust gases from the leaking right engine manifold exhaust system, the decision by the pilots to operate the aircraft with knowledge of the fuel leak, and the pilot-in-command's failure to maintain adequate clearance with the lake surface.
Source: NTSB Aviation Accident Database
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