California

The aircraft collided with trees and mountainous terrain about 9,500 feet msl. The wreckage was spread across the lee side of a mountain, in a grassy meadow surrounded by high mountainous terrain on all sides. The area, about 100 feet in front of the aircraft, was a rocky embankment which sloped upward approximately 30 degrees. About 100 feet from the tail of the aircraft, the terrain dropped off into a steep cliff, which sloped down about 65 degrees. At the base of the cliff was a valley, which was about 1/4 mile wide. The farthest piece of debris was found 410 feet away from the main wreckage site in a grove of trees. Fifteen tree disturbances were noted in the grove. The first disturbance began near the tops of the trees and continued in a descending path. Much of the airframe exhibited semicircular impressions consistent with the trunk diameters of the disturbed trees at the accident site. Organic material transfer was evident in the impressions. An analysis of the meteorological data showed that a clear or scattered cloud condition was likely in the accident area, and visibility was probably unrestricted. It also showed that an extended north-northwestward/south-southeastward cloud band was located over the Sierra Nevada Mountains about 9 to 10 miles southwest through west of the accident location around the time of the accident. The analysis estimated that the winds aloft at 10,000 to 12,000 feet msl in the mountains were from approximately 270 degrees at 40 to 45 knots. Further, moderate or greater turbulence and strong updrafts and downdrafts were reported along the pilot's route of flight. No mechanical discrepancies were found with the airframe or either engine during the postaccident examination.

After touching down to scoop another load of water, the pilot added power and the aircraft pitched forward. The pilot heard a pop and felt a sudden decelerative force. When the nose began to bowsuck, he applied more back pressure but the aircraft did not respond. The floor split open and water began rushing into the cockpit. The left nose gear door locking pin was found separated from its hydraulic actuator. It displayed a bend that corresponded to its retracted position in the pin guide. The deformation prevented investigators from reinserting the damaged pin back through the guide. The left mycarta block remained attached to the door and did not exhibit any damage.

The aircraft concluded an aerial survey and landed at Brown Field to clear U.S. Customs. On restart, as the left engine began running, a witness noticed two short, yellow flame bursts exit the exhaust. During taxi, the witness heard a popping sound coming from the aircraft. As power was applied to cross runway 26L, the sound went away. The aircraft stopped for a few seconds prior to pulling onto the runway; the witness did not observe or hear a run-up. Witnesses reported hearing a series of popping sounds similar to automatic gunfire and observed the aircraft between 600 and 1,000 feet above the ground with wings level and the landing gear up. The aircraft was observed to make an abrupt, 45-degree banked, left turn as the nose dipped down. Witnesses reported the nose of the aircraft then raised up toward the horizon. This was followed by the aircraft turning to the left and becoming inverted in an estimated 30-degree nose low attitude. With the nose still low, the aircraft continued around to an upright position and appeared to be in a shallow right bank. Witnesses then lost sight of the aircraft due to buildings and terrain. A May 20, 1997, work order indicated the left manifold pressure fluctuated in flight. Both wastegates were lubricated and a test flight revealed the left engine manifold pressure lagged behind the right engine manifold pressure. On June 18, 1997, the left engine differential pressure controller was noted to have been removed and replaced. This was the corrective action for a discrepancy write up that the left engine manifold pressure fluctuated up and down 2 inHg and the rpm varied by 100 in cruise. A test flight that afternoon by the accident pilot indicated the discrepancy still occurred at cruise power settings, but the engine operated normally at high and low power settings. Post accident functional checks were performed on various components. No discrepancies were noted for the left governor. The left engine differential pressure controller was damaged and results varied on each test. The left density controller was too damaged to test. The right engine density and differential pressure controllers tested satisfactory. The left and right fuel pumps operated within specifications. Both fuel servos were damaged. One injection nozzle on the left engine was partially plugged; all others flow tested within specifications.

Shortly after takeoff, the pilot radioed the air traffic control tower declaring an emergency and stating his intent to return for landing. He stated that he had taken off with an external boarding ladder attached to the aircraft. Several witnesses reported that the aircraft's downwind leg was too close to the airport causing the aircraft to overshoot the turn to the final approach course, and that the pilot increased the aircraft's bank angle as he tried to align the aircraft with the landing runway. As the aircraft was intercepting the final approach course, it abruptly rolled inverted, the nose dropped, and the aircraft spiraled onto the roof of an industrial building. A Boeing 757 aircraft, landing on the same runway, had passed over the accident site 2 minutes and 17 seconds earlier. The B-757 was cleared to land before the accident aircraft received a takeoff clearance and was on the runway when the pilot declared the emergency and turned downwind. The local controller did not issue a wake turbulence advisory. Experienced MS760 pilots reported that the aircraft will exhibit no adverse performance or safety affects with the boarding ladder attached.

Recorded radar data showed the aircraft was flying in an area of mountainous terrain. Mountain tops in the area were reported to be obscured. Radar data showed that the aircraft first descended to a low altitude as it flew up a valley, then it climbed until impacting rising terrain about 7,200 feet msl. Wreckage was scattered over 300 feet up the mountain slope. About 32 miles southwest at Bakersfield (elevation 507 feet), the 1000 pdt weather was in part: 4500 feet scattered, 6000 feet overcase, visibility 20 miles, wind from 260 degrees at 10 knots. Nearby residents reported that the mountain was obscured in clouds at the time of the accident. During postmortem toxicology tests, a low level of ethanol (23 mg/dl) was detected in muscle fluid specimen, probably from post-mortem production. No ethanol was detected in brain fluid.

The aircraft was destroyed after an uncontrolled descent into the Pacific ocean about 14 miles west-southwest of El Segundo, California. The pilot was presumed to have been fatally injured. According to a company search pilot, visual meteorological conditions prevailed at the accident area about 1.5 hours after the time of the accident. No flight plan was filed for the positioning flight which originated at Oxnard, California, on the morning of the accident for a flight to San Diego, California. The aircraft departed Oxnard on a special VFR clearance. The tops of the clouds were reported to be about 1,200 feet msl. The aircraft transitioned southbound through the NAWS Point Mugu airspace. The Point Mugu radar approach control monitored the aircraft on radar for about 25 miles. The pilot was subsequently given a frequency change to SOCAL Tracon. There was no contact made with that facility. A search was initiated when the aircraft failed to arrive at the intended destination. A review of the recorded radar data revealed the aircraft was level at 1,800 feet msl and then climbed to about 2,000 feet msl, at which time it disappeared from radar.

The aircraft impacted mountainous terrain in controlled flight during hours of darkness and marginal VFR conditions. The flight was being vectored for an instrument approach during the pilot's 14 CFR Part 135 instrument competency check flight. The flight was instructed by approach control to maintain VFR conditions, and was assigned a heading and altitude to fly which caused the aircraft to fly into another airspace sector below the minimum vectoring altitude (MVA). FAA Order 7110.65, Section 5-6-1, requires that if a VFR aircraft is assigned both a heading and altitude simultaneously, the altitude must be at or above the MVA. The controller did not issue a safety alert, and in an interview, said he was not concerned when the flight approached an area of higher minimum vectoring altitudes (MVA's) because the flight was VFR and 'pilots fly VFR below the MVA every day.' At the time of the accident, the controller was working six arrival sectors and experienced a surge of arriving aircraft. The approach control facility supervisor was monitoring the controller and did not detect and correct the vector below the MVA.

The pilot departed his home base in VFR conditions without filing a flight plan and did not request or receive a preflight or en route weather briefing from the FAA. While en route, he contacted Southern California TRACON (SOCAL) and requested an ILS runway 26 approach to the destination airport. SOCAL cleared the pilot for the approach and to change to an advisory frequency. There was no current weather report available at the airport because the tower was closed, but another pilot who was on the same frequency stated that the airport weather was 'zero zero.' (An automated weather observation system at the airport recorded 'zero zero' conditions near the time of the accident.) Ground witnesses heard the airplane as the pilot began a missed approach. However, the airplane collided with trees and a snack bar building about 1/4 mile northwest of the departure end of the runway. Impact occurred as the airplane was in a right turn through a heading of 345 degrees, which was the opposite direction of turn for the missed approach procedure. Toxicology test of the pilot's blood showed 1.518 mcg/ml Fenfluramine and 0.678 mcg/ml Phentermine; these are appetite suppressant drugs that are chemically related to amphetamines and have a high incidence of abuse. Neither of these drugs was approved by the FAA for use while flying aircraft. The amount of Fenfluramine in the pilot's blood was above a normal level for control of appetite.