DESCANSO, CA, USA
N5343M
Cessna 152
The purpose of the flight was to conduct the cross-country portion of the student's flight training to obtain a private pilot certificate. A coastal mountain range bisected the course between the takeoff airport, which was under the influence of cloud layers, and the destination airport, which was in clear weather conditions. Both the certified flight instructor (CFI) and student received three separate weather briefings stating that visual flight rules flight was not recommended along the intended route of flight due to mountain obscuration and moderate turbulence. As the flight proceeded into mountainous terrain, the flight encountered clouds that were merging with higher terrain and the CFI elected to turn around. The CFI said that half way through the 180-degree turn, they were struck by a strong downdraft that pushed the aircraft into the ground. A witness to the accident stated that he saw the airplane at 150 feet above ground level as it came out of the clouds executing a left turn, and then saw it abruptly descend and impact trees and terrain. The witness also said that there were strong gusty wind conditions present at the accident site. No discrepancies were found during an examination of the engine or airframe. A meteorological study was conducted that substantiated the National Weather Service forecast in effect at the time of the accident.
On June 7, 1998, at 1450 hours Pacific daylight time, a Cessna 152, N5343M, impacted mountainous terrain while maneuvering to avoid weather near Descanso, California. The aircraft, operated by the student pilot as an instructional flight under 14 CFR Part 91, was subsequently destroyed by a postimpact fire. The certified flight instructor (CFI) and student pilot received serious injuries. Visual meteorological conditions existed for the dual instruction cross-country flight and a visual flight rules (VFR) flight plan was filed. The flight originated from Montgomery Field, San Diego, California, at 1400 and was en route to Imperial, California. At the time of the accident reported ceilings at Gillespie Field, San Diego, approximately 9 nautical miles (nm) from the departure airport, were broken at 5,000 and at 8,000 feet, with 25 statute miles visibility. The CFI stated that after passing a casino located along Interstate 8 (I-8) it became apparent that they would be unable to continue the flight to their destination due to clouds which were obscuring the higher terrain. He elected to turn around and stated that halfway through a 180-degree turn they encountered a "very strong downdraft." The CFI stated that he leveled the wings and used full power to establish the best rate of climb airspeed, but the "strength of the vertical gust far exceeded the 152's climb ability." He stated that they were forced down in rough uneven terrain in a wings level attitude. In an interview with a Federal Aviation Administration (FAA) inspector, the student pilot reported that he and his instructor had both received weather briefings from the San Diego flight service station. According to the student pilot, the briefer reported forecast conditions of severe turbulence below 14,000 feet, with mountain obscuration, and ended the briefing with the phrase that VFR was not recommended. The student pilot reported that he did not note any discrepancies with the engine during the flight or accident sequence. The student pilot stated that at 4,000 feet above ground level (agl) they encountered clouds. The flight instructor took over the airplane controls and initiated a 180-degree turn to avoid the clouds. They lost altitude rapidly, approximately 200 feet in the turn, and the stall warning horn was sounding when the airplane collided with trees. The audiotape of the weather briefings provided by the San Diego Automated Flight Service Station (AFSS) were reviewed by an investigator from the Safety Board and a summary is appended to this file. A total of two standard weather briefings and one update briefing were given to the CFI and the student pilot on the day of the accident. The first contact occurred with the AFSS's preflight 7 position between 0810 and 0826. The second briefing was given between 0821 and 0835 by the specialists at the preflight 11 position. The final contact occurred with the preflight 1 position between 0951 and 1006. In summary, the CFI and student were advised of Airmets in existence for mountain obscuration and occasional moderate turbulence below 14,000 feet mean sea level (msl) with forecast cloud tops at 7,000 feet msl. One briefer stated that VFR flight below the clouds was not recommended due to mountain obscuration. Another briefer asked the student pilot whether this was a solo cross-country flight and if there would be an instructor on board because VFR solo flight into this area was not recommended. The third briefer stated that the student might want to adjust his departure time because VFR was not recommended due to mountain obscuration. At the end of this briefing the student pilot stated "I think we may decide to go another day." An eyewitness on the ground saw the aircraft turning left as it came out of the clouds at 150 feet agl, and then go down. The witness further noted that the winds at the time were gusty and strong. A representative from the Cessna Aircraft Company, a party to the investigation, inspected the aircraft on-scene under the supervision of the FAA. The representative established flight control continuity from the control surfaces to the cabin. He further reported that the empennage had separated from the aircraft during the postimpact fire, sustaining minimal damage. No discrepancies were noted with the airframe. The representative further stated that the propeller had separated from the engine and "exhibited torsional twisting." According to a weather study conducted by a Safety Board meteorologist, a cloud layer was present along the route of flight on the western side of the interior mountains near Descanso, and at the accident location. On the eastern side of the interior mountains, the flights' intended destination, skies were clear. The meteorologist further reported that the National Weather Service forecast was substantiated with the meteorological observation at the time of the accident.
the certified flight instructor's disregard of the weather briefings and forecasted en route weather conditions, and, his failure to maintain adequate altitude/clearance in mountainous terrain. Contributing to the accident were instrument meteorological conditions and mountainous terrain.
Source: NTSB Aviation Accident Database
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