NTSB Factual Report

HISTORY OF FLIGHT

On January 21, 1996, at 1615 hours Pacific standard time, a Cessna T-210N, N6452N, experienced an in-flight separation of the right wing and collided with terrain near Gorman, California. The aircraft was destroyed and the instrument rated private pilot and one passenger were fatally injured. The aircraft departed from Calexico, California, about 1330 and was en route to Oakdale, California. Weather at the accident site was not reported; however, law enforcement personnel reported that at the time there was rain mixed with snow, the mountains were obscured in clouds, and the winds were westerly about 30 knots. No flight plan was filed.

A co-owner of the aircraft told the NTSB investigator that the pilot and passenger departed from Oakdale on January 15, 1996, for a week long vacation trip to Mexico. On the morning of the accident the flight departed Guaymas, Sonora, Mexico, en route home and landed to clear customs at Mexicali, Sonora, Mexico, and Calexico, California.

A witness who was about 1 mile south of the accident location, reported that his attention was attracted to the aircraft by the sound of the engine "laboring". When he first saw the aircraft, "very high," it was in a "hazy" area below the clouds in a 45-degree nose down attitude. In the following seconds the nose dropped to vertical (nose down), the engine "whined loudly," and the aircraft spun straight down until impact. The witness noted that one wing was missing as the aircraft spun. Based upon knowledge of his local elevation and the height of nearby mountains, he believed the aircraft was at 8,000 to 9,000 feet msl when he first saw it.

Another witness at the same location reported that he heard a very high engine pitch, which he compared to that of a model airplane engine, and looked up to the north toward the Tehachapi mountains. He saw the aircraft come straight down out of the clouds in a spin which continued to impact. This witness estimated the cloud bases to be 3,000 to 4,000 feet agl [6,500 to 7,000 feet msl], and the time from when the aircraft came out of the clouds until impact to be about 5 seconds. He characterized the clouds to the north as "heavy and dark". He did not make an observation about the wing.

A third witness at the same location reported that he noticed the aircraft initially because it "came out of nowhere quickly". He looked northward and into "dense, snowy, sleety weather" and didn't see anything. He next heard a "thump" as though the airplane hit something but the engine kept going. He first saw the aircraft when it came out of the clouds 1 mile north of his position going straight down, spiraling slowly, and "clearly missing one wing".

On March 27, 1996, the NTSB investigator and parties to the investigation viewed a playback of CDR (continuous data recording) radar data at High Desert TRACON, an FAA facility located at Edwards Air Force Base, California. There was no communication or radar service provided to the aircraft by the TRACON, however, the flight path data of all aircraft transiting TRACON airspace is routinely recorded.

The radar displayed an area of light weather returns along a northwest-southeast line passing over Palmdale VORTAC. The accident aircraft was first visible on radar over the central Los Angeles metropolitan area on the Los Angeles VORTAC 067 degree radial at 21 nautical miles. The aircraft tracked 310 degrees passing approximately 7 miles east of the Burbank Airport (at 1540 hours) and 2 miles west of the Lake Hughes VORTAC. The radar data block was displaying a VFR code for the aircraft and no altitude information was displayed. Personnel at High Desert TRACON stated that had the aircraft's transponder mode C feature been operational and turned on by the pilot, an altitude would have been displayed.

Abeam the Lake Hughes VORTAC, the aircraft's VFR transponder return ended and the aircraft was tracked for the remainder of the flight as a primary return. At the same time that the transponder (secondary) target ended the distance between subsequent radar returns decreased. When 9 miles northwest of Lake Hughes VORTAC the aircraft entered a left hand spiral. The spiral continued through four complete turns while translating to the north until the flight path abruptly turned right and the target disappeared from the scope near the accident site. Over the ensuing 3 minutes a group of about five primary returns was visible drifting east-northeast from the point where the change in the flight path had been observed. This family of returns disappeared within about 3 miles from the accident location.

PERSONNEL INFORMATION

The private pilot, a businessman (farmer), received his private pilot license with airplane ratings for single engine land and instrument on March 26, 1980. The pilot's logbook was not located after the accident and the pilot's partner told the NTSB investigator that the pilot usually carried his logbook with him in the aircraft. On his medical application dated December 3, 1993, he reported a total pilot time of 1,985 hours, and on his medical application dated December 28, 1995, he listed total pilot time of 1,920 hours with 53 hours flown in the past 6 months. In an aircraft insurance application submitted after October 11, 1995, the pilot reported total flying time of 2,027 hours with 28 hours flown in the previous 90 days. On the same application he listed 207 hours in type and 512 hours in retractable gear aircraft. His last biennial flight review was conducted December 31, 1994, and his third-class airman medical certificate was issued December 28, 1995, without limitations.

The same co-owner provided the NTSB investigator partnership billing records indicating that the pilot flew the aircraft 16.9 hours in the period between August 30 and November 12, 1995. Billing records after November 12, 1995, were believed to have been aboard the aircraft; however, the co-owner could recall 4 trips that the pilot took after November 12th in the aircraft totaling approximately 25 hours and including the trip to Mexico.

A friend of the pilot, who is also a businessman/farmer and owns a Cessna 210, told the NTSB investigator that he and the pilot had flown together in each other's aircraft. The friend is an instrument rated private pilot with 4,000 hours flying experience. Some of their trips were for business or pleasure, and other times they flew safety (observer) pilot while they took turns flying under the hood. He doesn't know if the pilot was current under FAR 61.57(e) for instrument flight. The friend said that the pilot was a good instrument pilot who flew the aircraft well by reference to the instruments. He commented, however, that the pilot would "push the limits" with weather and "went into weather I wouldn't." He added that the pilot would "come home in weather where I'd leave my plane and rent a car."

AIRCRAFT INFORMATION

The 1978 Cessna T-210N had accumulated a total flying time of approximately 2,530 hours. The last major maintenance performed on the aircraft was an annual inspection on August 3, 1995, at 2,459 hours.

According to the pilot's partner, it was equipped with Cessna 400 NAV/COM's (2), ADF, DME, LORAN and a transponder with altitude encoding. The number one NAV/COM was connected to an HSI and number two to a conventional VOR/ILS CDI with glideslope. The aircraft was also equipped with a Cessna 400 (3-axis) autopilot. The partner told an NTSB investigator that he (the partner) had last flown the aircraft two weeks before the accident and that at that time there were no deferred maintenance items on the aircraft.

The aircraft was not equipped with wing or empennage deicing boots, nor propeller deicing. The aircraft was equipped with an electrically heated pitot tube and had dual vacuum pumps which were installed in accordance with STC SA4578SW. A 74-cubic-foot oxygen system was installed and two unpackaged nasal cannulas were found in the wreckage.

METEOROLOGICAL CONDITIONS

A Meteorological Factual Report was prepared by the NTSB staff meteorologist and is attached. Doppler Weather Radar Composite Reflectivity Images contained as attachments 10 and 11 to that report show an area of echoes over Los Angeles at the time of the accident.

The pilot contacted San Diego AFSS by telephone between 1230 and 1245 while on the ground at Calexico, closed his border crossing flight plan, and was briefed for the (VFR) flight on to Oakdale. The briefer described a cold front lying between Point Conception and Fresno, moving southeastward with accompanying low and mid-level moisture ahead of and behind the front. He also provided AIRMETS for IFR conditions in the central valley and along the coast and mountain obscuration north of Los Angeles. The briefer emphasized to the pilot an AIRMET calling for occasional light to moderate rime or mixed icing in clouds north of a line between Los Angeles and Santa Barbara between 5,000 and 20,000 feet, and that icing had been reported by a pilot over Santa Barbara at 8,000 feet. He then gave the pilot surface observations and terminal forecasts calling for marginal VFR conditions along the route of flight. The pilot said that they were "going to grab a bite to eat" before departing and estimated arriving at his destination about 1530. In issuing the winds aloft the briefer said "how high are you going to fly, about 10,000 feet?" and the pilot said yes. No flight plan was filed for the continuing flight.

The pilot of another aircraft, a Cessna 421, was navigating through the area near the accident at the time. The pilot happened to hold a Ph.D. in meteorology and operates a weather consulting business. That pilot told the NTSB investigator that he passed south of Lake Hughes VORTAC at 8,000 feet on the LYNXX SEVEN arrival to Van Nuys. He recalled passing Lake Hughes in clouds with light turbulence and moderate airframe icing which required use of the aircraft's de-ice boots (approximately 1/2 inch of ice). He recalled no severe weather or thunderstorms in the area.

There were three other pilot reports of light to moderate rime icing reported in the vicinity of the accident. At 1621, the pilot of a Swearingen Metro aircraft reported light to moderate rime icing at 12,000 feet while 10 miles north of Burbank. At 1639, the pilot of a Boeing 737 aircraft reported light rime icing conditions encountered between 17,000 and 19,000 feet while in the vicinity of Gorman VORTAC and at 1750, the pilot of a Boeing 737 reported moderate rime ice at 15,000 feet while 10 miles east of Palmdale VORTAC.

WRECKAGE AND IMPACT INFORMATION

The majority of the aircraft wreckage was located in the foothills of the Tehachapi mountains at latitude 34 degrees 52.28 minutes north, and longitude 118 degrees 40.40 minutes west, at 3,760 feet elevation. This position is approximately on the Gorman VORTAC 051 degree radial at 10 miles. The accident site is on a knoll which slopes downward to the southeast, south and southwest at 15 to 20 degrees. Pieces of the right wing, left horizontal stabilizer, and left elevator were located at a later date up to 2.59 miles east-northeast of the main wreckage.

At the main wreckage site the propeller and engine were found submerged slightly below surface level with the fuselage and empennage directly on top of them. The instrument panel, cabin, and fuselage forward of the empennage were destroyed. The left wing, wing center section (including a portion of the cabin ceiling), and the inboard 5 feet of the right wing aft of the main spar were 5 feet downslope of the fuselage wreckage lying bottom side up. The wing axis was aligned approximately 150 to 330 degrees with the left wing tip pointing in the 150-degree direction.

Missing from the main wreckage site was the right wing forward of the main spar, the outboard 10 to 12 feet of the right wing and wing spar, and the entire left-hand horizontal stabilizer and elevator. These components were not initially recovered. With the exception of these major assemblies and a small number of components downslope of the main wreckage (150 to 240 degrees), the remainder of the aircraft was confined to the immediate vicinity of the main wreckage.

The inboard portion of the right wing main spar exhibited a long, smooth, upward bend of approximately 20 degrees between wing stations 40 and 68 and separated from the outboard portion of the wing at wing station 82 which corresponds to the station of the center flap bracket. The spar web in that region exhibited a uniform set of compression wrinkles at 45 degrees to the spar caps. The entire wing separated at station 96, except for approximately an additional 4 feet of the lower spar cap which remained attached to the inboard wing. The cap exhibited a smooth downward bend of 15 to 20 degrees in the outboard 2 feet.

The inboard 5 feet of the right wing which remained with the fuselage and the entire left wing exhibited extensive chordwise compression damage. The left wing was separated at station 138 (the flap/aileron juncture) except for the main wing spar which joined the inboard and outboard sections together.

On March 26, 1996, three additional pieces of wreckage were located. The outboard 18 inches of the left elevator with the mass balance attached was located on a bearing of 125 degrees from the main wreckage at a distance of 0.17 miles. The outboard 2 feet of the right hand aileron with the mass balance in the leading edge was located on a bearing of 056 degrees from the main wreckage at a distance of 1.15 miles. The right wing inboard leading edge forward of the main wing spar containing the fuel cell was located on a bearing of 066 degrees from the main wreckage at a distance of 1.02 miles.

On April 16, 1996, three more pieces of wreckage were located. The outboard section of the right wing was located on a bearing of 061 degrees from the site at 2.36 miles, the left elevator was located on a bearing 061 degrees from the site at 2.45 miles, and the left horizontal stabilizer was located on a bearing of 060 degrees from the site at 2.59 miles. MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot by the Kern County Sheriff-Coroner and toxicological tests were performed by the FAA Civil Aeromedical Institute. Tests for carbon monoxide and cyanide were not possible due to a lack of a suitable specimen. Tests for volatiles and drugs were negative.

ADDITIONAL INFORMATION

The aircraft wreckage was released to Mr. Kelly McLendon, Claims Manager, United States Aviation Underwriters, on April 12, 1996.

NTSB Probable Cause

The loss of control of the aircraft in cruise flight for undetermined reasons and subsequent in-flight structural failure of the aircraft.