NTSB Factual Report

HISTORY OF THE FLIGHT

On March 9, 2001, about 1420 Pacific standard time, a North American Navion, N91445, collided with terrain near Santa Ysabel, California. The private pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. The pilot sustained fatal injuries; the airplane was destroyed. The personal cross-country flight departed Gillespie Field, San Diego, California, at 1348, en route to El Centro, California. Visual meteorological conditions prevailed at Ramona, California, the nearest reporting station. No flight plan had been filed. The primary wreckage was at 33 degrees 06.525 minutes north latitude and 116 degrees 43.288 minutes west longitude at an estimated elevation of 2,900 feet.

The National Transportation Safety Board investigator-in-charge (IIC) interviewed two witnesses. One had been a licensed pilot. A loud engine sound caught their attention. The engine sounded like it was revving to a high rpm. The airplane sounded very low. They heard the sound for 2 or 3 seconds before they saw the airplane. It came out of clouds with the nose pointing down more than 75 degrees. They were looking north at the side of the upright airplane as it moved right to left. They did not observe any rotation of the airplane. The nose of the airplane rose up a few degrees; they thought this was an attempt to pull up out of the dive. The airplane then disappeared behind a ridgeline, and they heard a muffled thud. The engine sound simultaneously ceased. They did not observe any pieces separate in flight. They could see the tops of two peaks to the southwest. The weather was overcast and misting.

The IIC reviewed recorded radar data. He noted a target with a secondary 1200 (VFR) beacon code appeared northwest of Gillespie about the time of N91445's departure. It maintained a northeasterly track for nearly 20 minutes. It then began a gradual left turn for 2 minutes. The target made a sharp left 90-degree turn, and then made a right turn. After 360 degrees, the right turn decreased in radius and continued for over 270 degrees until the last recorded target. This last target was near the accident site. There were no other target tracks in the vicinity of the accident site. The target reached a peak mode C reported altitude of 6,700 feet at the beginning of the first right turn. The last mode C reported altitude of 4,900 feet occurred about 180 degrees into the second right turn.

PERSONNEL INFORMATION

A review of Federal Aviation Administration (FAA) records revealed that the pilot held a private pilot certificate. He did not possess an instrument rating.

The IIC reviewed the pilot's logbook and estimated that he had accumulated about 750 hours of flight time.

AIRCRAFT INFORMATION

The airplane was a North American Navion, serial number NAV 4-95. A review of the airplane's maintenance records revealed a total airframe time of 5,241.0 hours at the last annual inspection. The logbooks contained an entry for an annual inspection dated May 3, 2000. The tachometer read 2,656.0 at the last inspection.

The engine was a Teledyne Continental Motors E-185-9 engine, serial number 5840-D-9-9.

METEOROLOGICAL INFORMATION

An aviation routine weather report (METAR) was issued for Gillespie Field at 1347. It stated: skies, overcast at 3,000 feet; winds 230 at 10 knots; temperature 59 degrees Fahrenheit; and altimeter 29.96 inHg.

A METAR was issued at 1353 for Ramona. It stated: skies, few clouds at 1,200 feet, broken at 1,800 feet, overcast at 3,600 feet; winds 260 degrees at 12 knots; temperature 52 degrees Fahrenheit; dew point 48 degrees Fahrenheit; and altimeter 29.94 inHg. Ramona is on a magnetic bearing of 236 degrees and 10 miles from the accident site. Ramona's field elevation is 1,393 feet.

A Safety Board staff meteorologist provided the following information.

The gestationary environmental operational satellite number 10 (GOES-10) imagery indicated a stratiform layer of clouds extending from the coast through the area where the accident occurred. Over the accident site at 2216Z, the GOES-10 infrared image indicated a mean radiative cloud top temperature of 275.4 degrees Kelvin or +2.24 degrees Celsius. Based on the closest upper air sounding, this indicated a cloud top near 4,000 feet. Further east, clouds increased to near 7,000 feet.

The specialist also examined several pilot reports surrounding the period on March 9, 2001, and they indicated a broken to overcast layer of clouds with cloud tops ranging from 4,500 to 9,000 feet. An urgent pilot report was received at 2235Z from a pilot operating a Lear jet in the vicinity of Van Nuys, north of the accident site, who reported encountering moderate to severe turbulence upon descending into the clouds. Another report from a flight crew in a Boeing 737 reported light to moderate turbulence descending through the overcast layer of clouds.

WRECKAGE AND IMPACT INFORMATION

The primary debris field occupied an area about 50 feet in diameter. The primary wreckage consisted of the cabin area, fuselage, right wing, and empennage; these sections remained attached to each other. The primary wreckage was about 5 feet from the principle impact crater. The pilot was a few feet forward of the cockpit area, and remained in his seat with the seat belt fastened.

Investigators found portions of the left wing, left horizontal stabilizer, and left elevator scattered about 50 yards from the primary debris field. The primary debris field was on a magnetic bearing of 260 degrees from the separated pieces.

The left wing tip separated about 6-feet inboard from the tip at a production splice. The left aileron separated. The inboard section of the left wing separated about 1 foot from the wing attach fittings. Three longerons bent up about 45 degrees. Their fracture surfaces were grainy, irregular in shape, and traversed diagonally across the horizontal and vertical axis.

The left horizontal stabilizer separated at the inboard attach fittings. About a 3-foot section of the inboard section of the left horizontal stabilizer rear spar separated. All fracture surfaces were irregular in shape. The top trailing edge skin covering the separated rear spar section bowed up. Rivet holes in this area were elongated aft and the rivet heads pulled through. The lower trailing edge skin of the left horizontal stabilizer bent down about 80 degrees along its entire length. Rivet holes in the inboard 3 feet were elongated aft and the adjacent skin bent aft.

The right horizontal stabilizer bent down about 20 degrees starting at midspan. The outboard half of the right elevator separated. The fracture surfaces were irregular and angled across the chord line. The separated section was on the ground next to the primary wreckage.

Investigators inspected the flight controls for continuity. They established control continuity for the rudder. Control cables for the right aileron were attached to the bellcrank and traced to the deformed cabin area. The right aileron's operating arm separated at the rod end, and the fracture surface angled across the longitudinal axis. The left aileron control cable separated near the fuselage in a broomstraw pattern. Investigators traced the elevator and elevator trim cables from the empennage to the deformed cabin area. The elevator control cables from the empennage to the separated tail pieces fractured in a broomstraw pattern. Both control yokes separated from their attach fittings on the cabin floor. The right control column bent outboard. Both handgrips fractured and separated from the right control yoke. The left control yoke separated from the control column. The fracture surface was irregular. Only the left handgrip separated from the left control yoke.

MEDICAL AND PATHOLOGICAL INFORMATION

The San Diego County Medical Examiner, San Diego, California, performed an autopsy on March 10, 2001. The pilot's death was attributed to injuries sustained in the accident sequence.

The FAA Toxicology and Accident Research Laboratory performed toxicological testing of specimens of the pilot. The results of analysis of the specimens were negative for carbon monoxide, cyanide, and tested drugs; they detected 20 (mg/dL, mg/hg) ethanol in muscle. A note indicated that the ethanol was from postmortem ethanol formation, and not from the ingestion of ethanol.

TESTS AND RESEARCH

The engine sustained mechanical damage and separated from the airframe. It could not be rotated. Investigator removed the top spark plugs. All spark plugs were clean with no mechanical deformation. The spark plug electrodes were gray in color, which corresponded to normal operation according to the Champion Aviation Check-A-Plug AV-27 Chart.

Both propeller blades separated from the hub. One blade exhibited angular chordwise striations and S-bends; the outer third of the blade was polished. The second blade had chordwise striations along its entire length. The tip was twisted and deformed.

ADDITIONAL INFORMATION

The IIC released the airplane wreckage to the owner's representative.

NTSB Probable Cause

the pilot's continued VFR flight into IFR conditions, which resulted in a loss of control due to spatial disorientation.