N37RVPiper PA-28-151

On January 28, 2019, about 2100 Pacific standard time, a Piper PA-28-151 airplane, N37RV, was substantially damaged when it was involved in an accident near Oceanside, California. The pilot was seriously injured, and the passenger was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

According to the pilot, the flight was departing Bob Maxwell Memorial Airfield (OKB), Oceanside, California, and was destined for Jack Northrop Field/Hawthorne Municipal Airport (HHR), Hawthorne, California. The pilot did not recall any part of the flight, who was at the flight controls, or the accident. He stated that the co-owner of the airplane, who was at OKB when the flight departed, later told him that the visibility was good at the time of departure and that he saw the pilot enter the airplane first, which would have placed him in the left seat.

Two witnesses who arrived at OKB about 1940 said they noted condensation on their airplane during a preflight inspection and fog coming in from the west. One witness stated that the weather forecast they had previously checked indicated “generally decent visibility” and ceilings of about 3,000 to 4,000 ft; however, they rechecked the weather, and the automated surface observing system at 1947 reported 1 3/4 statute mile (sm) visibility with ceilings of a few thousand feet. They watched another airplane depart to the west and, about 1/2 mile from OKB, become submerged in fog, which one witness estimated to be about 400-500 ft above ground level (agl). They decided not to fly and remained at the airport until about 2005; they noted that fog continued to develop around the airport. As they drove eastbound from OKB, they saw patches of fog for several miles.

Review of the airport video surveillance system revealed that the accident airplane arrived at OKB about 1833; it was refueled and tied down, and the pilot and passenger left the airport with the co-owner of the airplane. The video showed fog coming in about 2000, and the pilot and passenger returned to the airport about 2035. The video showed the accident airplane departed OKB about 2100.

A witness near OKB saw the airplane take off, turn left, and enter fog; he then heard a loud noise that sounded like a crash and called 911.

Oceanside Police Department officers responded the night of the accident but, due to inclement weather, were unable to find the wreckage. The next morning, after receiving a call that reported the wreckage on a hillside, officers located the wreckage.

A review of National Weather Service data showed a surface trough along the California coast in the immediate vicinity of the accident site. Troughs can act as lifting mechanisms to help produce clouds and precipitation if sufficient moisture is present. Station models around the accident site depicted air temperatures in the upper 40to -mid-50°F range, dew point temperatures in the upper 40°F range, calm winds, and mostly clear skies with overcast skies reported northeast of the accident site.

The closest official weather reporting facility was OKB. A special weather report issued at 2003 indicated calm wind, 3/4 sm visibility, mist, vertical visibility 300 ft agl, temperature 50°F, dewpoint 50°F, and an altimeter setting of 29.97 inches of Mercury. The remarks section indicated that the visibility varied between 1/4 mile and 4 miles. Reported weather at OKB at 2052 was wind from 040° at 3 kts, visibility 1/4 sm in fog, vertical visibility 200 ft agl, temperature 53.6°F, dewpoint 53.6°F, and an altimeter setting of 29.97 inches of Mercury.

The next closest official weather reporting station was Camp Pendleton MCAS (Munn Field) Airport (NFG), Oceanside, California, located 5 miles north of the accident site an at elevation of 78 ft. Reported weather at 1955 was calm wind, 2 miles visibility in mist, broken ceiling at 700 ft agl, temperature 48.2°F, dew point 48.2°F, and an altimeter setting of 29.98 inches of Mercury. Reported weather at 2055 was calm wind, 2 miles visibility in mist, broken ceiling at 600 ft agl, temperature 48.2°F, dewpoint 48.2°F, and altimeter setting of 29.98 inches of Mercury.

An upper air data high-resolution rapid refresh (HRRR) model sounding for the accident site reported a subsidence inversion at 2,235 ft mean sea level (msl). An inversion near the surface with close temperature and dew point, light winds, and no other large scale weather factors creates an environment favorable for fog or low stratiform cloud formation. Satellite data from the Geostationary Operational Environmental Satellite number 17 (GOES-17) indicated abundant cloud cover over the accident site at the accident time, with the cloud cover moving from west to east. Based on the brightness temperatures above the accident site and the vertical temperature profile provided by the HRRR sounding, the approximate cloud-top heights over the accident site were 23,000 ft at 2051.

There were no pilot reports within 100 miles of the accident site 2 hours before and 2 hours after the accident time. There were no SIGMETs, center weather advisories, or meteorological impact statements valid for the accident locatation and time. An AIRMET advisory Tango valid for the area including the accident site warned of moderate turbulence below 10,000 ft with conditions ending between 1900 and 2200.

A review of Leidos, ForeFlight, and other documented weather vendors revealed no evidence that the pilot requested a preflight weather briefing. It is unknown if the accident pilot checked or received additional weather information before or during the accident flight.

The airplane came to rest about 1/4 mile southwest of the airport on a magnetic heading of 110° just below the ridgeline of a 210-ft hill adjacent to a highway. The airplane exhibited crush damage and deformation throughout the entire fuselage. Flight control continuity was established on scene; the control cables from the cabin to the empennage were manually moved with corresponding movement observed from the cabin to the tail and from the cabin to the right wing. The left wing was separated from the fuselage, and the flight control cables were exposed at the fuselage. The landing gear had separated and was in the general location of the wreckage site. The two-bladed propeller had separated from the crankshaft and was found with the wreckage.

The engine remained attached to the airframe by the engine mount. The bottom forward portion of the engine had sustained impact damage; however, there was no evidence of a preimpact mechanical malfunction. The top spark plugs, and vacuum pump were removed, and the crankshaft was manually rotated; the crankshaft was free to rotate in both directions, and thumb compression was obtained in proper firing order on all cylinders. Valve train and mechanical continuity were established throughout the engine. The magnetos remained secure at their respective mounting pads, and the ignition harness P-leads were secured at each magneto. Both magnetos were removed; the right magneto was rotated and produced spark at all four leads. The left magneto was not tested due to impact damage. There was no evidence of a loss of lubrication or contamination. The intake valve tappets at each cylinder position displayed spalling signatures. Corresponding wear was identified at the intake valve camshaft lobes.

The propeller blades exhibited leading-edge gouging, torsional twisting, and chordwise striations throughout the length of the blades. Examination of the airframe and engine revealed no mechanical malfunctions or failures that would have precluded normal operation.