On February 17, 2010, about 0754 Pacific standard time, a Cessna 310R airplane, N5225J, was substantially damaged when it impacted multiple residential structures and terrain following an in-flight collision with power lines and a power line tower shortly after takeoff from the Palo Alto Airport (PAO), East Palo Alto, California. The commercial pilot and his two passengers were killed. There were no reported ground injuries. The airplane was registered to Air Unique Inc., Santa Clara, California, and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Instrument meteorological conditions prevailed and an instrument flight rules (IFR) flight plan was filed for the cross-country flight. The flight was originating at the time of the accident with an intended destination of Hawthorne, California.

Review of recorded air traffic control tower communications between the pilot and controller revealed that the pilot was issued his IFR clearance at 0741, which cleared the pilot to Hawthorne Airport via a right turn to a heading of 060 degrees within one mile of Palo Alto, vectors San Jose, Salinas as filed, climb and maintain 3,000 feet, expect 9,000 feet five minutes after departure. The pilot acknowledged the IFR clearance by reading it back to the controller. At 0746, the pilot contacted the air traffic control tower controller, stating he was "ready three one, IFR to Hawthorne." The controller responded, telling the pilot to hold for IFR release.

At 0749, the controller transmitted that information November was current, wind variable at 5 knots, visibility 1/8th mile, fog, vertical visibility of 100 feet above ground level (agl). At 0751, the controller transmitted to the pilot that he had his IFR release and stated "the runway is not visible, so it's at your own risk." The pilot responded shortly thereafter, "[I] understand." At 0752, the controller informed the pilot that he had two minutes for his IFR release. The pilot responded that he did not hear a "cleared for takeoff." The controller responded that "I cannot clear you for takeoff because I don't have visibility on the runway, so ah, the release is all yours and it's at your own risk sir." The pilot responded "ok, 25 Juliet, rolling." No further radio communications were heard from the pilot.

Multiple witnesses located adjacent to the accident site reported observing portions of the accident sequence. One witness, who was walking on a levee near the accident site, reported that she observed an airplane “suddenly” emerge from the fog to the left of her position. The witness stated that she continued to watch the airplane fly in a level or slightly nose up attitude from her left to her right at a low altitude until it impacted power lines shortly thereafter.


The pilot, age 56, held a commercial pilot certificate with airplane single-engine land, multi-engine land, and instrument airplane ratings. The pilot also possessed a flight instructor certificate with airplane single-engine and multi-engine ratings. A second-class airman medical certificate was issued on November 12, 2009, with the limitation “Must wear corrective lenses for near and distant vision." The pilot reported on his most recent medical certificate application that he had accumulated 2,900 total flight hours. Review of the pilot's logbook revealed that from May, 2009 to September 23, 2009, only dates were recorded with no flight time or aircraft information. No entries were recorded from September 23, 2009 to the most recent entry, dated January 27, 2010. The most recent logbook entry noted 1.8 hours of flight time, of which 1 hour was simulated instrument flight time and 0.2 hours in actual instrument conditions, flight time that was part of the pilot's most recent instrument competency-check. The pilot's most recent flight review was completed on November 11, 2009.


The six-seat, low-wing, fixed-gear airplane, serial number (S/N) 310R0807, was manufactured in 1977. It was powered by two Teledyne Continental Motors (TCM) IO-550-A (8) engines, rated at 300 horse power and equipped with McCauley variable-pitch propellers.

Review of copies of the aircraft maintenance logbook records recovered from the wreckage revealed that an annual inspection was completed on April 27, 2009, at a recorded tachometer reading of 743 hours, airframe total time of 6,350 hours, left engine total time since new of 150 hours, and right engine total time since new of 150 hours. The factory new left and right engines were installed on the airframe on August 25, 2004, at an airframe total time of 6,191 hours.


A review of recorded data from the automated weather observation station located at PAO revealed that at 0654, wind was variable at 4 knots, visibility (M)1/4 mile, fog, vertical visibility of 100 feet agl, and an altimeter setting of 30.03 inches of Mercury. At 0742, the ATCT controller at PAO reported wind variable at 5 knots, visibility 1/8th mile, fog, and a vertical visibility of 100 feet agl. Review of a weather log for the Palo Alto Air Traffic Control Tower revealed that at 0805, visibility was 1/16th mile, fog, and a vertical visibility of 100 feet agl.

At 0853, the weather observation station at PAO reported wind variable at 4 knots, visibility 1/8th mile, fog, and a vertical visibility of 100 feet agl.


Examination of the accident site by representatives from Cessna Aircraft Company and Teledyne Continental Motors under the supervision of the Federal Aviation Administration (FAA) and NTSB investigator-in-charge (IIC) revealed that the First Identified Point of Contact (FIPC) was an electrical tower located about 0.41 nautical miles northwest of the departure end of runway 31. Examination of the tower revealed that the airplane struck the tower and power lines about 40 to 50 feet agl. Wreckage debris from the aircraft was spread throughout the approximate 897-foot long wreckage energy path, which was oriented on a magnetic heading of about 237 degrees.

Two left propeller blade tips were located adjacent to the FIPC. Remains of the left engine cowling, nose cowling, left main gear door, and left gear door hinge were located near the FIPC. The outboard portion of the left wing (left fuel tank, left aileron, and a portion of the left flap) was located adjacent to a residential structure about 462 feet southwest of the FIPC and exhibited thermal damage. The inboard portion of the left wing (top left engine cowling, left engine nacelle, inboard portion of the left flap, left main gear) was located 560 feet from the FIPC and in a partially inverted position. The left main gear was observed secured within the wheel well. Forty-five degree striations were observed on the top middle area of the nacelle baggage door.

Three impact marks were observed on the street curb about 686 feet from the FIPC. The impact marks observed were consistent with propeller blade strikes. An impact mark on the adjacent sidewalk was consistent with engine impact. Additional scoring was observed on the sidewalk within the area of the propeller strike marks and was consistent with the main fuel tank impact.

About 15 feet beyond the strike marks on the curb, a portion of a landscaping retaining wall was displaced and extended towards the main wreckage. The main wreckage was observed adjacent to a residential structure, remaining partially on the residence driveway, yard, sidewalk, and street. Within the main wreckage, three vehicles and a light standard were observed. The main wreckage consisted of remains of the fuselage, cockpit structure, empennage, horizontal stabilizer, elevators, vertical stabilizer, rudder, right wing, and right engine. The main wreckage, vehicles, and light standard exhibited severe thermal damage.

The left and right engine and left and right propellers were shipped to their respective manufacturers for further examination.


The San Mateo County Coroner’s Office conducted an autopsy on the pilot on February 18, 2010. The medical examiner determined that the cause of death was “...Multiple Blunt Injuries.”

The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs were tested. The report noted the following positive results: "0.011 (ug/ml, ug/g) Diphenhydramine detected in Blood, Diphenhydramine detected in Urine, Metoprolol detected in Urine, Metoprolol detected in Blood."


The left and right engines were examined at the facilities of Teledyne Continental Motors (TCM) under the supervision of the Safety Board IIC on March 1, 2, and 3, 2010. The examination of the left and right engines revealed no preimpact mechanical anomalies that would have precluded normal operation.

A handheld Garmin GPS was located within the wreckage debris path. The GPS was sent to the NTSB Vehicle Recorders Laboratory, Washington, DC for further examination. The recovered recorded data revealed that on the day of the accident, a data track was observed from the parking area of PAO to runway 31. No further data was recovered from the GPS unit.

Examination of both recovered propellers was conducted at the facilities of McCauley Propeller Systems, Wichita, Kansas, on February 23, 2011, under the supervision of an NTSB investigator. The McCauley Propeller Systems representative reported that the examination found that propeller damage was a result of impact forces and no indications of propeller failure prior to impact were found. Both propellers were rotating at the time of impact and that neither propeller was at or near the feathered position at the time of impact. The representative further reported that both propellers were being operated under conditions of power at the time of impact, of which the exact amount of power was not determined.

Local law enforcement provided recordings from a Shotspotter recording system. The Shotspotter system is an array of acoustic sensors deployed in high-crime areas that are triggered by impulsive events such as explosions or gunshots in order to alert and provide information to law enforcement. Review of the audio recording system revealed that multiple recording sites recorded the accident sequence. The captured recordings were sent to the NTSB Vehicle Recorders Laboratory for further examination.

According to the NTSB Vehicle Recorders Laboratory specialist's report, the accident triggered five Shotspotter sensors. A sound spectrum study was performed to determine if any engine operating parameters such as RPM could be established. Five audio files approximately 2 minutes in length were provided to the Safety Board for analysis. The recordings, coupled with Airfield Surveillance Radar at Moffett Field, southeast of Palo Alto, which briefly tracked N5225J after departure, captured four radar targets, each approximately 4.5 seconds apart. When plotted, the first target appeared to the right of the runway. The radar data was corrected to place the aircraft on the runway during the takeoff roll. Using the initial impact point in addition to the four radar targets, a flight path was interpolated in one second intervals. The interpolated flight path showed an approximate 45-degree left turn shortly after departure to the FPIC.

A sound spectrum study was performed to determine the engine speed from recorded audio from 4 sensors on the ground at the time of the accident. Because the aircraft was moving at over 200 knots over the ground at the time of the accident, the Doppler frequency shift had to be calculated. The study determined that both engines were operating near full power. See the Sound Spectrum Study within the public docket for more details.

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