NTSB Factual Report

HISTORY OF FLIGHT

On March 21, 2016, about 1201 Pacific daylight time, an Airborne XT912 weight shift control (WSC) special light sport aircraft, N670EM, was destroyed when it impacted a fence and a roadway shortly after takeoff from Northrop/Hawthorne Municipal Airport (HHR), Hawthorne, California. The student pilot received fatal injuries. The aircraft was owned and operated by Pacific Blue Air (PBA) of Venice, California, and was based at HHR. The instructional flight was operated under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the flight.

According to multiple witnesses, the aircraft initiated its takeoff roll from HHR's runway 25 at a point before the displaced threshold. Just after liftoff, the aircraft began to bank and turn right and continued to do so until its flight track was nearly perpendicular to the runway heading. The initial segment of the flight was a climb but became a descent as the aircraft rolled and turned right. Witness estimates of the aircraft's maximum altitude ranged between 40 and 200 ft, and their maximum bank angle estimates ranged between 45° and 90°. All witnesses reported that the engine rpm either remained constant or increased during the flight and that the engine continued to run at least until impact. None of the witnesses mentioned the presence of any other aircraft.

The aircraft struck the airport perimeter fence and then impacted a 4-lane road north of the airport that ran roughly parallel to runway 25. According to witnesses, on impact, the aircraft immediately caught fire. A water pumping/construction crew was working about 100 ft from where the aircraft impacted, and several of these workers responded to the site within a few seconds and attempted to rescue the pilot and extinguish the fire. Two Los Angeles County Sheriff's Department deputies, who were located several hundred feet from the impact site, responded within a minute of the accident. Air traffic control tower (ATCT) personnel notified HHR operations personnel of the accident, and they responded within a few minutes of the accident. Los Angeles County Fire Department (LACoFD) equipment and personnel also responded very shortly after the accident. The pilot was extracted from the wreckage and transported to a hospital. The wreckage was examined and documented on scene by Federal Aviation Administration (FAA) and National Transportation Safety Board (NTSB) personnel later the same day and was then recovered and transported to a secure facility for additional examination.

PERSONNEL INFORMATION

Pilot's Flight Experience

The pilot held an FAA student pilot certificate that was issued in May 2014. Review of her pilot's logbook indicated that her first flight was conducted in October 2013 and that she flew about 2 to 3 times per month thereafter. All flight time recorded in the logbook was in WSC aircraft, and the PBA Chief Pilot reported that the pilot had no flight time in any other type of aircraft.

All of the pilot's flight time through June 2015 was in an Evolution Revo WSC aircraft that was also owned by PBA. The logbook indicated that the pilot had accrued about 38 hours in the Revo before she switched to the accident aircraft. The pilot's first flight in the accident aircraft was on June 8, 2015, and all her subsequent flights were in the accident aircraft. The logbook indicated that the pilot had accrued about 21 hours in the accident aircraft. The pilot's first solo flight was accomplished on November 2, 2015, when she had a total flight experience of about 48 hours. The logbook listed 8 solo flights, with a total flight time of 6.9 hours. Her most recent flight, which was a solo cross-country flight, took place on March 16, 2016.

Except for two flights, all the pilot's dual flights were conducted with the PBA Chief Pilot.

Pilot's Recent Activities

According to the pilot's family, the pilot had experienced a significant snowboarding accident about 3 days before the accident flight. The family members reported that she struck her head or neck in that event. She was wearing a helmet, did not lose consciousness, but did suffer a "strained neck." The pilot's fiancé reported that she was sore from that event, but her behavior, personality, and mental acuity were unchanged. The pilot's fiancé reported that she was happy when she left their residence for the accident flight and that he did not speak to her after she left.

A PBA co-owner reported that she witnessed the pilot arrive at the airport and stay in her car on the phone for about 20 minutes. According to the co-owner, when the pilot came into the hangar she appeared "slightly agitated." Review of the pilot's telephone records indicated that between 1040 and 1122 she made five calls to four different numbers and received one call from one of those numbers. The longest call was 3 minutes in duration; the rest were 1 minute in duration. In that same period, she was sent one text message from a fifth telephone number. The investigation did not determine the persons or agencies associated with those telephone numbers.

AIRCRAFT INFORMATION

FAA information indicated that the aircraft, commonly referred to as a "trike," was classified and registered as a light sport aircraft (LSA). It was manufactured in 2007 and was equipped with a Rotax 912 series engine. The maximum takeoff weight was 992 lbs. The aircraft manufacturer (Airborne) was based in Australia, and the engine manufacturer (Rotax) was based in Austria. According to the PBA Chief Pilot, the aircraft was acquired by PBA about a year before the accident and was equipped with an "SST" model wing.

According to the aircraft manufacturer's publications, the SST wing is "a high performance flex wing, which utilises struts to react the negative flight and landing loads imposed on the wing airframe. Removal of the king post and associated top rigging results in a significant decrease in drag, which improves cruise performance and reduces fuel consumption." The documentation also stated that, "Handling is improved and speed ranges are increased... pitch stability is achieved by using wire braced washout struts…which serve to keep the trailing edge of the sail raised, maintaining washout and therefore pitch stability." The documentation closed by stating that, "The SST retains all of the great handling characteristics of the Airborne wing range. The performance benefit of the strutted version ...makes the XT912 / SST aircraft the choice for the discerning cross country pilot."

Review of the aircraft maintenance records revealed that the most recent annual condition inspection was completed on June 3, 2015, when the airframe and engine each had accumulated 232 hours since new. The most recent 100-hour inspection was completed on November 10, 2015. The records indicated that, at that time, the airframe and engine each had accumulated 400 hours since new. The maintenance records did not contain any entries documenting maintenance actions that were indicative of, or could be associated with, any previous significant damage or problems.

METEOROLOGICAL INFORMATION

The 1153 HHR automated weather observation included calm winds, visibility 10 miles, clear skies, temperature 19°C, dew point 11°C, and an altimeter setting of 30.12 inches of mercury. The next HHR observation was issued at 1253 and reported winds from 270° at 8 knots.

About 8.5 minutes before the aircraft was cleared for takeoff, the ATCT local controller broadcast, "Attention all aircraft ATIS [automated terminal information service] lima is now current wind two six zero at four altimeter three zero one four." Between that broadcast and the accident, the local controller did not issue any other wind information to any of the aircraft that he was handling.

COMMUNICATIONS

The HHR ATCT was operating at the time of the accident. The ATCT was a non-federal facility that was operated and staffed by the private contractor Serco. At the time of the accident, there were three controllers on duty in the ATCT. Those three individuals were performing the functions of ground control (GC), local control (LC), and controller-in-charge (CIC). All three controllers' statements indicated that each witnessed the airplane's right turn, descent, and impact. None of the three statements mentioned the presence or activity of any other aircraft.

Serco-generated transcripts of the ATCT communications with the accident aircraft were provided to the investigation. Review of these transcripts indicated that they did not document any communications with, or any references to, any other aircraft.

The investigation obtained and reviewed the archived radar tracking data for HHR for the period leading up to the accident. That data indicated that a DeHavilland DHC-6 conducted an approach to HHR runway 25 just before the accident. The radar coverage did not extend to ground level, but the DHC-6 did not re-appear, which was consistent with the DHC-6 landing at HHR.

The audio recordings of the HHR communications were obtained and reviewed, and these indicated that the DHC-6 landed about 40 seconds before the accident aircraft was cleared to depart from the same runway. The audio recordings indicated that the accident pilot radioed the LC that she was ready for departure and that the LC then held the accident aircraft until the DHC-6 landed. Once the DHC-6 vacated the runway, the LC cleared the accident pilot for takeoff. The LC did not issue any wake turbulence advisory to the accident pilot.

The two pilots of the DHC-6 reported that they both witnessed the accident and then discussed (between themselves) the possibility that the accident aircraft had flown into their wake, resulting in the pilot's loss of control and the accident.

AIRPORT INFORMATION

FAA-published information indicated that HHR was equipped with a single paved runway, designated 7/25, which measured 4,956 ft by 100 ft. Runway 25 had a displaced threshold of 463 ft. Airport elevation was 65 ft above mean sea level.

HHR was situated in a mixed industrial/semi-urban area of the Los Angeles basin, within 3 miles of Los Angeles International Airport. Due to this location, HHR operations included a significant number and mixture of aircraft types, including many business aircraft. The accident operator (PBA) was a relatively long-term resident of HHR, and one of the very few, and possibly only, WSC aircraft operators at HHR. However, due to the nature of PBA's business, its operational frequency for WSC aircraft was high, frequently conducting several flights per day.

The airport was not equipped with a dedicated, on-site rescue and firefighting (RFF) division. As specified in the HHR Emergency Plan, the airport relied upon the services of the LACoFD. The nearest LACoFD station was located less than 1 mile from HHR, and personnel and equipment from that LACoFD station responded to the accident.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located about 280 ft north of the HHR runway 7/25 centerline, and about 1,400 ft west of the east end of the paved runway surface. The airport boundary was a 6-ft-high steel chain link fence, and ground scars indicated that the aircraft struck and damaged the fence, and then first impacted the road about 15 ft north of the fence. The aircraft came to rest at the north edge of the road, adjacent to and in contact with a fenced electrical equipment enclosure. The fence damage, road scar, and wreckage formed a line that was perpendicular to the runway.

Except for the right main wheel assembly and about a dozen windscreen, fairing, and propeller fragments, all the wreckage was tightly contained. The airframe (carriage) and wing structure consisted primarily of aluminum tubing of varying diameters, stabilized by a number of steel cables. Portions of several tubes had been damaged or consumed by fire. The carriage came to rest on its right side, oriented with the nose pointed about southeast. All the steel cables remained intact and securely attached to the structure at each of their respective ends. The forward carriage frame and nose landing gear assembly was fracture- and/or fire-separated from the aft carriage frame. The right wheel assembly was fracture-separated from the aircraft just above where its three support struts attached to the wheel assembly. The wheel exhibited significant localized crush damage, consistent with contact with the top crossbar of the airport boundary fence.

The seats were not located/identified in the wreckage, consistent with consumption by fire. Four instruments (an airspeed indicator, a radio, a transponder, and an EFIS [electronic flight instrumentation system]) were identified in the wreckage, but all were severely fire-damaged. The airframe recovery parachute was found out of its container; it remained reefed/folded but was partially extended lengthwise, and much of it was fused or consumed by fire. The parachute extraction rocket was also found out of its container, and its propellant load was absent, consistent with having been consumed in the ground fire.

Detailed examination of the airframe wreckage did not reveal evidence of any pre-impact mechanical deficiencies or failures that would have precluded normal flight.

The engine remained attached to its steel frame portion of the carriage and did not exhibit any evidence of any preimpact failures. The engine sustained significant impact and fire damage, to the point where its pre-accident integrity and operability could not be ascertained.

The three-blade Warp Drive composite propeller remained attached to the engine. Two propeller blades were fracture-separated from the hub; the full lengths of all three propeller blades were identified on scene. All propeller damage was consistent with impact effects with the engine operating.

For additional details, refer to the NTSB public docket for this accident.

MEDICAL AND PATHOLOGICAL INFORMATION

According to the FAA, the 41-year-old pilot had never had an aviation medical examination.

The Los Angeles County Medical Examiner, Los Angeles, California, performed an autopsy of the pilot and determined that the pilot's cause of death was "multiple traumatic injuries." No significant natural disease was identified. The toxicology screenings performed by the medical examiner found 0.22 ug/dl of diphenhydramine in chest blood and 0.05 ug/mL of benzoylecgonine in vitreous fluid. Diphenhydramine is a sedating antihistamine available over the counter in many products intended to treat colds, allergies, and induce sleep and is frequently sold with the name Benadryl. The therapeutic range for diphenhydramine in blood is 0.0250 to 0.1120 ug/ml. Diphenhydramine undergoes post mortem redistribution, and central levels may be elevated above peripheral levels by a factor of about three. Benzoylecgonine is a metabolite of cocaine.

Toxicology testing performed by the FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, identified cocaine (at a level too low to quantify), its metabolite benzoylecgonine at 0.029 ug/ml, and another metabolite that occurs with smoking cocaine, anhydroecgonine methyl ester (at a level too low to quantify) in cavity blood. In addition, diphenhydramine was identified at 0.326 ug/ml in cavity blood and at a level too low to quantify in liver tissue.

The active effects of cocaine include a rush of euphoria, heightened awareness, excitement, and irritability, and it can cause paranoia and hallucinations. As the level drops via metabolism, other effects including sleep disturbance, depression, irritability, and drug craving can occur.

ORGANIZATIONAL AND MANAGEMENT INFORMATION

PBA Information

PBA was based at HHR and was situated in a hangar on the southeast side of the airport. At the time of the accident, PBA owned and operated two aircraft, both of which were WSC aircraft. The hangar faced runway 25, served as the office for PBA personnel and customers, and housed at least one of PBA's two aircraft.

According to the chief pilot, he was a founding member and co-owner of PBA when it began operations about 3 years before the accident. Shortly after the company began

NTSB Probable Cause

The weight shift control aircraft encounter with a wake vortex from a preceding airplane, which resulted in a roll upset at an altitude too low for recovery. Contributing to the accident was the accident pilot's failure to recognize the potential for a wake vortex encounter.