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Accidents · NTSB WPR16FA124 · Final report

Grumman American Avn. CORP. AA 1B accident near Hawthorne, California, June 11, 2016

On June 11, 2016, a 1974 Grumman American Avn. CORP. AA 1B, registered N4SU, was destroyed in an accident during takeoff near Hawthorne, California (Jack Northrop Field/Hawthorne). It was an instructional flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

The failure of both pilots to land the airplane on the remaining runway when a sufficient rate of climb could not be attained. Contributing to the accident was a reduction of available engine power due to severe camshaft lobe wear.

Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.

What the record shows

Date
June 11, 2016
Place
Hawthorne, California · Jack Northrop Field/Hawthorne · map
Type
Accident
Injuries
2 people were killed.
Weather
visual conditions (good weather)
Aircraft
Grumman American Avn. CORP. AA 1B, built 1974 · all AA 1Bs on the register
Registration
N4SU · no longer on the register · serial AA1B-0346
Damage
Destroyed
Flight
Instructional flight · general aviation rules (Part 91)

The NTSB's narrative final · quoted from the NTSB record

The 90-year-old private pilot, who was the owner of the airplane, was receiving a flight review from the 71-year-old flight instructor. The airport tower controllers reported that, during takeoff, the airplane became airborne, settled back onto the 4,956-ft-long runway about 1,500 ft from its initial rotation point, and then become airborne again. The airplane remained low as it proceeded away from the airport. One witness reported that the engine sounded "rough" and that the airplane's rate of climb was "much lower" than that of a typical airplane on departure. The witness observed the pilot repeatedly lowering and raising the airplane's nose as if trying to gain altitude. Each time the airplane pitched up, it lost altitude, consistent with operation at or very near the airplane's critical angle of attack.  The airplane subsequently impacted a tree and a residence about 1 nautical mile west of the airport and was destroyed by a postcrash fire. Examination of the flight controls and airframe revealed no anomalies. Examination of the engine revealed continuity of the valvetrain and drivetrain; however, disassembly revealed radial scoring of the crankshaft bearings, spalling of the tappet faces corresponding to the intake valves of all 4 cylinders, and extensive wear of the corresponding camshaft lobes. The severely worn camshaft lobes would have reduced the amount and duration of the intake valve openings, resulting in decreased power output. The magnitude of the power loss could not be determined. The airplane was operating within its weight and balance limitations, and, given the atmospheric conditions at the time of the accident, the takeoff distance should have been about 1,000 ft. When the airplane settled back onto the runway long after it should have become airborne, the pilots should have stopped the airplane and any further takeoff attempts; rather they chose to continue with a second takeoff and climb toward a densely-populated area. The pilot purchased the 42-year-old airplane about 7 months before the accident. The most recent annual inspection was conducted about the time of the purchase at an airframe and engine total time of 1,724 hours. Although manufacturer guidance specified that the engine should be overhauled at 2,000-hour intervals or every 12 years, whichever occurred first, the engine had never been overhauled. The airplane had been operated less than 20 hours per year in the 2 years before the most recent annual inspection; according to the manufacturer, engines that are not operated on a regular basis may accumulate internal corrosion due to a loss of protective oil film. Although the pilot had medical issues and used several medications, none of these should have caused a cognitive issue. Whether or not he had age-related cognitive issues that might have contributed to his failure to recognize the airplane's poor performance and abort the takeoff could not be determined. The instructor had a series of medical conditions, including coronary artery disease, bypass surgery, kidney failure requiring dialysis, chronic back pain, atrial fibrillation, and psychiatric disease. The instructor's serious medical conditions placed him at risk for sudden impairment or incapacitation; however, it is unlikely that these conditions contributed to the accident. Additionally, three central nervous system depressant medications were found in toxicology specimens from the instructor. Due to the limited information from the toxicology testing regarding blood levels of the drugs, it could not be determined whether the instructor's use of multiple impairing medications contributed to the accident.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record from the NTSB's investigation tables, in plain English

What happened, in order

  1. Loss of engine power (partial) during takeoff defining event
  2. Loss of control in flight during initial climb
  3. Collision with terrain or object (not controlled flight into terrain) during initial climb

The NTSB's findings

  • cause Personnel issues › Action/decision › Action › Incorrect action selection › Pilot
  • cause Personnel issues › Action/decision › Action › Incorrect action selection › Instructor/check pilot
  • cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Climb rate › Attain/maintain not possible
  • cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Capability exceeded
  • cause Aircraft › Aircraft oper/perf/capability › Aircraft capability › Climb capability › Not attained/maintained
  • factor Aircraft › Aircraft power plant › Engine (reciprocating) › (general) › Damaged/degraded

Pilot

  • Certificate: private
  • Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: glider
  • Flight time: 3,000 hours in all
  • Medical certificate: Class 3 (with waivers/limitations)
  • Seat: left
  • Injury: fatal

Flight instructor

  • Certificate: airline transport pilot, flight instructor
  • Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
  • Flight time: 18,000 hours in all
  • Medical certificate: Class 3 (with waivers/limitations)
  • Seat: rgt
  • Injury: fatal

The aircraft

  • Airframe total time: 1,724 hours
  • Last inspection: annual inspection, November 16, 2015
  • Maximum gross weight: 1,561 lb
  • Seats: 2
  • Landing gear: fixed
  • Engine: Lycoming O-235-C2C (piston); 1,724 hours total
  • Fire on the ground

The flight

  • Departed from: HHR Hawthorne CA
  • Flight plan: none
  • Runway 25, 4,956 ft by 100 ft
  • A second pilot was aboard

Weather at the time

  • Light: daylight
  • Wind: from 270° at 8 knots
  • Visibility: 10 statute miles
  • Sky: clear
  • Temperature: 72°F (22°C), dew point 57°F (14°C)
  • Altimeter: 29.88 inHg
  • Observation at 11:53 pm from KHHR, 1 miles away

Injuries

FatalSeriousMinorNone
Flight crew2

Documents from the investigation the NTSB's docket: the evidence folder behind the report

10 documents, released by the NTSB on April 6, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.

The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.

Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.