Grumman AA1 accident near Phoenix, Arizona, August 1, 2017
On August 1, 2017 at about 8:00 pm local time, a 1972 Grumman AA1, registered N6216L, was substantially damaged in an accident during initial climb near Phoenix, Arizona (Phoenix Deer Valley airport). It was a personal flight under general aviation rules (Part 91). 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The partial loss of engine power during initial climb due to the No. 3 cylinder exhaust valve becoming stuck open due to deposit buildup in the exhaust valve stem and guide and the pilot’s exceedance of the airplane’s critical angle of attack while attempting to turn back to the airport, which resulted in an aerodynamic stall.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 1, 2017 · about 8:00 pm local time
- Place
- Phoenix, Arizona · Phoenix Deer Valley · map
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman AA1 B, built 1972
- Registration
- N6216L · no longer on the register · serial AA1B-0016
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Shortly after the private pilot took off for the local flight, about 200 to 300 ft above ground level, the engine experienced a partial loss of power. The airport was bordered on the south, west, and north by buildings, and there were high-traffic arterial roads on both the west and south sides of the airport; the pilot turned the airplane back toward the departure runway to make an emergency landing to the east. During the turn, the pilot exceeded the airplane's critical angle of attack, which resulted in an aerodynamic stall. The pilot was unable to regain control, and the airplane pitched nose down and subsequently impacted terrain and then collided with an airport perimeter fence and a tree before coming to rest. Postaccident examination of the propeller blades revealed chordwise striations across the cambered surface, torsional twisting, and trailing edge "S" bending, consistent with the engine producing power at the time of impact. The engine teardown examination revealed that the No. 3 cylinder's exhaust valve was stuck open, which would have degraded the engine power. Further, the exhaust valve stem and guide exhibited heavy combustion deposits, which likely led to the valve becoming stuck. No preaccident deficiencies were found with the cylinder.
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
- Loss of engine power (partial) during initial climb defining event
- Aerodynamic stall/spin during emergency descent
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Capability exceeded
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Aircraft › Aircraft power plant › Engine exhaust › (general) › Malfunction
- Personnel issues › Task performance › Maintenance › (general) › Maintenance personnel
- Environmental issues › Physical environment › Object/animal/substance › Fence/fence post › Contributed to outcome
- Environmental issues › Physical environment › Object/animal/substance › Tree(s) › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 270 hours in all; 226 in this make and model; 85 in the last 90 days; 33 in the last 30 days; 207 as pilot in command
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: serious injuries
The aircraft
- Airframe total time: 4,196 hours
- Last inspection: 100-hour inspection, May 11, 2017; 125 hours since
- Maximum gross weight: 1,600 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O320 A3A (piston); 0 hours total
The flight
- Departed from: DVT Phoenix AZ at 8:00 pm
- Destination: SEZ Sedona AZ
- Flight plan: none
- Runway 25L, 8,196 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: from 180° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 93°F (34°C), dew point 61°F (16°C)
- Altimeter: 29.93 inHg
- Observation at 7:53 pm from DVT, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
19 documents, released by the NTSB on November 16, 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.