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Accidents · NTSB WPR20LA147 · Final report

Cessna 172 accident near Tucson, Arizona, May 14, 2020

On May 14, 2020 at about 4:50 pm local time, a 1981 Cessna 172, registered N63931, was substantially damaged in an accident during maneuvering near Tucson, Arizona. It was an aerial observation flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

The pilot improper fuel management, which resulted in running the left fuel tank empty and a subsequent total loss of engine power due to fuel starvation.

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

What the record shows

Date
May 14, 2020 · about 4:50 pm local time
Place
Tucson, Arizona · map
Type
Accident
Injuries
No one was hurt; 1 person was on board or involved.
Weather
visual conditions (good weather)
Aircraft
Cessna 172 P, built 1981 · all 172s on the register
Registration
N63931 · no longer on the register · serial 17275497
Damage
Substantial damage
Flight
Aerial observation flight · general aviation rules (Part 91)

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

The pilot reported that about 3.5 hours into an aerial observation flight, the engine started to sputter. He stated that he double checked the fuel selector, enriched the mixture, checked the magnetos, and looked at the gauges. The left tank fuel gauge indicated it was empty and the right tank fuel gauge indicated it was full. He immediately turned away from nearby mountains and initiated an off-field landing toward a roadway. During short final, he encountered a downdraft, and the airplane landed short of the roadway in heavy brush, substantially damaging the right wing. A postaccident wreckage examination and engine run did not reveal any anomalies with the airframe or engine that would have precluded normal operation. The accident flight was the first flight post-maintenance. The maintenance facility’s standard policy for mechanics is to place the fuel selector on the left fuel tank after conducting maintenance. In addition, the mechanic who conducted the work recalled moving the selector to the left when the airplane was moved to the tie-down area and secured. The operator reported that he specifically instructs pilots to fly with the fuel selector in the BOTH position at all times. He further mentioned that the end of the “busy” season is May 31, 2020, and that it is not uncommon for pilots to get “burned out” or “complacent” toward the end of a season. When the NTSB IIC contacted the pilot to ask additional questions about the event, he reported that he had been flying the same airplane for the last 6 months and knew it well. He said that the fuel selector was in the BOTH position before and during the flight. He said he did not note anything abnormal with the fuel gauges during the flight. Nor did the engine make any abnormal noises prior to it starting to sputter, he said it sounded as if the engine was “choking.” He further reported that after the engine quit, he noticed that the left fuel gauge indicated empty and the right indicated full, but he did not turn the selector to the right fuel tank when attempting to restart the engine. He used primer and throttle; the engine got some fuel, but it would not continue to run. When the pilot was informed of the maintenance facility’s standard procedures regarding the fuel selector placement, he stated that he saw the fuel selector was on the left tank and he switched it to BOTH before the flight. Despite the pilot saying that the fuel selector was on the BOTH position both before and during the flight, he never mentioned that it was ever on the left tank until after learning about the maintenance facility’s standard procedures. In addition, a postaccident engine examination revealed fuel in the fuel lines throughout the airframe all the way to the carburetor inlet, and the engine ran with no issue. Therefore, it is likely that the pilot did not ensure the fuel selector was in the BOTH position after it came out of maintenance, nor was he properly monitoring the fuel gauges during the flight which resulted in a total loss of engine power due to fuel starvation.

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. Fuel starvation during maneuvering defining event
  2. Loss of engine power (total) during maneuvering
  3. Off-field or emergency landing during maneuvering
  4. Collision with terrain or object (not controlled flight into terrain) during maneuvering

The NTSB's findings

  • Personnel issues › Task performance › Use of equip/info › Use of equip/system › Pilot
  • Aircraft › Fluids/misc hardware › Fluids › Fuel › Fluid management

Pilot

  • Certificate: commercial pilot
  • Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
  • Flight time: 1,054 hours in all; 728 in this make and model; 314 in the last 90 days; 83 in the last 30 days; 975 as pilot in command; 188 on instruments
  • Last flight review: August 10, 2019
  • Medical certificate: Class 1 (with waivers/limitations)
  • Seat: left
  • Injury: no injuries

The aircraft

  • Airframe total time: 15,736 hours
  • Last inspection: annual inspection, September 23, 2019; 1,089 hours since
  • Maximum gross weight: 2,400 lb
  • Seats: 2
  • Landing gear: fixed
  • Engine: Lycoming O-320 SERIES (piston); 2,504 hours total
  • Operator: Skylens LLC

The flight

  • Departed from: TUS Tucson AZ at 2:50 pm
  • Destination: TUS Tucson AZ
  • Flight plan: none

Weather at the time

  • Light: daylight
  • Wind: from 020° at 3 knots
  • Visibility: 10 statute miles
  • Sky: clear
  • Temperature: 75°F (24°C), dew point 27°F (-3°C)
  • Altimeter: 29.98 inHg
  • Observation at 4:53 pm from TUS, 14 miles away

Injuries

FatalSeriousMinorNone
Flight crew1

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

9 documents, released by the NTSB on April 5, 2022. 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.