Cessna 172RG accident near Grand Canyon, Arizona, May 7, 2005
On May 7, 2005 at about 11:37 pm local time, a Cessna 172RG, registered N4970V, was substantially damaged in an accident near Grand Canyon, Arizona (Grand Canyon airport). It was a personal flight under general aviation rules (Part 91). 3 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the pilot-in-command's failure to properly lean the mixture, which resulted in a power deficiency, a degraded climb capability, and the inability to attain/maintain an adequate airspeed that led to a stall/mush condition while departing during high density altitude conditions. Also causal, was the pilot-in-command's inaccurate preflight performance and weight and balance calculations.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 7, 2005 · about 11:37 pm local time
- Place
- Grand Canyon, Arizona · Grand Canyon · map
- Type
- Accident
- Injuries
- 3 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172RG · all 172RGs on the register
- Registration
- N4970V · no longer on the register · serial 172RG60435
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During an attempted takeoff, the airplane settled back to the ground and impacted a field about 1 mile south of the airport. The pilot reported that prior to the flight he performed performance calculations for the airplane to ensure that it was capable of departing the higher altitude airport. Performance calculations indicated that with the gross weight near the specified maximum, the airplane would need about 4,500 feet to take off. Prior to departure, the pilot configured the airplane with the flaps retracted and the mixture control in the full forward (rich) position. The Safety Board calculated gross weight of the airplane was 2,767 pounds (117 pounds over the airplane's maximum certified gross weight of 2,650 pounds). The pilot reported that his instructor told him to use an airplane empty weight of 1,624 pounds in his calculations, which the instructor said was typical for the airplane type and could be used for this specific airplane. Using this weight, the airplane would still have been 47 pounds in excess of the maximum gross weight. Performance calculations using the Pilot Operating Handbook (POH) for the airplane indicated a ground roll of 3,118 feet (zero wind 3,464 feet) and the distance to clear a 50- foot obstacle was 3,741 feet (zero wind 4,157 feet) with a predicted 327 feet per minute rate of climb. The POH notes that prior to takeoff from fields above 3,000 feet elevation, the mixture should be leaned to give maximum power in a full throttle, static run-up. The runway the pilot attempted to depart from was 8,999 feet in length with an elevation of 6,609 feet mean sea level (msl). The density altitude was calculated to be 7,728 feet msl. Following the accident, the spark plugs were removed and were black and sooty, an indication that the engine was running rich. The engine was then test-run with no operational anomalies noted.
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
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 206 hours in all; 51 in this make and model; 10 in the last 90 days; 8 in the last 30 days; 158 as pilot in command
- Last flight review: April 1, 2005
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 5,716 hours
- Last inspection: 100-hour inspection, March 1, 2005; 64 hours since
- Maximum gross weight: 2,650 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming O-360-F1A6 (piston); 0 hours total
The flight
- Departed from: KGCN Grand Canyon AZ at 11:36 pm
- Destination: KCRQ Palomar Airport CA
- Flight plan: VFR
- Runway 21, 8,999 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 260° at 9 knots, gusting 15
- Visibility: 10 statute miles
- Sky: overcast at 8,000 ft; scat at 5,500 ft
- Temperature: 54°F (12°C), dew point 30°F (-1°C)
- Altimeter: 30.01 inHg
- Observation at 10:54 pm from KGCN
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.