# NTSB WPR10LA251: Cessna 210A, N6630X, Benson, AZ, May 21, 2010

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: May 21, 2010, 10:30 local (17:30 UTC)
- Place: Benson, AZ
- Coordinates: 31.999444, -110.35778 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.9994&lon=-110.3578&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report July 12, 2011
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 76076
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10LA251
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/76076/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=76076
- Page: https://openairdocs.org/ntsb/WPR10LA251

## Probable cause

A loss of engine power due to fuel starvation as a result of a loss of fuel pressure caused by the fuel pump screws being loose. Contributing to the accident was inadequate maintenance.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Fuel system: fuel pumps](https://openairdocs.org/ntsb-findings/01022822): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Cessna 210A, 1 case](https://openairdocs.org/ntsb-findings/01022822/cases.md?model=2073408), [All aircraft, 71 cases](https://openairdocs.org/ntsb-findings/01022822/cases.md)
- [Fuel system: fuel pumps](https://openairdocs.org/ntsb-findings/01022822): Aircraft › Aircraft systems · Damaged/degraded (probable cause); cases with it: [Cessna 210A, 1 case](https://openairdocs.org/ntsb-findings/01022822/cases.md?model=2073408), [All aircraft, 71 cases](https://openairdocs.org/ntsb-findings/01022822/cases.md)
- [Fuel system: fuel pressure](https://openairdocs.org/ntsb-findings/01022844): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna 210A, 1 case](https://openairdocs.org/ntsb-findings/01022844/cases.md?model=2073408), [All aircraft, 16 cases](https://openairdocs.org/ntsb-findings/01022844/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Cessna 210A, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=2073408), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md)
- [Landing: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 210A, 6 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2073408), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 210A, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073408), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 210A, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2073408), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot reported that when he initiated a turn to final approach for landing, the engine suddenly lost power. He checked the cockpit gauges and the fuel selector, before attempting an unsuccessful engine restart. Unable to reach the runway, the pilot initiated a forced landing onto a ridge. During the landing, the left main landing gear and nose landing gear separated and the airplane slid to a stop on its nose. During the postaccident examination of the engine, the fuel system was tested and the fuel manifold diaphragm was found to be brittle and stiff. The engine driven fuel pump was fuel stained and when further inspected, the four screws that hold the body of the fuel pump together were found loose. When the pump was submerged in fuel and manually rotated, it emitted fuel along with large air bubbles. The four screws were then tightened and the pump was again submerged in fuel. The fuel flowed normally without any air bubbles present. It is likely that the fuel manifold valve would require more fuel pressure than normal for it to function properly because of the fuel diaphragm’s brittleness and stiffness. It is also likely that the four loose screws on the fuel pump body allowed air to mix in with the fuel causing the pump to cavitate. Therefore, the fuel pressure dropped to a level that would cause the fuel manifold valve to close, subsequently starving the engine of fuel. An annual inspection was reported to have been completed 11.1 hours prior to the accident.

## Factual narrative

On May 21, 2010, about 1030 mountain standard time, a Cessna 210A, N6630X, lost engine power during approach to landing at Benson Municipal Airport (E95), Benson, Arizona. The airplane subsequently collided with terrain during the off airport landing, substantially damaging the left wing. The pilot was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot and one passenger received minor injuries. The local personal flight departed Benson about 1130. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot reported that he extended the downwind leg of the traffic pattern to test the landing gear warning system before he turned to the base leg. As the pilot initiated a turn to final, the engine suddenly lost power. The pilot scanned all of the gauges and confirmed the fuel selector valve was on the fullest fuel tank; he then turned on the boost pump and attempted to restart the engine, but was unsuccessful. The pilot observed a nearby road and attempted to land on it, however, the airplane landed short onto a ridge. Both the left main landing gear and the nose wheel landing gear were sheared off and the airplane slid on its nose until it came to a rest. Post accident examination of the engine by a certificated airframe and powerplant mechanic and a Federal Aviation Administration inspector reported that the fuel system was tested and the diaphragm in the fuel manifold valve was found to be brittle and stiff. The engine driven fuel pump had fuel stains on it, and when further inspected, the four screws that hold the body of the fuel pump together were found loose. The pump was submerged in fuel and manually rotated with a drill motor at 2,000 rpm; it emitted fuel along with large air bubbles. The four screws were tightened and the pump was again submerged in the fuel; it flowed normally without any air bubbles present. Examination of the airplane records indicated that an annual inspection had been completed on February 1, 2010, with a reported tach time of 4,736.7. The tach time at the time of the accident was 4,747.8.

## Aircraft

- Registration: [N6630X](https://openairdocs.org/deregistered/N6630X-2017-06-30), registration cancelled 2017-06-30, S/N 21057630, built 1960 (OpenAirDocs)
- Reported make and model: CESSNA 210A
- Registry model: [Cessna 210A](https://openairdocs.org/model/cessna-210a) (registry code 2073408) (OpenAirDocs)
- Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 21057630
- Airframe hours: 4737
- Engines: CONT MOTOR IO-470 SERIES 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Waylon D. Crump
- Registered owner: Tri Rotor Ag Services
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, February 1, 2010
- Departed: E95, Benson, AZ
- Destination: E95, Benson, AZ
- Airport: E95, Benson Municipal Airport, runway 28, 4,000 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 31; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review November 9, 2008; seat: left; flight hours: 153 total, 1 in this make and model, 118 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 3 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 27 °F
- Altimeter: 29.98 inHg
- Observed at: FHU, 24 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20100521006009A](https://openairdocs.org/incident/20100521006009A), May 21, 2010: Cessna 210A, Benson, AZ, Substantial damage. On the 21st of may 2010, N6630X made an emergency landing near Benson airport (E-95). The aircraft was configured for landing with full flaps and landing gear…

## Docket (3 files)

The files NTSB released with the investigation on May 13, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=76076. 662 KB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 354 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40347246&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Email Correspondence: Engine Exam (item 2, .PDF, 12 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40347248&FileExtension=.PDF&FileName=Email%20Correspondence%3A%20Engine%20Exam-Redacted.PDF
- Annual Inspection Logbook Entry (item 3, .PDF, 295 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40347434&FileExtension=.PDF&FileName=Annual%20Inspection%20Logbook%20Entry-Redacted.PDF

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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