# NTSB ERA11LA221: Cessna 310F, N6781X, Sanford, FL, April 1, 2011

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 1, 2011, 15:45 local (19:45 UTC)
- Place: Sanford, FL
- Coordinates: 28.780307, -81.270492 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=28.7803&lon=-81.2705&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report August 15, 2012
- Report: Approved by Office Director
- NTSB office: Eastern Region Aviation
- Parties: FAA/FSDO
- NTSB case key (mKey): 78739
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA11LA221
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78739/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78739
- Page: https://openairdocs.org/ntsb/ERA11LA221

## Probable cause

The failure of the nose landing gear due to inadequate servicing of the nose gear strut reservoir.

## Findings

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

- [Landing gear system: nose/tail gear strut/axle](https://openairdocs.org/ntsb-findings/01023222): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Cessna 310F, 1 case](https://openairdocs.org/ntsb-findings/01023222/cases.md?model=2074216), [All aircraft, 36 cases](https://openairdocs.org/ntsb-findings/01023222/cases.md)
- [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Other (probable cause); cases with it: [Cessna 310F, 1 case](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=2074216), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md)
- [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna 310F, 1 case](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=2074216), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md)

## Sequence of events

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

- [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Cessna 310F, 1 case](https://openairdocs.org/ntsb-events/094/sequence.md?model=2074216), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md)

## Analysis

The flight instructor and private pilot were performing touch-and-go landings. While retracting the landing gear, they heard a loud bang. The gear-up light illuminated, indicating that all three landing gears were retracted and the doors were closed. The instructor concluded that the noise came from the landing gear doors closing into each other. The flight continued, and two more landings were planned: one touch-and-go and one full stop. The landing gear appeared to operate normally during the touch-and-go. Upon extending the gear for the full stop landing, the gear-down light failed to illuminate. After checking the gear down indicating system, a visual check with the tower controllers confirmed that all three landing gears were in the down position. During touchdown, the nose gear collapsed. A postaccident examination of the nose gear assembly revealed that the nose landing gear strut reservoir lacked air pressure and the fluid level was very low. This underserviced condition caused binding in the nose gear fork assembly and failure of a nose gear push rod, which prevented the nose gear from extending to the full down and locked position.

## Factual narrative

On April 1, 2011, at 1545 eastern daylight time, a Cessna 310F, N6781X, registered to a private individual, incurred substantial damage to the fuselage after the nose gear collapsed during landing rollout at Sanford Orlando International Airport (SFB), Sanford, Florida. The certified flight instructor (CFI) and his private pilot-rated dual student were not injured. The instructional flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated from SFB at 1500. The CFI reported that after takeoff, while retracting the landing gear, a loud “bang” was heard. It was assumed by the CFI that the noise came from the landing gear doors closing into each other. The gear-up light illuminated indicating that the landing gear were retracted and the doors were closed. The flight returned to SFB for two planned landings; first a touch-and-go and then a full stop. On the first landing; the gear were extended and a gear-down light illuminated. A touch-and-go was conducted without incident. Upon extending the gear for the second landing, the gear-down light failed to illuminate. The landing gear were recycled, and the gear light gave a gear-up indication. Another gear extension was attempted, and a gear-down indication was not received. The CFI contacted the SFB tower to request a low fly-by for a visual inspection of the gear position. The tower controller reported all three gear were down and the airplane was cleared to land. The touchdown on the main gear was normal; but as weight was applied to the nose wheel, the nose gear collapsed. The airplane was examined by a Federal Aviation Administration (FAA) inspector under the direction of a NTSB investigator. The airplane was raised using aircraft jacks to take the weight off of the wheels. The nose gear shock strut trunnion assembly remained in the compressed position. Approximately one inch of the strut trunnion surface was visible. An attempt to retract the nose landing gear was unsuccessful, due to the strut fork assembly coming into contact with the nose landing gear door attachment brackets. The nose strut trunnion was manually extended out of the cylinder until approximately three inches of the piston surface was visible. The nose landing gear assembly was then manually raised up into the wheel well area and fully retracted. The nose landing gear strut trunnion reservoir was checked for air pressure and was totally empty of air. The strut trunnion reservoir was checked for fluid which was found to be very low. There were no signs of fluid leakage around the nose landing gear strut trunnion. A review of the maintenance logbooks did not reveal any prior discrepancies with the nose landing gear assembly.

## Aircraft

- Registration: [N6781X](https://openairdocs.org/deregistered/N6781X-2017-10-20), registration cancelled 2017-10-20, S/N 310-0081, built 1961 (OpenAirDocs)
- Reported make and model: CESSNA 310F
- Registry model: [Cessna 310F](https://openairdocs.org/model/cessna-310f) (registry code 2074216) (OpenAirDocs)
- Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 310-0081
- Airframe hours: 3245
- Engines: CONT MOTOR I0-470 SERIES 260 horsepower reciprocating; CONT MOTOR I0-470 SERIES 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Edward Moon
- Registered owner: Edward Moon
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, February 11, 2011, 23 hours before
- Departed: SFB, Sanford, FL
- Destination: SFB, Sanford, FL
- Airport: SFB, Orlando Sanford International, runway 27, 9,601 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Flight instructor; age 43; injuries: none; flight instructor, airline transport, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review October 19, 2010; seat: right; flight hours: 2,400 total, 300 in this make and model, 1,965 as pilot in command, 40 in the last 90 days, 20 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 11 knots, gusting 19
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 46 °F
- Altimeter: 29.84 inHg
- Observed at: SFB

## 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 20110401005319A](https://openairdocs.org/incident/20110401005319A), Apr 1, 2011: Cessna 310F, Sanford, FL, Substantial damage. On April 01, 2011, at approximately 16:15PM, while conducting a multi-engine training flight, the pilot in command of aircraft N6781X entered the landing…

## Docket (6 files)

The files NTSB released with the investigation on June 26, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78739. 3.2 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 655 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355848&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Reports from Federal Agencies-FAA statement (item 2, .PDF, 953 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355849&FileExtension=.PDF&FileName=Reports%20from%20Federal%20Agencies-FAA%20statement-Redacted.PDF
- Aicraft logbooks (item 3, .PDF, 598 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355860&FileExtension=.PDF&FileName=Aicraft%20logbooks-Redacted.PDF
- Photo 1-Courtesy of FAA-Strut fully compressed after recovery (item 4, .PDF, 210 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355856&FileExtension=.PDF&FileName=Photo%201-Courtesy%20of%20FAA-Strut%20fully%20compressed%20after%20recovery-Master.PDF
- Photo 2-Courtesy of FAA-Compressed strut not fully retracted (item 5, .PDF, 440 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355858&FileExtension=.PDF&FileName=Photo%202-Courtesy%20of%20FAA-Compressed%20strut%20not%20fully%20retracted-Master.PDF
- Photo 3-Courtesy of FAA-Strut extended and fully retracted (item 6, .PDF, 339 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355859&FileExtension=.PDF&FileName=Photo%203-Courtesy%20of%20FAA-Strut%20extended%20and%20fully%20retracted-Master.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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