# NTSB WPR09LA029: Cessna 421C, N421PC, Mesa, AZ, October 30, 2008

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 29, 2008, 19:59 local (Oct 30, 2008, 02:59 UTC)
- Place: Mesa, AZ
- Coordinates: 33.460834, -111.728332 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.4608&lon=-111.7283&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach-VFR pattern final: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330)
- Highest injury: No injuries
- Injuries: 5 uninjured
- Status: Completed, report September 30, 2009
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 69379
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA029
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/69379/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=69379
- Page: https://openairdocs.org/ntsb/WPR09LA029

## Probable cause

The failure of the hydraulic landing gear extension systems due to a ruptured line.

## Findings

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

- [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Cessna 421C, 2 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=2076016), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md)
- [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Damaged/degraded (probable cause); cases with it: [Cessna 421C, 2 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=2076016), [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.

- [Approach-VFR pattern final: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Cessna 421C, 4 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2076016), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md)
- [Landing-flare/touchdown: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Cessna 421C, 7 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=2076016), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md)
- [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Cessna 421C, 9 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=2076016), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md)

## Analysis

At the conclusion of the business flight, the pilot placed the landing gear selector in the down position. The gear did not extend. Then, the pilot attempted to extend the gear using the emergency procedure, and he was similarly unsuccessful. The pilot landed with the gear partially extended. The airplane swerved off the runway and was substantially damaged. An examination of the landing gear system revealed that an aluminum hydraulic line had ruptured at a 45-degree bend near the location of an Adel clamp. The subsequent loss of fluid rendered the primary and emergency gear extension systems inoperative.

## Factual narrative

On October 29, 2008, about 1959 mountain standard time, a Cessna 421C, N421PC, experienced the collapse of its landing gear during rollout at the Falcon Field, Mesa, Arizona. The airplane was owned and operated by Dry Force, Inc., Mesa. The airplane was substantially damaged, and neither the commercial certificated pilot nor four passengers were injured. Visual meteorological conditions prevailed at the time of the business flight, and an instrument flight rules flight plan was filed. The flight was performed under the provisions of 14 Code of Federal Regulations Part 91, and it originated from San Diego, California, about 1737 Pacific daylight time. The pilot reported to the National Transportation Safety Board investigator that, at the conclusion of the flight on approach to Falcon Field, he placed the landing gear selector in the down position. Thereafter, he observed that the landing gear's green position light failed to illuminate for the left gear. The pilot attempted to lower the gear several times and finally attempted to extend the gear using the emergency "blow down" procedure. None of the procedures worked. The pilot landed on runway 22 with a partially extended landing gear. The airplane touched down softly on the runway, but substantial structural damage occurred as the airplane swerved off the runway and slid to a stop. Belly skin was punctured, and several ribs were bent upward. The pilot reported that he smelled a strong odor of hydraulic fluid in the cabin. An examination of the landing gear system revealed that an aluminum hydraulic line associated with the gear's operation had ruptured beneath an Adel clamp. There was a crack in the line at a 45-degree bend near this location. The pilot also reported that the emergency gear extension system was rendered inoperative when the hydraulic leak occurred. The total time on the airframe and broken line was about 4,113 hours.

## Aircraft

- Registration: [N421PC](https://openairdocs.org/deregistered/N421PC-2010-09-27), registration cancelled 2010-09-27, S/N 421C0255 (OpenAirDocs)
- Reported make and model: CESSNA 421C
- Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (registry code 2076016) (OpenAirDocs)
- Category: Airplane
- Serial number: 421C0255
- Airframe hours: 4113
- Engines: Continental GSTIO-520L 375 horsepower reciprocating; Continental GSTIO-520L 375 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Dry Force Inc
- Registered owner: Dry Force Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 10, 2008, 31 hours before
- Departed: MYF, San Diego, CA
- Destination: FFZ, Mesa, AZ
- Flight plan: IFR
- Airport: FFZ, Falcon Field, runway 22L, 5,101 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review April 30, 2008; seat: left; flight hours: 12,700 total, 156 in this make and model, 11,660 as pilot in command, 74 in the last 90 days, 34 in the last 30 days, 0 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night
- Wind: calm
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 41 °F
- Altimeter: 29.97 inHg
- Observed at: FFZ

## 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 20081029850129A](https://openairdocs.org/incident/20081029850129A), Oct 29, 2008: Cessna 421C, Mesa, AZ, Substantial damage. (-23) On October 29, 2008, at 0295 zulu (1959 MST), Cessna 421C, N421PC, made a partial gear-up landing at Falcon field in Mesa, Arizona. The flight departed…

## Docket (7 files)

The files NTSB released with the investigation on August 10, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=69379. 1.3 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 531 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40304290&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Cessna 421 IPC and Service Manual (Extracts) Provided by Pilot (item 2, .PDF, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316736&FileExtension=.PDF&FileName=Cessna%20421%20IPC%20and%20Service%20Manual%20(Extracts)%20Provided%20by%20Pilot-Master.PDF
- Email from FAA to NTSB Regarding Hydraulic Leak (item 3, .PDF, 17 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316794&FileExtension=.PDF&FileName=Email%20from%20FAA%20to%20NTSB%20Regarding%20Hydraulic%20Leak-Master.PDF
- Letter to FAA Regarding Damage (item 4, .PDF, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316795&FileExtension=.PDF&FileName=Letter%20to%20FAA%20Regarding%20Damage-Master.PDF
- Letter to FAA Regarding Rib Damage (item 5, .PDF, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316796&FileExtension=.PDF&FileName=Letter%20to%20FAA%20Regarding%20Rib%20Damage-Master.PDF
- Photo 1. Partial view of airplane's crushed belly frame. (FAA photo #3656) (item 6, .PDF, 503 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316797&FileExtension=.PDF&FileName=Photo%201.%20Partial%20view%20of%20airplane%27s%20crushed%20belly%20frame.%20(FAA%20photo%20%233656)-Master.PDF
- Photo 2. Close up view of split hydraulic line (FAA photo) (item 7, .PDF, 120 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316798&FileExtension=.PDF&FileName=Photo%202.%20Close%20up%20view%20of%20split%20hydraulic%20line%20(FAA%20photo)-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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