# NTSB ATL04LA148: Cessna 401B, N7983Q, Naples, FL, July 10, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 10, 2004, 09:20 local (13:20 UTC) - Place: Naples, FL - Coordinates: 26.1525, -81.775001 - Nearby events: https://openairdocs.org/map.md?lat=26.1525&lon=-81.7750&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report September 13, 2005 - Report: Approved by Office Director - Parties: Miami FSDO - NTSB case key (mKey): 59850 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL04LA148 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59850/pdf - Page: https://openairdocs.org/ntsb/ATL04LA148 ## Probable cause The fracture of the right landing gear down lock stud which resulted in the right main landing gear collapse during landing roll. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - roll - landing gear,gear locking mechanism - failure,total (cause) - Gear collapsed, landing - roll - Dragged wing,rotor,pod,float or tail/skid, landing - roll ## Analysis During landing roll, a vibration was felt that simulated a "wheel shimmy condition". According to the pilot, as the airplane crossed the intersection of runway 14 and runway 23, the airplane became "light". As the pilot attempted to maintain control of the airplane, the right wing collided with the runway and the airplane slid to the right and came to a stop in the grass on the south side of the intersection of runway 14 and taxiway "A", about 2,650 feet from the approach end of runway 14. The pilot did not report any mechanical malfunctions with the airplane prior to the accident. Examination of the airplane revealed damaged to the propeller, a broken drag brace, the left flap bent upwards, damage to the underbelly of the fuselage, the right main gear collapsed and the right elevator tip scraped. Also, the right wing inboard was bent, right aileron was damaged and right flap and right wing rear spar was damaged. Further examination of the right landing gear assembly revealed that the down lock adjustment stud was broken. According to a mechanic, the visual examination of the stud fracture face disclosed that approximately 3/4 of the fracture face appeared to be old, and 1/4 of the fracture face appeared to be a fresh fracture. The maintenance history of the down lock adjustment stud was not determined nor were subsequent efforts to secure the fractured stud for further examinations successful. ## Factual narrative HISTORY OF FLIGHT On July 10, 2004 at 0920 eastern daylight time, a Cessna 401B, N7983Q, registered to and operated by Parrot Air, LLC right landing gear collapsed during landing roll on runway 14 at Naples Municipal Airport, Naples, Florida. The flight operated under the provisions of Title 14 CFR Part 91. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed. The airplane was substantially damaged. The pilot, pilot rated passenger and other passengers were not injured. The flight originated from Key West International Airport, Key West, Florida, on July 10, 2004 at 0850. The personal flight from Key West to Naples was uneventful, however, the pilot stated that during landing roll, there was a vibration that felt like a "wheel shimmy condition". According to the pilot, as the airplane crossed the intersection of runway 14 and runway 23, the airplane became "light". As the pilot attempted to maintain control of the airplane, the right wing collided with the runway and the airplane slid to the right and came to a stop in the grass on the south side of the intersection of runway 14 and taxiway "A", about 2,650 feet from the approach end of runway 14. PERSONNEL INFORMATION Review of information on file with the FAA Airman's Certification Division, Oklahoma City, Oklahoma, revealed that the airman held a private pilot certificate with ratings for airplane single engine land, airplane multiengine land and instrument airplane. His pilot certificate was issued on May 25, 2004. The review of medical records on file with the FAA revealed the pilot held a third class medical certificate issued on January 28, 2004 with the limitation that the pilot must wear corrective lenses. The pilot reported having a total flight time of 607 hours with 31.4 hours in a Cessna 401B. Review of information on file with the FAA Airman's Certification Division, Oklahoma City, Oklahoma, revealed that the co-pilot held a commercial pilot certificate with ratings for airplane single engine land, airplane multiengine land and instrument airplane. His last biennial flight review at the time of the accident was February 19, 2004 in a Piper Aztec, PA 23-250. The review of medical records on file with the FAA revealed the co-pilot held a third class medical dated August 2002 with the limitation that he must wear corrective lenses. The co-pilot reported having a total flight time of 1,393 hours with 115 hours in a Cessna 401B. AIRCRAFT INFORMATION The airplane was a fixed wing, multiengine, 1971 Cessna 401B. It's maximum gross weight was 6,210 pounds and it had 7 seats installed. The airplane was equipped with two TSIO-520E reciprocating, 300 horsepower engines manufactured by Teledyne Continental Motors. The last recorded annual inspection was conducted on December 1, 2003. The airframe total time was 6,320.3 hours and there was 31.4 hours recorded since that last inspection. METEOROLOGICAL INFORMATION The weather reporting facility was at the Naples Municipal Airport in Naples, Florida. The 1353 Zulu surface weather observation was: winds variable at 03 knots, visibility 10 statute miles, cloud condition clear, temperature 29-degrees Celsius, dewpoint 25-degrees Celsius, and altimeter 30.10 inches of mercury. Visual meteorological conditions prevailed at the time of the accident. WRECKAGE AND IMPACT INFORMATION The post-accident examination of the airplane revealed damaged to the propeller, a broken drag brace, the left flap bent upwards, damage to the underbelly of the fuselage, the right main gear collapsed and the right elevator tip scraped. Also, the right wing inboard was bent, right aileron was damaged and right flap and right wing rear spar was damaged. The pilot did not report any mechanical malfunctions with the airplane prior to the accident. Further examination of the right landing gear assembly revealed that the down lock adjustment stud was broken. A visual examination of the stud fracture face disclosed that approximately 3/4 of the fracture face appeared to be old, and 1/4 of the fracture face appeared to be a fresh fracture. The maintenance history of the down lock adjustment stud was not determined nor was subsequent efforts to secure the fractured stud for further examination successful. ## Aircraft - Registration: [N7983Q](https://openairdocs.org/aircraft/N7983Q), registered now, S/N 401B0202, built 1971 (OpenAirDocs) - Reported make and model: Cessna 401B - Registry model: [Cessna 401B](https://openairdocs.org/model/cessna-401b) (registry code 207590E) (OpenAirDocs) - Registry engine: [TCM Cont TSIO-520 series](https://openairdocs.org/engine/tcm-cont-tsio-520-series) (registry code 17060, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 0202 - Airframe hours: 6320.3 - Engines: Continental TSIO 520E 300 horsepower reciprocating; Continental TSIO-520E 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Parrott Air, LLC - Registered owner: Parrott Air LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 1, 2003, 31.4 hours before - Departed: EYW, Key West, FL - Destination: APF, Naples, FL - Airport: KAPF, Naples Municipal Airport, runway 14, 5,000 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; last flight review March 7, 2004; seat: left; flight hours: 607 total, 31 in this make and model - Co-pilot; age 50; injuries: none; commercial, private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, expired; last flight review February 19, 2004; seat: right; flight hours: 1,393 total, 115 in this make and model, 1,312 as pilot in command, 20 in the last 90 days, 9 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 3 knots - Visibility: 10 statute miles - Temperature: 84 °F, dew point 77 °F - Altimeter: 30.10 inHg - Observed at: KAPF ## 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 20040710017369A](https://openairdocs.org/incident/20040710017369A), Jul 10, 2004: Cessna 401B, Naples, FL, Substantial damage. (-23) During the landing rollout, the pilot reported that the right gear started to shudder, including a flat tire. Then the right gear collapsed, causing the… 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.