# NTSB MIA06LA105: Cessna 421B, N988GM, Marathon, FL, May 8, 2006 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: May 8, 2006, 08:00 local (12:00 UTC) - Place: Marathon, FL - Coordinates: 24.7322222222222, -81.0363888888889 - Nearby events: https://openairdocs.org/map.md?lat=24.7322&lon=-81.0364&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed, report January 31, 2008 - Report: Approved by Office Director - Parties: Cessna, Teledyne Continental, FAA - NTSB case key (mKey): 63660 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA06LA105 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/63660/pdf - Page: https://openairdocs.org/ntsb/MIA06LA105 ## Probable cause The pilot's failure to extend the landing gear prior to landing, which resulted in the propellers striking the runway, an aborted landing, and an in-flight collision with terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Wheels up landing, landing - flare/touchdown - wheels up landing - inadvertent, pilot in command (cause) - Loss of control - in flight, landing - aborted - propeller system/accessories,blade - blade strike - In flight collision with terrain/water, descent - uncontrolled - terrain condition - water ## Analysis The commercial certificated pilot was positioning the multi-engine, retractable landing gear airplane for a corporate passenger flight under Title 14, CFR Part 91, when the accident occurred. Upon landing at the destination, the pilot aborted the landing, and after climbing to about 100 feet agl descended, impacting in a canal. A witness who was not looking towards the runway, reported hearing the sound of a twin engine airplane approaching with the engines at reduced power, and then heard a scraping noise similar to the recent gear-up landing he had witnessed. Looking toward the runway, he said the airplane was midfield, left of the runway centerline, about 20 feet in the air with the landing gear retracted, and that he saw a cloud of dust, and heard what he thought was full engine power being applied. He said the airplane climbed to about 100 feet agl, and disappeared from view. Another witness with a portable VHF radio tuned to the unicom frequency, reported hearing the pilot say he was "doing an emergency go-around." The airplane descended striking utility poles, and impacted in a saltwater canal. An examination of the airport runway revealed a set of parallel propeller strike marks. The left and right sets of marks were 109 and 113 feet long, and the mark's center-to-center measurement is consistent with the engine centerline-to-centerline measurement for the accident airplane. No landing gear marks were observed. The airplane's six propeller blades had extensive torsional twisting and bending, as-well-as extensive chord wise scratching and abrasion. Several of the blades had fractured or missing tips. An examination of the cockpit showed the landing gear retraction/extension handle was in the up/retracted position, and the landing gear extension warning horn circuit breaker was in the pulled/tripped position. The landing gear emergency extension handle was in the stowed position. The nose landing gear was damaged during final impact, and was not functional. During the postimpact examination, both the left and right main landing gear were stowed in the up-and-locked/retracted position. The landing gear were released/unlocked and operated appropriately using the emergency extension handle. An examination of the left and right main landing gear showed no damage to the wheel doors, leg doors, wheels, or tires. All linkages and locking devices were undamaged, and appeared to function normally. ## Factual narrative On May 8, 2006, about 0800 eastern daylight time, a twin-engine Cessna 421B, N988GM, operated by BCL, LLC, Pompano Beach, Florida, impacted in a canal following an aborted landing at The Florida Keys Marathon Airport, Marathon, Florida. Visual meteorological conditions prevailed, and an Instrument flight rules (IFR) flight plan was filed for the Title 14, CFR Part 91, corporate flight. The airplane sustained substantial damage, and the commercial pilot and sole pilot-rated passenger were seriously injured. The flight originated about 0720, from Pompano Beach Airpark, Pompano Beach. According to witnesses on the airport, the airplane was observed near the midfield of runway 07/25, flying eastbound approximately 20 feet above ground level (agl), with the landing gear retracted. One witness who recently witnessed a gear-up landing, but was not looking towards the runway, reported hearing the sound of a twin engine airplane approaching with the engines at reduced power as if for landing. He then heard a scraping noise similar to the recent gear-up landing he had witnessed. He said he looked toward the runway, and the accident airplane was at midfield, left of the runway centerline, and he saw a cloud of dust and heard what he thought was full engine power being applied. He reported the airplane climbed to about 100 feet agl, then disappeared from his view to the east. Another witness with a portable VHF radio, reported hearing on the unicom frequency, "gulf mike doing emergency go around." The airplane descended striking utility poles, and impacted in a saltwater canal about one mile east of the airport . An on-site investigation commenced on May 11. In attendance were representatives of the airplane and engine manufacturers. The airport runway revealed a set of parallel propeller strike marks near the area of the dust cloud observed by the witnesses. The left and right sets of marks were 109 and 113 feet long respectively, and the 16 feet,10-inch center-to-center measurement is consistent with the engine centerline-to-centerline measurement for the Cessna 421 series airplane. There were no landing gear marks present. An examination of the airplane's six propeller blades showed that all six blades had extensive torsional twisting and bending. All of the propeller blades had extensive chord-wise scratching and abrasion. Several of the blades had fractured or missing tips. An examination of the airplane's cockpit showed the landing gear retraction/extension handle was in the up/retracted position during the final impact. The landing gear extension warning horn circuit breaker was in the pulled/tripped position. The landing gear emergency extension handle was in the stowed position. During the final impact the nose landing gear was severely damaged and was not functional. At the impact site, both the left and right main landing gear were stowed in the up-and-locked/retracted position. The landing gear were released/unlocked and operated with the emergency extension handle. The main landing gear functioned appropriately. An examination of the left and right main landing gear showed no damage to the wheel doors, leg doors, wheels, or tires. All linkages and locking devices were undamaged, and appeared to function normally. ## Aircraft - Registration: [N988GM](https://openairdocs.org/deregistered/N988GM-2009-11-16), registration cancelled 2009-11-16, S/N 421B0535, built 1973 (OpenAirDocs) - Reported make and model: Cessna 421B - Registry model: [Cessna 421B](https://openairdocs.org/model/cessna-421b) (registry code 2076014) (OpenAirDocs) - Registry engine: [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c) (registry code 17035, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 421B0535 - Airframe hours: 5307 - Engines: Continental GTSIO-520-H 375 horsepower reciprocating - Damage: Substantial damage - Flight: Executive/Corporate, Part 91 - Registered owner: Bcl, LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 1, 2006 - Departed: KPMP, Pompano Beach, FL - Destination: KMTH, Marathon, FL - Flight plan: IFR - Airport: MTH, Marathon, runway 070, 5,000 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: serious; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 1, 2006; seat: left; flight hours: 1,450 total, 1,100 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 68 °F - Altimeter: 30.00 inHg - Observed at: KMTH ## 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 20060508006809A](https://openairdocs.org/incident/20060508006809A), May 8, 2006: Cessna 421B, Marathon, FL, Destroyed. (-23) Gear was not extended. Aircraft propellers came into contact with the runway and pilot initiated a go-around, became airborne but was unable to gain… 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.