# NTSB DEN05LA140: Cessna A185F, N4807, Boulder, CO, September 14, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 14, 2005, 15:45 local (21:45 UTC) - Place: Boulder, CO - Coordinates: 40.039443, -105.22583 - Nearby events: https://openairdocs.org/map.md?lat=40.0394&lon=-105.2258&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 28, 2006 - Report: Approved by Office Director - Parties: Denver Flight Standards District Office - NTSB case key (mKey): 62486 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN05LA140 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/62486/pdf - Page: https://openairdocs.org/ntsb/DEN05LA140 ## Probable cause the pilot's improper flare which resulted in a hard landing and his subsequent failure to recover from the bounced landing. Contributing factors were the pilot's improper in-flight decision to land in deteriorating weather conditions, turbulence associated with thunderstorms, tailwind, and the wet runway. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, approach - vfr pattern - final approach - in-flight planning/decision - improper, pilot in command (contributing factor) - weather condition - turbulence (contributing factor) - Hard landing, landing - flare - improper, pilot in command (cause) - Loss of control - on ground/water, landing - recovery from bounced landing - not performed, pilot in command (cause) - airport facilities,runway/landing area condition - wet (contributing factor) - weather condition - tailwind (contributing factor) - On ground/water encounter with terrain/water, landing - terrain condition - runway ## Analysis On the final approach leg, the airplane encountered "light to moderate" turbulence and the airspeed "dropped." The pilot stated that the airplane touched down on the right main landing gear and the airplane proceeded to bounce. Both main gears touched down on the wet runway and the airplane drifted from left to right. The airplane became airborne and "turned approximately 10 to 15 degrees to the right and almost instantly set back down on the runway." The pilot said he applied full right aileron and full left rudder and the airplane turned sharply to the right causing the left wing to scrape on the tarmac. The airplane exited the right side if the runway and came to rest oriented at a 90 degree angle to the runway approximately 30 feet from the edge of the runway. According to a pilot who witnessed the accident, he said the airplane landed with a "tailwind." ## Factual narrative On September 14, 2005, approximately 1545 mountain daylight time, a Cessna A185F, N4807, registered to and piloted by a private pilot, was substantially damaged when it ground looped during landing at Boulder Municipal Airport (1V5), Boulder, Colorado. Visual meteorological conditions prevailed at the time of the accident. The personal cross-country flight was being conducted under Title 14 CFR Part 91. An instrument flight rules (IFR) flight plan had been filed. The pilot and passenger were not injured. The flight departed Springfield, Missouri (SGF), approximately 1110. According to the accident report submitted by the pilot, he was "routed" to the north as he approached Denver due to thunderstorm and traffic activity. Monitoring 1V5's automated weather observation station (AWOS), he learned there was lightning to the west. Approximately 12 miles out, the pilot was cleared to 1V5. "Denver asked if I wished to close my flight plan which I declined as I was concerned about the crosswind at 1V5, thinking I might have to divert to the Jefferson County Municipal Airport (BJC)." While monitoring AWOS, the wind shifted and lightning was reported to the north, south, and west. The pilot observed wind and rain as he approached 1V5 from the east. The pilot said he "joined on [a] left downwind leg for runway 08, checked the windsock and noted the wind to be a crosswind as reported on AWOS." While on the downwind leg, the airplane entered light rain. The pilot said the visibility was still "good", but he noticed heavier rain showers over 1V5. On final approach leg, the airplane encountered "light to moderate" turbulence and airspeed decayed. The airplane touched down on its right main landing gear and started bouncing. When both main gears touched down on the wet runway, the airplane drifted from left to right. The airplane became airborne and "turned approximately 10 to 15 degrees to the right and almost instantly put back on the runway." The pilot said he applied full right aileron and full left rudder and the airplane turned sharply to the right and the left wing scraped the tarmac. The airplane departed the right side of the runway and came to rest 30 feet off the edge and at a 90 degree angle to the runway. According to a pilot who witnessed the accident, the airplane landed with a "tailwind." According to the pilot, the left wingtip was bent upwards approximately 5 degrees, the left outboard aileron tip sustained damage, the left main landing gear was bent, and the tip of the left elevator was bent up approximately 3 degrees. ## Aircraft - Registration: N4807 (not matched to a registry record) - Reported make and model: Cessna A185F - Category: Airplane - Serial number: 18503532 - Airframe hours: 6053.9 - Engines: Teledyne Continental IO-520-D 280 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Michael C. Gerhardt, doing business as G-4 Air LLC - Registered owner: G-4 Air LLC. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 1, 2004, 176.6 hours before - Departed: SGF, Springfield, MO - Destination: 1V5, Boulder, CO - Flight plan: IFR - Airport: 1V5, Boulder Municipal Airport, runway 08, 4,100 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 1, 2005; seat: left; flight hours: 1,100 total, 218 in this make and model, 906 as pilot in command, 101 in the last 90 days, 28 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 18 knots, gusting 22 - Visibility: 20 statute miles - Lowest ceiling: 6,000 ft broken - Temperature: 54 °F, dew point 41 °F - Altimeter: 30.10 inHg - Observed at: BJC, 9 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 20050914021149A](https://openairdocs.org/incident/20050914021149A), Sep 14, 2005: Cessna A185F, Boulder, CO, Substantial damage. (-23) On September 14, 2005, at 1545 mountain daylight time, a Cessna A185F, N4807, was substantially damaged during landing roll out at the Boulder Municipal… 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.