# NTSB FTW97LA357: Mooney M20M, N9140Z, Broomfield, CO, September 20, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 20, 1997, 10:53 local (16:53 UTC) - Place: Broomfield, CO - Coordinates: 39.890495, -105.109878 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.8905&lon=-105.1099&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 2, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 20352 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW97LA357 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20352/pdf - Page: https://openairdocs.org/ntsb/FTW97LA357 ## Probable cause The pilot's flaring of the airplane prematurely at a low airspeed that resulted in a hard landing, and an inadvertent stall during the attempted go-around and subsequent loss of control. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - lowering of flaps - performed, pilot in command - speed brakes - selected, pilot in command - flare - premature, pilot in command (cause) - airspeed - inadequate, pilot in command (cause) - In flight collision with terrain/water, landing - flare/touchdown - go-around - initiated, pilot in command - stall - inadvertent, pilot in command (cause) - aircraft control - not maintained, pilot in command (cause) ## Analysis The pilot said his landing approach speed was between 80 and 90 knots, and he used full flaps before deploying the speed brakes. The airplane landed hard and bounced twice. The pilot applied full power in an attempt to abort the landing. The airplane stalled, landed on the nose gear, and veered off the runway. According to the Mooney Aircraft Corporation, normal approach speed with full flaps (33 degrees) deployed is 75 knots. The speed brakes may also be deployed during the landing approach. ## Factual narrative On September 20, 1997, at 1053 mountain daylight time, a Mooney M20M, N9140Z, was substantially damaged when it collided with terrain while landing at Broomfield, Colorado. The private pilot and two passengers were not injured. Visual meteorological conditions prevailed, and an IFR flight plan had been filed for the personal flight conducted under Title 14 CFR Part 91. The flight originated at Tulsa, Oklahoma, at 0845 central daylight time. The following is based on a telephone interview with the pilot, and his accident report. The pilot said his approach speed was between 80 and 90 knots and he used full flaps, then deployed the speed brake. "Ground effect floated us to the point that airspeed was too slow," he wrote. The airplane landed approximately 2,500 feet down runway 11L. The pilot said the airplane "bounced on the main gear two times." The pilot applied full power to abort the landing. The airplane stalled, landed on the nose gear, and veered left off the runway at taxiway A-13 before coming to a halt facing south. According to a Mooney Aircraft Company spokesman, normal approach speed is 80 KIAS (knots indicated airspeed) with 10 degrees flaps deployed, and 75 KIAS with 33 degrees (full) flaps deployed. The spokesman said the airplane is equipped with "speed brakes," not "spoilers," and may be deployed during the landing approach. ## Aircraft - Registration: [N9140Z](https://openairdocs.org/aircraft/N9140Z), registered now, S/N 27-0085, built 1991 (OpenAirDocs) - Reported make and model: Mooney M20M - Registry model: [Mooney M20M](https://openairdocs.org/model/mooney-m20m) (registry code 5870222) (OpenAirDocs) - Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 0085 - Airframe hours: 970 - Engines: Lycoming TIO-540-AF1A 270 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Troy W. Wormell - Airworthiness certificate: Standard, Normal - Departed: RVS, TULSA, OK - Destination: BJC - Flight plan: IFR - Airport: BJC, Jeffco, runway 11L, 9,000 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 385 total, 65 in this make and model, 300 as pilot in command, 60 in the last 90 days, 30 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 6 knots - Visibility: 15 statute miles - Lowest ceiling: 1,000 ft broken - Temperature: 54 °F, dew point 46 °F - Altimeter: 30.00 inHg - Observed at: BJC ## 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 19970920047929A](https://openairdocs.org/incident/19970920047929A), Sep 20, 1997: Mooney M20M, Broomfield, CO, Substantial damage. (-16) A poorly planned and executed landing approach resulted in a porpoise landing. The pilot attempted to abort the landing, but was unsuccessful. 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.