# NTSB FTW98LA335: Cessna 172M, N5147N, Franktown, CO, July 27, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 26, 1998, 22:00 local (Jul 27, 1998, 04:00 UTC) - Place: Franktown, CO - Coordinates: 39.380119, -104.749984 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.3801&lon=-104.7500&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 43549 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA335 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43549/pdf - Page: https://openairdocs.org/ntsb/FTW98LA335 ## Probable cause Flight at an altitude insufficient to clear terrain. Factors were the pilot's failure to reset or correct a precessing directional gyro, his becoming lost/disoriented, and dark night light conditions. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, cruise - heading indicator - not set, pilot in command (contributing factor) - flight/nav instruments,directional gyro - false indication (contributing factor) - became lost/disoriented, pilot in command (contributing factor) - clearance - not maintained, pilot in command (cause) - light condition - dark night (contributing factor) ## Analysis The pilot flew to Centennial Airport to practice touch and go landings. He departed the airport traffic pattern on an easterly heading, tuned the no. 1 navigation receiver to the Falcon Vortac, and rotated the OBS (Omni Bearing Selector) to 350 degrees. It was his intention to cross the 360 degree radial (sic, 180 degree radial), and then fly direct to the Falcon Vortac and direct to Front Range Airport. This route would avoid the Buckley ANG and Denver International Airport airspace. After he flew what he thought was an easterly heading the evidence indicates it was most probably a south-southeasterly heading) for 8 to 10 minutes and noting the CDI (Course Deviation Indicator) needle had failed to center, he made a shallow 360 degree turn and looked for recognizable landmarks. He then rotated the OBS to go direct to the Falcon Vortac, 'reset the directional gyro to the magnetic compass, making a significant correction,' and descended to 6,500 feet msl. After flying this heading for a minute, the airplane collided with terrain 11 miles southeast of Centennial Airport. Weather conditions at Centennial Airport consisted of clear skies and greater than 10 miles visibility. The pilot said it was a dark night. ## Factual narrative On July 26, 1998, approximately 2200 mountain daylight time, a Cessna 172M, N5147N, collided with terrain while in cruise flight near Franktown, Colorado. The private pilot, the sole occupant onboard, was not injured. The aircraft was being operated as a personal flight under Title 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated at Front Range Airport, Watkins, Colorado, at 2045. According to the pilot's accident report, he had flown to Centennial Airport to practice touch and go landings. He said he departed the airport traffic pattern on an easterly heading, tuned the no. 1 navigation receiver to the Falcon Vortac, and rotated the OBS (Omni Bearing Selector) to 350 degrees. It was his intention to cross the 360 degree radial (sic, 180 degree radial), and then fly direct to the Falcon Vortac and direct to Front Range Airport. By flying this route, he would avoid the Buckley ANG and Denver International Airport airspace. After he flew what he thought was an easterly heading (the evidence indicates it was most probably a south-southeasterly heading) for 8 to 10 minutes and noting the CDI (Course Deviation Indicator) needle had failed to center, he made a shallow 360 degree turn and looked for recognizable landmarks. He then rotated the OBS to go direct to the Falcon Vortac and "reset the directional gyro to the magnetic compass, making a significant correction." (In a telephone interview with the pilot, he said he then descended to 6,500 feet msl). After flying this heading for a minute, the airplane collided with terrain. The accident location was near Franktown, Colorado, about 11 miles south-southeast of Centennial Airport (see the attached Denver TCA chart). Weather conditions at Centennial Airport (the point of departure) consisted of clear skies and greater than 10 miles visibility. The pilot said it was a dark night. Airplane damage consisted of a bent propeller, nose landing gear bent aft, broken windshield, crumbled engine cowling, and a broken left wing tip. ## Aircraft - Registration: [N5147N](https://openairdocs.org/aircraft/N5147N), registered now, S/N 17261417 (OpenAirDocs) - Reported make and model: Cessna 172M - Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs) - Category: Airplane - Serial number: 17261417 - Airframe hours: 9078 - Engines: Lycoming O-320-E2D 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Flight Training, Inc. - Registered owner: Peter Carlson - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 6, 1998, 90 hours before - Departed: FTG, WATKINS, CO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 22; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 200 total, 90 in this make and model, 170 as pilot in command, 51 in the last 90 days, 37 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night/dark - Wind: 180° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 59 °F - Altimeter: 30.00 inHg - Observed at: APA, 11 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 19980726017679A](https://openairdocs.org/incident/19980726017679A), Jul 26, 1998: Cessna 172M, Franktown, CO, Substantial damage. (-23)The pilot had been at centennial airport to practice touch and go landings. After departing the airport eastbound, he became disoriented. The pilot… ## Other investigations on N5147N (1) 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. - [NTSB GAA18CA141](https://openairdocs.org/ntsb/GAA18CA141), Feb 23, 2018: Cessna 172 (N5147N), Show Low, AZ, substantial damage. Probable cause: The flight instructor’s failure to maintain directional control during the landing roll in gusting crosswind and tailwind conditions. 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.