# NTSB CEN18LA335: Cessna R172E, N146AC, Colorado Springs, CO, August 16, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 16, 2018, 11:00 local (17:00 UTC) - Place: Colorado Springs, CO - Coordinates: 38.973331, -104.819999 - Nearby events: https://openairdocs.org/map.md?lat=38.9733&lon=-104.8200&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 20, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Continental Motors, FAA Denver FSDO - NTSB case key (mKey): 98087 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN18LA335 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98087/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98087 - Page: https://openairdocs.org/ntsb/CEN18LA335 ## Probable cause The airplane’s failure to maintain a climb after takeoff, which resulted in a forced landing on unsuitable terrain; the reason for the airplane’s failure to climb could not be determined based on the available evidence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna R172E, 2 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2072413), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Effect on operation; cases with it: [Cessna R172E, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=2072413), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) (defining event); cases with it: [Cessna R172E, 2 cases](https://openairdocs.org/ntsb-events/000/sequence.md?model=2072413), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna R172E, 3 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072413), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna R172E, 6 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072413), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The flight instructor reported that the student pilot was flying the airplane during the first takeoff of an instructional flight. The engine sounded normal and was operating properly with a fuel flow of about 14 gallons per hour and between 2,800 to 2,900 rpm. The instructor stated that, during the takeoff roll, the student rotated the airplane about 60 mph. Initially, the pitch was high, but then the student lowered the airplane's nose to the horizon. Subsequently, the airplane reached about 100 ft above ground level but then stopped climbing, and the airspeed began decreasing. The instructor reported that the fuel flow and rpm were still normal. The instructor stated that he took the flight controls, lowered the flaps to 10°, and lowered the airplane's nose to hold 55 to 60 mph, "hoping that the ground effect would enable a speed increase." He turned the airplane right to avoid a tree line and conducted a forced landing in a field. The airplane landed on its main wheels, but the nose landing gear impacted rough terrain, and the airplane nosed over, which resulted in substantial damage to the wings and fuselage. Postaccident examination of the airframe, engine, and propeller governor revealed no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation. Therefore, the reason for the airplane's failure to maintain a climb could not be determined. ## Factual narrative On August 16, 2018, about 1100 mountain daylight time, a Cessna R172E, N146AC, sustained substantial damage during a forced landing after takeoff from the USAF Academy Airfield (AFF), Colorado Springs, Colorado. The flight instructor and student pilot were not injured. The airplane was owned and operated by the United States Air Force under the provisions of Title 14 Code of Federal Regulations Part 91 as an instructional flight. Visual meteorological conditions prevailed at the time of the flight, which was not on a flight plan. The flight was departing from AFF on a local flight. The flight instructor reported that the preflight and run-up were normal. He stated that he intended to stay in the traffic pattern to practice landings. He reported that the student pilot was flying the airplane during takeoff from the 4,480 ft by 75 ft asphalt runway. The engine was operating properly with a fuel flow of about 14 gallons per hour and 2,800 – 2,900 rpm, and the engine sounded normal. During the takeoff roll, the student pilot rotated about 60 mph. Initially, the pitch was high but then she lowered the nose to the horizon. The flight instructor reported that the airplane attained about 100 ft of altitude above ground level; however, the airplane was not climbing, and the airspeed was decreasing with normal fuel flow and rpm. The flight instructor took the controls, lowered the flaps to 10°, and lowered the nose to hold 55 – 60 mph, "hoping that the ground effect would enable a speed increase." He turned the airplane to the right to avoid a tree line and executed a forced landing in a field. The airplane landed on its main wheels, but the nose landing gear impacted rough terrain and the airplane nosed over, resulting in substantial damage to the wings and fuselage. The airplane's maintenance logbooks indicated that the last annual maintenance inspection was performed on January 7, 2018. The airplane had a total time of 10,571.8 hours with an engine hour meter indicating 1,566.6 hours. The engine logbook indicated that the engine had been installed on the airplane during the last annual maintenance inspection on January 7, 2018. The engine was a 210 horsepower Continental IO-360-DB, serial number 808785-R, with a rated rpm of 2,800 rpm. The engine had 5,680.1 hours total time and 0.0 hours since major overhaul. The tach time on the day of the accident was 1,634.9 hours and it had operated 68.3 hours since the last annual inspection. The engine was shipped to the manufacturer for an examination and an engine run in a test stand. During the initial engine run, the engine was able to reach full rpm and produced rated horsepower; however, during subsequent engine runs, it only reached 2,600 rpm. The fuel system was checked, and it was determined that two fuel nozzles were partially clogged. The fuel nozzles were cleaned, and the engine was run again on the test stand. The engine operated normally and reached approximately 2,830 rpm. The engine power wasreduced to idle speed and advanced to full throttle several times. The engine responded without hesitation and reached over 2,800 rpm each time the throttle was advanced to full throttle. The propeller governor was shipped to the manufacturer for bench testing. The examination and bench test of the propeller governor revealed no indications of any type of governor failure or malfunction prior to impact, and the governor met all the tested specifications. The 58-year-old pilot held an airline transport certificate with airplane single-engine land, airplane multi-engine land, and airplane instrument ratings, as well as being a flight instructor pilot with airplane single-engine, airplane multi-engine, and airplane instrument ratings. He had a total of 17,631 flight hours which included 2,469 hours in single-engine airplanes, and 20 hours in make and model of the accident airplane. At 1058, the surface weather observation at AFF was: wind 360° at 9 knots; visibility 10 miles; few clouds at 17,000 ft; scattered clouds at 20,0000 ft and 22,000 ft; temperature 26° C; dew point 6° C; and altimeter 30.29 inches of mercury. ## Aircraft - Registration: [N146AC](https://openairdocs.org/aircraft/N146AC), registered now, S/N R1720147, built 1967 (OpenAirDocs) - Reported make and model: Cessna R172E - Registry model: [Cessna R172E](https://openairdocs.org/model/cessna-r172e) (registry code 2072413) (OpenAirDocs) - Registry engine: [Continental IO-360 series](https://openairdocs.org/engine/continental-io-360-series) (registry code 17025, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: R1720147 - Year built: 1967 - Airframe hours: 10571 - Engines: Continental Motors IO-360-DB 210 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 7, 2018, 65 hours before - Departed: AFF, Colorado Springs, CO - Destination: AFF, Colorado Springs, CO - Airport: AFF, USAF Academy Airfield, runway 34, 4,480 × 75 ft, asphalt - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; injuries: none; airline transport, flight engineer; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; seat: right; restraint: 3-point; flight hours: 17,631 total, 20 in this make and model, 15,527 as pilot in command, 68 in the last 90 days, 42 in the last 30 days, 4 in the last 24 hours - Student pilot; age 20; injuries: none; seat: left; restraint: 3-point; flight hours: 6 total, 0 in this make and model, 6 in the last 90 days, 6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 43 °F - Altimeter: 30.29 inHg - Observed at: AFF ## 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 20180816014299A](https://openairdocs.org/incident/20180816014299A), Aug 16, 2018: Cessna R172E, Colorado Spring, CO, Substantial damage. Pilot stated that the preflight and engine runup was normal. At 1100 mountain daylight time (MDT) the airplane took off from rwy 34R. The takeoff roll was… ## Other investigations on N146AC (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 DEN92LA053](https://openairdocs.org/ntsb/DEN92LA053), May 18, 1992: Cessna R172E (N146AC), Colorado Spring, CO, substantial damage. Probable cause: THE PILOT DID NOT MAINTAIN CLEARANCE AND THE AIRPLANE COLLIDED WITH A FENCE POST. ## Docket (8 files) The files NTSB released with the investigation on October 17, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98087. 8.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476799&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - NTSB Record of Conversations (item 2, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476800&FileExtension=.PDF&FileName=NTSB%20Record%20of%20Conversations-Master.PDF - USAF Academy Weather (item 3, .PDF, 701 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476801&FileExtension=.PDF&FileName=USAF%20Academy%20Weather-Master.PDF - Aircraft Log (item 4, .PDF, 490 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476802&FileExtension=.PDF&FileName=Aircraft%20Log-Master.PDF - Maintenance Logbook Excerpts (item 5, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476803&FileExtension=.PDF&FileName=Maintenance%20Logbook%20Excerpts-Master.PDF - Engine Run and Propeller Governor Bench Test (item 6, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476804&FileExtension=.PDF&FileName=Engine%20Run%20and%20Propeller%20Governor%20Bench%20Test-Master.PDF - Photo Log (item 7, .PDF, 2 photos, 330 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476805&FileExtension=.PDF&FileName=Photo%20Log-Master.PDF - NTSB Wreckage Release (item 8, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40476806&FileExtension=.PDF&FileName=NTSB%20Wreckage%20Release-Master.PDF 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.