# NTSB CEN16LA267: Aeronca 7BCM, N2576E, Longmont, CO, July 16, 2016 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 16, 2016, 10:20 local (16:20 UTC) - Place: Longmont, CO - Coordinates: 40.164443, -105.163612 - Nearby events: https://openairdocs.org/map.md?lat=40.1644&lon=-105.1636&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 12, 2016 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Flight Standards District Office - NTSB case key (mKey): 93613 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN16LA267 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93613/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93613 - Page: https://openairdocs.org/ntsb/CEN16LA267 ## Probable cause The pilot's decision to continue the takeoff after observing a partial loss of engine power, the reason for which could not be determined because postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Aeronca 7BCM, 3 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2110106), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Aeronca 7BCM, 1 case](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=2110106), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) - [Runway/land/takeoff/taxi surface](https://openairdocs.org/ntsb-findings/03023000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Aeronca 7BCM, 1 case](https://openairdocs.org/ntsb-findings/03023000/cases.md?model=2110106), [All aircraft, 253 cases](https://openairdocs.org/ntsb-findings/03023000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Aeronca 7BCM, 3 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2110106), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) ## Analysis The commercial pilot was taking off in the light sport aircraft for a local personal flight. The pilot reported that, while attempting to take off from the 4,799-ft-long runway, he noticed a lower-than-normal engine rpm and that the takeoff roll was significantly longer. Despite the extended takeoff roll and low engine rpm, the pilot chose to continue the takeoff. The airplane lifted off and slowly climbed to about 200 ft above ground level. Due to concerns about rising terrain, the pilot chose to make a forced landing, during which the airplane hit power lines. The airplane then skipped across a road and nosed over. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures. Carburetor icing was likely not a factor given the environmental conditions at the time of the accident and the pilot's report of a short taxi time. ## Factual narrative On July 16, 2016, about 1020 mountain daylight time, an Aeronca 7BCM airplane, N2576E, impacted terrain while departing from Vance Brand Airport (LMO), Longmont, Colorado. The pilot sustained minor injuries and the airplane was substantially damaged. The airplane was registered to and operated by 2576E LLC under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions existed at the time of the accident and no flight plan had been filed. The local flight was departing at the time of the accident. On the day prior to the accident, the pilot serviced the airplane with 10 gallons of aviation fuel for a total fuel onboard of 13 gallons. The pilot stated that the elapsed time from engine start to takeoff roll was less than 5 minutes. While performing an engine runup at 1,700 rpm, he checked the carburetor heat and magnetos, which he reported as normal. He recalled the wind conditions as calm. During takeoff roll from Runway 29, the pilot observed the engine was only producing about 2,000 rpm, versus the 2,200 rpm he typically noticed. He continued the takeoff and observed a significantly longer takeoff roll. After liftoff, the airplane was unable to climb normally and after reaching about 200 ft agl, the pilot executed a forced landing due to concerns with terrain. During the forced landing, the airplane hit power lines, skipped across a road and nosed over, which damaged both wings. A pilot witness near the departure end of the runway noticed the airplane liftoff much later than he expected, about 3,000 ft down the 4,799 ft long runway. After liftoff, he noticed the airplane climb slowly to about 200 ft and then bank left and descend out of sight. During the takeoff, the witness observed the windsock indicating a tailwind of 3 or 4 knots. At 1014, the weather observation station at LMO reported the following conditions: wind calm, visibility 7 miles, clear skies, temperature 24 degrees C, dew point 14 degrees C, and altimeter setting 29.98 inches of mercury. At 1034, the conditions were wind 100 degrees at 4 knots. Density altitude was calculated to be 7,388 ft. The Federal Aviation Administration (FAA) icing probability chart indicated there was potential for serious carburetor icing at glide power at the time of the accident. FAA inspectors examined the airplane and determined the fuel from the main tank had leaked out while the airplane was inverted after the accident. The gascolator contained about 2 ounces of fuel, which was clear and bright, with no water or debris. No anomalies were noted with the ignition or carburetor systems. Compression testing of the cylinders was accomplished, with normal results. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. ## Aircraft - Registration: [N2576E](https://openairdocs.org/aircraft/N2576E), registered now, S/N 7AC-6159, built 1946 (OpenAirDocs) - Reported make and model: AERONCA 7BCM (NO SERIES) - Registry model: [Aeronca 7BCM](https://openairdocs.org/model/aeronca-7bcm) (registry code 2110106) (OpenAirDocs) - Registry engine: [Continental C85 series](https://openairdocs.org/engine/continental-c85-series) (registry code 17008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 7AC-6159 - Year built: 1946 - Airframe hours: 3763 - Engines: Continental C85-12FT 85 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 16, 2015, 4 hours before - Departed: LMO, Longmont, CO - Destination: LMO, Longmont, CO - Airport: LMO, Vance Brand, runway 29, 4,799 × 75 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 74; injuries: minor; flight instructor, commercial; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review May 2, 2015; seat: front; restraint: 4-point; flight hours: 792 total, 107 in this make and model, 792 as pilot in command, 3 in the last 90 days, 3 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 4 knots - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 57 °F - Altimeter: 29.97 inHg - Observed at: KLMO ## 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 20160716016699A](https://openairdocs.org/incident/20160716016699A), Jul 16, 2016: Aeronca 7BCM, Longmont, CO, Substantial damage. On 07/16/2016 at approximately 1020 MDT, N2576E an Aeronca 7BCM airplane was substantially damaged after impacting terrain approximately 0.5 statute miles… ## Docket (4 files) The files NTSB released with the investigation on October 13, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93613. 1.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445368&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Witness Statement (item 2, .PDF, 35 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445369&FileExtension=.PDF&FileName=Witness%20Statement-Master.PDF - FAA Examination of Airplane (item 3, .PDF, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445370&FileExtension=.PDF&FileName=FAA%20Examination%20of%20Airplane-Master.PDF - Carburetor Icing - FAA SAIB (item 4, .PDF, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445371&FileExtension=.PDF&FileName=Carburetor%20Icing%20-%20FAA%20SAIB-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.