# NTSB CEN13LA291: Diamond Aircraft Ind DA 20-C1, N571MA, Englewood, CO, May 22, 2013 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 22, 2013, 17:30 local (23:30 UTC) - Place: Englewood, CO - Coordinates: 39.570278, -104.849441 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.5703&lon=-104.8494&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report February 10, 2014 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 86971 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN13LA291 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/86971/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=86971 - Page: https://openairdocs.org/ntsb/CEN13LA291 ## Probable cause The in-flight separation of the engine throttle lever and throttle cable due to maintenance personnel not applying sufficient torque to the self-locking nut or improperly reusing a degraded self-locking nut. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine controls: power lever](https://openairdocs.org/ntsb-findings/01057603): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Diamond Aircraft Ind DA20-C1, 1 case](https://openairdocs.org/ntsb-findings/01057603/cases.md?model=2990001), [All aircraft, 95 cases](https://openairdocs.org/ntsb-findings/01057603/cases.md) - [Info processing/decision: understanding/comprehension](https://openairdocs.org/ntsb-findings/02041515): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [Diamond Aircraft Ind DA20-C1, 1 case](https://openairdocs.org/ntsb-findings/02041515/cases.md?model=2990001), [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/02041515/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Diamond Aircraft Ind DA20-C1, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=2990001), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Diamond Aircraft Ind DA20-C1, 12 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2990001), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Roll over](https://openairdocs.org/ntsb-events/097); cases with it: [Diamond Aircraft Ind DA20-C1, 1 case](https://openairdocs.org/ntsb-events/097/sequence.md?model=2990001), [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md) ## Analysis While on final approach during an instructional flight, the engine became unresponsive to throttle movements. The flight instructor took control of the airplane from the student pilot and made a forced landing, during which the airplane rolled onto soft ground and nosed over to an inverted position. Engine examination revealed that the engine throttle lever and throttle cable had become disconnected and that the bolt connecting these two components was located at the bottom of the engine cowling. A self-locking nut, which normally secures this bolt, was missing and not located. Therefore, it is likely that maintenance personnel did not apply sufficient torque to the nut or improperly reused a degraded self-locking nut, which resulted in the eventual loosening of the nut and the in-flight separation of the engine throttle lever and throttle cable. ## Factual narrative On May 22, 2013, about 1730 mountain daylight time, a Diamond DA-20-C1 airplane, N571MA, was substantially damaged during a forced landing at Centennial Airport (KAPA), Englewood, Colorado. The flight instructor and student pilot received minor injuries. The airplane was registered to 5280 Flying Club LLC and operated under the provisions of 14 Code of Federal Regulations Part 91 as an instructional flight. Day visual meteorological conditions prevailed for the local flight, and no flight plan had been filed. The flight instructor stated that the student pilot was flying a visual approach to a full stop landing at KAPA. While on final approach, the engine became unresponsive to throttle movement. The flight instructor took control of the airplane and attempted to restart the engine. With no increase in engine power, a forced landing was made and the airplane touched down just short of the runway threshold. After touchdown, the airplane rolled onto soft terrain and nosed over to an inverted position. During the engine examination, Federal Aviation Administration (FAA) personnel discovered that the engine throttle lever and throttle cable were disconnected. The bolt normally connecting these two components was located at the bottom of the engine cowling. A self-locking nut (Diamond part number MS21042-3), which normally secures this bolt, was missing and not located. No other anomalies were noticed with the engine. FAA review of airplane records indicated that the engine was removed and re-installed on March 15, 2013 to facilitate the repair of a loose crankcase stud. The airplane flew 100.1 hours after engine re-installation until the accident. ## Aircraft - Registration: [N571MA](https://openairdocs.org/deregistered/N571MA-2013-09-16), registration cancelled 2013-09-16, S/N C0271, built 2004 (OpenAirDocs) - Reported make and model: DIAMOND AIRCRAFT IND INC DA 20-C1 - Registry model: [Diamond Aircraft Ind DA20-C1](https://openairdocs.org/model/diamond-aircraft-ind-da20-c1) (registry code 2990001) (OpenAirDocs) - Registry engine: [Continental IO-240-B](https://openairdocs.org/engine/continental-io-240-b) (registry code 17177, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: C0271 - Airframe hours: 3360 - Engines: CONT MOTOR IO-240-B 125 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: 5280 Flying Club LLC - Registered owner: 5280 Flying Club LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, May 10, 2013 - Departed: KAPA, Englewood, CO - Destination: KAPA, Englewood, CO - Airport: KAPA, Centennial Airport, runway 17R, 7,000 × 77 ft, asphalt - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 30; injuries: minor; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review October 9, 2012; seat: right; restraint: 3-point; flight hours: 475 total, 26 in this make and model, 395 as pilot in command, 146 in the last 90 days, 90 in the last 30 days, 4 in the last 24 hours - Student pilot; age 21; injuries: minor; student; restraint: 3-point; flight hours: 14 total, 12 in this make and model, 0 as pilot in command, 14 in the last 90 days, 14 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 34 °F - Altimeter: 29.92 inHg - Observed at: KAPA, 1 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 20130522007589A](https://openairdocs.org/incident/20130522007589A), May 22, 2013: Diamond Aircraft Ind Inc DA 20-C1, Centennial, CO, Substantial damage. On may 22, 2013 at approx 17:30 LCL N571MA a Diamond DA20 aircraft sustained substantial damage on landing at the arapahoe county airport (apa). 2 soles on… ## Docket (4 files) The files NTSB released with the investigation on December 10, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=86971. 2.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 826 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405714&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA photos of bolt and throttle body (item 2, .PDF, 934 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405716&FileExtension=.PDF&FileName=FAA%20photos%20of%20bolt%20and%20throttle%20body-Master.PDF - FAA exam of aircraft (item 3, .PDF, 48 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40406170&FileExtension=.PDF&FileName=FAA%20exam%20of%20aircraft-Redacted.PDF - Diamond DA-20 Maintenance Practices excerpt (item 4, .PDF, 361 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405718&FileExtension=.PDF&FileName=Diamond%20DA-20%20Maintenance%20Practices%20excerpt-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.