# NTSB ERA15LA291: Sontonastaso Mosquito, N285XE, Winchendon, MA, July 29, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 29, 2015, 14:00 local (18:00 UTC) - Place: Winchendon, MA - Coordinates: 42.68111, -72.049163 - Nearby events: https://openairdocs.org/map.md?lat=42.6811&lon=-72.0492&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 18, 2019 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 91667 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA15LA291 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91667/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91667 - Page: https://openairdocs.org/ntsb/ERA15LA291 ## Probable cause A partial loss of engine power due to a faulty electrical wiring crimp in the engine’s ignition system. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ignition system: ignition system wiring](https://openairdocs.org/ntsb-findings/01057497): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Matthew Santonastaso MOSQUITO, 1 case](https://openairdocs.org/ntsb-findings/01057497/cases.md?model=056337P), [All aircraft, 16 cases](https://openairdocs.org/ntsb-findings/01057497/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Matthew Santonastaso MOSQUITO, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=056337P), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Matthew Santonastaso MOSQUITO, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=056337P), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Matthew Santonastaso MOSQUITO, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=056337P), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Matthew Santonastaso MOSQUITO, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=056337P), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis According to the commercial pilot, about 1 hour into a local flight, he felt the helicopter suddenly "kick from loss of torque." He then observed that the engine rpm had dropped to about 30%, and he was unable to increase engine power using the throttle control. The pilot responded by performing an autorotation to an open field. During the landing, the helicopter touched down hard, and the main rotor system struck the tailboom, which resulted in substantial damage to the airframe and tail rotor drive system. During a postaccident engine run, the pilot found that a faulty wiring crimp resulted in a loss of electrical power to the coil pack of one of the cylinders, which resulted in the engine experiencing a partial loss of power. ## Factual narrative On July 29, 2015, about 1400 eastern daylight time, an experimental amateur-built Mosquito helicopter, N285XE, was substantially damaged during a forced landing near Winchendon, Massachusetts. The commercial pilot/owner/builder was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which originated from Jaffrey Airport (AFN), Jaffrey, New Hampshire. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91.The pilot completed an uneventful 40-minute flight in the airport traffic pattern at AFN, then landed and refueled the helicopter with 93 octane automotive fuel. He subsequently departed about 1300 for a flight in the local area. About 1 hour into the flight, and while flying at an altitude of 2,500 feet msl, the pilot felt the helicopter suddenly "kick from loss of torque." He then observed that the engine rpm had dropped to about 30%, and he was unable to increase engine power using the throttle control. The pilot responded by performing an autorotation to an open field. During the landing, the helicopter touched down "hard," and the main rotor system struck the tailboom, resulting in substantial damage to the airframe and tail rotor drive system. About two weeks after the accident, the pilot conducted a test run of the engine on the airframe. Review of video from the test run showed the engine started without hesitation and ran at idle rpm with no obvious deficiencies noted. During a subsequent engine test run, the pilot accidently bumped an ignition system wire harness and the engine partially lost power. After examining the wire harness, he found that a "bad crimp" had resulted in a loss of electrical power to the coil pack of one cylinder, which resulted in a loss of spark for that cylinder, and the engine running on only one cylinder thereafter. According to Federal Aviation Administration (FAA) airworthiness records, the single-seat helicopter was issued experimental amateur-built aircraft operating limitations on April 20, 2015. The helicopter was equipped with an Innovator Technologies Inntec 800 two-stroke engine, rated at 85 horsepower, equipped with a Rotor Flight Dynamics Dragon Wings controllable pitch rotor. At the time of the accident, the airframe and engine had accumulated 25 total flight hours. According to FAA records, the pilot held a commercial pilot certificate with ratings for rotorcraft-helicopter. In addition, he held a repairman experimental aircraft builder certificate for a Mosquito helicopter. His most recent FAA second-class medical certificate was issued on March 11, 2011. The pilot reported 183 hours of total time, of which 25 hours were in the same make and model as the accident helicopter. His most recent flight review was dated January 3, 2015. ## Aircraft - Registration: [N285XE](https://openairdocs.org/aircraft/N285XE), registered now, S/N MXE1249A14B, built 2015 (OpenAirDocs) - Reported make and model: SONTONASTASO MOSQUITO - Registry model: [Matthew Santonastaso MOSQUITO](https://openairdocs.org/model/matthew-santonastaso-mosquito) (registry code 056337P) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Helicopter, amateur-built - Serial number: MXE1249A14B - Year built: 2015 - Airframe hours: 25 - Engines: Innovator Technologies Inntec 800 85 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, April 20, 2015, 25 hours before - Departed: AFN, Jaffrey, NH - Destination: AFN, Jaffrey, NH - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 26; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review January 3, 2015; seat: single; restraint: lap only; flight hours: 183.1 total, 25 in this make and model, 167 as pilot in command, 15.6 in the last 90 days, 8.3 in the last 30 days, 1.5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 63 °F - Altimeter: 29.98 inHg - Observed at: KAFN, 8 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 20150729015659A](https://openairdocs.org/incident/20150729015659A), Jul 29, 2015: Matthew Santonastaso MOSQUITO, Winchendon, MA, Substantial damage. On July 29, 2015, at approximately 10:30 local, the pilot performed a preflight of the aircraft and departed from jaffrey airport (afn). He flew for… ## Docket (4 files) The files NTSB released with the investigation on November 16, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91667. 6.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 5.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468384&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot's Statement (item 2, .PDF, 297 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468385&FileExtension=.PDF&FileName=Pilot%27s%20Statement-Master.PDF - Memorandum for Record - Pilot Email (item 3, .PDF, 100 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468386&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20-%20Pilot%20Email-Master.PDF - Photo Array (item 4, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468387&FileExtension=.PDF&FileName=Photo%20Array-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.