# NTSB ERA22LA159: Dwyer Michael D Q, N3QP, Spring Hill, FL, March 17, 2022

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 3 · Limited · Final report
- Date: March 17, 2022, 11:30 local (15:30 UTC)
- Place: Spring Hill, FL
- Coordinates: 28.491776, -82.487623
- Nearby events: https://openairdocs.org/map.md?lat=28.4918&lon=-82.4876&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: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Eastern Region Aviation
- Parties: FAA/FSDO
- NTSB case key (mKey): 104798
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA22LA159
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104798/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104798
- Page: https://openairdocs.org/ntsb/ERA22LA159

## Probable cause

The pilot’s improper modification of the pull starter motor, which resulted in its failure and the subsequent loss of engine power.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Maintenance: modification/alteration](https://openairdocs.org/ntsb-findings/02062030): Personnel issues › Task performance · Owner/builder (probable cause); cases with it: [Dwyer Michael D Q-200, 1 case](https://openairdocs.org/ntsb-findings/02062030/cases.md?model=05645VS), [All aircraft, 69 cases](https://openairdocs.org/ntsb-findings/02062030/cases.md)
- [Engine starting: starter](https://openairdocs.org/ntsb-findings/01058011): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Dwyer Michael D Q-200, 1 case](https://openairdocs.org/ntsb-findings/01058011/cases.md?model=05645VS), [All aircraft, 2 cases](https://openairdocs.org/ntsb-findings/01058011/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: [Dwyer Michael D Q-200, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=05645VS), [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: [Dwyer Michael D Q-200, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05645VS), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md)
- [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Dwyer Michael D Q-200, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05645VS), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Dwyer Michael D Q-200, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05645VS), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot was also the owner and builder of the experimental amateur-built airplane. While returning to the airport after a local flight, the engine lost oil pressure, so the pilot diverted toward the nearest airport. The engine then began to run roughly and lost partial power. The airplane was not able to glide to the runway and collided with a ditch in a field during the forced landing. The pilot described that his postaccident examination of the engine revealed that the pinion gear on the pull starter motor fractured into several pieces that entered the accessory gear case, likely seizing the oil pump. About 4 years and 100 flight hours before the accident, the pilot had modified the pull starter motor from its original design so that the motor would fit in the airplane. Postaccident metallurgical examination found that the pull starter motor’s pivot lever was shortened. The pivot lever arm was designed to move the starter clutch and engage the pinion (small) gear to the crankshaft gear. The pinion gear teeth displayed indentations in their surfaces that indicated that they were only partially engaged to the crankshaft gear when the starter was being operated, a condition which was likely the result of the shortened pivot lever. This ultimately resulted in increased stress on the gear teeth during engine start and the subsequent failure of the gear in overstress. The liberated gear teeth likely damaged and seized the engine oil pump, and resulted in the partial loss of engine power.

## Factual narrative

On March 17, 2022, about 1130 eastern daylight time, an experimental amateur-built Q 200 airplane, N3QP, was substantially damaged when it was involved in an accident near Spring Hill, Florida. The private pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot, who was also the airplane owner, built the airframe and engine. He stated that, during a local flight, the engine lost oil pressure, so he diverted toward the nearest airport. The engine then began to run roughly and lost partial power. Because the airplane would not be able to glide to the runway, the pilot performed a forced landing to a field. Subsequently, the airplane collided with a ditch, resulting in substantial damage to the wings and fuselage. The airplane was equipped with a pull starter motor, which turned a large gear (through a sprag clutch) to a small gear, which drove the crankshaft. The pilot stated that the starter motor was a certificated airplane part that had been operated for about 100 hours since its overhaul in 2018. The pilot also stated that he had modified the pull starter motor to fit in the airplane. The pilot’s postaccident examination of the small gear found that it was fractured into several pieces that had entered the accessory gear case. The pilot added that oil streaks were present on the empennage. The pull starter motor was provided to the National Transportation Safety Board Materials Laboratory, Washington, DC. Metallurgical examination confirmed that the pull starter motor had been modified from its original design. Specifically, the pivot lever was shortened, and the starter motor power switch was removed and replaced with a power cable leading to a battery post. The pivot lever arm that was shortened was designed to move the starter clutch and engage the pinion (small) gear to the crankshaft gear. The pinion gear teeth had displayed indentations in their surfaces that indicated that they were only partially engaged to the crankshaft gear when the starter was being operated. The pinion gear teeth had fractured edges consistent with overstress.

## Aircraft

- Registration: [N3QP](https://openairdocs.org/aircraft/N3QP), registered now, S/N 2841, built 1985 (OpenAirDocs)
- Reported make and model: DWYER MICHAEL D Q (200)
- Registry model: [Dwyer Michael D Q-200](https://openairdocs.org/model/dwyer-michael-d-q-200) (registry code 05645VS) (OpenAirDocs)
- Registry engine: [Continental O-200-D](https://openairdocs.org/engine/continental-o-200-d) (registry code 17409, 4 cycle) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 2841
- Year built: 1985
- Airframe hours: 1415
- Engines: Continental O-200A 100 hp reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, February 1, 2022, 2 hours before
- Departed: PIE, Saint Petersburg, FL
- Airport: BKV, Brookville-Tampa Bay Regional Airport, runway 21, 5,014 × 150 ft, concrete
- Equipment: ADS-B, Electronic flight bag or handheld device, Electronic multifunction display, Electronic primary flight display

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; injuries: none; private; airplane ratings: single-engine land; medical: basicmed, with waivers/limitations; last flight review September 25, 2020; seat: left; restraint: 4-point; flight hours: 2,300 total, 1,400 in this make and model, 2,300 as pilot in command, 10 in the last 90 days, 10 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: 2,600 ft broken
- Temperature: 72 °F, dew point 61 °F
- Altimeter: 30.09 inHg
- Observed at: KBKV, 2 nm away
- METAR: KBKV 171532Z 28004KT 10SM BKN026 BKN031 22/16 A3009

## 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 20220317003559A](https://openairdocs.org/incident/20220317003559A), Mar 17, 2022: Dwyer Michael D Q-200, Spring Hill, FL, Destroyed. On March 17, 2022 at 1130 EST a 1985 Dwyer Michael D, model Q-200, N3QP that is [privacy data omitted], contacted bkv tower west of bkv with an emergency due…

## Docket (5 files)

The files NTSB released with the investigation on September 20, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104798. 2.4 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 934 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13594995&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf
- Memoranda for the record (item 2, PDF, 2 pages, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14819765&FileExtension=pdf&FileName=MFRs-Rel.pdf
- Photo array (item 3, PDF, 2 pages, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13594859&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf
- Materials laboratory report 22-091 (item 4, PDF, 8 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14812147&FileExtension=pdf&FileName=Materials%20Laboratory%20Factual%20Report%2022-091-Rel.pdf
- Evidence control form (item 5, PDF, 1 page, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14829287&FileExtension=pdf&FileName=Evidence%20Control%20Form-Rel.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.

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