# NTSB CEN24LA015: Dehavilland Tiger Moth DH 82A, N41DH, Greeley, CO, October 17, 2023

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: October 17, 2023, 14:30 local (20:30 UTC)
- Place: Greeley, CO · 40.424728
-104.637917
- Coordinates: 40.424728, -104.63791
- Nearby events: https://openairdocs.org/map.md?lat=40.4247&lon=-104.6379&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Defining event: [Initial climb: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Central Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 193262
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN24LA015
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193262/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=193262
- Page: https://openairdocs.org/ntsb/CEN24LA015

## Probable cause

The pilot’s decision to turn out early during the initial climb and failure to maintain adequate airspeed/angle-of-attack, which resulted in an aerodynamic stall and impact with airport hangars. Contributing to the accident was the variable wind conditions above the hangars and the pilot’s lack of awareness of those conditions.

## Findings

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

- [Wind: variable wind](https://openairdocs.org/ntsb-findings/03034025): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 1 case](https://openairdocs.org/ntsb-findings/03034025/cases.md?model=2801002), [All aircraft, 113 cases](https://openairdocs.org/ntsb-findings/03034025/cases.md)
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2801002), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)
- [Wind: variable wind](https://openairdocs.org/ntsb-findings/03034025): Environmental issues › Conditions/weather/phenomena · Awareness of condition (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 1 case](https://openairdocs.org/ntsb-findings/03034025/cases.md?model=2801002), [All aircraft, 113 cases](https://openairdocs.org/ntsb-findings/03034025/cases.md)
- [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 2 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=2801002), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md)
- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 2 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=2801002), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 3 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2801002), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Wind: variable wind](https://openairdocs.org/ntsb-findings/03034025): Environmental issues › Conditions/weather/phenomena · Awareness of condition (probable cause); cases with it: [Dehavilland TIGER MOTH DH 82A, 1 case](https://openairdocs.org/ntsb-findings/03034025/cases.md?model=2801002), [All aircraft, 113 cases](https://openairdocs.org/ntsb-findings/03034025/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Initial climb: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) (defining event); cases with it: [Dehavilland TIGER MOTH DH 82A, 2 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=2801002), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md)
- [Initial climb: Stall warn/stick-shaker/pusher](https://openairdocs.org/ntsb-events/430); cases with it: [Dehavilland TIGER MOTH DH 82A, 1 case](https://openairdocs.org/ntsb-events/430/sequence.md?model=2801002), [All aircraft, 37 cases](https://openairdocs.org/ntsb-events/430/sequence.md)
- [Initial climb: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Dehavilland TIGER MOTH DH 82A, 2 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=2801002), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md)

## Analysis

The pilot and pilot-rated-passenger intended to complete a personal cross-country flight with variable wind about 6 knots at the departure airport. The pilot noted the windsock nearest the airplane indicated a tailwind, but the other windsocks farther down the runway indicated a headwind or crosswind. During takeoff, the airplane became airborne faster than expected and climbed well, so the pilot made an early right turn over airport hangars. The airplane’s upper wing slats fluttered which indicated to the pilot that the airspeed was low, then they “came out hard,” which indicated the airplane was near a stall. The pilot ensured the throttle was full forward and decreased pitch attitude to maintain airspeed but felt like the airplane “was being forced down.” Unable to maintain altitude, and with no suitable forced landing area, he maneuvered the airplane to collide with the side of a hangar and the ground, then it nosed over. The airplane sustained substantial damage to the wings, fuselage, and empennage. The pilot reported that there were no preaccident mechanical malfunctions or failures that would have precluded normal operation. Airport surveillance video showed the airplane at low altitude and appeared to climb until it overflew airport hangars. The airplane maintained a climb pitch attitude as it descended into the hangars.

## Aircraft

- Registration: [N41DH](https://openairdocs.org/aircraft/N41DH), registered now, S/N 84734, built 1972 (OpenAirDocs)
- Reported make and model: DEHAVILLAND TIGER MOTH DH 82A
- Registry model: [Dehavilland TIGER MOTH DH 82A](https://openairdocs.org/model/dehavilland-tiger-moth-dh-82a) (registry code 2801002) (OpenAirDocs)
- Registry engine: [Dehav ENG GIPSY MAJOR](https://openairdocs.org/engine/dehav-eng-gipsy-major) (registry code 20004, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 84734
- Year built: 1941
- Airframe hours: 2766.8
- Engines: de Havilland Gipsy Major 130 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Voyager 180 LLC
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 27, 2023
- Destination: AFF, Colorado Springs, CO
- Flight plan: VFR
- Airport: GXY, Greeley-Weld County, runway 10, 5,801 × 100 ft, asphalt
- Equipment: Electronic flight bag or handheld device

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review May 8, 2023; seat: rear; restraint: 4-point; flight hours: 3,854 total, 16 in this make and model, 89 in the last 90 days, 22 in the last 30 days, 0 in the last 24 hours
- Pilot-rated passenger; age 78; injuries: none; seat: center; restraint: 4-point

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 6 knots
- Visibility: 12 statute miles
- Lowest ceiling: none
- Temperature: 80 °F, dew point 30 °F
- Observed at: KGXY

## 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 20231017016939A](https://openairdocs.org/incident/20231017016939A), Oct 17, 2023: Dehavilland TIGER MOTH DH 82A, Greeley, CO, Substantial damage. Pilot stated AWOS winds prior to taxi were variable at 4, and da was 7294. Pilot had noticed traffic using rwy 35 during Pre-flight preparations and thought…

## Other investigations on N41DH (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 CHI73FEI44](https://openairdocs.org/ntsb/CHI73FEI44), Jun 12, 1973: Dehavilland DH 82A (N41DH), Fremont, OH, substantial damage

## Docket (3 files)

The files NTSB released with the investigation on November 16, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=193262. 22.7 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 5.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16282045&FileExtension=pdf&FileName=6120%20-%20Pilot_Redacted-Rel.pdf
- Photos (item 2, PDF, 3 pages, 2 photos, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16320301&FileExtension=pdf&FileName=Docket%20photos-Rel.pdf
- Airport video (item 3, AVI, 15.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16306767&FileExtension=avi&FileName=Greeley%20Weld%20Airport_Terminal%20Lot%20West_10-17-2023%2014-30-50_69-Rel.avi

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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