FTW96TA222 · McDonnell Douglas MD-520N
McDonnell Douglas MD-520N · Accident while standing
From Wiley Post Airport (PWA) to an unrecorded destination
Event
- NTSB case
- FTW96TA222
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
McDonnell Douglas MD-520N
- Aircraft type
- McDonnell Douglas MD-520
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N520DD
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Wiley Post Airport (PWA)To not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Standing · idling rotors
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Miscellaneous/other
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Rotor system, main rotor blade › Blade strike
- Weather condition › Gusts
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
Prior to the landing, the instructor pilot verified the wind from the tower (180 degrees at 19 knots, gusting to 22 knots). With the helicopter stable on the ground, downwind from a nearby building, the flight controls were frictioned down and normal shut down procedures were started. Passing through 19% rotor RPM, the rotor brake was applied. To demonstrate that the rotor would continue turning without rotor brake application, the instructor released the brake at 10% RPM and allowed the rotors to turn down to 9% RPM. The rotor brake was then re-applied, and while the rotor was decelerating, 'two or three thumps were heard', and the instructor observed the rotors 'jerk and come to a stop.' The instructor stated that wind being redirected around the building may have caused the rotors to flap down into the tail boom. Examination of the aircraft revealed that at least two of the three main rotors contacted the tail boom. No mechanical defects were found in the flight control and rotor systems. According to the manufacturer's flight manual, the shut down sequence and rotor brake application were conducted in accordance with current published procedures.
Probable cause
The main rotor blades' contact with the tail boom due to gusting winds during rotor deceleration.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW96TA222
- Event ID
- 20001208X05781
- Case number
- FTW96TA222
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 022b1040edda6d5cb176f57e3f62fff3ed12842a0a54e26469351c6e1dd5426d; retrieved 2026-09-22T22:29:41.549Z.