# NTSB ATL84FA045: Robinson R22, N8414H, Gaithersburg, MD, November 5, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: November 5, 1983, 16:10 local (21:10 UTC)
- Place: Gaithersburg, MD
- Coordinates: 39.169483, -77.179244 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.1695&lon=-77.1792&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6234
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL84FA045
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6234/pdf
- Page: https://openairdocs.org/ntsb/ATL84FA045

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, maneuvering
  - maneuver - performed, pilot in command
  - cyclic - improper use of, pilot in command (cause)
  - rotor drive system,main rotor mast(drive shaft) - overload
  - rotor system,main rotor hub yoke(spindle) - overload
  - rotor system,main rotor hub - overload
  - rotor system,main rotor hub stop(static/dynamic) - overload

## Analysis

DURING HIS 2ND SOLO FLT IN THE ROBINSON R22, THE PLT PERFORMED 2 LOW 'G' MANEUVERS. THE 1ST MANEUVER WAS ESSENTIALLY THE SAME AS WHEN HE PRACTICED IT DURING A CHECK-OUT FLT. HOWEVER, THE 2ND MANEUVER PRODUCED A RAPID RIGHT ROLL TO APRX 60 DEG OF BANK. THE PLT RECOVERED IN A DESCENDING RIGHT TURN. AFTER RECOVERY, THE ACFT SEEMED TO BE OPERATING NORMALLY. BEFORE LANDING, HE PRACTICED AN AUTOROTATIVE APCH TO A POWER ON RECOVERY WITHOUT TOUCHING DOWN. SEVERAL LANDING WERE MADE, BUT HE STATED ALL TOUCHDOWNS WERE NORMAL. A POST FLT INSPECTION REVEALED THE MAIN ROTOR SPINDLES HAD BUMPED THE MAST AT THE TEETERING STOPS, RESULTING IN DENTS UP TO .045 TO .50 INCH IN THE MAST. ALSO, THE MAIN ROTOR SPINDLE ARMS (HORNS) HAD CONTACTED THE DROOP STOPS, SHEARING THE DROOP STOP RETAINER BOLT & BENDING THE SPINDLE HORNS. ACCORDING TO THE MANUFACTURER, THE DROOP STOP/BOLT DAMAGE COULD ONLY OCCUR DURING A HARD LANDING OR NEGATIVE 'G' FLT. THE FLT MANUAL & SAFETY NOTICE #11 WARNS: RECOVERY FROM ROLL DUE TO LOW 'G' MUST BEGIN WITH AFT CYCLIC FIRST TO PREVENT MAST BUMPING.

## Aircraft

- Registration: [N8414H](https://openairdocs.org/deregistered/N8414H-2013-06-07), registration cancelled 2013-06-07, S/N 0355, built 1983 (OpenAirDocs)
- Reported make and model: ROBINSON R22
- Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 0355
- Airframe hours: 153
- Engines: LYCOMING O-320 124 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Aero Flight Ltd
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 29, 1983, 75 hours before
- Airport: GAI, Montgomery County

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; flight instructor, airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 22,735 total, 5 in this make and model, 22,515 as pilot in command, 153 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 10 knots
- Visibility: 12 statute miles
- Lowest ceiling: 2,000 ft broken
- Temperature: 45 °F, dew point 34 °F
- Altimeter: 29.00 inHg
- Observed at: DCA, 21 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 19831105071319A](https://openairdocs.org/incident/19831105071319A), Nov 5, 1983: Robsin R22, Gaithersburg, MD, Substantial damage. Rotor head and spindle arms damaged by incorrect control input during a low g maneuver that caused mast bumping.

## Other investigations on N8414H (2)

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 NYC02LA086](https://openairdocs.org/ntsb/NYC02LA086), Apr 20, 2002: Robinson R-22 (N8414H), Islip, NY, substantial damage. Probable cause: The flight instructors failure to maintain aircraft control during a wind gust. A factor in the accident was a sudden gust of wind.
- [NTSB IAD97LA037](https://openairdocs.org/ntsb/IAD97LA037), Dec 22, 1996: Robinson R22 HP (N8414H), Islip, NY, substantial damage. Probable cause: The students pilot's failure to maintain control of the helicopter and the instructor's inadequate supervision of the flight.

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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