# NTSB LAX95LA039: Robinson R-22B, N31MK, Honolulu, HI, November 22, 1994

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: November 22, 1994, 13:30 local (23:30 UTC)
- Place: Honolulu, HI
- Coordinates: 21.340749, -157.939163 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=21.3407&lon=-157.9392&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report October 13, 1995
- Report: Approved by Office Director
- NTSB case key (mKey): 28983
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX95LA039
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28983/pdf
- Page: https://openairdocs.org/ntsb/LAX95LA039

## Probable cause

the student pilot's improper use of the collective and throttle controls and his failure to maintain adequate main rotor rpm during a practice autorotation.

## Sequence of events

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

- Hard landing, landing - flare/touchdown
  - collective - improper use of, pilot in command (cause)
  - throttle/power control - improper use of, pilot in command (cause)
  - rotor rpm - not maintained, pilot in command (cause)

## Analysis

THE STUDENT PILOT WAS TAKING A PRIVATE PILOT PRACTICAL FLIGHT TEST WITH A DESIGNATED EXAMINER ON BOARD. ACCORDING TO THE EXAMINER, THE APPLICANT COMPLETED THE FIRST PART OF THE PRACTICAL TEST SATISFACTORILY. THE LAST MANEUVER TO BE PERFORMED WAS A RECOVERY FROM A 180-DEGREE AUTOROTATION. THE APPLICANT ENTERED THE MANEUVER SATISFACTORILY; HOWEVER, AT THE BOTTOM HAD ALLOWED THE MAIN ROTOR RPM TO DECAY AND BEGAN TO ADD COLLECTIVE INPUT WITHOUT ADEQUATE THROTTLE INPUT. THE EXAMINER SAID HE TOOK CONTROL OF THE HELICOPTER, BUT COULD NOT REGAIN MAIN ROTOR RPM PRIOR TO GROUND IMPACT.

## Factual narrative

On November 22, 1994, at 1330 Hawaii standard time, a Robinson R22B helicopter, N31MK, collided with the ground at the Honolulu International Airport, Honolulu, Hawaii, while performing a practice autorotation.  The aircraft was owned and operated by Rainbow Pacific Helicopters, Ltd., of Honolulu, Hawaii, and was engaged in a private pilot practical flight test with a designated examiner on board.  Visual meteorological conditions prevailed at the time and no flight plan was filed.  The aircraft incurred substantial damage.  The private pilot applicant and the examiner sustained minor injuries.  The flight originated at the Honolulu International Airport on the day of the accident at 1230 as a local area flight.

According to a written statement from the examiner, the applicant completed the first part of the practical test satisfactorily.  The last maneuver to be performed was a recovery from a 180-degree autorotation.  The applicant entered the maneuver satisfactorily; however, at the bottom had allowed the main rotor rpm to decay and began to add collective input without adequate throttle input.  The examiner said he took control of the helicopter, but could not regain main rotor rpm prior to ground impact.

## Aircraft

- Registration: N31MK (not matched to a registry record)
- Reported make and model: ROBINSON R-22B
- Category: Helicopter
- Serial number: 0930
- Airframe hours: 4155
- Engines: LYCOMING O-320-B2C 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Rainbow Pacific Helicopters, L
- Registered owner: Rainbow Pacific Helicopters, L
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, November 10, 1994, 56 hours before
- Departed: HNL
- Destination: HNL, HI
- Airport: HNL, Honolulu International

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 27; student; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 62 total, 62 in this make and model, 12 as pilot in command, 62 in the last 90 days, 25 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 60° at 16 knots
- Visibility: 20 statute miles
- Lowest ceiling: 25,000 ft broken
- Temperature: 84 °F, dew point 64 °F
- Altimeter: 30.00 inHg
- Observed at: HNL

## 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 19941122038759A](https://openairdocs.org/incident/19941122038759A), Nov 22, 1994: Robsin R22BETA, Honolulu, HI, Substantial damage. Private pilot flight test. Autorotation and 180 degree recovery. Rotor decay. Examiner tried recover but unable.

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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