# NTSB LAX93LA101: Robinson R22B, N2335Q, Palomar Mtn, CA, January 23, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 23, 1993, 10:30 local (18:30 UTC)
- Place: Palomar Mtn, CA
- Coordinates: 33.310684, -116.840522 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.3107&lon=-116.8405&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report October 25, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27910
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA101
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27910/pdf
- Page: https://openairdocs.org/ntsb/LAX93LA101

## Probable cause

THE STUDENT PILOT'S INITIAL FAILURE TO MAINTAIN ROTOR RPM DURING THE GO AROUND AND THE INSTRUCTOR'S IMPROPER USE OF THE FLIGHT CONTROLS AND FAILURE TO ADEQUATELY SUPERVISE THE CONDUCT OF THE FLIGHT.

## Sequence of events

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

- Loss of control - in flight, approach - vfr pattern - final approach
  - go-around - initiated, dual student
  - rotor rpm - not maintained, dual student (cause)
  - rotorcraft flight controls - improper use of, pilot in command(cfi) (cause)
  - supervision - inadequate, pilot in command(cfi)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - mountainous/hilly

## Analysis

ACCORDING TO THE STATEMENTS OF BOTH PILOTS, AFTER A HIGH RECONNAISSANCE OF A RIDGELINE THE INSTRUCTOR SET THE HELICOPTER UP FOR A PRACTICE PINNACLE APPROACH AND TURNED THE CONTROLS OVER TO THE STUDENT AT ABOUT 500 FEET ABOVE THE RIDGE. SHORTLY AFTER INITIATING THE APPROACH, THE INSTRUCTOR SAID HE NOTICED EVIDENCE OF STRONG SURFACE WINDS AND ORDERED A GO AROUND. BOTH PILOTS STATED THAT AS THE GO AROUND WAS INITIATED THE LOW ROTOR RPM WARNING HORN CAME ON. THE INSTRUCTOR SAID HE ATTEMPTED TO REGAIN ROTOR RPM AND ACCELERATE THE HELICOPTER; HOWEVER, THEY WERE 'HIT BY A VERY STRONG DOWNDRAFT THAT FORCED US DOWN TO THE SURFACE.' THE INSTRUCTOR SAID HE THEN LOWERED THE NOSE TO ATTEMPT TO FLY AWAY FROM THE RIDGELINE BUT THE HELICOPTER SETTLED INTO THE BRUSH ON THE RIDGE AND ROLLED OVER.

## Aircraft

- Registration: [N2335Q](https://openairdocs.org/deregistered/N2335Q-1998-10-26), registration cancelled 1998-10-26, S/N 2154 (OpenAirDocs)
- Reported make and model: ROBINSON R22B
- Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2154
- Airframe hours: 600
- Engines: LYCOMING O-320 124 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Civic Helicopters
- Registered owner: Chin And Pauline Tu
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, December 28, 1992, 90 hours before
- Departed: CRQ, CARLSBAD, CA
- Destination: CRQ

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 31; flight instructor, airline transport; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 2,800 total, 1,400 in this make and model, 2,600 as pilot in command, 150 in the last 90 days, 50 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 25 knots, gusting 35
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 50 °F

## 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 19930123000819A](https://openairdocs.org/incident/19930123000819A), Jan 23, 1993: Robsin R22BETA, Palomar Mtn, CA, Substantial damage. Encountered high winds and strong downdraft. Low rotor RPM. Unable to recover. Settled in brush and rolled over.

## Other investigations on N2335Q (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 LAX98LA274](https://openairdocs.org/ntsb/LAX98LA274), Aug 21, 1998: Robinson R22B (N2335Q), Ramona, CA, substantial damage. Probable cause: The failure of the pilot to maintain rotor rpm while practicing autorotations and subsequent hard landing and roll over.
- [NTSB LAX92LA315](https://openairdocs.org/ntsb/LAX92LA315), Jul 25, 1992: Robinson R-22B (N2335Q), Carlsbad, CA, substantial damage. Probable cause: THE STUDENT PILOT'S FAILURE TO MAINTAIN ADEQUATE ROTOR RPM DURING A SIMULATED ENGINE FAILURE, AND THE FLIGHT 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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