# NTSB LAX94LA172: Robinson R-22B, N4081P, Simi Valley, CA, March 23, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 23, 1994, 13:00 local (21:00 UTC) - Place: Simi Valley, CA - Coordinates: 34.249351, -118.779998 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.2494&lon=-118.7800&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 14, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28703 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA172 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28703/pdf - Page: https://openairdocs.org/ntsb/LAX94LA172 ## Probable cause THE STUDENT PILOT'S IMPROPER HOVERING AUTOROTATION BY ALLOWING THE HELICOPTER TO DRIFT LATERALLY AND REARWARD, RESULTING IN THE HELICOPTER ROLLING OVER DURING TOUCHDOWN, AND THE FLIGHT INSTRUCTOR'S INADEQUATE SUPERVISION OF THE FLIGHT. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - emergency procedure - simulated - autorotation - improper, dual student (cause) - supervision - inadequate, pilot in command(cfi) (cause) - Roll over, landing - flare/touchdown ## Analysis A FLIGHT INSTRUCTOR AND STUDENT PILOT WERE PRACTICING HOVERING AUTOROTATIONS IN AN OPEN FIELD. THE STUDENT PILOT ALLOWED THE HELICOPTER TO DRIFT LATERALLY DURING THE AUTOROTATION. THE HELICOPTER'S SKID TUBE CAUGHT ON THE GROUND AS THE STUDENT PILOT INCREASED THE COLLECTIVE. THE HELICOPTER ROLLED OVER. THE INSTRUCTOR PILOT INDICATED HE DID NOT HAVE TIME TO CORRECT THE STUDENT PILOT. ## Factual narrative On March 23, 1994, at 1300 hours Pacific standard time, a Robinson R-22B helicopter, N4081P, landed hard and rolled over during a practice hovering autorotation near Simi Valley, California. The helicopter was being operated by Orbic Helicopters, Inc., Van Nuys, California, as a local instructional flight. The helicopter sustained substantial damage. Neither the commercial pilot/certified flight instructor (CFI), nor the noncertificated student pilot was injured. Visual meteorological conditions prevailed. The flight originated at Van Nuys Airport, Van Nuys, California, at 1230 hours. The CFI stated the student pilot was practicing a hovering autorotation over a level dirt area. The student pilot entered the maneuver between two and three feet above the ground. The student pilot allowed the helicopter to drift left and rearward as the helicopter settled. The heal of the left skid tube caught in the dirt. The student pilot increased the collective control and the helicopter rolled left onto its side. The CFI also stated he did not have time to apply corrective actions before the helicopter rolled over. ## Aircraft - Registration: [N4081P](https://openairdocs.org/deregistered/N4081P-1996-01-11), registration cancelled 1996-01-11, S/N 1786 (OpenAirDocs) - Reported make and model: ROBINSON R-22B - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Category: Helicopter - Serial number: 1786 - Airframe hours: 1297 - Engines: LYCOMING O-320-B2C 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Orbic Helicopter, Inc - Registered owner: Briles Wing And Rotor - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 22, 1994, 1 hours before - Departed: VNY, VAN NUYS, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 2,400 total, 1,500 in this make and model, 75 in the last 90 days, 55 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 10 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 70 °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 19940323006559A](https://openairdocs.org/incident/19940323006559A), Mar 23, 1994: Robsin R22BETA, Simi Valley, CA, Substantial damage. Student was practicing a hover. Drifted backwards left skid caught in dirt. Helicopter rolled over. ## Other investigations on N4081P (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 LAX92LA199](https://openairdocs.org/ntsb/LAX92LA199), May 4, 1992: Robinson R-22B (N4081P), Sun Valley, CA, substantial damage. Probable cause: 1) FUEL EXHAUSTION DUE TO IMPROPER PREFLIGHT PLANNING BY THE CFI AND HIS FAILURE TO REFUEL THE AIRCRAFT PRIOR TO DEPARTURE ON THE ACCIDENT FLIGHT, AND 2) THE CFI'S MISJUDGEMENT OF THE LANDING FLARE… 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.