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19990518005389A

Accident · Substantial damage
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FAA accident report · Robsin R22 ALPHA · San Luis Obispo, CA · May 18, 1999

FAA Aviation Safety Information Portal

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Date
May 18, 1999 · 17:30 local
Place
San Luis Obispo, CA
Phase of flight
Sfl Autorotation
Operating rules
General operating rules (Part 91)
Damage
Substantial damage
Aircraft
N8558N
NTSB investigation
NTSBLAX99LA186
Reported as
Robsin R22ALPHA
Reported engine
Lycoming O320B3C
Fatal injuries
0
Pilot’s flight hours
369 total364 in this make and model164 in the last 90 days
N8558NRegistration cancelled Aug 4, 2000 · Robinson Helicopter R22 ALPHAS/N 0466Airframe modelRobinson Helicopter R22 ALPHA

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

Robinson R-22 helicopter was involved in auto rotation practice when the acft caught a down draft, struck the ground hard, rolled over, and was destroyed, other circumstances are unknown. (.4)the instructor stated the student entered a practice autorotation at 1,400 feet (600 feet AGL) to a landing site on top of a hill about 800 feet high. As the flare was initiated at 40 to 50 feet, the instructor mentioned to the student that the cyclic trim was engaged. When the student unexpectedly reached forward and tried to push the trim control knob in, he inadvertently pushed forward on the cyclic control. The instructor said this pitched the nose of the helicopter down and resulted in a bleed off of main rotor RPM. When the low rotor horn and warning light came on the instructor took control of the helicopter and rolled in throttle. The lowest RPM he recalls seeing was slightly above 90 percent. He made a left turn to avoid hitting the hill and encountered a strong downdraft due to the gusty winds. The helicopter touched down on the left skid during the turn and rolled over twice. (-23)LAX99LA1186

As the FAA filed it

ROBINSON R-22 HELICOPTER WAS INVOLVED IN AUTO ROTATION PRACTICE WHEN THE ACFT CAUGHT A DOWN DRAFT, STRUCK THE GROUND HARD, ROLLED OVER, AND WAS DESTROYED, OTHER CIRCUMSTANCES ARE UNKNOWN. (.4)THE INSTRUCTOR STATED THE STUDENT ENTERED A PRACTICE AUTOROTATION AT 1,400 FEET (600 FEET AGL) TO A LANDING SITE ON TOP OF A HILL ABOUT 800 FEET HIGH. AS THE FLARE WAS INITIATED AT 40 TO 50 FEET, THE INSTRUCTOR MENTIONED TO THE STUDENT THAT THE CYCLIC TRIM WAS ENGAGED. WHEN THE STUDENT UNEXPECTEDLY REACHED FORWARD AND TRIED TO PUSH THE TRIM CONTROL KNOB IN, HE INADVERTENTLY PUSHED FORWARD ON THE CYCLIC CONTROL. THE INSTRUCTOR SAID THIS PITCHED THE NOSE OF THE HELICOPTER DOWN AND RESULTED IN A BLEED OFF OF MAIN ROTOR RPM. WHEN THE LOW ROTOR HORN AND WARNING LIGHT CAME ON THE INSTRUCTOR TOOK CONTROL OF THE HELICOPTER AND ROLLED IN THROTTLE. THE LOWEST RPM HE RECALLS SEEING WAS SLIGHTLY ABOVE 90 PERCENT. HE MADE A LEFT TURN TO AVOID HITTING THE HILL AND ENCOUNTERED A STRONG DOWNDRAFT DUE TO THE GUSTY WINDS. THE HELICOPTER TOUCHED DOWN ON THE LEFT SKID DURING THE TURN AND ROLLED OVER TWICE. (-23)LAX99LA1186

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.

NTSB LAX99LA186Accident · Minor injuriesLimited investigationFinal reportSan Luis Obispo, CAThe student's inadvertent and uncoordinated application of forward cyclic during an autorotation flare, which resulted in a loss of main rotor rpm; and the flight instructor's inadequate supervision.May 19, 1999 · Substantial damage