A helicopter pilot experiences engine failure in his mini-500 while hovering in ground effect at 3-5...

Attributes
ACN	368694
Time
Date	199705
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : sck
State Reference	CA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sck
Operator	general aviation : personal
Make Model Name	Helicopter
Operating Under FAR Part	Part 91
Flight Phase	landing other other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 225 flight time total : 20500 flight time type : 250
ASRS Report	368694
Events
Anomaly	aircraft equipment problem : critical conflict : ground critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : detected after the fact other
Consequence	other
Supplementary
Primary Problem	Aircraft

Narrative:

I was in a hover-taxi in a mini-500 experimental kit helicopter in a slight right turn at 3-5 ft with a light right rear quartering tailwind when the rotax 582 engine quit, I 'gunned' the throttle once to try and recover engine RPM, however, the decay was rapid in engine and rotor RPM. I did a hovering autoland level touchdown. The helicopter bounced up slightly and came down again on the left skid which collapsed outward just below the xmember attach points. The helicopter rolled onto its left side, cushioned by the 'folding' left struts. No pilot injuries however, all rotor blades damaged beyond repair. No one understands why the strut did not fold underneath me, or simply 'spread out' and absorb the shock considering the level touchdown and/or the quartering tailwind. During a subsequent discussion with the manufacturers' representative in excelsior springs, mo, I found out that a 'strut stiffener' kit is now available (but not necessarily recommended by the manufacturer) to prevent such an occurrence. I had an early kit model #6Y and was unaware of such an available modification. Otherwise, I would have suffered no damage! Recommend all mini-500 builders avail themselves of the 'strut stiffener' kit -- just in case! Engine failure cause has yet to be determined.

Original NASA ASRS Text

Title: A HELI PLT EXPERIENCES ENG FAILURE IN HIS MINI-500 WHILE HOVERING IN GND EFFECT AT 3-5 FT. HE LANDS HARD WITH DAMAGE TO THE SKIDS AND BLADES. NO INJURIES.

Narrative: I WAS IN A HOVER-TAXI IN A MINI-500 EXPERIMENTAL KIT HELI IN A SLIGHT R TURN AT 3-5 FT WITH A LIGHT R REAR QUARTERING TAILWIND WHEN THE ROTAX 582 ENG QUIT, I 'GUNNED' THE THROTTLE ONCE TO TRY AND RECOVER ENG RPM, HOWEVER, THE DECAY WAS RAPID IN ENG AND ROTOR RPM. I DID A HOVERING AUTOLAND LEVEL TOUCHDOWN. THE HELI BOUNCED UP SLIGHTLY AND CAME DOWN AGAIN ON THE L SKID WHICH COLLAPSED OUTWARD JUST BELOW THE XMEMBER ATTACH POINTS. THE HELI ROLLED ONTO ITS L SIDE, CUSHIONED BY THE 'FOLDING' L STRUTS. NO PLT INJURIES HOWEVER, ALL ROTOR BLADES DAMAGED BEYOND REPAIR. NO ONE UNDERSTANDS WHY THE STRUT DID NOT FOLD UNDERNEATH ME, OR SIMPLY 'SPREAD OUT' AND ABSORB THE SHOCK CONSIDERING THE LEVEL TOUCHDOWN AND/OR THE QUARTERING TAILWIND. DURING A SUBSEQUENT DISCUSSION WITH THE MANUFACTURERS' REPRESENTATIVE IN EXCELSIOR SPRINGS, MO, I FOUND OUT THAT A 'STRUT STIFFENER' KIT IS NOW AVAILABLE (BUT NOT NECESSARILY RECOMMENDED BY THE MANUFACTURER) TO PREVENT SUCH AN OCCURRENCE. I HAD AN EARLY KIT MODEL #6Y AND WAS UNAWARE OF SUCH AN AVAILABLE MODIFICATION. OTHERWISE, I WOULD HAVE SUFFERED NO DAMAGE! RECOMMEND ALL MINI-500 BUILDERS AVAIL THEMSELVES OF THE 'STRUT STIFFENER' KIT -- JUST IN CASE! ENG FAILURE CAUSE HAS YET TO BE DETERMINED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A helicopter pilot experiences engine failure in his mini-500 while hovering in ground effect at 3-5 ft. He lands hard with damage to the skids and blades. No injuries.