Narrative:

On jul/xx/95 I departed VER289 en route to EC189. I had approximately 75 pounds of cargo in the baggage compartment, and 620 pounds of fuel. The flight was just under 30 mins at 1250 ft altitude. When I arrived at EC189, it was X044 hours and the winds were out of approximately 210 degrees s-sw. I made a wide, gradual turn to set up on final and land into the wind. I had what appeared to be a normal approach angle and closure rate. After the pre-landing checks, I did a reconnaissance of the platform and noted my passenger on the stairwell, ready to load. I looked right to assure the crane was clear, left to check the wind sock and flareboom were clear, and left of the stairwell to confirm that no discharge was coming from the exhaust stack as I crossed over the platform, I felt what I then thought was the aircraft passing through effective translational lift. I applied a slight amount of collective and a slight amount of aft cyclic in plans for terminating to a hover. I realized that my approach angle was a little low and that I would have to come to a lower hover than normal. I continued to apply collective slowly, and started to hover forward as I crossed onto the platform pad. I felt something hit the aircraft and set it down. I couldn't figure out what might have happened because I felt like the approach had been slightly low but otherwise normal. After shutdown, my inspection found damage to the vertical fin, both tail rotor blades and right side of the baggage compartment. The aircraft had hit the helicopter pad skirting and had apparently thrown a piece of wire forward to the baggage compartment. In feel that the setting of the aircraft was not ELT but a loss of lift combined with entering turbulent air coming off the platform below and around the quarters building. The helicopter deck sits directly on top of the quarters, the crane rises above the deck on the west side and the exhaust stack and flareboom are on the east side. The north side at the deck has a raised platform approximately 8-10 ft below. The deck skirt is attached to the top of the pad, rises approximately 4-5 inches and extends out. The passenger attached his statement of witness to this incident. There is a gas compressor located under the helicopter pad on the north side of the platform. I feel this and the heat of the day (plus 38 degrees C) with the wind conditions created unseen and unknown turbulence, combined with a slightly low approach angle created the environment for this incident to occur. On this date at XA44 hours, helicopter X made an approach to east cameron 189, every thing looked normal. I was waiting on the landing just below the heliport. I sat on the step to be sure my head was below the heliport and glanced over my right shoulder and noticed the helicopter flaring as normal. Then helicopter rose a couple ft and pilot landed as normal. I opened the front door on the passenger side and pilot asked what he had hit. I stepped back to look at the back of the helicopter and noticed the vertical fin was damaged. Pilot shut down helicopter X and started to check for damage. Besides the vertical fin, it appeared the tail rotor blades skinned the fence railing. The sun was on the pilot's side and getting low in the sky and may have had some affect on the landing. Callback conversation with reporter revealed the following information: ec 189 platform is not 'normal' as there is no 'breezeway' between the crew quarters and the helicopter deck. An elevated deck tends to break up turbulence caused by wind and generators. The day was extremely hot, 38 degrees C, and both upwind generators were producing more heat and turbulence. The reporter admits that he added on collective and aft cyclic to account for the loss of effective translational lift, but not enough to counter the turbulence. The company maintenance department considered this to be a 'sudden stoppage' and sling-lifted a new tail assembly including rotor, gear box, fin, etc. The reporter believes that there was no 'sudden stoppage,' but agrees with the logistical decision to change the tail assembly on the platform. The 'skirting' around the deck is higher than 'normal.' the tail rotor blades 'scuffed' the skirting. The reporter 'lost all of his clean air' on approach to the platform.

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Original NASA ASRS Text

Title: AN SMA HELI HIT ITS TAIL BOOM AND ROTOR WHILE COMING ABOARD AN OIL PLATFORM HELIPAD.

Narrative: ON JUL/XX/95 I DEPARTED VER289 ENRTE TO EC189. I HAD APPROX 75 LBS OF CARGO IN THE BAGGAGE COMPARTMENT, AND 620 LBS OF FUEL. THE FLT WAS JUST UNDER 30 MINS AT 1250 FT ALT. WHEN I ARRIVED AT EC189, IT WAS X044 HRS AND THE WINDS WERE OUT OF APPROX 210 DEGS S-SW. I MADE A WIDE, GRADUAL TURN TO SET UP ON FINAL AND LAND INTO THE WIND. I HAD WHAT APPEARED TO BE A NORMAL APCH ANGLE AND CLOSURE RATE. AFTER THE PRE-LNDG CHKS, I DID A RECONNAISSANCE OF THE PLATFORM AND NOTED MY PAX ON THE STAIRWELL, READY TO LOAD. I LOOKED R TO ASSURE THE CRANE WAS CLR, LEFT TO CHK THE WIND SOCK AND FLAREBOOM WERE CLR, AND L OF THE STAIRWELL TO CONFIRM THAT NO DISCHARGE WAS COMING FROM THE EXHAUST STACK AS I CROSSED OVER THE PLATFORM, I FELT WHAT I THEN THOUGHT WAS THE ACFT PASSING THROUGH EFFECTIVE TRANSLATIONAL LIFT. I APPLIED A SLIGHT AMOUNT OF COLLECTIVE AND A SLIGHT AMOUNT OF AFT CYCLIC IN PLANS FOR TERMINATING TO A HOVER. I REALIZED THAT MY APCH ANGLE WAS A LITTLE LOW AND THAT I WOULD HAVE TO COME TO A LOWER HOVER THAN NORMAL. I CONTINUED TO APPLY COLLECTIVE SLOWLY, AND STARTED TO HOVER FORWARD AS I CROSSED ONTO THE PLATFORM PAD. I FELT SOMETHING HIT THE ACFT AND SET IT DOWN. I COULDN'T FIGURE OUT WHAT MIGHT HAVE HAPPENED BECAUSE I FELT LIKE THE APCH HAD BEEN SLIGHTLY LOW BUT OTHERWISE NORMAL. AFTER SHUTDOWN, MY INSPECTION FOUND DAMAGE TO THE VERT FIN, BOTH TAIL ROTOR BLADES AND R SIDE OF THE BAGGAGE COMPARTMENT. THE ACFT HAD HIT THE HELI PAD SKIRTING AND HAD APPARENTLY THROWN A PIECE OF WIRE FORWARD TO THE BAGGAGE COMPARTMENT. IN FEEL THAT THE SETTING OF THE ACFT WAS NOT ELT BUT A LOSS OF LIFT COMBINED WITH ENTERING TURBULENT AIR COMING OFF THE PLATFORM BELOW AND AROUND THE QUARTERS BUILDING. THE HELI DECK SITS DIRECTLY ON TOP OF THE QUARTERS, THE CRANE RISES ABOVE THE DECK ON THE W SIDE AND THE EXHAUST STACK AND FLAREBOOM ARE ON THE E SIDE. THE N SIDE AT THE DECK HAS A RAISED PLATFORM APPROX 8-10 FT BELOW. THE DECK SKIRT IS ATTACHED TO THE TOP OF THE PAD, RISES APPROX 4-5 INCHES AND EXTENDS OUT. THE PAX ATTACHED HIS STATEMENT OF WITNESS TO THIS INCIDENT. THERE IS A GAS COMPRESSOR LOCATED UNDER THE HELI PAD ON THE N SIDE OF THE PLATFORM. I FEEL THIS AND THE HEAT OF THE DAY (PLUS 38 DEGS C) WITH THE WIND CONDITIONS CREATED UNSEEN AND UNKNOWN TURB, COMBINED WITH A SLIGHTLY LOW APCH ANGLE CREATED THE ENVIRONMENT FOR THIS INCIDENT TO OCCUR. ON THIS DATE AT XA44 HRS, HELI X MADE AN APCH TO E CAMERON 189, EVERY THING LOOKED NORMAL. I WAS WAITING ON THE LNDG JUST BELOW THE HELIPORT. I SAT ON THE STEP TO BE SURE MY HEAD WAS BELOW THE HELIPORT AND GLANCED OVER MY R SHOULDER AND NOTICED THE HELI FLARING AS NORMAL. THEN HELI ROSE A COUPLE FT AND PLT LANDED AS NORMAL. I OPENED THE FRONT DOOR ON THE PAX SIDE AND PLT ASKED WHAT HE HAD HIT. I STEPPED BACK TO LOOK AT THE BACK OF THE HELI AND NOTICED THE VERT FIN WAS DAMAGED. PLT SHUT DOWN HELI X AND STARTED TO CHK FOR DAMAGE. BESIDES THE VERT FIN, IT APPEARED THE TAIL ROTOR BLADES SKINNED THE FENCE RAILING. THE SUN WAS ON THE PLT'S SIDE AND GETTING LOW IN THE SKY AND MAY HAVE HAD SOME AFFECT ON THE LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: EC 189 PLATFORM IS NOT 'NORMAL' AS THERE IS NO 'BREEZEWAY' BTWN THE CREW QUARTERS AND THE HELI DECK. AN ELEVATED DECK TENDS TO BREAK UP TURB CAUSED BY WIND AND GENERATORS. THE DAY WAS EXTREMELY HOT, 38 DEGS C, AND BOTH UPWIND GENERATORS WERE PRODUCING MORE HEAT AND TURB. THE RPTR ADMITS THAT HE ADDED ON COLLECTIVE AND AFT CYCLIC TO ACCOUNT FOR THE LOSS OF EFFECTIVE TRANSLATIONAL LIFT, BUT NOT ENOUGH TO COUNTER THE TURB. THE COMPANY MAINT DEPT CONSIDERED THIS TO BE A 'SUDDEN STOPPAGE' AND SLING-LIFTED A NEW TAIL ASSEMBLY INCLUDING ROTOR, GEAR BOX, FIN, ETC. THE RPTR BELIEVES THAT THERE WAS NO 'SUDDEN STOPPAGE,' BUT AGREES WITH THE LOGISTICAL DECISION TO CHANGE THE TAIL ASSEMBLY ON THE PLATFORM. THE 'SKIRTING' AROUND THE DECK IS HIGHER THAN 'NORMAL.' THE TAIL ROTOR BLADES 'SCUFFED' THE SKIRTING. THE RPTR 'LOST ALL OF HIS CLEAN AIR' ON APCH TO THE PLATFORM.

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.