Aviation Accident Summaries

Aviation Accident Summary CHI95FA035

CAMERON, LA, USA

Aircraft #1

N2620

Sikorsky S-76A

Analysis

The crew went visual at the termination of a Copter approach. Conditions were a dark night with 300-400 foot overcast and fog. The point where the crew went visual was over the water, 1 mile offshore. The only visual references available were several lights on land, approximately 4 miles ahead. The local altimeter was 30.02. The captain's altimeter was set at 30.05 and the copilot's was set at 30.12. These settings would result in the captain's altimeter indicating 30 feet high, and the copilot's altimeter indicating 100 feet higher than the actual altitude. The copilot flying transitioned from instruments to an outside visual scan, for a transition to the landing site. The non-flying captain was looking down while changing radios. Neither pilot was aware of a descent until the level impact with the water. The helicopter came to rest submerged, inverted, with all windows on the left side broken. The copilot escaped through his missing window. The captain was not able to open his door and became disoriented. He exhausted the air in his emergency air bottle during the 4 minutes it took him to egress. The passenger drowned.

Factual Information

History of Flight On November 8, 1994, at 2020 central standard time (all times are in central standard time), N2620, a Sikorsky S-76A helicopter (s/n 76-0211), operated by Mobil Administrative Services Company, Inc. (MASCI), crashed 2 miles offshore from Cameron, Louisiana. The helicopter was destroyed, the single passenger drowned, and the two pilots on board sustained minor injuries. The flight had departed the Baltic-1 oil rig (position N27-56.12, W93-57.12), 118 nautical miles offshore in the High Island 572-C block of the Gulf of Mexico, at 1930, and was returning to MASCI's Cameron, Louisiana base. The flight was conducted under the provisions of 14 CFR Part 91, and was to be the crews' final flight of the day. A company flight plan was filed, and instrument meteorological conditions prevailed at the time of the accident. At 2011:18 the ERA Helicopters weather observer transmitted to N2620 that the altimeter setting "was uh, zero zero zero at five, I'm sorry that was six o'clock, not five." At 2011:59 the captain asked the copilot "he said 30.05 at six o'clock?," who replied "yeah." The altimeter setting recorded for Lake Charles at 1950, and provided to the flight by Lake Charles Approach at 2018:21 was 30.02. (No discrepancies were found with the calibration of the barometric equipment at the ERA Cameron facility.) At 2017:04 the captain stated "... we're gonna need to slow it down because we are going to go IFR." The copilot replied "alright, you talk me through the mileages now." The captain stated "I got everything taken care of. You're, you're doing good." The crew stated to the Investigator-In-Charge (IIC) that the captain was setting up the navaids and cockpit instruments for the approach, and the copilot was visually confirming the captain's actions during this conversation. The captain stated that after telling the copilot that he had the lights of the village in sight, he remembered seeing 300 feet on the radar altimeter, called Lake Charles Approach to cancel his IFR clearance, and then looked down at the center console to change radio frequencies. He reported no unusual sensations or noises, and then "it felt like I closed my eyes and ran into a wall." He described being upside down under water, completely pitch black, and having no idea where he was. The copilot stated that the first indication he had that anything was abnormal was when he realized he was upside down, under water. He stated that he began to struggle, then realized he was still strapped to his seat. He forced himself to calm down, and remembered from his training, that if strapped in his seat he knew where he was, and that the exit door must be to his left. He reached for the door, felt the outside of the helicopter (all windows on the left side of the helicopter had broken out at impact), unbuckled his seatbelt and shoulder straps, and pulled himself clear of the helicopter. After he surfaced, he climbed onto the belly of the inverted helicopter. He stated that since no other persons appeared, he believed he was the only one who was able to escape. The captain described attempting to open his (the right) door; he did not use the emergency exit handle or unlock the door, which did not open. He unbuckled his seat belt and shoulder harness, and stated he immediately became disoriented, and then began to panic as he ran out of air. He then remembered that he carried a portable breathing air bottle (HEED - Helicopter Emergency Egress Device) in his survival vest. He removed it, began to breathe, and then continued to try to find a way out of the submerged helicopter. He estimated that he had remained disoriented for at least 2 minutes, when the air in the HEED was exhausted. His vest became tangled inside the helicopter, so he removed it and continued trying to escape. He stated that as the air supply in his lungs was exhausted, he took a series of normal breaths, except that he inhaled water. While still lost inside the aircraft, he ran into an illuminated emergency exit light positioned on the ceiling of the passenger cabin, swam toward it, and then his head broke the surface of the water. He stated he had no idea where he was until he saw the light, which he knew was on the cabin ceiling. He did not know how he got out of the helicopter. The pilot estimated that he was underwater for 4 minutes, and this was confirmed by the copilot. The emergency exit lights installed on the accident helicopter consisted of a single red light bar which read " <-EXIT-> ." This bar was positioned above the non-opening window between the cabin door and the pilots door, with an arrow pointing forward and aft. The windows on the left side of the helicopter were all missing, and no other exit paths were available. Communications During the inbound flight, the crew maintained radio communications and flight following with MASCI and ERA in accordance with MASCI's procedures. Approximately 2007 hours and 50 miles from Lake Charles, the flight contacted Lake Charles Approach Control, requested an IFR clearance to conduct the VOR- DME COPTER 010 approach to Cameron, and were issued a discreet transponder code. At 2017 the flight transmitted "I don't know if you ever picked us up...we're 28 DME...is it ok to go ahead and shoot this uh, uh, Copter One approach?" This was 2 miles from the final approach fix. Lake Charles Approach replied, "...I just picked you up, right when you called...you appear to be just comin' on the final approach fix." N2620 responded "yes sir we are...we're 27 DME indicated." Lake Charles responded "...2620 roger, I'll monitor you to uh, you can cancel IFR and uh, and uh, we'll just go from there... radar contact." N2620 replied "OK, good deal. Radar contact." During interviews, the accident pilot and copilot stated they understood this to mean that they had been given an IFR clearance to conduct the approach in IMC conditions. At 2016:32 on the LCH Tower tape N2620 reported "leaving final approach fix and starting our descent to three hundred sixty." They reported to Lake Charles that "...we just broke out here, at 400 feet...we got Cameron in sight. Looks like we got underneath here, we got about...5 miles visibility... ." The LCH ATC Tower tape transcript shows N2620 transmitted at 2018:31, "Hey Lake Charles uh Sikorsky 2620 we just broke out here at 400 feet and Cameron in sight." At 2019:00, 29 seconds later, LCH ATCT transmitted "Sikorsky 2620 report cancellation this frequency." No reply was received. Statements received from LCH ATCT, and the Principal Operations Inspector, were that N2620 was not issued an IFR clearance. The CVR transcript shows the same transmission. Thirteen seconds later the CVR records impact sounds. No response by LCH ATCT was recorded on the CVR prior to the sound of impact. (Note: the sequence of transmissions is consistent, but the time channels vary slightly between the CVR and the FAA tower tape.) Pilot Information The captain, age 47, held an airline transport pilot (ATP) certificate with a rotorcraft helicopter rating, and commercial privileges for airplane single and multiengine land and instrument airplane. He held type ratings in the SK-76, BH-206, and BH-214. He held a flight instructor certificate for helicopters, and single engine airplanes, with instrument instructor privileges in both. His first class medical certificate dated December 1, 1993, reverted to a valid second class certificate, and contained the limitation of "Holder shall wear lenses that correct for distant vision... ." The captain had accumulated approximately 15,000 hours of total flight time. He was hired by MASCI on May 28, 1985, as a BH-206 captain, and began S-76 copilot training in August 1991. At the time of hire, he had both military and civil experience as a pilot and flight instructor. He had accumulated a total of 1,036.5 hours in the S-76 at the time of the accident. Of these, 395 were as PIC or Instructor. He had accumulated 3,500 hours in the BH-206 while employed by MASCI, 552 hours after beginning S-76 training. He passed a line evaluation as an S-76 captain in September 1993, initial check airman ground training for the S-76 on June 10, 1994, a proficiency and line check per FAR's 135.293, 297, and 299 on July 17, 1994, and initial FAR Part 135 ground training on August 19, 1994. He owned his own company specializing in safety and survival equipment, and had purchased and carried in his survival vest his own Helicopter Emergency Egress Device (HEED). The HEED is a pocket size compressed air cylinder designed to provide an emergency source of breathing oxygen in case of underwater immersion. For the three months prior to the accident, the captain had been the senior S-76 pilot assigned to the Cameron base during his 7 day rotation. As such, he was the aviation point of contact between the Mobil Marine dispatchers and the aviation base at Morgan City. The day prior to the accident, he asked the rig supervisor on the Baltic-1 if he could shut down sometime and provide a brief to the rig hands on helicopter operations, and planned to schedule an opportunity in the future. During 1992, the captain logged no night or instrument flight time with MASCI. In 1993, he logged 1.5 hours at night, 2.8 hours of actual instruments, and 5 instrument approaches. On July 11-13, 1994, the captain attended recurrent simulator training which included 1.5 hours of instrument flight, an instrument competency check, and 3 instrument approaches. No discrepancies were noted. The annual proficiency training received in 1992, 1993, and 1994, at Flight Safety International (FSI) included nine hours of simulated flight time, all in a night environment. The 1994 FSI training report stated "...instrument flying skills and procedural knowledge was good. Crew Resource Management and Decision Making was excellent." In 1994, the captain flew 11.9 hours at night, 1.5 hours actual instruments, 5.6 hours simulated instruments, and 16 instrument approaches. Of these, in the last 30 days he flew 1.9 hours at night, 1.5 hours actual instruments, and 1.5 hours simulated instruments. In the last 4 days he flew 3 instrument approaches, of which 2 were the Copter VOR/DME 010 to Cameron. During the 24 hours, 30 days, and 90 days preceding the accident, the captain had flown 8, 83, and 244 hours, respectively. Copilot Information The copilot, age 56, held an airline transport pilot (ATP) certificate with both rotorcraft helicopter and airplane multiengine land ratings. He had type ratings in the BH-206, CE- 500, and IA-JET, also had a certified flight instructor certificate with airplane single engine and multiengine land ratings. His first class medical certificate, issued on December 31, 1993, had reverted to a valid second class certificate, and contained the limitation of "Must wear lenses for distant, possess glasses for near vision." According to company records, the copilot had 7,973 hours total time, of which 1,646 were in helicopters, and 1,012 were in the S-76. During the 24 hours, 30 days, and 90 days preceding the accident, the copilot had flown 8, 23, and 256 hours, respectively. The copilot was an employee of Excalibur Support Services, a company which provided contract pilots to MASCI. He began to fly for MASCI and passed both proficiency and line checks as a VFR captain on the BH-206, administered by the chief pilot on April 5 and 6, 1993, and began training as a copilot on the S-76. He passed a proficiency check in the BH-206 on September 16, 1993. He did not fly the line as a BH-206 pilot for MASCI. MASCI initially assigned him to the position of copilot on the S-76. On February 11, 1994, the copilot passed a line evaluation in the S-76, which was administered by the accident captain acting as check airman. In 1994, company records showed the copilot had flown 2.4 hours at night, and 15.6 hours in actual or simulated instrument conditions, 2.0 in the last 30 days. Aircraft Information N2620 was owned and operated by Mobil Administrative Services Company, Inc., of Morgan City, Louisiana. It was configured with 12 passenger seats, 2 pilot seats, and was certificated as a Transport Category aircraft. The helicopter was equipped with 2 Allison 250-C30 turboshaft engines, each rated at 650 shaft horsepower. At the time of the accident the total time accumulated on the airframe was 12,121 hours. The left and right engines had accumulated 5,676 and 8,980 hours respectively. The helicopter was maintained under a continuous airworthiness inspection program, and the last inspection occurred on November 7, 1994, the day prior to the accident. All of the major components of the helicopter were located except for the main rotor blades and tail gear box/rotor head assembly. The wreckage, maintenance records, testing of components, and interviews with the flight crew revealed no evidence of preexisting airframe, system, engine or flight instrument malfunction. At the time of the accident, the helicopter had a current airworthiness certificate, and was operated within weight and balance limitations. The helicopter was equipped with a Collins ALT-50A Radar Altimeter system, with a 339H-4 Radio Altitude Indicator installed in front of the captain. The indications presented to the pilot are a needle which indicates height above the surface, and a single light which illuminates when the aircraft descends below the decision height selected by the pilot. The copilot was provided with a DH setting and readout, with a DH light on his ADI, which was slaved to the captain's indicator. According to Collins Publication 523-0766822-002118; ALT-50 Theory, the ALT-50A has four adjustable altitude thresholds which are factory set at 200, 500, 1,000, and 1,500 feet, but may be locally changed. According to Collins, these settings can provide fixed altitude visual or aural warnings to the pilots, if installed. The accident helicopter did not have these fixed altitude settings, nor aural warnings installed. Weather The captain received an abbreviated weather brief from the Federal Aviation Administration DeRidder Flight Service Station at 1643. The forecast for the time period of this flight was to remain VFR until after 2400. The temperature/dewpoint spreads at Galveston and Beaumont, Texas, and Lake Charles, Louisiana, were all greater than 6 degrees Fahrenheit. Fog was forecast after 2400. Time of sunset was 1710, and the accident occurred during hours of darkness. The captain stated that the weather at the time of the accident was a 500 foot ceiling with 5 miles visibility. He stated that the weather rapidly deteriorated while they were on the water. The recorded weather observation taken by the Lake Charles Air Traffic Control Tower, 23 miles north of the accident, at 2055 was: Ceiling 500 foot broken, 3 miles visibility in fog, with temperature and dewpoint both at 72 degrees. ERA Helicopters, Inc., was maintaining radio communications and flight following for N2620. When communications were lost, and they confirmed that the helicopter had not arrived at the Cameron Heliport, an ERA rescue helicopter was launched from Lake Charles Airport at 2118. The rescue helicopter crew described the weather at Lake Charles as 500 foot ceilings with 2 mile visibility in fog. As they proceeded toward Cameron, the ceilings lowered, and they were unable to remain in visual conditions at 300 feet. They climbed above the overcast and conducted the same approach as N2620, the COPTER VOR-DME 010. At 2130, after descending to 380 feet above mean sea level they performed a missed approach and returned to Lake Charles. They were unable to descend below the ceiling. The crew of the first Coast Guard helicopter to conduct a search at 2135 for N2620 reported on-scene visibility of 1/4 mile in fog. Navigational Aids The primary navigation source used by the flig

Probable Cause and Findings

the copilot's failure to maintain altitude and the pilot-in-command's inadequate supervision of the operation. Factors include the dark night and low ceiling, and the flightcrew's failure to set the proper altimeter setting.

 

Source: NTSB Aviation Accident Database

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