Casualties unknown

2005-09-06: Sikorsky S76 (N90421) — Gulf OF Mexico, TX

Gulf OF Mexico, TX, US

On September 6, 2005, a Sikorsky S76 (registration N90421) was involved in an aviation accident near Gulf OF Mexico, TX. Investigators recorded the probable cause as: The pilots' delayed response to the No. 1 engine fire warning and the loss of power to both engines, which occurred for undetermined reasons. The pilots' delayed response was most likely due to stress and fatigue. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 4 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A helicopter experienced an engine fire warning and lost power to both engines, leading to a forced landing in the Gulf of Mexico. The pilots did not follow emergency procedures, and the wreckage was lost to Hurricane Katrina.

Accident Overview

Approximately 18 minutes into a flight over the Gulf of Mexico, the No. 1 (left) engine fire warning light illuminated in the cockpit. Crew and passenger interviews indicated that additional engine warnings and visible smoke in the cockpit and passenger compartment followed. Shortly after, the helicopter lost power to both engines, and the flight crew executed a forced landing into the open waters of the Gulf of Mexico.

Wreckage and Investigation

The helicopter wreckage was located, and the cockpit voice recorder (CVR) was recovered shortly after the accident. However, efforts to recover the remainder of the wreckage were suspended due to an approaching hurricane. The wreckage could not be located after the hurricane; therefore, the cause of the in-flight fire warnings and the loss of power to both engines could not be determined.

Pilot Performance

CVR evidence revealed that, after the first engine fire warning, neither pilot acknowledged the fire warning, called for a checklist, or verbalized a plan of action. According to the Sikorsky S-76A Flight Manual, emergency procedures for an engine fire warning include pressing the fire warning light, establishing safe single-engine flight airspeed (76 knots), fully retarding the affected engine's illuminated T-handle, and, if necessary, selecting and activating the fire extinguishing system. The pilots, who had been on duty for more than 10 hours and completed 13 landings that day, only completed the first step during the 2 minutes before impact with water. Performance calculations indicated that if the pilots had immediately completed the first three steps, they may have been able to maintain single-engine flight to a suitable landing location before the No. 2 engine failed.

Communication and Procedures

The first officer transmitted a "mayday" call before the second engine failure, but he did not provide essential information needed for emergency assistance. He also did not inform the passengers of the forced landing. Before flight, the crew did not provide the required preflight passenger safety briefing, which would have included instructions on retrieving and inflating a liferaft; the passengers did not retrieve either of the two liferafts. These performance deficiencies are consistent with the known effects of situational stress and fatigue.

Flight Following and Company Deficiencies

The flight crew did not file a flight plan with the FAA or HHI, contrary to company procedures. Although Houston area ATC facilities monitored emergency frequencies, controllers did not hear the distress call because the helicopter was outside and below ATC radio coverage. Commercial and military pilots heard the call, but none could provide additional information because the first officer only stated, "mayday... Houston 421... going in" without location or emergency type.

At the time, HHI's communication network and Gulf cellular towers were nonfunctional due to Hurricane Katrina, and HHI did not provide an alternate means for pilots to communicate with base operations. The accident pilot was reluctant to use his personal satellite cell phone because HHI would not reimburse him. Flight crews were expected to contact an FAA automated flight service station if they could not contact base operations, but the accident crew did neither. HHI did not report the overdue helicopter to the FAA until almost 2 hours after its expected return. HHI did not ensure adherence to flight-following procedures and lacked adequate procedures for reporting overdue flights, delaying search and rescue efforts.

Safety Recommendations

As a result, the Safety Board recommended that the FAA provide offshore helicopter crews with personal flotation devices equipped with a waterproof 406 MHz personal locator beacon with GPS and another signaling device. The 7.5 hours passengers spent in water exposed them to hypothermia-inducing conditions, and lack of a beacon delayed rescue. The recommendation was classified "Open-Acceptable Response" on July 25, 2008.

FAA Oversight

As early as 2003, the FAA was aware of safety deficiencies at HHI, including lack of passenger briefings and inadequate flight-locating training. In February 2005, a principal operations inspector recorded HHI's lack of adherence to flight-locating procedures. In August 2005, he attempted to suspend operations, but the Houston office gave an extension due to Hurricane Katrina. After communications loss, the FAA improperly assumed HHI had an alternate communication method. The principal maintenance inspector failed to inspect all PFDs and repair manuals. Inadequate FAA surveillance contributed to an unsafe corporate culture at HHI, leading to disregard for briefings, improper emergency handling, lack of flight-following, and noncompliance.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20051128X01894. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.