Navy report casts doubt on Sea Dragon’s reliability

NORFOLK

A month ago, when the Navy released one of its investigations into a crash that killed three sailors, an official said the service remained “absolutely confident” in the safety of the Sea Dragon, its oldest helicopter.

An internal Navy review of the crash suggests otherwise.

The confidential safety investigation report, obtained by The Virginian-Pilot, says a full risk analysis is needed to ensure the aging MH-53E Sea Dragon fleet is safe to fly for another decade.

The report is also critical of the three-star command responsible for developing, equipping and maintaining all Navy and Marine Corps aircraft, including the Sea Dragon.

The Navy does not typically release post-crash safety investigations, which are prepared by a panel of aviation officers known as an aircraft mishap board. The Navy considers safety reports a form of internal communication, exempting most of their findings from public records disclosures.

Navy officials declined to discuss the findings in the report, which still must be endorsed by officers up the chain of command and is subject to change.

Finalized or not, the document reveals internal Navy concerns about the long-term viability of the service’s most crash-prone helicopter.

The Jan. 8 accident off the coast of Virginia Beach was the latest in a string of mishaps involving Sea Dragons. Investigators traced the crash to a wiring bundle that had been chafing against a worn-out gas line inside the helicopter’s cabin. The tattered wire released an electrical arc that connected with fuel, igniting an uncontrollable fire. The blaze filled the cabin with thick smoke and flames, blinding the pilots and causing the helicopter to crash tail-first into the ocean. Three of the five crew members died.

After the crash, the chafing problem – which had never come up during the helicopter’s three decades in service – was discovered in all of the Navy’s remaining 29 Sea Dragons, revealing that each was at risk of a similar catastrophe.

The Navy announced last month that it had fixed worn wires and fuel lines across its fleet of Sea Dragons shortly after the crash, and it said it is developing new inspection standards to check for future wiring problems. The safety investigation authors said those measures should help prevent a repeat of the same malfunction.

They also sounded an ominous warning:

“The discovery of this defect is a leading indicator that other age-related discrepancies that could lead to loss of aircraft and crew in the future may be present.”

In other words, while the Navy has fixed the wiring problem that caused this crash, it’s possible there are other potentially lethal problems with the aircraft that have not been discovered.

The safety report calls for “a thorough risk analysis” to determine whether other aging components are at risk of unexpected failure.

The Navy doesn’t have a plan to replace the Sea Dragon – the military’s only helicopter powerful enough to tow a massive mine-sweeping sled through water. Originally slated for retirement a decade ago, the helicopters are expected to remain in service through 2025. The Navy already is having trouble finding replacement parts, many of which are no longer manufactured.

A separate crash investigation the service released last month pointed to the same cause – electrical wires rubbing against a fuel line. That report, known as a judge advocate manual investigation, cited no individuals or commands for actions or inactions contributing to the January crash. And other than calling for more thorough wiring inspections, it made no recommendations about the future of the Sea Dragon program.

The authors of the safety report were more critical. They faulted Naval Air Systems Command, headquartered in Patuxent River, Md., for failing to develop regular maintenance procedures to check for chafing wires.

The safety investigation “revealed no required maintenance to the suspect wire bundle or fuel transfer line,” they wrote. Even when the helicopters were sent to the Navy’s fleet readiness center in Cherry Point, N.C., for more intensive maintenance, there was no requirement that wires or fuel lines be checked for chafing.

Further, the safety report’s authors found, the routing of wires so near a fuel line runs counter to Naval Air Systems Command’s own wiring manual. But because the manual gives blanket priority to original manufacture specifications – and because the suspect wiring matched Sikorsky Aircraft Corporation’s 1970s Sea Dragon design drawings – the questionable placement of the wiring bundle near a fuel line went unscrutinized.

This minor design flaw, the report noted, was exacerbated by decades of wear and tear.

“While this bundle routing may have posed minimal risk early in the service life of the MH-53E… it poses a significant risk in an aging airframe,” the report said.

Improved maintenance procedures are necessary but not sufficient to eliminate the risk of future fires, the mishap board wrote. It called on Naval Air Systems Command to move wires to ensure they don’t come into contact with “critical aircraft components,” especially fuel lines. That step, the report said, “is necessary to prevent catastrophic chafing between maintenance intervals.”

Citing the “need to maintain the integrity” of the ongoing safety investigation process, a spokeswoman for Naval Air Systems Command wouldn’t say whether the command plans to conduct a risk analysis for other age-related problems in the helicopters, or if it intends to move wires away from critical components.

Cmdr. Mike Kafka, a spokesman for Naval Air Force Atlantic in Norfolk, said he couldn’t discuss the pending safety report findings, but he emphasized that the Navy is “taking a variety of steps to ensure the long-term viability” of the Sea Dragon program.

After a deadly crash in 2012 revealed significant maintenance and leadership failures, the Navy acknowledged it had neglected the Sea Dragon community and spent millions of dollars in the hopes of turning things around.

Before the January crash, it upgraded the aircraft with night vision technology and new sensors to better detect mechanical failures. It added dozens of maintenance personnel. It beefed up pilot training. It began the process of making sure all the helicopters are equipped for the core mine-clearing mission.

In addition to new wiring inspections initiated since then, the Navy is working on additional measures “to address issues related to the aging of the airframe,” Kafka said. Those plans have not been finalized, he said.

The Sea Dragons – based only at Norfolk Naval Station and two overseas posts – were grounded immediately following the January crash. Most of the helicopters began flying training missions again a few weeks later, once the wires and fuel lines were fixed.

Later this month, a few of the Sea Dragons are expected to participate in an international mine-clearing exercise in the Persian Gulf.

In their final recommendation, the safety report’s authors called for their findings to be shared with every helicopter squadron in the Navy, not just the Sea Dragons. They concluded by saying, regardless of what the Navy is doing to improve maintenance, it is the responsibility of pilots, aircrew and maintainers to thoroughly inspect helicopters before take off.

“If something doesn’t look right, ask questions and demand answers,” the safety report said. “If guidance is unclear, ask questions and demand answers.”

Mike Hixenbaugh, 757-446-2949, mike.hixenbaugh@pilotonline.com