Aircraft’s dispatch reliability plummets as safety concerns rise
Supply-chain woes continue to adversely impact offshore helicopter operators, according to a notice recently issued by the International Association of Oil & Gas Producers’ (IOGP) aviation subcommittee (ASC). In a recent IOGP ASC safety notice to members, the organization branded the situation as “serious and deteriorating,” saying it presented “significant safety and operational risks.”
While the problems were particularly acute with regard to the Sikorsky S-92, with 86 percent of its fleet flying offshore energy, the ASC said the situation pervaded the entire industry. But the S-92, with its unique capacity to carry 19 passengers and service deepwater clients, drew the majority of the ASC’s attention based on operator surveys.
Data from the three largest civil S-92 operators—Bristow, CHC, and PHI, which together account for 61 percent of the fleet—revealed that 20 aircraft (13 percent of the fleet) are AOG while waiting for replacement main gearboxes. Three other operators reported another 11 S-92s are also AOG.
The overall AOG number is likely to double by the end of 2024 given Sikorsky’s low aircraft production rates—it delivered four S-92s in 2022. One operator reported that S-92 AOG days at the parts level increased from 214 in 2022 to 3,009 year-to-date.
Overall fleet dispatch reliability now hovers at 80 percent, as opposed to the industry average of 96 percent. The situation has triggered a variety of adverse maintenance practices, according to the ASC, including parts cannibalization, up by 50 percent to 106 percent, with more than 50 parts being taken from an aircraft entering maintenance “not uncommon.”
Maintenance extension requests to the OEM have increased by an average of 850 percent year-to-date. The time to complete a 1,500-hour inspection has increased by 75 percent (to 75 days), requiring 25 percent more manpower, and triggered a 57 percent increase in overtime.
The ASC concluded that the climate created the “potential and conditions for a serious safety event that is clearly growing unless action is taken.” Operators are forced into contracts that apply “punitive financial penalties for not meeting aircraft availability targets.”
According to the ASC, such provisions “will not improve availability, but will worsen the operators’ position further and potentially add further stress and risk to their maintenance departments.” It predicted that S-92 parts availability “has the potential to deteriorate further in the coming 12 months, leading to further reductions in aircraft availability.”
IOGP reiterated operator “resilience strategies” suggested earlier in the year, including raising stakeholder awareness and transparency, temporary sharing of contracted aircraft assets, and not punitively adding to operational risks via contract penalty clauses.
The ASC concluded that “effective local action and engagement between individual clients and contracted operators is essential if the safety risks are to be mitigated and our normal very high levels of safety performance maintained.”
Sikorsky president Paul Lemmo said the OEM was working diligently to resolve supply chain issues, significantly increasing main gearbox production and assisting its own suppliers with resolving bottlenecks. He partially attributed the issue to a post-Covid surge in S-92 flying hours, which increased by a fifth.
In a statement provided to AIN, Lemmo said the company is taking various actions to address the “unprecedented” S-92 spares situation, in part driven by a “22 percent increase in S-92 aircraft flight hours over the last three years. This increased utilization has added to the fleet operating hours but also created more pressure on parts required.”
“Sikorsky experts have provided S-92 suppliers technical and operational support so they can accelerate delivery of parts,” he added. The company “has been assisting S-92 suppliers throughout all tiers of the supply chain to source specialty metals, components, and other raw material.”
Lemmo said these efforts were beginning to produce results, noting that “we have increased main gearbox output by 40 percent in 2023 compared to 2022. We have delivered 31 year-to-date and project providing 40 in 2023 versus 28 delivered in 2022.” He said Sikorsky “will continue these efforts for as long as it takes to accelerate delivery of the parts our customers need.”
His comments built on remarks made by Sikorsky executives speaking at Heli-Expo earlier this year. Leon Silva, Sikorsky’s executive v-p of global, commercial, and military systems, admitted that ongoing supply chain problems had dragged down S-92 fleet utilization rates and dispatch reliability percentages “into the high eighties.”
He said the company “continues to work diligently on the supply chain” and had established what amounts to an emergency center at Sikorsky’s Trumbull, Connecticut facility to work with suppliers to resolve issues.
Aside from ongoing supply chain woes, Sikorsky’s commitment to the civil market remains suspect after the company was acquired by defense contractor Lockheed Martin in 2015. It has discontinued production of the S-76 rather than manufacture it with a federally-mandated crash-resistant fuel system.
Earlier this year, Sikorsky announced it was shelving the S-92B program and moving the anticipated certification date of its A+ upgrade for the helicopter into 2025, some three years later than originally planned. As a result, deliveries of A+ kits ordered today will not happen until 2026.
Several helicopters in the installed fleet of more than 300 S-92s have nearly reached their 30,000-hour life limit, but Sikorsky has no plans to extend it. Though the company continues to accept orders for the $40 million S-92, it cannot deliver one for at least two to three years, it said.