The Coast Guard’s fleet of MH-60 Jayhawk helicopters could grow from its current size of 45 aircraft to upward of potentially between 115 and 117, Commandant Adm. Karl Schultz said last week.

The MH-60s are supplied by Lockheed Martin’s [LMT] Sikorsky unit and are a maritime variant the venerable Black Hawk helicopter.

In January 2021, the Coast Guard awarded Lockheed Martin a potential $850 million contract as part of the service’s ongoing service life extension program (SLEP) for the MH-60 and has contracted for 31 new hulls under the contract so far. Delivery of the fust hull is expected in early to mid-2023.

The SLEP is part of a program to keep the medium-range aircraft in the Coast Guard inventory through the mid-2030s. The legacy fleet of MH-60s began operations with the Coast Guard in the early 1990s and are approaching their end of expected service life, which is 20,000 flight hours per hull.

The Coast Guard says that 90 percent of the current MH-60 fleet will reach the 20,000-flight hour limit by 2028.

The Coast Guard had planned to maintain a mix of MH-60s and MH-65s, which are short-range helicopters previously supplied by a division of Airbus Group, but a delay in the Defense Department’s plans for a maritime variant within its Future Vertical Lift program led the Coast Guard to decide to phase out the short-range helicopters sooner than planned.

The MH-65s are also going through a SLEP while the Coast Guard transitions to an MH-60-only rotary wing fleet.

The Coast Guard is still evaluating its sources for the MH-60 hulls, some of which are former Navy hulls that the service is pulling from storage in the desert, also called the boneyard. Speaking at the annual Surface Navy Association National conference last week, Schultz said these aircraft have between 8,000 and 9,000 flight hours on them and the SLEP will extend their life out to 20,000 hours.

“There has been no decision on the source of the hulls that will eventually make up the fleet of Coast Guard MH-60Ts,” the Coast Guard said in an email response to questions. “As the service evaluates the final count of airframes necessary to meet mission demand, it will continue to weigh operational efficiency, affordability and timing of delivery into the decision to utilize Navy conversion hulls or acquire new hulls from Sikorsky. The use of new hulls provides an excellent value for the Coast Guard, as they provide an airframe service life of 20,000 flight hours, approximately 12,000 more than converted Navy hulls.”

The Coast Guard is also modifying its MH-60s to a blade-fold, tail-fold configuration to be able to hangar the aircraft on its national security cutters, and future fleet of offshore patrol cutters and polar security cutters to “get them out of the salt” air, Schultz said. Work on the first blade-fold, tail-fold conversion has been completed, he said. The Coast Guard soon hopes to begin “ramping up” these conversions, he said.