The Government Accountability Office (GAO) has taken the Pentagon to task over the progress of several new military rotorcraft programs in its recently released Weapons Systems Annual Assessment. They included the VH-92A (Marine One), CH-53K heavy lift replacement helicopter for the Marines, the CH-47F Block II for the Army, and the MH-139A and HH-60W for the Air Force. The programs are all late, in varying degrees, and continue to face technical and operational challenges. With the exception of the CH-53K, all the programs utilize pre-existing airframes and attempt to modify them to mission requirements.
Sikorsky VH-92A, 23 aircraft with a combined development and procurement cost of $5.023 billion.
The GAO found that the VH-92A presidential helicopter replacement program (Marine One) likely has corrected previously reported performance problems with the classified, government-developed missions communications systems on board the aircraft; however, “technical modifications may be needed to address issues identified in follow-on operational testing.” The GAO also noted that the Navy was working to improve aircraft availability and reduce engine exhaust and fluid discharges in landing zones. A final fix for the exhaust problem, which singes the grass at landing zones, has yet to be implemented. A solution proposed by manufacturer Sikorsky involving blade pitch changes “will require the aircraft to undergo certification for landing zone suitability from the Federal Aviation Administration.” Fifteen of the 23 new aircraft are expected to be fully operational no later than January 2023.
Sikorsky CH-53K, 200 aircraft with a combined development and procurement cost of $32.41 billion.
As for the CH-53K heavy replacement helicopter for the Marine Corps, the aircraft’s program office reported 126 technical issues last year and 119 have been subsequently resolved. However, significant problems remain. They include: excess sand and dirt ingestion into the compressor during hover that will require a redesign of the engine intakes; a short lifespan of the main rotor damper and intermediate gearbox; main gearbox supplier limitations that are necessitating the recruitment of new suppliers; difficulties with the supplier of the fuel cell bags encountered in achieving specifications, triggering the need for rework and improved tooling; and the resignation of the supplier for the data concentration units, requiring the search for a new supplier. The CH-53K achieved initial operational capability in April.
Boeing CH-47F Block II, 542 aircraft with a combined development and procurement cost of $17.3 billion.
Development testing has revealed problems with two critical components on the latest Chinook tandem rotor helicopter upgrade program. The Advanced Chinook Rotor Blade (ACRB) induces vibrations significant enough to cause safety concerns and the new Ferrium C61 steel shafts are susceptible to stress-related cracking and corrosion. Consequently, the Army scrapped programs to include the new blades and part of the upgrade and will subject the new shafts to additional testing. The aircraft’s new fuel system also failed in testing. The GAO reported that “Future assessments of the rotor components are planned.”
Boeing MH-139A Gray Wolf, 80 aircraft with a combined development and procurement cost of $3.243 billion.
This militarized version of the Leonardo AW139 medium twin for Air Force VIP and security missions has faced a variety of challenges integrating components that are new to the airframe, causing a delay in FAA certification approval, according to the GAO. “Program officials stated that Boeing underestimated the scale of design work.” This has contributed to a 16-month production delay in the program, and additional delays are possible. “Program officials stated that they continue to work with Boeing to address these significant schedule delays, but Boeing has not submitted some contractually required data on time. Consequently, the program reported withholding 10 percent of its progress payments.” The GAO noted that “given the [program’s] design instability, there are risks that later design changes could result in significant rework of aircraft already in production and retrofit of aircraft already delivered.”
Sikorsky HH-60W Jolly Green II, 113 aircraft with a combined development and procurement cost of $9.647 billion.
Operational testing of the Air Force’s next-generation rescue helicopter was delayed by eight months due to a “lack of access to mission-ready aircraft equipped with an operational radar warning receiver,” according to the GAO. Pandemic-related supplier delays also manifested in sustainment, the gun mount system, and training.