Laser Alignment Fixture Streamlines H-60 Structural Repairs
It’s been almost six year since Fleet Readiness Center Southwest (FRCSW) began using its hard-point alignment fixture and laser system in repairs to H-60 Seahawk helicopters.
Located in Building 325, the steel-framed alignment fixture encompasses the 64-foot Seahawk, and enables artisans to align the aircraft’s beams, drive shaft and engine mounts. The alignment tool’s precision saves manhours in troubleshooting and costs for parts, minimizing aircraft down time.
Artisans guide the aircraft into the fixture by using a winch. The unit uses wireless remotes for maneuvering and lifting the aircraft to fine tune and make adjustments. Electric motors control threaded rods that drive the jacks.
Tracking balls, or mirrors, are mounted at designated laser points. When a laser hits the mirror, data is sent to a computer that compares readings of the aircraft’s alignment to the fixture and the aircraft drawing fuselage station, water line (a method of location on an aircraft) and butt line requirements, creating a 3-D skeletal image of the aircraft.
Costing more than $1.5 million and manufactured by ADC Engineering, the fixture is applicable to all H-60 models and is predominantly used on aircraft that have suffered mishaps or hard landings.
Aircraft subject to a mishap would undergo visual inspections to locate damages. Artisans would typically replace structural related parts 10 to 20 percent beyond the damaged area hoping to ensure a comprehensive repair.
The cumulative effect of hard landings can cause misalignment of the overall structure, and in the case of helicopters, significantly affect driveline and dynamic component premature wear.
Hard-landed aircraft and those experiencing dynamic component premature wear were similarly serviced like mishap aircraft: The replacement of major sections of structure and dynamic components with the hope of catching all damage.
Because the alignment fixture identifies the location of the problem, artisans no longer need to replace unrelated structure or components.
The alignment fixture may play a future role in the airframe’s Integrated Maintenance Program (IMP). The IMP targets the aircraft’s structural integrity.
Under the IMP, the H-60 airframe undergoes Planned Maintenance Interval 1 (PMI-1) and PMI-2. PMI work divides the aircraft into six sections and is performed in two, three-year cycles. Four sections of the aircraft are evaluated during each cycle.
If added to the IMP, the alignment fixture would be used during PMI-2 when the aircraft’s engine and transmission are removed.
During fiscal year 2019, FRCSW returned 60 H-60 Seahawk helicopters to the fleet.