VRAJ
PATEL

Analyzed two years of Maintenance Action Forms against the fuel cell, then went deep into mechanical schematics and theory of operation in flight to see whether adjacent components were contributing. FMECA review for derivable testability information. Gave management a holistic reliability picture through FRACAS-CARTS: failure driver heat map, failure modes quad chart, AMSAA chart of MFHBR versus flight hour. Mapped the organizations needed to close it: government engineers, Bell Helicopter engineering and production technicians, supplier engineering and manufacturing, flight-line maintainers across the Marines, Air Force and Navy, and Boeing mechanical design, materials and RMT.

Supplier benchmark testing on fuel cell weight, cure date and damage location documentation, and refolding behavior. Boeing and supplier material testing: FTIR spectroscopy, microscopic inspection of the damage, and controlled fuel exposure on bladder samples. Damage resolved into four modes — tearing, surface imperfections, ply delamination and hanger breakage — matching what the fleet had reported before the investigation opened.

Pulled prior-year Notices of Escapement to identify affected serial numbers, then reviewed Discrepancy Notices to document what rework each failed cell had received before shipment. The bladder curing process turned out to be outdated and unrepeatable. On the install side, a Maintenance Task Analysis showed excessive time between folding and complete install, no pressure test before installation, no pull test on hangers, no specialized tooling to prevent accidental damage, and a wing access opening small enough to warrant a structural study of enlarging it.

Organized findings on a KNOT chart and fishbone diagram to drive consensus. Supplier actions: simulate the installation fold before final stand test, fasten hangers to the shipping crate, map post-cure and final-inspection rework areas, and improve serial-number and quality-concern tracking. Bell-Boeing actions: stencil fold lines in structurally sound areas, guarantee fleet oven access at install, enable flight-line hanger replacement, add maintenance tasks for hanger torque, pre- and post-install pressure tests and hanger pull tests — and redesign the hangers in a stronger material and shape.