Just like humans, airframes constructed from composite materials can sustain superficial skin wounds. These “hangar rash” incidents usually involve minor damage occurring while the aircraft is on the ground, typically near a hangar. This damage often results from contact with vehicles or ground equipment, leading to cosmetic scratches or laminate punctures. More severe damage, such as “delamination,” typically stems from significant impact forces, like collisions with hangar doors or mid-air bird strikes. Delamination involves the separation or fracture of the laminated reinforcement layers or plies.
A Sobering Statistic: Data reported by international airlines to the Flight Safety Foundation (FSF) paints a concerning picture. Approximately 27,000 ground accidents occur each year, translating to one incident and nine personnel injuries for every 1,000 departures. These preventable accidents amount to a staggering $10 billion in damages, often borne by the owner/operator, as the costs frequently fall below the insurance claim threshold.
Advancements in Composite Repairs: While Maintenance, Repair, and Overhaul (MRO) operations have conducted composite repairs for years, these were primarily reserved for parts too large or costly to remove. However, advancements in materials and technology have ushered in a new era, where repairs on the line are becoming the norm, reducing Aircraft on Ground (AOG) time.
Composite Revolution in Aircraft Manufacturing: Composite materials gained prominence with Boeing’s 787 and Airbus’s A350 XWB. Their use has expanded beyond control surfaces and engine components to encompass entire forward wing structures and fuselages.
Benefits Beyond Weight Reduction: Apart from reducing weight for enhanced fuel efficiency, composite airframes significantly cut down on corrosion and fatigue-related maintenance. Airbus claims a remarkable 60% reduction in these tasks for the A350 XWB, reducing both maintenance check time and the overall number of checks needed throughout the aircraft’s service life.
Challenges in a Congested World: Despite these advancements, congested airports and surging air traffic make accidents almost inevitable, despite collision prevention efforts.
Challenges for MRO Providers: Working on aircraft with complex composite structures presents challenges for MRO providers. These include performing more repairs on aircraft rather than in hangars, reducing repair durations without compromising quality, and expanding the scope of approved bonded repairs to complex primary structures.
The Time Challenge: Composite repairs often demand more downtime due to curing times for specific resins and adhesives. Adhesives and prepreg layers used in bonded composite repairs can take 8-12 hours to cure. Additionally, non-destructive inspection, material removal, and preparation processes are typically time-consuming.
The Solution: Inflatable Cleanrooms: A critical aspect during adhesive curing is absolute cleanliness. J B Roche offers an innovative solution with their patented CompShop®, a portable inflatable cleanroom. This lightweight, weatherproof unit ensures an optimal environment for repairing composite parts removed from the aircraft. It can be swiftly relocated, and erected in just 15 minutes, and requires minimal training.
The patented CompShop® portable composite cleanroom from JB Roche
Further information on the range of inflatable maintenance shelters suitable for enclosing any part of the aircraft, can be found here: