News United States Air Force
 Arresting cable mission stands ready to save livesPublished July 3, 2017
                        
                        By Master Sgt. Eric M. Sharman
                        
                        
                        386th Air Expeditionary Wing Public Affairs
                **SOUTHWEST ASIA (AFNS)  --**
                The Airmen in the 386th Expeditionary Civil Engineer Squadron power production shop are unsung heroes. Nobody thinks about the constant, never-ending generator mission until the grid power goes down. The fleet of light carts is overlooked until night operations occur. The arresting cable mission requires routine maintenance and daily inspection. If this particular asset has to be used, it can save a life.
The mobile aircraft arresting system consists of a hydraulic braking system connected to a woven steel cable which is stretched across the runway, and connected to another MAAS prior to use. If a fighter aircraft has an in-flight emergency, and it is believed that the aircraft cannot brake safely under its own power, the cable is stretched across the runway and upon landing, the tail hook of the aircraft will catch the cable.
When the aircraft pulls on the cable it engages the BAK-12 hydraulic braking system. The harder the cable is pulled, the harder the brakes are applied. This ratio of pull-to-drag allows the aircraft to be slowed down in a safe and controlled manner. When this procedure happens correctly, the aircraft stops safely. To ensure this happens correctly, maintenance is required.
Staff Sgt. Michael Weixlmann and Senior Airman Quentin Palmore, both 386th Expeditionary Civil Engineer Squadron power production specialists, conduct daily inspections that ensure the four MAAS units remain operational.
“We’re looking for basic things like hydraulic fluid levels, pressure readings, and any cracked or dry-rotted hoses,” said Weixlmann, “This isn’t a terribly complex system, but if it doesn’t work right it could mean a badly damaged aircraft, or worse, a pilot gets injured or killed.”
The maintenance performed on this system is performed daily, weekly, monthly, quarterly, semi-annually, and annually. Daily maintenance is an overall system check to look for anything abnormal on the system. Weekly maintenance includes bleeding the braking system fluid from the unit.
“Monthly inspections consist of a 200 foot cable pull-out, which performs a system check, and it also removes any rust on the brakes themselves. The quarterly inspection changes this to an 800 foot pull-out, and we have to synchronize the two barrier hydraulic systems together so they can work in tandem to arrest an aircraft,” said Weixlmann.
The synchronization operation ensures that the two units are braking at the same rate, which ensures even stopping of the aircraft and even wear on the BAK-12s.
Further maintenance includes a procedure called a tape crop, which is performed semi-annually. This removes the portion of the rubberized tape that has been exposed to the sun and elements. This tape is considered “degraded” and has lost its strength. Annual inspections include changing the oil, and the multiple filters the BAK-12 engine has.
While it may seem repetitive, the maintenance on the MAAS units is crucial to the protection of life and assets. When needed, a successful cable arrest operation is fulfilling to those who maintain these systems.
The most memorable experience Weixlmann has of “catching” a plane was at his home station of Mountain Home Air Force Base, Idaho.
“On an in-flight emergency call, I was able to see the plane come in, take the cable, and watch our system successfully stop the aircraft. This was the first time I was able to watch everything happen. I remember thinking ‘I hope nothing goes wrong when he hits the cable.’ There was instant gratification when I saw the system perform exactly how it was supposed to,” said Weixlmann.Mountain Home AFB 



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386th Expeditionary Civil Engineer Squadron