C-135/KC-10

Flying Safety, Jan, 2001 by Phil Schroeder

The air refueling business is always busy and challenging. Whether passing gas, hauling cargo, training students, or a combination of the above, there is always plenty to watch out for. Fiscal Year 2000 saw no flight-related fatality or lost aircraft for both the C-135 and KC-10 community. Let's continue that trend!

KC-10

In the KC-10 community, Fiscal Year 2000 saw a Class A, a Class B, and various Class C, E, and FOD mishaps.

The single Class A involved an abort due to the number two engine that wouldn't reach takeoff power. The Class B resulted during a towing operation when the tow vehicle was disconnected from the aircraft on sloping terrain and the brake system was not pressurized. The aircraft rolled backwards and impacted a stationary tail stand.

The Class Cs were varied. In one case drogue mount bolts were improperly installed or left out, a hairline fracture developed, and during flight the drogue broke away from the coupling. In another situation the centerline drogue would not retract due to a failed V-6 valve. While air refueling with an AV-8B during turbulence, the hose was separated from the basket, leaving the basket attached to the AV-8B refueling probe. While refueling with Navy F/A-18s, one of the pilots attempted to engage the wing air refueling pod with excess closure. As a result the KC-10 went home with about 12 inches of F/A-18 air refueling probe. A flock of birds caused a KC-10 to abort at 140 KIAS, resulting in failure of the number 10 tire. On another sortie the number three tire experienced a sidewall gouge after running over a hole in the runway. During traffic pattern work, the number three engine was shut down due to a failed weld on the 14th stage bleed air duct that allowed extremely hot bleed air to vent into the engine nac elle. The hot bleed air caused significant damage to components.

In the Class E area we saw a KC-10, during a three sortie period, where the crew had problems with inadvertent stick shaker activation without auto-slat extension; inadvertent stick shaker accompanied by auto-slat extension; and unscheduled auto-slat staff warning. After each sortie, maintenance replaced various components, including a loose cannon plug on the flap transmitter, the number one and two auto-throttle speed control computers, and the left and right AOA vanes. No further problems were noted.

Another KC-10 experienced inadvertent, unscheduled auto-slat extension accompanied by the stick shaker. At approximately the same time the crew noticed the number one generator load reading fluctuating accompanied by large generator frequency variations. Maintenance replaced the CSD after landing. The unscheduled auto-slat extension and stick shaker were the results of false electrical signals. During the next sortie, similar generator load and frequency variations to the previous sortie were observed. No auto-slat extension or stick shaker occurred. After landing, maintenance replaced the load controller box. No further problems occurred.

Next we saw a KC-10 departing a deployed location with numerous pallets of maintenance equipment, including three air-conditioning units that were not properly drained and purged of fuel. During initial climb out, the fuel in one of the air-conditioning units shifted and leaked out. Due to the cargo configuration, the crew couldn't determine the extent of the spill and where it might leak, so they terminated the mission and landed.

In the FOD area, three KC-l0s experienced acoustic panel damage from ice. In all cases, the engine anti-ice system was used. Two of the events occurred in the traffic pattern, with visible moisture present, broken cloud layers, and temperatures between 10-15 degrees Celsius. The third incident occurred when the crew completed air refueling and climbed from FL200 to FL260 through a layer of moderate icing.

Another good year for the KC-10 community. Keep up the good work.

C-135

InFYCO the C-135 saw no Class A mishaps, one Class B, and a variety of Class Cs, Es, and HAPs. A high interest item in the C-135 community continues to be uncommanded stabilizer trim inputs.

KC-135E engine damage, discovered during a maintenance inspection, accounted for the Class 13.

Class Cs came from a variety of scenarios. During air refueling with a C-17, a disconnect was initiated. As the C-17 continued to the forward lower limit, the boom operator called a breakaway. During the breakaway, the C-17 continued beyond the forward limit, the nozzle appeared to bind in the receptacle before retracting, and the boom hoist cable failed. The KC-135E landed with the boom in trail.

In another case, while attempting to refuel with an F-16, the boom hoist cable snapped and separated from the fuselage, but remained attached to the boom. The KC135R also landed with the boom in trail.

Next, we had a Tornado that underran its tanker. It removed the drogue basket assembly from the tanker, FODing out the number one Tornado engine after ingesting pieces of the assembly, and taking the basket home on the refueling probe.