In the end, the exercise became a complicated math problem. It had fixed quantities—2,300 miles, twelve required aerial refuelings, more than nine hours of flight time, and three KC-130J Super Hercules tankers. The solution had to equal four MV-22B Osprey aircraft crews flying nonstop across the US and landing safely with 3,000 pounds of fuel reserves. The big variable was the weather.
"Our mission is to plan and execute a multiship transcontinental flight from California to North Carolina," says Lt. Col. Dave Krebs, commander of Marine Aerial Refueler Transport Squadron 252 (VMGR-252), the KC-130J unit at MCAS Cherry Point, North Carolina. "We want to refine the aerial refueling skills for the MV-22 crews—particularly in weather—and to practice pathfinder operations with the Ospreys."
The first combat deployment for the Osprey started in September as Marine Medium Tiltrotor Squadron 263 (VMM-263), based at MCAS New River, North Carolina, began operations in Iraq. It had been a long, and sometimes arduous, road for the MV-22 to reach this milestone—as development of the Osprey, a helicopter/aircraft hybrid, had taken more than a decade. The improved Marine MV-22B is now flown by two operational squadrons and one training unit.
The Osprey is a joint-service, multi-mission tiltrotor transport operated by the Marine Corps and the Air Force. The MV-22 takes off vertically like a helicopter. Its large rotors and engines then translate downward ninety degrees to a horizontal position, and the Osprey becomes a turbo-prop aircraft with long range and good high-speed cruise performance. The Osprey lands like a helicopter, with the motors and rotors translating up prior to touchdown.
For the Marines, the Osprey's primary mission is to fly from an amphibious assault ship at twice the speed of a helicopter and land in a confined space or on a beach to drop off twenty-four combat troops or 20,000 pounds of cargo. Because it is designed to spend most of its career at low altitude, the Osprey is not pressurized. It also does not have advanced radar. For its mission, the MV-22 simply doesn't need either one. However, the lack of this equipment becomes a consideration when the Osprey is deploying.
In the work-up to the first operational deployment, VMM-263 Osprey crews trained for months with their Super Hercules tanker-flying neighbors at Cherry Point. The unit practiced with VMGR-252, the oldest continually active squadron in the Marine Corps, which flies the KC-130Js stationed on the US East Coast.
With the first Osprey squadron deployed, the second squadron, VMM-162, also based at New River, is training. Known as the Golden Eagles, VMM-162 is scheduled to deploy in mid-2008. But in early September, the KC-130J squadron and this MV-22 unit teamed up for a cross-country transit exercise, called Whirlybird West Transcon, to fly nonstop from MCAS Miramar, near San Diego, California, back to eastern North Carolina. The exercise provides valuable experience to the VMM-162 Osprey crews.
Formation Takeoff
"The flight is a large formation movement to simulate a long-range, over-water scenario to the maximum extent possible," notes Krebs. "The Marine Corps is going to deploy the Osprey over open water at some point. The tanker squadrons and the MV-22s both have to be ready."
The seven aircrews held a mass briefing the afternoon before the flight, covering everything from takeoff procedures to route of flight, formation rules, and radio frequencies. The briefing was detailed, even noting exactly where the Osprey crews would break formation and proceed to a landing at New River.
"Then the weather changed, and we had to replan the entire mission in about thirty minutes," recalls Capt. Aleksander Martin-Nims, the pilot of one of the KC-130Js. The remnants of Tropical Storm Henrietta, which had moved over New Mexico overnight, precipitated the change.
"We have to have three KC-130Js to make this mission work," notes Krebs. The crew in pathfinder KC-130J takes off thirty minutes ahead of the main formation. That crew's job is to find clear skies around the clouds and storms using the aircraft's AN/APN-241 color low-power weather radar and the crew's own Mk. 1 eyeballs. They relay that information to the Refueling Aerial Commander, or RAC, who is in charge of the overall mission. Krebs served as the RAC on this flight.
The RAC takes the information from the pathfinder (radio callsign Otis 50) and makes the decision on course changes and how best to proceed. The RAC also works the radios, coordinating with air traffic control, the other tanker, and the Ospreys.
Departing Mitscher Field at MCAS Miramar, the two tankers with the fuel for the Ospreys (callsigns Otis 51 and Otis 52) took off one behind the other from the right runway, while the four MV-22s (callsigns Talon 13, 14, 15, and 16) took off in formation from the parallel left runway.
The Marines use their KC-130Js in both the tanking and transport role, and on this Friday, Otis 51 fills both roles. The VMM-162 maintainers who had previously deployed with their MV-22s to California are also going home. With the cargo compartment being used by the maintainers and their equipment, the large fuselage fuel tank normally used on refueling missions is not installed on Otis 51. The aircraft has 58,000 pounds of fuel for itself and the Ospreys.
Otis 52 does carry the fuselage tank, which can hold more than 23,000 pounds of fuel—roughly 3,500 gallons. With a total of 74,000 pounds of fuel in the fuselage and wing tanks, Otis 52 is near max gross takeoff weight. Even with that heavy load, the KC-130J needs only about half of Miramar's 12,000-foot runway to get airborne.
The Ospreys began their takeoff roll simultaneously to Otis 52. Once airborne, the four MV-22s quickly form up behind the KC-130J in tight echelon left and right formation, two aircraft behind and to each side of the tanker. Otis 52 is a half-mile in trail behind Otis 51, with 500 feet of vertical separation.
Get In Position
Although the formation quickly climbed to 18,000 feet, it had to climb and change altitude rapidly from 15,000 feet to 19,000 feet several times over the course of the day to get around the weather or to respond to directions from air traffic control.
"Fighters, which refuel at about 20,000 to 25,000 feet, are faster to tank than the Ospreys," Martin-Nims notes. "On a mission like this, the MV-22s operate right in the heart of the weather and in the middle of sometimes congested airspace."
"All the aircraft in the formation are using autothrottles and autopilot for high-speed cruise," Krebs adds. "We also use the altitude hold as much as possible. We want to make it as easy as possible for everyone." Flying above 10,000 feet with no pressurization, the MV-22 crews are required to wear oxygen masks during the entire flight, or as Krebs describes it, "They have to breathe through the nose hose."
The first aerial refueling comes three hours into the mission. Krebs directs two of the Ospreys to break off from Otis 52 and reform on Otis 51. The move puts one Osprey on each side and behind both tankers.
"We want to go with single-tanker operations in the tight part of the weather," Krebs explains. "The Ospreys need to be able to penetrate weather in this formation for up to an hour if necessary. We have to prepare for all kinds of conditions."
The KC-130J can refuel two helicopters at one time. However, the Osprey's large size allows only one MV-22 at a time to tank. At the start of refueling operations, the KC-130J crew streams its two eighty-five-foot long refueling hoses from the aircraft's wing-mounted pods. When cleared in by the RAC, the Osprey pilot, with his aircraft's refueling probe extended, closes in on the basket-shaped refueling drogue.
The tanker today uses the smaller, high-speed drogue, which is designed for the higher refueling speeds of the fighters. "MV-22s can't tank on KC-10s or KC-135s—the tankers have to put their flaps down, and that creates dirty air over the Ospreys," Krebs observes. "If you are going to refuel an Osprey, the Battleherk is the only tanker that can be used."
A crew chief on the tanker acts as an observer during this process, watching the hose operation and monitoring the receivers from the KC-130J's paratroop door windows. After receiving confirmation from the observers that the receivers are in sight, the RAC clears the receiving Osprey into the pre-contact position, about ten feet behind the extended drogue. When both the drogue and the receiver are stable, the RAC clears the receiver for contact. Once the receiver's probe makes contact, the receiving pilot pushes the hose forward a few feet to ensure connection. Fuel then begins to flow.
Gas And Go
"The MV-22s refuel at about 210 knots," notes Martin-Nims. "They have a little power and speed margin left if they have to chase the drogue if it is bouncing around."
A crew chief sitting on the flight deck of the tanker runs the refueling panel. With the reduced crew requirements in the KC-130J, the role of crew chiefs has changed. Not only do they fix the aircraft, they also serve as the in-flight observers and fuel panel operators. They can even run engines and taxi the aircraft on the ground.
"The crew chief keeps the aircraft in balance," says Sgt. Isaiah Ybarra. "With an MV-22, we have to use the transfer pumps only. We can't use the higher-pressure pumps in the center tank like we do with the fighters. When the refueling evolution is done, we redistribute the fuel to keep the tanker aircraft balanced. The system is user-friendly."
The first refueling on this flight begins over New Mexico and ends over the Texas panhandle. The second refueling is complete over southwest Arkansas. At that point, Otis 51, which had started the day with less fuel, peels off and lands at Arkadelphia, Arkansas, to fill up. The two Ospreys that had tanked off Otis 51 pull back and rejoin Otis 52.
After the second refueling, Otis 50, the pathfinder crew, reports bad weather. The formation is rerouted to take a longer, more southerly route. This means Otis 52 has less available fuel to transfer to the Ospreys.
After some quick replanning, Krebs, in his role as the refueling aerial commander, pulls Otis 50 off its pathfinder duties and redirects that crew to meet the formation in a military operating area, or MOA, over South Carolina. Talon 13 and Talon 14 pull up to Otis 50 and take on 5,000 pounds of fuel, while Otis 52 tops off the other two MV-22s. On training missions like this one, the restricted airspace of the MOAs is the preferred place to run the aerial refueling track. The areas are safer because no other air traffic is present.
The sun is setting as the formation approaches MCAS New River. The math had worked. All four of the tiltrotors have more than 3,000 pounds of fuel reserves and would be landing in minutes. Otis 52 lands at Cherry Point, about fifteen minutes behind them.
For nine and one-half hours, the MV-22 pilots had said nothing but "Thirteen," "Fourteen," "Fifteen," and "Sixteen," to acknowledge the RAC's radio transmissions and directions. But as they broke off for their home nest, the lead Osprey pilot said, "Thanks. We appreciate it. I'll call you on Monday, and we can debrief."
Jeff Rhodes is the associate editor of Code One.
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