Sikorsky’s CH-53K King Stallion Lifts Like a Beast

By crosscheckpres on March 11, 2018.

The U.S. Marine Corps is a step closer to taking delivery of a new heavy lift helicopter that will make them the envy of rotorcraft aviators around the world. On February 10, 2018, Sikorsky (a division of Lockheed Martin) performed a maximum performance sling load test as part of its envelope expansion testing for the new CH-53K King Stallion heavy-lift helicopter. The King Stallion is destined to supplant the existing Sikorsky CH-53E Super Stallion in the Marine heavy transport role.

The February 10th test—held at Sikorsky’s flight test facility in West Palm Beach, Florida—lifted a 36,000 pound load and successfully maneuvered both in and out of ground effect. This load is triple what the legacy CH-53E can lift. The total gross weight of the helicopter and the load was 91,000 pounds, which is the highest gross weight ever achieved by a Sikorsky helicopter, and second only to the Russian Mi-26 Halo in vertical lift capability among production model helicopters. View the Sikorsky test video below:

According to Wikipedia, the Sikorsky CH-53K King Stallion is powered by three 7,500 shp General Electric GE38-1B turboshaft engines driving a seven-bladed composite rotor. The design cruising speed is 170 knots, and the service ceiling is 14,400 feet MSL.

Interestingly, the tail rotor on both the CH-53E and K models is canted 20° from vertical. Generally this design feature enlarges the allowable cg range and offers nominal improvements in low-speed stability, but at the expense of significant flight control complexity due to the flight control couplings introduced by the tail rotor vertical lift component.

Stay tuned to the CrossCheck Flight Test Services blog for an upcoming article in the Flight Test Best Practices page concerning helicopter and tilt-rotor sling load testing. Thanks for reading!

The Superior Pilot

It was cool and blustery on that overcast morning in the autumn of 1996. There was snowpack in Anchorage, Alaska by that time of the year, but the runway and taxiways were clear and dry. I was only a few flight hours away from my final check flight before earning my private pilot’s license, and was pre-flighting my Cessna 152 before another solo practice run.

The wings rocked in the wind, tugging at the tie-downs and I remember feeling a tinge of unease. “Wind’s not too bad,” I nervously told myself as I checked the aileron travel and flap freeplay. Then another gust hit, and the aileron tugged at my hand. My unease grew. I continued around the empennage and couldn’t help noticing the horizontal tail bobbing around against the tail tie-down. “Wind’s alarming me a bit,” I mused, “Not sure if I can handle it.”

The thought had scarcely entered my mind when I regretted even thinking it. I was on the cusp of being a pilot, after all, and there’s never a completely windless day to go flying. Dealing with the wind is just part of the job!

But even after un-tethering the airplane and climbing in, every gust-driven wing-rock sapped my courage. I thought of my flight instructor, a tall lanky Texan who had to be shoe-horned into the cramped Cessna cockpit. He had shared a classical piece of pilot wisdom—in full-throated East Texan drawl—just a couple of flights earlier: “The superior pilot is one who uses his superior judgment to avoid situations requiring the use of his superior skills.”

Not sure why this particular piece of advice came to mind—but I’m glad it did. It led me to decide not to fly that particular morning because I didn’t feel capable enough to handle the plane in that kind of wind. So I tied the airplane down again and glumly trudged inside to confess to my instructor that I was too scared to fly. I wondered what he’d think of me—after all, other people were flying that morning.

“I was hoping you’d decide to stay on the ground,” Jim said as I walked into his office, “saves me the trouble of going out in the cold to stop you. Little windy for flying today, don’t ya think?”

Feeling shocked and relieved at the same time, I sat down with Jim and debriefed the flight that never was. One key take-away from our ensuing discussion was this: while pilot judgment does improve with piloting skill, sound judgments can be made at any skill level. Another pearl of wisdom: knowing what you aren’t proficient at is just as important as knowing what you are proficient at. Discovering that I wasn’t proficient in gusty crosswind landings would do me precious little good after I was airborne, because I’d still have to land the damn plane!

There were two valuable lessons I learned that day. First, that I needed some more dual-time with my instructor practicing crosswind landings. And secondly, that I should always listen to my gut when making a judgment call on whether to fly or not. The latter lesson probably saved my life—and my date’s life—a couple years later in Arizona when I called off a flight during the ground run-up as a desert thunderstorm quickly built near the airport. I’d barely gotten the plane tied back down before the cell had moved directly overhead and begun unloading torrential gust-driven rain. As additional storm cells rapidly developed around the airport, I came to realize how much trouble we would have been in if I’d continued with the planned flight. Although disappointed in having to cancel my date, I was proud of the decision I’d made to stay on the ground. And although I never got a chance for another date with that girl, I did become a better pilot from the experience.

In short, your conscience is a superior pilot to your ego, so listen to that little nagging voice in your head! In flying, if something doesn’t feel right, something’s wrong, and it’s better for all concerned that you figure out what it is while still on the ground.

Bell V-280 Valor First Flight

In the aviation world, few events are as anticipated, exciting and momentous as the first flight of a new prototype. Bell Helicopter’s V-280 Valor development team experienced that emotional rush on December 18, 2017 when the product of many years’ hard work lifted off the tarmac in Amarillo, Texas for the first time.

Check out this first flight video, courtesy of Bell Helicopter:

The V-280 Valor is Bell’s entry in the U.S. Army’s Future Vertical Lift–Medium (FVL-M) competition to replace the storied UH-60M Blackhawk, and possibly also the AH-64A Apache medium helicopters. The Valor can cruise at 280 knots, nearly double that of the Blackhawk. Additionally, its combat range of 500-800nm is far superior to the UH-60M, and it carries 14 troops, which is 2 more than the Blackhawk.

Bell is competing with the entry from the Boeing-Sikorsky team, the SB-1 Defiant. Also unconventional, the Defiant features a coaxial contra-rotating main rotor paired with a pusher propeller to improve cruising speed and range. The Defiant is expected to begin flight testing later this year.

It will be interesting to watch this procurement battle play out. Whichever team ultimately wins the contract, the U.S. Army will be getting a stellar replacement for the venerable Blackhawk. Furthermore, the boundaries of vertical flight technology will be stretched ever-outward.


Boeing Introduces U.S. Navy Tanker Drone

On December 19, 2017, Boeing unveiled its prototype in the U.S. Navy’s MQ-25 Stingray unmanned tanker drone competition. Boeing’s prototype will compete with entries from Lockheed-Martin and General Atomics. This aircraft will be carrier-based and is expected to have a 15,000lb payload of off-loadable fuel (around 2,300 gallons).

It’s appears to have stealth characteristics designed in, which will make it a nice compliment to the F-35B/C Lightning fighters it will be refueling. It doesn’t make much sense to send stealth fighters off to battle accompanied by refueling tankers that betray the squadron’s position with barndoor-sized RCS signatures!

On the flip side, however, 2,300 gallons isn’t a whole lot of gas for a thirsty squadron of fighter jets! It’ll be interesting to watch this procurement dance play out.