For spectators on the ground, watching a 500,000 pound, six-engined, twin-fuselage jet fly a low approach about 100 feet above the runway was thrilling, to say the least. But for Stratolaunch pilot Mark “Gidro” Giddings, who was flying left seat in the world’s largest airplane, it was the result of months of simulator practice and years of experience.
Giddings, along with co-pilot Evan Thomas and flight engineer Jake Riley, successfully completed Sunday’s third test flight of the world’s largest airplane—nicknamed Roc—which is scheduled to begin air-launching hypersonic test vehicles later this year.
The massive airplane took off from Runway 30 at Mojave Air & Space Port (KMHV) a little before 9 a.m. Visibility was clear, the air was smooth, winds calm.
“It was a great day to fly,” Thomas says. “The cloud deck was down to 7,000 feet, and we just decided to hope for the best and it kind of opened up and allowed us to fly.”
This was Giddings’ first time in Roc’s left seat. Eight months earlier, during test flight two, Giddings sat in the right seat, running the throttles and watching Thomas handle the landing. This time, it was Giddings’ turn to wrangle the beast.
The nearly four-and-a-half-hour mission turned out to be the program’s most productive so far, expanding the proven flight test envelope to an altitude of 23,500 feet and a maximum speed of 180 kias. The crew successfully moved Roc’s landing gear doors and retracted and re-extended one of its landing gear, proving for the first time that the system would operate during flight.
So, as a veteran U.S. Air Force test pilot, how did landing an airplane with a 385-foot wingspan rank against landing other notable jets in his career?
“For me, this was up there with landing the U2,” Giddings told FLYING in an exclusive interview shortly after the flight. “It was definitely exciting.”
To ensure the safest landing possible, the flight crew flew two low approaches over the runway. During the second pass, as Stratolaunch chief technical officer Daniel Millman describes it: Giddings “carefully controlled the airplane about 100 feet off the ground, flying along the black line, to ensure he had the controllability he was looking for— what we used to call in the B-52—a landing attitude demo.”
The team is rounding out a successful Roc carrier aircraft test flight with two low approach maneuvers before landing. We’re excited to get the aircraft on the ground and start analyzing all of the great data we collected today! #LetsRoc pic.twitter.com/FcwHbv8qmo— Stratolaunch (@Stratolaunch) January 16, 2022
Giddings says it was interesting “because the first approach wasn’t as stable as I wanted it to be. But that was my first time in the pattern. So for the second pass, he worked on increasing Roc’s stability “and all of the training that we did came into play with that.”
His training has taught him that “a nice landing doesn’t come from the end game. It comes from being stable from 10 miles out.” In fact, Giddings had come into the sim facility the day before the flight to practice the entire profile with the parachute and the helmet on.
“After practicing all those approaches, I had so many cues starting from 10 miles to get the airplane stable.”
And specifically with Roc, that’s no simple task.
“The plane has definite lateral characteristics and oscillations and they’re pronounced in the landing phase,” Giddings says. “It’s definitely a very high-gain maneuver and you’ve got to make sure the airplane’s track is straight. It’s not very forgiving for any crabbing that you have with the fuselage.”
While Giddings flew the low approach, he was simultaneously planning how he was going to handle a lateral deviation or a wind gust during the actual landing. “I had in my mind: ‘If I see this, I’m going to do this. If I see this, I’m going to do that.’ I had practiced that—just focusing on keeping the wings level and the fuselages driving straight down the runway.”
And—even with all of that—the flight crew had to deal with Roc’s quirky yaw characteristics.
To offset the airplane’s yaw, engineers are testing a yaw augmentation system. The low approaches were also intended to evaluate it. During part of the first approach, the yaw augmentation system would have to be activated. During the second approach it would have to be turned off.
Essentially, says Thomas, the yaw augmentation system is similar to what many GA or bizjets have. It’s basically an aileron-rudder interconnect and a yaw damper combination.
“When you’re flying a one-of-a-kind airplane that has very unique handling and flying qualities and you’re presented with the challenge of landing, that’s kind of why you’re a test pilot,” Giddings says. “You look forward to those kinds of challenges.”
Chase Plane Support
Another key mission goal on Sunday: retract and extend the mid-main gear on the left fuselage in flight for the first time.
For this, the pilots would need assistance from Stratolaunch’s Cessna Citation chase airplane. Roc pilots have always coordinated with a chase airplane during flight. Chase airplanes are part of the standard formation. Crew aboard the chase airplane become an extra set of eyes for what’s happening with the rest of the airplane.
And on an airplane the size of Roc, the more eyes the better.
During the gear test, the crew monitored gear indicators and instruments as well as a slew of cameras to make sure the gear retracted and extended in flight as expected.
But for the angle they needed to see the mid-main left gear, none of the cameras provided that ideal view.
Two Stratolaunch design engineers who helped build the gear retraction system and the gear doors boarded the chase airplane, armed with binoculars to view and report to Roc’s pilots how the gear was performing in flight.
The chase airplane crew was able to position the aircraft in the perfect spot. “It enabled us to make the right call,” Thomas says.
In the coming months, we can expect to see Roc flying more often, Millman says. Plans are already underway for a fourth test flight. Following that, a pylon will be installed on the airplane’s wing on Roc’s fifth flight to allow it to carry and launch its hypersonic test vehicles.
Later this year, Roc is expected to drop a separation test vehicle over the Pacific to verify the airplane’s ability to launch in flight.
“Before the end of the year, we plan and hope to launch our first hypersonic test vehicle,” Millman says.
On Sunday, after Roc landed back at Mojave, Giddings, Thomas, and Riley exited the aircraft to find their colleagues had gathered to celebrate.
“Everybody—all the maintenance folks and everybody—were all at the bottom of the ladder cheering and clapping,” Thomas says. “Obviously, that makes you feel good. I think everybody was proud of what happened today.”
All mission objectives were met. And for Giddings, there’s a big reason behind that.
“A lot of people think test pilots take a lot of risks,” Giddings says. “Well, I think we prepare, and I felt well-prepared.”