Page 10 - Aerotech News and Review, September 17, 2021

STRATOLAUNCH, from 8
the cockpit placement on top of the fin, On the first flight profile, they were were made for the second flight of
because they were considering having to take off with no flaps, climb to Stratolaunch, which included: new
an emergency egress system where the 15,000 feet at 150 knots, and do a few outboard aileron control system; new
crew would slide through the vertical pitch, yaw and roll maneuvers to check yaw control augmentation system; run-
fin and out the bottom somehow. It was the handling qualities. Then during the way alignment display for landing and
completely unusual and out of the box flight, one of the big test points was flutter instrumentation.
thinking.” to check the flaps. The flaps have two The outboard ailerons were con-
settings, up or full down 70-degrees, verted to command-by-wire with direct
Stratolaunch carrier aircraft which makes them act as flaps or speed control law. “We added a yaw augmen-
During Hutchinson’s presentation, brakes. tation system in parallel with mechani-
he reiterated how impressed he was Thomas described an item in the cal yaw signals,” said Thomas. “We
that the donor 747 aircraft parts and flight profile, a simulated landing that also converted all of the purely steel
systems were able to be reused in the would be done at altitude. He said, cable loops to hybrid steel and carbon
building of Stratolaunch. Not only the “When we looked at doing the roll configuration.
landing gear and engines, but the cock- authority maneuvers, we were doing “Our second flight results, all sys-
pit windows were placed into the two them essentially feet on the floor with tems again performed really well,
fuselages of Stratolaunch. Many other some coordination. We realized there complex as they are,” Thomas said.
parts were harvested from the 747 as was potential to build sideslip which “It really is amazing that we got two
well, including the yokes, rudder ped- Photograph by Alan Radecki we had not looked at before.” As they flights on this airplane with virtually
als, control seat rails, cockpit cabin Stratolaunch in the air. kept looking at different possibilities, no significant write-ups for mainte-
floors, and instrument panels. their flight profile list changed over nance.
As he concluded his presentation, time. “We had a better lineup with the
Hutchinson asked the question, “So, in flight,” Hutchinson said. “The pilots described where the aircraft carries Before the first flight, Thomas told runway with the new runway align-
how big is it? 385-foot wingspan, are sequestered only to the pressure most of its weight. how the simulator was essential in ment device and we made a better
280-feet long and max takeoff design vessel of the right forward cabin and “The fuel tanks are all outboard of the preparation for actual flight. They landing, which made me very happy”
weight is intended to be 1.3-million are unable to actually transfer into the the fuselages in the wing. There are also got a surrogate aircraft, the Cal- said Thomas.
pounds. We haven’t tested to that point fuselage while in flight. But, that be- no fuel tanks in the fuselages, they are span VSS (Variable Stability System) “On the second landing we were
yet, but we are using the airplane with ing said, you cannot walk through the basically hollow tubes,” Thomas said. Learjet with matched feel and Roc-like a little bit longer on the lineup,” said
the intent to build up to carry more wing either.” “If you want a physical analogy, it’s a dynamics to do touch and go’s, giving Thomas. He showed a video taken
weight eventually. Hutchinson showed photos of the bit like a shopping cart with a heavy great in-flight training. They conducted from the center wing. He said, “As
“We think that we also have the Talon One unmanned autonomous, barbell strapped to the top. in-flight rehearsals of the Stratolaunch
world’s largest single aircraft compo- Mach-6 rocket that will be launched “It’s got a lot of inertia and weight flight profile that sharpened their han- you watch this video, you can see the
underlying, very slow yaw, it’s only a
nent, which would be the wing spars from a Stratolaunch carrier aircraft in out in the wings and that comes into dling qualities and observation skills. half of a degree to a degree, but it’s
which are only partial span. They go the future. play later in the flight. “It sounds like a cliché to say that
“For our first flight, all of our flight our first flight was just like being in very hard for the pilots to suppress that
controls were mechanically-signaled the simulator, but it almost was,” said and stop it. The bank is changing as
cables, cables running from the right Thomas. “We did find that we had a I try to adjust the lateral error as we
cabin all the way out to both empen- larger than predicted yaw due to roll.” come in to the runway and make those
nages, all of the four elevators, four fine corrections.”
rudders, both banks of ailerons on both Innovations for First Flight Thomas is responsible for safe and
sides, so a lot of cable,” said Thomas. Thomas said, “We had a hot mic be- effective flight test and operational use
“First flight had one objective, and tween the crew and the control room in of the Stratolaunch carrier aircraft and
that was to land safely,” Thomas said. both directions, and hot mic reception other company aircraft, and ensuring
“The risks we looked at for the first in the chase aircraft so they were able readiness and compliance for all flight
flight was runway departure on land- to completely keep up with what we crew.
ing was a big one, but also stability were doing with the test cards. He was raised in Southern Califor-
and control, or the possibility of pilot “We did not pressurize the fuselage nia, and pursued his dream of flying
induced oscillations. Also because it is on the first flight and in fact, we end- by attending the United States Air
a very large carbon structure, so the ed up going with a fabric cabin door Force Academy, graduating in 1986
possibilities of getting some odd struc- which sounded kinda crazy when an with a Bachelor of Science degree in
tural vibrations, bio mechanical feed- engineer first proposed it, but in actu- Astronautical Engineering. After earn-
back between us and the control inputs ality, it worked great,” said Thomas. ing his Air Force pilot wings, Thomas
and then pilot conceptual concerns of “The biggest innovation was de- completed two operational tours flying
Courtesy graphic sitting there in the right fuselage way signing, building, testing and then fly- the F-16, including leading 52 combat
How the Stratolaunch compares to other aircraft. out front. ing a 385-foot wingspan, composite, missions over Iraq and occupied Ku-
“Ultimately the first flight was about complex six-engine aircraft,” Thomas wait, highlighted by the rescue of an
handling to precisely control the air- concluded. encircled Special Forces team. In 1994
from the dihedral break or planform “The payoff in this job is I get to craft to a stable, centered landing,” he was a pilot on the Overall Top Team
break to the other planform break. work with my best friends, and every said Thomas. “The big landing chal- Second Flight — April 2021 at the U.S. Air Forces ‘William Tell’
They are approximately 250-feet long single day it doesn’t feel like a job, it is lenges — we have a 200-foot wide Thomas listed some changes that Air-to-Air Weapons Meet.
each. We have not been informed of an experience,” Hutchinson concluded. runway at Mojave, and it is 114-feet
any other piece larger than this. We from the outside of one set of landing
think that is the largest aircraft com- gear to the outside of the other set, so
ponent ever built.” He asked the audi- we are pretty wide there, which gives
ence to let him know if there was any us 43-feet on either side to play with.
other aircraft component that might be “We come into the flare a bit nose
larger. down, much like a B-52, so that con-
Hutchinson showed a drawing that cern was that we didn’t want to land
illustrated the systems complexity of nose gear first and start porpoising,”
Stratolaunch. “There are four hydrau- he stated.
lic systems, almost a quarter statute He showed a photo that was taken
mile of control cable. Each engine from space of Stratolaunch on Runway
has an air-driven hydraulic pump, an 30 at Mojave.
engine-driven hydraulic pump and an
electric hydraulic driven pump, togeth- First Flight Profile
er making more than two-hundred total Courtesy photograph “We started with handling qualities
horsepower of hydraulic service to the evaluation basics, which is four pri-
flight controls, the landing gear, and Evan “Ivan” Thomas. mary steps. First we want to do thor-
the braking systems. Each engine pro- ough ground test so you understand
vides electrical power that is pumped First Flight — April 13, 2019 your system. Then when you are air-
into two massive power bus systems Col. Evan “Ivan” Thomas is the borne you want to do some open loop
that meet at the center wing.” director of Flight Operations for Stra- responses and see what the aircraft’s Scaled Composites photograph
“It is not possible to access the fuse- tolaunch, LLC and he described how natural response is to inputs and some The Stratolaunch flies over the Mojave Air and Space Port in Southern
lage or convey through the wing while the crew sits in the right fuselage and basic capture tasks,” Thomas said. California.

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