Australian Aviation — January 2018

process for long overwater flights and
the available engine technology.
“We needed a relatively large core
and the largest cores that are available
work great as a tri-jet,” Scholl says.
The Boom chief executive says
leveraging the existing technologies is
a key factor in ensuring the aircraft’s
operating costs are such that they
allow airlines to charge no more for
business class than what they do for
subsonic flights today.
“We do not allow any technology on
the aircraft that isn’t already certified
on another aircraft and that makes
this way more practical as a project,”
Scholl says.
“We couldn’t have done it 10 years
ago when there was no certification
path for composite. But that has been
done and we just have to follow the
rules that Boeing helped develop.
“Over time, we will add more
technology to subsequent aircraft
but not for the first one. This makes
it more feasible than it would be
otherwise.”
Scholl says there are a number of
advantages of using carbon composites
compared with aluminium, including
the ability to handle the 150 degrees
Celsius temperatures the fuselage was
expected to reach while cruising at
supersonic speeds.
“Composites are even better than
aluminium in taking temperatures
during high speed flight,” Scholl says.
“Aluminium would get mushy at
that temperature. You don’t really
want a mushy airplane.
“They also don’t expand the way
aluminium does.”
Carbon composites are also easier
to work with.
“There is not a straight line hardly
anywhere in the airplane. The fuselage
is a bit bigger up front and skinnier in
the back,” Scholl says.
“So it is a very complex shape that
you need to be efficient at high speed
and building it with composites helps
you to do that economically.”
Further, the decision to go with a
55-seat cabin initially offered the best
configuration for airlines to deploy the
aircraft on routes with heavy premium
demand.
“People often say Concorde was too
small with 100 seats. In my view it was
actually too big because you cannot
fill 100 seats at the kind of fares
required,” Scholl explains.
“Basically, the more expensive the
ticket the smaller the airplane needs
to be in order to be able to work on a
lot of routes and keep the seats filled.
With business class, we are putting

you don’t actually have to pay

much more at all for speed versus a

subsonic economy fare and at that

point subsonic will be for either

very short flights or for cargo but for

humans we get to get there faster.”

Next steps

The most immediate target for Boom

is getting the XB-1 demonstrator,

dubbed Baby Boom, ready to take

flight. The company has set a target

of first flight in late 2018.

At 21m in length and with a

wing span of 5.2m, Baby Boom is a

one-third scale version of the full-

sized aircraft. It will be powered by

General Electric CJ610 turbojets and

have a maximum takeoff weight of

6,100kg.

The XB-1 fuel system is capable

of storing 3,175kg of jet fuel in 11

separate tanks and would be capable

of reaching Mach 2.2 with 1,000nm

of range. It will have a two-crew

flightdeck. And as with the full-sized

version, Baby Boom will also feature

a composite fuselage.

“We are looking at first flight late

2018,” Scholl says.

55 seats, about the same as you would

find in a sub-sonic widebody.

“Then it works on a lot of routes,

you get economies of scale, you get

good aircraft utilisation and that

further helps you get the overall cost of

travel down.”

Boom has forecast demand for

1,000-2,000 supersonic aircraft

by 2035, which Scholl describes

as conservative, saying the actual

demand will be larger than that.

As the sector develops and the

technology improvements continue,

that will lead to larger aircraft.

And in a bit of blue sky thinking,

Scholl talks optimistically of

supersonic flight eventually replacing

subsonic flights.

“Internally we call the airplane

Model A because this is the first of a

whole series,” Scholl explains.

“You build a bigger aircraft you

can make it more fuel efficient, which

means that the fares can come down

and more people can afford to go more

places more often, which means bigger

airplanes.

“A couple of generations of aircraft

later, there is a tipping point where

Boom Supersonic

Boom’s Model A would seat

55 in an all-business class

configuration.BOOM

‘This is the

first of a

whole series.’

BLAKE SCHOLL

The XB-1 demonstrator, or

‘Baby Boom’, should fly in

late 2018.BOOM