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APRIL 2015
AEROSPACETESTINGINTERNATIONAL.COMz US Navy UAS
The first MQ-8C EMD vehicle flew
in October 2013. “The Fire-X does not
exist anymore,” notes Twomey. “It’s
been well over a year since we retired
the aircraft. We really did everything
we needed to do with it. It costs a lot
of money out of the company’s pocket
to keep flying those things.”
TEST FOR PRODUCTION
Production representative MQ-8Cs
dispensed with optional manned
flight controls altogether and
relocated the VMC and other UAS
elements to the cockpit. “Today, all
the gear we had in the back of the
airplane is where the pilots would sit,”
notes Twomey. MQ-8C production
starts with a standard Bell 407 built
in Mirabel, Canada.
A Faraday cage (a mesh enclosure
formed from conductive material to
block electric fields) supplied by
Summit Aviation protects cockpit
avionics from shipboard
electromagnetic interference. A 304
US gallon (1,151-liter) fuel tank in the
passenger cabin gives the unmanned
helicopter 12 hours’ endurance. The
longest MQ-8C flight so far lasted six
hours, and analysis of the remaining
fuel quantity verified full endurance.
Northrop Grumman has now taken
the helicopter back for UAS
completion. “Once the sheet metal and
the gas tank are put in the airplane, it’s
sent to Moss Point, Mississippi, for the
electronics.” The MQ-8C inherits dual
VMCs, flight and auxiliary power
Ethernet bus and router for payload
control. “There were a lot of
enhancements we did in a rapid
fashion,” acknowledges Twomey.
The USS Jason Dunham had pilot
and sensor operator stations integrated
into the ship. The Fire Scout verified
the UCARS and TCDL (Tactical
Common Data Link) worked out to
specified ranges, and showed that the
UAS could use the same datalink as the
manned MH-60R Seahawk. “It was a
full-up system as if it were going to go
to sea. We used some of the same
things the MH-60R uses.” Sensor and
aircraft data ordinarily go to the Fire
Scout ground stations through the
TCDL. The MQ-8B link carries 291
vehicle parameters to the ground.
MQ-8C aircraft downlink a little more
data from their VMCs, but MQ-8B
experience that showed operators
actually had more aircraft information
than they needed to operate the
system. On the MQ-8C test aircraft,
most engineering data is stored on the
airplane and downloaded to a laptop
computer for post-flight analysis.
The five days at sea on the Dunham
enabled take-offs and landings at
different weights. “You had to take-off
lightly loaded and work your way up
to 6,000 lb gross take-off weight,”
notes Twomey. “It’s really to verify
the stability of the aircraft at all those
weights. We did take-offs and landings
in different wind conditions over the
deck. We’re doing 30kts and the thing
pops off the deck and lands like a
regular helicopter does.” Follow-on
testing awaits ship availability.
“We have more test points, but we
can do those test points on land. We
verified on a DDG that we’re good to
go to take-off and land on that class of
ship,” Twomey explains. The MQ-8C
will be tested on the new Littoral
Combat Ships (LCSs) later this year or
early 2016. “The LCS will be another
dynamic interface test. It won’t be as
involved, but we’re going to have to
show we can work on both classes of
LCS. It’s no different than a manned
helicopter, Twomey concludes.” zFrank Colucci is a specialist in rotorcraft design, civil
and military operations, test and avionic programsRIGHT: At-sea
testing was
preceded by sloped
platform landings
at Point Mugu,
California (Photo:
US Navy/Northrop
Grumman)BELOW: Northrop
Grumman and Bell
Helicopter flew the
Fire-X demonstrator
as a risk reduction
tool for the Fire
Scout Endurance
upgrade engineering
and manufacturing
development
vehicles (Photo:
Northrop Grumman)17,000
Operational ceiling height in feet140
Maximum speed in knots5,900
Hours flown by MQ-8C operationally
from ships and on landconditioning units, payload and engine
interface units, and ARC-210 radios
from the MQ-8B. The bigger helicopter
also uses control actuators identical
to those in the MQ-8B, but the dual-
channel full-authority digital electronic
control on the Rolls-Royce 250-C47B
engine eliminates two of the six
actuators on the smaller aircraft. Air
vehicle software for the new helicopter,
with its hydraulic flight controls, is
nevertheless nearly identical to that
flying the smaller UAV.
The Fire Scout endurance upgrade
benefits from a more reliable, less
costly GPS/INS navigator, but carries
the same BriteStar II laser-designating
electro-optical/infrared sensor payload
as on the MQ-8B. Like the MQ-8B,
the MQ-8C also carries the automatic
identification system for cooperative
ship targets, and an undisclosed
electronics package, but the new
aircraft augments the original
MILSTD-1553 databuses with an