Modified business aircraft can often satisfy military needs
From AEW to command and control, civil sector OEMs provide COTS solutions for government roles.
By Doug Wilson
Beneath the multiple antennas and large fairings lies a COTS Gulfstream G550—Israel Aerospace Industries' conformal AEW and control aircraft. The fairings house a phased array radar package that provides 360° of coverage without the need for an obtrusive rotating dome.
Ever since World War II, the military has been at the leading edge of technological advances in aviation. Most such advances have, in turn, trickled down to civil and general aviation.
Technologies such as the turbojet engine and supersonic aircraft were offshoots of military projects. In more recent decades, GPS and head-up displays (HUDs) have been born of the same military/industrial complex technologies procured and perfected by the military and then passed down to civilian use.
After years of service experience, current military technologies such as tiltrotor—powered-lift aircraft in FAA nomenclature—may be among the next military programs to gain commercial acceptance.
But with military and civil aircraft, the trickle-down paradigm shifted long ago. Today, it is private-sector business aviation—such as efficient turboprops and globetrotting ultralong-range business jets and commercial airliners—that is often without equal in military circles.
As military R&D budgets have dwindled in the fielding of all-new airframes, commercial aircraft in particular have played ever increasing roles in military and government affairs.
From a pure investment standpoint, it is far more affordable to take a "commercial off the shelf" (COTS) aircraft, paint it in military colors and fill it with electronics and/or weaponry, than it is to create an entirely new military airframe to perform essentially the same role.
COTS—a short history
Several arguments may be made for the title of first "true" COTS aircraft, but it is generally accepted that WWII was the defining event that made military forces, both in the US and abroad, turn to civilian aircraft markets for quick solutions. Many of those early solutions were found in the larger, COTS transport-type aircraft.
In sheer numbers, an obvious early example of a COTS aircraft is the venerable DC3, which started life as a commercial airliner. First flown in 1935, the DC3 became the C47 Skytrain in US military service and the Dakota in Royal Air Force use.
The DC3 went through several well known permutations as a COTS aircraft, including liaison, radar, flight check and, with the US Air Force, a gunship platform. Today, 75 years after its introduction, the DC3 is still in military use with (among others) the Colombian Air Force, which operates the AC47 gunship variant, converted still further to Basler BT67 turboprop standard, as the Fantasma (Ghost).
While transport aircraft such as the DC3/C47 and DC4/C54 lent themselves readily to a similar transport role in military circles, the advent of radar provided another complementary COTS role for large aircraft—as airborne early warning and control (AEWC) platforms.
One of the first COTS aircraft to prove this concept was the shapely Lockheed Constellation. In the late 1940s, the US Navy began experiments with patrol aircraft carrying AEW radars, and in 1949 the L749 Connie became the US Navy's PO1W. The PO1W eventually led to the definitive military use of the airframe—the EC121 Warning Star.
EC121s were fitted with dorsal and ventral radar domes, which housed, respectively, height finder and air search radar packages. Eventually, they received an identification friend or foe (IFF) package that could interrogate the Soviet-made transponders in use on Mikoyan i Gurevich (MiG) fighters. The EC121 served as the test bed for the now-familiar rotating radar dome found atop other COTS platforms, starting with the Boeing 707, which became the E3A Sentry AEWC aircraft.
Light utility fixed-wing COTS
Britain's RAF uses the Bombardier Global Express as a platform for the airborne stand-off radar (ASTOR) role. In service as the Sentinel R1, the 5th and last aircraft was delivered to the RAF in Feb 2009.
Large transports aside, Hawker Beechcraft has a long history with COTS aircraft for military use. While the Beech 18 served in multiple roles during WWII, including as an advanced trainer and transport—the AT7 Navigator and C45 Expeditor respectively—it is Beechcraft's post-war COTS aircraft that have shaped its long affiliation with the US military, particularly with the Army and Air Force.
Hawker Beechcraft's King Air family has fulfilled COTS roles for decades. Purchased in droves by the US Army in 1952 as the L23/U8A Seminole— an airframe based on the Twin Bonanza—this aircraft evolved into the Model 65 Queen Air, which was also procured in large numbers as the U8F.
The Queen Air evolved into the King Air, and was again snapped up by Army and Air Force as the C12 Huron. This long affiliation was marked most recently by the USAF order for 37 MC12W Liberty aircraft for the intelligence, surveillance and reconnaissance (ISR) role.
These are COTS examples of the current production King Air 350 and 350ER.
While more than 300 of the various C12 Hurons are in use with US military forces, the MC12W program represents a continuing commitment to the original King Air airframe as a COTS aircraft.
In May this year, the first squadron of MC12Ws deployed to Kandahar, Afghanistan with the 361st Expeditionary Reconnaissance Squadron. As an ISR aircraft, the Liberty in full operational form incorporates various ground sensors, satcom datalinks, a voice communications suite and, notably, an MX15i infrared pointer, which allows the MC12W to "paint" a target so that troops on the ground, wearing special goggles, can be guided to the target more effectively.
Another COTS airframe from the Hawker Beechcraft stable is the US Air Force's T1A Jayhawk advanced training aircraft, which is a stock Beechjet 400A (now Hawker 400) modified to accept higher cycles and hold additional fuel, plus other militarization.
The initial award to Beechcraft in 1990 covered some 148 T1As at a total cost of $680 million—an extremely valuable program for the Wichita-based OEM. In 1994, a further commitment for 32 brought the total order book to 180 for a program value of $755 million. The post-delivery logistics, parts and maintenance support contract was awarded to L3 Communications.
The T1A, which traces its lineage to the Mitsubishi Diamond 1A, was also ordered by Japan Air Self Defense Force in small numbers, the only minor difference being the JT15D-5F engines, as opposed to the 5Bs in the USAF aircraft.