|
|
|
Special mission business jets
By Volker K. Thomalla
Business jets can do a lot more than simply transport passengers pressed for time from A to B. Government agencies and armed forces all over the world call on the special services of these fast aircraft to execute their missions in a cost-effective manner. But before they can take up a given role, they need to be adapted to accommodate the necessary special-purpose equipment.
Fisheries protection, search and rescue, airborne early warning, electronic reconnaissance, battlefield surveillance, medical evacuation, calibration of radio beacons and training of pilots and astronauts: never before have the uses to which business jets are put been as diverse. “About ten percent of the 1,600 aircraft we have delivered are equipped for special missions,” says Gulfstream spokesman Robert Baugniet.
Some of the special mission business jets are indistinguishable from their civilian sisters apart from the paintwork or relatively small appendages. The US Coast Guard's Medium Range Command and Control Aircraft (MRC2A), for example, just has one extra, mushroom-shaped antenna on the upper side of the fuselage, otherwise it is unmistakably a Challengers 604. Again, the US Navy's long-range Gulfstream C-20 und C-37 jets, which are used to carry mission critical parts and personnel needed in a hurry, do not strike one at first glance as obviously special aircraft.
By contrast, other variants have been so heavily modified that it is difficult to identify the original type. One of these is the Gulfstream Conformal Airborne Early Warning (CAEW) aircraft for the Israel Defense Forces. Equipped with all manner of sensors, from sideways looking radar to an infrared warning sensor and a “forest of antennae” on the upper side of the fuselage, these are based on the Gulfstream 550, but the original aircraft has been so massively modified that, as well as structural tests, extensive flight testing had to be carried out to verify the aerodynamic design. Another example of a type which is scarcely recognisable after modification is the UK Sentinel battlefield surveillance aircraft, which is based on the ultra-long-range Bombardier Global Express (see FR 11/2007).
Integration of the mission equipment into a business jet is time-consuming and in some cases takes several years. The more conversion work required, the longer it takes. Including the ground stations, development of the British battlefield surveillance system took seven years. It goes without saying that the modifications affect aircraft performance. The more antennae and protective enclosures there are to disturb the flow of air around the aircraft, the slower it flies. And the more weight is added, the less far it can fly. But despite this, the robust construction of the business jets and their attractive flying performance still make conversion of an existing type into a special aircraft less expensive than the complete design of a type when only a small number of units will be required.
Dassault Aviation has a wealth of experience in the area of special mission business jets and even supplied the US Coast Guard with Falcon 20/200's, 41 of which are still in service under the designation Hu-25 Guardian. Again, for the French Navy Dassault modified the Falcon 200 and the Falcon 50. For example, the Falcon 50 has a big observation window along the side next to the entry door and the cabin is fitted with mechanisms for releasing dinghies and marker buoys. The five-person crew can perform search and rescue missions or fisheries monitoring flights of up to six and a half hours' duration.
Training of tanker pilots and navigators is another application for which business jets are suited. At the beginning of the 1990s Raytheon Aircraft won a contract to supply the US military with 180 twin-engined T-1 Jayhawk trainers. This type is based on the civil Beechjet 400, which only required minor modifications.
The most exciting job of all the special mission business jets is without a doubt that of the flying space shuttle simulators, four Gulfstream II's maintained at NASA which now serve in the role of Shuttle Training Aircraft (STA). These are used to train future shuttle pilots to land the space shuttle. To achieve the 20 degree glide angle of the shuttle, the main landing gear is extended at 37,000 feet (the nose gear remains retracted), the flaps are moved upwards and the reverse thrust is activated! To qualify as a shuttle pilot it is necessary to complete around 900 of these STA landings, the very thought of which is enough to make one's hair stand on end.
From page 8 of FLUG REVUE 6/2007
|
|
|
|
|