C-17 No. 03 is landing! Photo © by Robert Westerberg from airshow at Malmen 2010-06-13

Strategic Airlift Capability (SAC)

Around the millennium, the question how to increase the transport capacity of the Swedish Armed Forces was discussed among politicians and military. The new commitments to intervene quickly in trouble spots and disaster areas meant that the existing eight TP 84 Hercules aircraft did not have sufficient capacity for such missions.

To buy one or two large aircraft in the size of C-17 would mean a huge cost for a small country like Sweden. Instead, Sweden joined the SAC (Strategic Airlift Capability). The organisation consists when this is written (September 2010) of two countries associated to the Partnership for Peace (PfP) programme, Sweden and Finland, and ten NATO countries. The NATO members are the United States, Bulgaria, Estonia, Hungary, Lithuania, the Netherlands, Norway, Poland, Romania and Slovenia.

Sweden is the second largest country in the SAC, with 550 flying hours per year. United States is the largest with 1000 hours.

The aircraft fleet consists of three Boeing C-17A Globemaster III, all delivered in 2009. They are operated by the Heavy Airlift Wing (HAW) from the Pápa Air Base in Hungary. Sweden has since 2009 a staff of approximately 25 employees stationed in Hungary. They are able to bring their families with them.
 

Description and Technical Data

The C-17A Globemaster III is a high-wing, T-tailed military transport with a cargo space about twice as long (20,8 m) as that of the TP 84 Hercules. It is capable to load up to 75 tons of cargo. This includes two HKP 10 Super Puma or HKP 15 Agusta A109LUHS, one Combat Boat 90 (CB 90 - stridsbåt 90) or two Combat Vehicles 90 (CV 90 - stridsfordon 90). Other alternatives are 134 equipped soldiers or 36 stretchers and 54 ambulatory patients.

The wings and tail have a sweep angle of 25 degrees. The flaps are of a fixed-vane, double-slotted, simple-hinged design.

The crew consists of two pilots and one cargo master. The cockpit has also two positions for observers.

The aircraft has a pressurized cabin (including the cargo space). This is a great advantage when transporting personnel.
 

USAF C-17A Globemaster III, serial # 90-0535 with a Swedish CV 90. Airshow, F 7,Såtenäs 2006

The cockpit is provided with two full-time all-function head-up displays (HUD) and 4 multi-function active matrix liquid crystal displays of Honeywell’s make and a cargo system.

The flight controls system consists of a Quadruple-redundant electronic flight control with a mechanical backup system.
 
There are two Lockheed Martin central processing computers, one Hamilton Sundstrand data management computer and two Honeywell air data computers.

The C-17 is equipped with AN/ALE-47 countermeasure flare dispensers and the ATK AN/AAR-47 missile warning system.

AN/AAR-47 has a number of surface-mounted thermal sensors around the aircraft, which detect the thermal signature of the missile exhaust plume. The system provides a warning to the crew via the cockpit indicator unit of the presence and direction of the missile threat. A signal is automatically sent to the ALE-47 dispenser.

AN/ALE-47 is capable of carrying a mix of expendable countermeasures, including jammers.

Due to a propulsive lift system the C-17 can use runways of a length of only 900 m and a width of 27 m. The runways may be unpaved, but this is usually avoided due to damage risks. The propulsive lift system uses engine exhaust to generate lift. The exhausts are led to large flaps, which extend into the exhaust stream, allowing the aircraft to make a steep approach at a relatively low landing speed.

The aircraft is powered by four fully reversible Pratt & Whitney F117-PW-100 turbofans of 180 kN thrust each. The thrust reversers direct air upward and forward, reducing the chance of foreign object damage and providing enough thrust to back the aircraft on the ground. It can also turn the aircraft 180 degrees (star turn) in 24 m). The thrust reversers can also be used in flight at idle-reverse for added drag in maximum-rate descents.

C-17 is may be refuelled in the air.

Main particulars:

Length: 53 m. Span: 51,75 m. Height: 16,8 m. Empty weight: 128.100 kg. Maximum take-off weight: 265.350 kg. Fuel capacity 134.500 l. Cruising speed: 830 km/h = 450 knots.

For the Model Builder

Revell has plastic model kit of C-17A Globemaster III in scale 1:144. Decals for two USAF Airlift Wings (62nd and 437th) are included. Catalouge number 04044. Click on the thumbnail for larger image.
 

Mighty C-17! Photo © by Robert Westerberg from airshow at Malmen 2010-06-13

© Lars Henriksson