Sentinel
Sentinel R.1 ZJ690
Role	Airborne battlefield and ground surveillance
Manufacturer	Raytheon, Bombardier
First flight	26 May 2004
Introduced	2008
Status	Initial Operating Capability (IOC)
Primary user	Royal Air Force
Number built	5
Unit cost	£954m (for a fleet of 5 aircraft plus 8 vehicle-based ground stations)[1]
Developed from	Bombardier Global Express

Raytheon Sentinel prototype 9001, with normal cabin windows

ZJ692, aircraft No. 3, takes off from the Mojave Spaceport during a visit to the National Test Pilot School

ZJ692 lifts from Runway 08 at Mojave

The Raytheon Sentinel is a Bombardier Global Express modified as an airborne battlefield and ground surveillance platform for the British Royal Air Force. Originally known as the ASTOR (Airborne STand-Off Radar) programme the aircraft is operated by a RAF squadron manned by both air force and army personnel. The Sentinel is interoperable with other allied systems such as JSTARS and the NATO Alliance Ground Surveillance (AGS) system.

[edit] Design and development

The Sentinel R1 is a modified Global Express powered by two Rolls-Royce Deutschland BR710 turbo fan engines. The first flight of the modified prototype was in August 2001, which validated the modifications required for the ASTOR system. The first production Sentinel R1 made its 4.4 hour maiden flight on 26 May 2004. The aircraft entered operational service with the RAF based at RAF Waddington and operated by 5 Sqn.^[2]

The programme involved five aircraft and eight mobile ground stations (six on wheeled all terrain vehicles and two in air transportable containers), and a training facility at RAF Waddington.

The Sentinel cockpit has a centrally housed, pull-down screen capable of displaying a moving map, Link 16 datalink information and defensive aids subsystem (DASS) data. The DASS comprises a towed radar decoy, missile approach warning system and chaff and flare dispensers and can be operated in automatic, semi-automatic or manual mode.

The aircraft normally operates at over 15,000 m (40,000 ft) to ensure a high resolution view of a large battlefield area. It is crewed by a pilot, a co-pilot, an Airborne Mission Commander (AMC) and 2 image analysts. Mission endurance should be about 9 hours.^[3] While the image analysts can analyse the images on board the aircraft it is expected that, unlike the JSTARS, the actual battle management will occur on the ground.^{[citation needed]}

The main radar is a Raytheon Systems dual-mode Synthetic Aperture / Moving Target Indication (SAR/MTI) radar.

While suffering from delays the project is one of few procurement projects to be below cost estimates.^{[citation needed]}

[edit] Specifications

Closeup of the Sentinel's radar pod

General characteristics

• Crew: 5
• Length: 30.3 m (99 ft 5 in)
• Wingspan: 28.5 m (93 ft 6 in)
• Height: 8.2 m (27 ft 0 in)
• Wing area: 94.9 m² (1022 ft²)
• Empty weight: 24000 kg (54000 lb)
• Gross weight: 42400 kg (93500 lb)
• Powerplant: 2 × Rolls-Royce BR710, 65.6 kN (14,750 lbf) thrust each

Performance

• Maximum speed: Mach 0.75
• Range: 9250 km (5800 miles)
• Endurance: 9 hours
• Service ceiling: 12200 m (40000 ft)

[edit] See also

• Airborne Early Warning and Control (AWACS)
  

Related development

• Bombardier Global Express
  

Comparable aircraft

• E-8 Joint STARS
• Embraer R-99B
  

Related lists

• List of aircraft of the Royal Air Force
  

[edit] References

• Winchester, Jim. "Aircraft of the RAF Part 5 - Raytheon Sentinel R1". Air International, Volume 75 No.3, September 2008. pp.54-57.

[edit] External links

• Raytheon UK: ASTOR
• Raytheon: ASTOR
• ASTOR is born
• RAF - Sentinel R1/ASTOR