Dassault Br.1150 Atlantic

Country of Origin: France.
Type: Maritime patrol and ASW aircraft.
Powerplant: Two 4638 kW (6106ehp) Rolls-Royce Tyne RTy 20 Mk 21 turbo-props, each driving a Ratier-built HSD four-blade constant-speed propeller.
Performance: Max speed 355kt (658km/h). Patrol speed 169kt (315km/h). Service ceiling 32,810ft (10,000m). Range 7970km (4950 miles) with 10% reserve fuel.
Weights: Empty 24000kg (52,900lb), max take-off 43,500kg (95,900lb).
Accommodations: Normal flight crew of 12 comprising observer in nose; pilot and co-pilot on flight deck; a tactical co-ordinator, navigator, two sonobuoy operators, and radio, radar and ECM/MAD/Autoycus operators in tactical compartment; and two observers in beam positions. On long-range patrol missions a further 12 crew can be carried as relief crew. The upper, pressurised section of the fuselage, from front to rear, comprises the nose observer's compartment, flight deck, tactical operations compartment, rest compartment for crew and beam observers' compartment.
Armament: Internal bay accommodates all standard NATO bombs, mines, 385 lb depth charges, four homing or nine acoustic torpedoes, or two Exocet air-to-surface missiles. Four underwing pylons can carry rockets or ASMs.
Operators: France, Italy, Germany, Pakistan.

History: The Atlantic resulted from a NATO requirement to find a replacement for the Lockheed Martin P-2 Neptune. The NATO requirement for a long range maritime patrol aircraft was issued in 1958. Breguet was the successful bidder, with its Br.1150 design selected over 24 other designs submitted from nine countries.

The Atlantic first flew in prototype form on October 21 1961 and entered service with the navies of France and Germany in 1965. In all 87 production Atlantics were produced through to 1974 by a European consortium led by Breguet. Other customers were Italy and Netherlands while Pakistan's three ex-French navy Atlantics were delivered in 1975. Germany also operates five Atlantics modified for Elint.

Design features of the Atlantic are Cantilever mid-wing monoplane. Wing section is of NACA 64 series. Dihedral on outer wings only and fixed-incidence tailplane. There are six integral fuel tanks with total capacity of 21,000 litres (5,547 US gallons; 4,619 Imp gallons). with provision for wingtip tanks as well if need be.

Flying controls are conventional all-metal ailerons actuated by SAMM twin-cylinder jacks. All-metal slotted flaps, with bonded light-alloy honeycomb filling, over 75 per cent of span. Three hinged spoilers on upper surface of each outer wing, forward of flaps. Metal airbrake above and below each wing and no trim tabs. Tail unit control surfaces operated through SAMM twin-cylinder jacks.

Atlantics have an all-metal three-spar fail-safe structure, with bonded light-alloy honeycomb skin panels on torsion box and on main landing gear doors. The fuselage is an all-metal `double-bubble' fail-safe structure, with bonded honeycomb sandwich skin on pressurised central section of upper fuselage, weapons bay doors and nosewheel door. The tail unit is a cantilever all-metal structure with bonded honeycomb sandwich skin panels on torsion boxes.

The landing gear is retractable tricycle type, supplied by Messier-Hispano, with twin wheels on each unit. Hydraulic retraction, nosewheels rearward, main units forward into engines nacelles. Kléber-Colombes dimpled tyres, size 956 × 319-392 mm on mainwheels, 637 × 190-319 mm on nosewheels. Tyre pressures: main 9.52 bars (138 lb/sq in), nose 6.07 bars (88 lb/sq in). Messier-Hispano disc brakes with Maxaret anti-skid units.

Basic systems include a SEMCA air conditioning and pressurisation system. Hydraulic system pressure is207 bars (3,000 lb/sq in). Electrical system provides 28.5 V DC, 115/200 V variable-frequency AC and 115/200 V stabilised-frequency AC. AirResearch GTCP 85-100 APU in starboard side of front fuselage, adjacent radar compartment, for engine starting and ground air conditioning, can also power one 20 kVA AC alternator and one 4 kW DC generator for emergency electrical power supply.

The pressurized upper deck in the double-bubble fuselage is roomy enough for both the normal operational crew (two pilots, a flight engineer, three observers, a radio navigator, ESM/ECM/MAD operator, radar/IFF operator, tactial coordinator, and two acoustic sensor operators) and a relief crew for long-duration missions.

Main weapons carried in bay in unpressurised lower fuselage. Weapons include all NATO standard bombs, 175 kg (385 lb) US or French depth charges. HVAR rockets, homing torpedoes, including types such as the Mk 46 Brush or LX.4 with acoustic heads, or four underwing air-to-surface missiles with nuclear or high-explosive warheads. Electronic equipment includes a retractable Thomson-CSF radar installation, a MAD tailboom and an electrical countermeasures pod at the top of the tailfin. Sonobuoys are carried in a compartment aft of the main weapons bay, while the whole of the upper and lower rear fuselage acts as a storage compartment for sonobuoys and marker flares. Compartment for retractable Thomson-CSF radar `dustbin' forward of the main weapons bay. Forward of this, the lower nose section acts as additional storage for military equipment and the APU. Weapons system includes Plotac optical tactical display, 80 × 80 cm (31.5 × 31.5 in) in size, consisting of separate tables for search display and localisation and attack display. At 1:30,000 scale, this gives coverage of any area 21,950 × 21,950 m (72,000 × 72,000 ft) to an accuracy of 1 mm (that is less than 30.5 m; 100 ft at that scale). Heading references provided by duplicated gyroscopic platforms of the three-gyro (1º of freedom) four-gimbals type, with magnetic compasses as back-up system. Janus-type Doppler has stabilised antenna and works in the Ke band to provide direct indication of ground speed and drift. In case of failure an automatic switch is made to the air data system. The analogue type navigation computer is accurate to 0.25 per cent. The MAD is of the atomic resonance type and uses light simulation techniques. Plotac system has provision to accept additional detectors. Radar has `sea-return' circuits and stabilised antenna enabling it to detect a submarine snorkel at up to 40 n miles (75 km; 46 miles) even in rough seas.


Service with PN: In 1974, the Naval Air Arm (NAA) placed an order for three second-hand French Navy Atlantics, which were needed to fulfill a sea sureillance role that the navy urgently required. These were delivered in 1975. In 1986, NAA ordered another Atlantic from the French Navy and at the same time all Atlantics were wired to carry the AM 39 Exocet anti-shipping missile in addition to the torpedoes they could already carry. One Atlantic, No.91, was lost on August 10, 1999 while on a training sortie near Ran of Kutch when it was shot down by intruding Indian Air Force Mig-21s for loss of all 16 onboard. They are operated by No. 29 Squadron of the Pakistan Navy from their base at PNS Mehran. Three more arrived from France later to be used only to provide spares for the existing trio and are used by the Air Engineering Department (AED) which overhauls and maintains all of Pakistan Navy aircraft..

Original equipment included a retractable radar, magnetic anomaly detector (MAD) tailboom, and an Arar electronic surveillance measures (ESM) pod on the fintip. Sonobuoys and marker flares are stowed in the rear fuselage. Flight and mission crews occupy the pressurized upper deck.

In 1991, when the US government embargoed the three P-3C Orions that had been ordered by the Navy, it was decided to upgrade the existing Atlantics. In 1993, France's Thomson-CSF won three Pakistani contracts worth nearly $60 million for the modernization of maritime patrol aircraft. AED was tasked to carry out the work with the help of Thompson-CSF. The upgradation began in 1993 and four aircraft were mordernized by 1998. The first contract involved upgrading two Breguet atlantic MPAs, with an option to upgrade the Pakistani Navy's other two Atlantics later. Under the contract, Thomson-CSF acted as prime contractor in a 'global venture' which will install the company's Airborne Maritime situation Control System (Amascos) mission system with corresponding modifications to the airframe, on a turnkey basis. The first upgraded Atlantic was delivered in 1995 and was due to fly in Pakistan by the end of September.

Amascos system includes the Thomson-CSF/Daimler-Benz Aerospace Ocean Master OM-100 pulse compression frequency agile radar with a range of 180 miles (288km), the Thomson-CSF DR3000A airborne electronic countermeasures system with interferometry, the latest generation Thomson Sintra Activités Sous-Marines SADANG 1000 sonobuoy signal processing system from Thomson Sintra Activites sous-Marines (designed and developed for the French Navy's Atlantique 2) and a Sextant Avionique navigation suite (GPS, computer, radio navigation). The upgrade is fully rated and certified, and final acceptance took place in 1999.

Using a fuselage of an ex-Aeronavale Atlantic 1, the company produced the necessary kits to retrofit the Ocean Master surveillance radar, DR 3000 ESM (which required a new fin-mounted radome), the SADANG ASW processing system and a Sextant Avionique navigation system.

Ocean Master is designed to fulfil both civil and military maritime missions including economic exclusion zone (EEZ) surveillance; search and rescue (SAR); anti-surface vessel warfare (ASVW) and anti-submarine warfare (ASW); air-to-air detection. Two basic versions of the radar are offered: the Ocean Master 100 and the Ocean Master 400. These designations relate to the use of either a 100W fully coherent traveling wave tube (TWT) amplifier, or a 400W fully coherent TWT amplifier. Options and growth potential are available to meet specific user requirements, including inverse synthetic aperture radar (ISAR) processing to provide ship classification capability.

Ocean Master would perform the following other modes: multitarget track-while-scan operation; ground mapping; target classification; weather detection and beacon mode. Ocean Master in the basic version comprises only three units: antenna unit (360 rotation and/or sector scan); transmitter unit; exciter/ receiver/processor. In addition, the man- machine interface includes display and controls. The system is in production; first deliveries were made at the end of 1994. More than 30 systems have been ordered by France, Indonesia, Japan, and Pakistan including for use on Falcon 50, C-212 and Atlantique MPAs.