Also known as the Alto, the Derby missile is a beyond visual range (BVR) air-to-air medium-range (~50 km) active radar homing missile (AAM) developed by collaborative effort between Israeli defence company Rafael Advanced Defense Systems and Israel Aircraft Industries MBT to meet the combat needs of the armed forces.
Though technically not part of the "Python" family, the missile is an enlarged version of the Python-4 with an active-radar seeker.
The Derby AAM can be integrated onto a variety of fighter aircraft such as F-5, F-16 Fighting Falcon, Gripen E and Mirage and is capable of engaging aerial threats from short ranges and near-beyond visual range.
Derby can be configured as a surface-to-air missile (SAM) for launch from a Spyder-SR / MR short and medium range mobile air defence system, which also incorporates Python-5 dual waveband imaging infrared (IIR) missile.
Derby missile development
Development of the Derby began in early-1980s, while the missile was introduced in mid-1990s. The missile entered service in 1998 and is operational with six countries.
Rafael Armament Development Authority received a $25m contract in February 2005 to supply 20 Derby BVR missiles and six practice missiles for integration onto the Indian Navy's Sea Harrier aircraft.
Design and features
The Derby missile, featuring lightweight design, is equipped with four main wings and four conventional planar fins in the tail assembly. It is designed to offer increased operational flexibility and multi-shot capability.
The weapon has a length of 362cm, a wing span of 64cm and a diameter of 16cm. It weighs 118kg and is armed with a 23kg warhead. The seeker and guidance system are fitted in the front of the missile, while the rocket motor is placed at the rear.
The missile can operate in lock-on before launch (LOBL) and lock-on after launch (LOAL) modes. In LOAL mode of operation, it receives target information after being deployed from its launch platform, while in LOBL mode, which is enabled in tight dogfights, the seeker is locked onto the target before the missile is launched.
Guidance and warhead
The active radar seeker provides guidance and improved target accuracy at radio frequency (RF). The radar's look-down / shoot-down capability enables the missile to attack targets below and along the line of the horizon.
Derby's high-explosive fragmentation (HE-FRAG) warhead defeats non-armoured targets and light material targets.
The weapon features fire-and-forget engagement capability and can be optionally fitted with advanced, programmable electronic counter countermeasures (ECCM) for operation in hostile environments.
Performance of the Derby missile for enemy target launch
Powered by a rocket motor, the Derby missile has a speed of Mach 4 and can hit targets at a range of up to 50km. It can be launched at an enemy target under all weather conditions, both during day and at night.
Variants
Derby's variants include I-Derby and I-Derby ER (Extended Range). The upgraded I-Derby AAR missile is equipped with a software-defined active radar seeker and was unveiled at the Aero India 2015 exhibition held in Bengaluru, India.
The I-Derby ER advanced active radar missile was unveiled at the Paris Air Show 2015. It features a solid-state active radar seeker and a dual pulse rocket motor, which provides an operational range of up to 100km. To achieve greater range, a dual-pulse solid rocket motor is added, where the secondary pulse of energy as the missile nears the target extends flight time. It also combines the seeker and fuse into an integrated sensor and fusing system to make room for the new motor. The new seeker is Software-Defined, enabling full operational flexibility by controlling all functional parameters, including waveform and duty cycle, via software allowing a unique performance.
This capability facilitates upgrading missile performance against new emerging threats and enemy tactics, such as new EW threats or new airborne targets.
The I-Derby ER can be used as an interceptor in the combat-proven SPYDER Short and Medium Range Air Defense Systems.
The new missile is designed to fit inside an existing SPYDER-SR launcher. All SPYDER systems are designed to engage and destroy a wide spectrum of threats, such as fighter aircraft, helicopters, cruise missiles, UAVs and stand-off weapons.
The I-Derby ER also contains advanced Electronic Counter-Counter Measures (ECCM) designed to meet the challenges of air combat in hostile environments and with its exceptional operational flexibility, it can be tailored to the customer's operational requirements.
The missile can be launched from Sea Harrier jet fighter, F-16 (Block 52) Fighting Falcon, F-15, Sukhoi-30, JAS-39 Gripen, Mirage-2000, LCA, F/A-50, F-5E Tiger II, and IAI Kfir combat aircraft. It was exhibited during the Seoul International Aerospace and Defence Exhibition (ADEX) held Seoul, South Korea, in October 2015.
The I-Derby ER has been selected by India to equip the LCA Tejas light combat supersonic fighter. Integration tests are underway and a test-fire is set for March 2016.