and M261 are used with the Mk 66 series of rocket motor, which replaced the Mk 40 series. The Mk 66 has a reduced system weight and provides a remote fuze setting interface. Hydra 70s have also been fired from UH-60 and AH-6 series aircraft in US Army service. The AH-1G Cobra and the UH-1B "Huey" used a variety of launchers including the M158 seven-tube and M200 19-tube rocket launchers designed for the Mk 40 rocket motor; however, these models have been replaced by upgraded variants in the U.S. Marine Corps because they were not compatible with the Mk 66 rocket motor. The Hydra 70 rocket system is also used by the U.S. Navy, and the U.S. Air Force. Common U.S. Mk 66 compatible launchers Accidents In 2019, a 72-year-old Taiwanese man was killed by a discarded Hydra rocket which he had cut into with an electric saw, believing it to be a length of pipe. The rocket had been caught in the net of a fishing vessel and then discarded by the crew ashore as scrap metal. Warheads Hydra 70 warheads fall into three categories: Unitary warheads with impact-detonating fuzes or remote-set multi-option fuzes. Cargo warheads with air burst-range, with settable fuzes using the "wall-in-space" concept or fixed standoff fuzes. Training warheads. Fuzing options Common warheads The most common warhead for the Hydra 70 rocket is the M151 "10-Pounder," which has a blast radius of 10 meters and lethal fragmentation radius of around 50 meters. Mk 66 rocket motor technical data Weight: Length: Burn time: 1.05–1.10 sec Average thrust (): (Mod 2/3) (Mod 4) Motor burnout range: Motor burnout velocity: Launch spin rate: 10 rps, 35 rps after exiting launcher Velocity at launcher exit: Acceleration: 60–70 g (initial) 95–100 g (final) Effective Range: depending on warhead and launch platform Maximum Range: under optimum conditions Precision guided Hydra 70 There are several design efforts to turn the Hydra 70 rocket into a precision guided munition (PGM) to produce a weapon with greater accuracy but at less cost than other guided missiles. These include: The BAE Systems Advanced Precision Kill Weapon System (APKWS) II U.S. Navy Low-Cost Guided Imaging Rocket (LOGIR) Lockheed Martin Direct Attack Guided Rocket (DAGR) The ATK/Elbit Guided Advanced Tactical Rocket – Laser (GATR-L) Raytheon TALON Forges de Zeebrugge SAL-Laser Guided Rocket (FZ275 LGR) The APKWS was the first to be fielded in March 2012, and the TALON