29 January 2011

The First Operational Helicopter UAV: DASH and the Gyrodyne QH-50

The Kaman HTK-1, forerunner of the DASH
In the years following the end of the Second World War, the Soviet Navy expanded its submarine force considerably to offset the powerful surface fleet of the United States Navy. In response to this growing threat, the Chief of Naval Operations at the time, Admiral Arleigh Burke, envisioned a two-layer stand-off system to knock out Soviet subs. The innermost layer of defense consisted of the ASROC weapons system. ASROC (Anti-Submarine ROCket) consisted of a solid rocket motor booster that lofted a Mk 44 torpedo on a ballistic trajectory to the suspected location of the enemy submarine. Later versions of ASROC could deliver a nuclear depth charge or the Mk 46 torpedo. However, ASROC only had a range of five miles and the launch and control system couldn't be readily added to the existing fleet of World War II-era destroyers. As a result, the second outer layer of defense became the DASH system- Drone Anti-Submarine Helicopter. At the time, funding was hard to come by given the limits of the technology of the day until aeronautical engineer Charles Kaman proved that a remotely-controlled drone helicopter could be stably operated with his own HTK-1 test drone, based on the HTK helicopter trainer. The transition to turbine power improved the capability of Kaman's tests when a QH-43G Huskie was successfully tested from the USS Wright (CVL-49) and the USS Mitscher (DL-2), proving that a drone helicopter could be operated from warships. Secret tests at the time with the QH-43G showed that not only could a warload be carried and delivered, but dunking sonar could be used as well as communication to friendly subs. Kaman's tests proved that DASH would work as the outer defense layer against the Soviet threat. As a result, in 1958, the Navy invited submissions from industry for the DASH contract. 

The final round in the competition left Bell, Kaman, and Gyrodyne standing- and to the surprise of many who expected Kaman to win, Gyrodyne was selected the winner in December 1958. Gyrodyne already had a contract with the Navy dating from 1951 to study the co-axial rotor arrangement which the Navy felt offered promise as it was compact compared to conventional helicopter designs (the same reason that the Russians went with Kamov co-axial designs for their shipboard helicopters). The founder of Gyrodyne, Peter Papadakos, started the company in 1946 when he acquired the assets of the Bendix Helicopter Company which included an unfinished design for a one-man helicopter which he finished and perfected as the Rotorcycle. At one point, the US Marine Corps was considering acquiring the Rotorcycle as a one-man reconnaissance vehicle- and this undoubtedly won Gyrodyne the DASH competition as the company's design was based on the Rotorcycle- and having flying hardware that was more compact that Kaman's designs won the contest for Papadakos and Gyrodyne. 

DASH QH-50 recovering aboard the USS Allen M. Sumner
To make the Gyrodyne design as compact and light as possible, many safety and redundancy systems used on manned helicopters were dispensed with and the first versions of what would become the QH-50 weighed only 1,200 lbs and used a Volkswagen automobile engine. The initial plans were for the QH-50 to be essentially disposable in delivering a nuclear depth charge to the target. However, the need for extensive security and safety measures made storing nuclear depth charges on the modernized destroyers impractical, so a single Mk 44 torpedo became the DASH weapons load. The first shipboard landing was made on 1 July 1960 aboard the USS Mitscher with a safety pilot cumbersomely strapped to a bicycle seat behind the rotors! The first unmanned landing was made in 7 December 1960 aboard the USS Hazelwood (DD-531). Following development testing off the coast of Key West, Florida, the QH-50 was upgraded  in 1962 to use a more powerful Boeing T50 turbine engine which increased the warload to two Mk 44 torpedoes. After having been impressed by a DASH demonstration, in 1963 President John F. Kennedy authorized deployment of the system to provide two helicopters and associated equipment (hangar, control center, transmitting/receiving antennas) for the 240 destroyers upgraded to FRAM I and FRAM II standards (Fleet Rehabilitation And Modernization).

Project Snoopy QH-50 showing the underslung tray of equipment
The simplicity of the QH-50 and the DASH system (lack of redundancy) proved to be its weakness- without feedback from the QH-50, the ship's radar had to be used to track its location. If there was an equipment failure in any of the electronics, the drone would be lost. As a result, of the 746 QH-50s produced for the US Navy, fully 80% were lost due to electronics failures! By 1966, Secretary of Defense Robert McNamara pushed for a reduction in DASH funding as the growing conflict in Vietnam was consuming a significant portion of the US defense budget. Given that the submarine threat was nil during Vietnam, the Navy and Gyrodyne were eager to show that the QH-50 could perform other roles. Under Project Snoopy in 1967, QH-50s were modified with telemetry and transmission systems in a tray underslung where the torpedoes were usually carried. A television camera was also mounted in the tray and the Project Snoopy drone were used in Vietnam operationally to spot the fall of naval gunfire on enemy targets. Under a series of DARPA programs code named "Blow Low", "Night Panther", and "Night Gazelle", armed QH-50s were flown operationally in Vietnam. Some of the helicopters carried bombs to attack enemy river shipping and some QH-50s also flew with a TV-camera-aimed 40mm grenade launcher. Another operational test program fielded in Vietnam had QH-50s carrying underslung cargo loads to resupply Special Forces units deep in enemy territory. Of all the QH-50s produced for the US Navy, 5% were lost in combat action in Vietnam. 

The last QH-50 was delivered to the US Navy in August 1969 and the only foreign operator of the DASH system was Japan, which took delivery of 18 helicopter drones for service from seven destroyers in their fleet. The last Project Snoopy missions in Vietnam were flown in 1970, after which most DASH systems had been phased out from the fleet with the introduction of Kaman SH-2 Seasprite as LAMPS- Light Airborne Multi Purpose System- that offered greater manned capability from ships too small to operate the larger Sikorsky SH-3 Sea King. The US Army at White Sands Missile Range and the US Navy at the Naval Air Weapons Station at China Lake gave the QH-50 a new lease on life flying test and research missions and ending their days as targets in anti-helicopter trials. The last QH-50 mission was flown in 2006 by the US Army at White Sands, New Mexico. As a result, Gyrodyne has claim to first and so far only production and operationally-deployed helicopter UAV until the deployment of the Northrop Grumman MQ-8 Firescout in 2009. 

Source: Helicopter Gunships: Deadly Combat Weapon Systems by Wayne Mutza. Specialty Press, 2010, p97-101.

No comments:

Post a Comment