Ryan AQM-91 Firefly

AQM-91 Firefly

Teledyne Ryan AQM-91A Compass Arrow at the National Museum of the United States Air Force.
Role	Aerial reconnaissance unmanned aerial vehicle
National origin	United States
Manufacturer	Ryan Aeronautical
First flight	September 1968
Number built	28

The Ryan AQM-91 Firefly was a developmental drone developed during the Vietnam War to perform long-range reconnaissance, especially into China.

Development

The Ryan Model 147 Lightning Bug reconnaissance drone was enjoying success in Vietnam in the early 1960s, but it lacked the range to fly deep into China and back out again. In particular, the Chinese nuclear development facility at Lop Nor was far out of reach of the Lightning Bugs, and was barely within reach of the Lockheed U-2 spyplane, which had become far too vulnerable to SAMs. US intelligence thus needed a long-range drone with a high degree of survivability. Such requirements spelled out a completely new design, not a modification of a target drone.

Ryan pursued advanced drone concepts on a part-time basis. After discussions with the CIA that went nowhere, Ryan pitched their advanced reconnaissance drone concepts to the Air Force in early 1966. The USAF was interested, and opened up a design competition, with Ryan competing with North American Aviation. Ryan won the competition in June 1966, and the new design was designated the "Model 154 / AQM-91A Firefly". The basic design concept resembled that of the Model 136 Red Wagon drone that Ryan had proposed earlier in the decade, but which had been turned down in favor of a modified Firebees. The name "Firefly" was resurrected from the early Model 147 program for the new drone, though it was also referred to as "Compass Arrow" after the program name. The test flights were conducted over the US Southwest. The project was highly secret, but on 4 August 1969 one of the prototypes failed and parachuted to ground inside the Los Alamos nuclear research complex during lunch hour. Unfortunately, it didn't land in a restricted area, and local newspeople were able to take and publish photographs of the aircraft. The Air Force released a statement that the aircraft was a "high altitude target", but though such a statement might have been believed in 1959, it wasn't in 1969.

Test flights were halted for a few weeks while procedures were reviewed. The flights then resumed, culminating in long-range evaluations in late 1971. The Model 154 passed with flying colors, exceeding its altitude requirements by a good margin, and proving almost invisible to radar. However, by this time the need for the Model 154 had vanished. In July 1971, President Richard Nixon began a diplomatic effort to build ties with China, and reconnaissance overflights were cancelled. Satellite reconnaissance capabilities had improved through the 1960s, leading to the first launch of the advanced KH-9 Hexagon satellite on 15 June 1971, which could provide strategic intelligence without provoking the Chinese.

The Model 154 program lingered on for a few more years, but the drones were finally put into mothballs in 1973, and scrapped a few years after that. 28 had been built, including 20 production machines.

Design

Stealth

The Model 154 had an engine on the top of the fuselage to reduce its radar cross-section and infrared signature as seen from below, as well as twin inward-canted tailfins to conceal the exhaust stream. It had sloped flat sides to deflect radar signals, and was built using a high percentage of plastic composite materials, which had a lower radar reflectivity than metal (see radar-absorbent material). The aircraft was powered by a General Electric YJ97-GE-3 turbojet providing 4,000 pounds (1,815 kg) thrust, with the engine exhaust mixed with cool air to reduce its infrared signature. The YJ97 was derived from a General Electric demonstrator engine designated the "GE1".

Avionics

The Model 154 was to be launched by a DC-130 Hercules director aircraft, and recovered in midair by helicopter. It had a precision-navigation autopilot system, a reconnaissance payload, a self-destruct system to ensure that none of its sensitive gear fell into enemy hands, and was to carry electronic countermeasures to further improve its survivability. The primary reconnaissance payload was an Itek panoramic camera, but in principle it could also carry thermographic camera or a Signals intelligence payload.

The guidance system was designed to provide navigation accuracies with an error of no more than half a percent. The guidance system proved to be very tricky, and first powered flight of a Model 154 did not take place until September 1968.

Specifications

General characteristics

Crew: None
Length: 34 ft 2 in (10.40 m)
Wingspan: 47 ft 8 in (14.50 m)
Empty weight: 3,800 lb (1,725 kg)
Gross weight: 5,400 lb (2,450 kg)
Powerplant: 1 × General Electric YJ97-GE-3, 4,000 lbf (17.8 kN) each

Performance

Maximum speed: 505 mph (815 km/h)
Range: 4,370 miles (7,030 km)

References

This article contains material that originally came from the web article Unmanned Aerial Vehicles by Greg Goebel, which exists in the Public Domain.

External links

Wikimedia Commons has media related to Ryan AQM-91 Firefly.

1962 United States Tri-Service missile and drone designation system

1–50	MGM-1 RIM-2 MIM-3 AIM-4 MGM-5 RGM-6 AIM-7/RIM-7 RIM-8 AIM-9 CIM-10 PGM-11 AGM-12 CGM-13/MGM-13 MIM-14 RGM-15 CGM-16 PGM-17 MGM-18 PGM-19 ADM-20 MGM-21 AGM-22 MIM-23 RIM-24 HGM-25A/LGM-25C AIM-26 UGM-27 AGM-28 MGM-29 LGM-30 MGM-31 MGM-32 MQM-33 AQM-34 AQM-35 MQM-36 AQM-37 AQM-38 MQM-39 MQM-40 AQM-41 MQM-42 FIM-43 UUM-44 AGM-45 MIM-46 AIM-47 AGM-48 LIM-49 RIM-50

51–100	MGM-51 MGM-52 AGM-53 AIM-54 RIM-55 PQM-56 MQM-57 MQM-58 RGM-59 AQM-60 MQM-61 AGM-62 AGM-63 AGM-64 AGM-65 RIM-66 RIM-67 AIM-68 AGM-69 LEM-70 BGM-71 MIM-72 UGM-73 BQM-74 BGM-75 AGM-76 FGM-77 AGM-78 AGM-79 AGM-80 AQM-81 AIM-82 AGM-83 AGM-84/RGM-84/UGM-84 AGM-84E AGM-84E/H/K RIM-85 AGM-86 AGM-87 AGM-88 UGM-89 BQM-90 AQM-91 FIM-92/AIM-92 XQM-93 YQM-94 AIM-95 UGM-96 AIM-97 YQM-98 LIM-99 LIM-100

101–150	RIM-101 PQM-102 AQM-103 MIM-104 MQM-105 BQM-106 MQM-107 BQM-108 BGM-109/AGM-109/RGM-109/UGM-109 BGM-110 BQM-111 AGM-112 RIM-113 AGM-114 MIM-115 RIM-116 FQM-117 LGM-118 AGM-119 AIM-120 CQM-121/CGM-121 AGM-122 AGM-123 AGM-124 RUM-125/UUM-125 BQM-126 AQM-127 AQM-128 AGM-129 AGM-130 AGM-131 AIM-132 UGM-133 MGM-134 ASM-135 AGM-136 AGM-137 CEM-138 RUM-139 MGM-140 ADM-141 AGM-142 MQM-143 ADM-144 BQM-145 MIM-146 BQM-147 FGM-148 PQM-149 PQM-150

151–	FQM-151 AIM-152 AGM-153 AGM-154 BQM-155 RIM-156 MGM-157 AGM-158A/B/AGM-158C AGM-159 ADM-160 RIM-161 RIM-162 GQM-163 MGM-164 RGM-165 MGM-166 BQM-167 MGM-168 AGM-169 MQM-170 MQM-171 FGM-172 GQM-173 RIM-174 MQM-175 AGM-176 BQM-177 MQM-178

Undesignated	ASALM Brazo Have Dash MA-31 NLOS Pershing II Senior Prom Sprint Wagtail

See also: United States tri-service rocket designations post-1962

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