China overflights The Lightning Bugs remained a potentially valuable reconnaissance asset. The first opportunity for operational use came in August 1964. On 2 August, the destroyer
USS Maddox was sailing in international waters off the
North Vietnamese coast when it was allegedly attacked by three North Vietnamese PT boats in what is known as the
Gulf of Tonkin incident, which became a
pretext for a major expansion of U.S. involvement in the
war in Vietnam. The
Johnson Administration feared Communist Chinese intervention in the widening war, and decided to use the Lightning Bugs to monitor Chinese activities. The drones were sent with their DC-130 director aircraft to
Kadena Air Base on
Okinawa to conduct overflights of southern
China. The first Lightning Bug mission took place on 20 August 1964, though there were problems. The
DC-130 controlling the mission was loaded with a pair of Model 147Bs. One drone failed to launch, and was later lost when it fell off its underwing pylon. The second 147B successfully completed its mission over China, flew back to
Taiwan, deployed its
parachute and splashed down in a rice paddy. The drone, however was dragged over the ground by the parachute which badly damaged the machine. Its film payload was recovered intact and although the drone's navigation hadn't been as accurate as hoped, images of several primary targets were recovered. A total of five Lightning Bug missions were performed over China While they were a good asset to USAF capabilities during
Operation Rolling Thunder, these medium-altitude Combat Angel
ECM RPVs saw little use after the November 1968 official halt to air strikes on North Vietnam. The
Model 147NC, which entered service in 1969 with the
11th Tactical Drone Squadron was generally similar to the Model 147NA, with the addition of endplate auxiliary fins on its
tailplane. Some 147SDs were converted to the
Model 147SDL which featured a navigation system that obtained position information from the
LORAN radio location network, providing the drone with greater accuracy. One Model 147SD served as a testbed for the USAF's Compass Robin program, which aimed to develop expendable radio frequency sensors that could be covertly ejected from RPVs or drones in areas defended by
Soviet S-75 Dvina SNR-75 radars and thus provide the capability to collect
electronic intelligence information.
Ryan Model 147SK The
U.S. Navy also decided to get into the reconnaissance drone business for a while. They ordered a batch of Model 147SCs modified for ship launch using a
RATO booster. Navy Lightning Bugs were designated
Model 147SK and were generally similar to the 147SC, except for the RATO bottle brace on lower rear
fuselage/
empennage and having a
wingspan. First operational flight was in November 1969. After RATO launch, a Model 147SK was guided to an initial checkpoint under radio control from a
Grumman E-2A Hawkeye aircraft. From that checkpoint the drone conducted the rest of the flight with its autonomous navigation system and then was recovered by helicopter. Several dozen operational flights were performed which the Navy (for some obscure reason) referred to as "Belfrey Express"; these concluded in May 1970. The Air Force's
100th Strategic Reconnaissance Wing Strategic Reconnaissance 1956-1976: A History of the 4080th/100th SRW unit history book, on page 207, states that (based on statistical mission reliability data provided by
Teledyne Ryan) the Wing provided "assistance to the Navy on thirty-one 147SK flights." The Navy did not pursue the Lightning Bug further. Damaged airframes displayed by China and North Vietnam are reported to include some Model 147SK wreckage.
Ryan Model 147T and 147TE/TF Combat Dawn By 1968 most of the Lightning Bug missions were low-altitude flights; yet the Air Force still regarded the high-altitude mission as important enough to obtain a refined version of the Model 147H, the
Model 147T. Its main improvement was a more powerful engine, the
Teledyne CAE J100-CA-100 with 2,800 pounds of thrust (1,270 kgp) which allowed the drone to operate at higher altitudes up to almost . The initial 147T mission was flown in April 1969 but overall frequency of high-altitude reconnaissance missions continued to decline, with the last Model 147T missions over Southeast Asia performed during June 1971. Despite the general decline in high-altitude reconnaissance RPV use, new mission roles would emerge. In April 1969 a Lockheed
EC-121 Super Constellation SIGINT aircraft was
shot down in international airspace by North Korean fighters, killing all 31 crew members on the aircraft. This incident led to consideration of using an unmanned drone to do the SIGINT job, resulting in the
Model 147TE or
Combat Dawn RPV. The Model 147TE's first operational flight was in February 1970, although this flight and those that followed over two months were really just evaluation tests. The tests proved successful and an order for fifteen production Model 147TE drones followed, with the first operational flight of a production 147TE in October 1970.
inflight capture of a
556th Reconnaissance Squadron AQM-34R (Ryan Model 147TF) Combat Dawn RPV. The Model 147TEs did not overfly hostile airspace; they stayed well out to sea at relatively high altitude, or cruised along the border between North and South Korea. They could fly under their own guidance or be controlled by their
DC-130 launch aircraft. The drones relayed SIGINT data over a
data link to ground stations for analysis. This data link technology would be developed for use in other reconnaissance aircraft, such as the Lockheed U-2 and the
Beechcraft RC-12 Guardrail. Late in the Model 147TE program, underwing external tanks were added to improve time on-station from five to eight hours. In 1973 an updated version, the
Model 147TF, with external tanks as standard and improved SIGINT gear went into operation. Almost 500 missions were flown by Model 147TE and 147TF Combat Dawn RPVs between 1970 and 1975.
The last days of the Lightning Bugs 1969-1975 In 1969, the U.S. Air Force officially redesignated the Ryan 147 program model numbers as
AQM-34 (see
chart below), although the
manufacturer-assigned numbers remained in popular use. Back in Southeast Asia, Lightning Bugs continued their overflights. A number of missions focused on a
prisoner of war (POW) camp near the city of
Sơn Tây in North Vietnam, in order to determine if American POWs were being held there. The drone overflights of the Son Tay camp were halted in favor of overflights with the
Lockheed SR-71 Blackbird spy plane, as U.S. intelligence officials felt that too many drone overflights might make the enemy suspicious; this was apparently so, because when the camp was finally raided on November 21, 1970, during
Operation Ivory Coast no American POWs were there. It was a disappointing result to one of the more daring operations of the war. By 1970 the Model 147 program was beginning to become public knowledge.
Aviation Week magazine carried an article on the drones that November, though it was based on informal and unconfirmed information. The following spring, the Air Force released pictures of the drones along with a very general statement that they were used for reconnaissance. No technical or operational details were released. The number of drone
sorties continued to increase through 1971 and 1972. The Model 147SC was the workhorse for low-altitude reconnaissance during this period; in December 1972 during
Operation Linebacker II the USAF depended almost entirely on the Buffalo Hunter AQM-34L/M RPVs for
bomb damage assessment due to bad weather. High altitude flights by the 147T series continued. The Model 147H was on the way out by this time, performing its last mission in September 1972. The Soviets had updated the S-75's electronics, thus American electronic countermeasures needed to be updated as well. Cameras were replaced by a "
SAM sniffer" payload, and a Model 147H flight on September 28 was able to obtain the necessary data before the drone was destroyed by an S-75. The North Vietnamese conducted an
invasion of South Vietnam in the spring of 1972 which was broken by American air power. U.S. President
Richard Nixon then retaliated with a renewed bombing campaign against North Vietnam, codenamed
Operation Linebacker, to persuade the North Vietnamese to negotiate. The two sides seemed to be close to an agreement, but in December 1972 the talks collapsed and President Nixon ordered the
Operation Linebacker II campaign which continued into the final days of 1972. The bombing stopped completely after the January 1973 peace agreement. Reconnaissance flights continued after signing of
the peace treaty in order to ensure that the North Vietnamese were honoring their side of the bargain. By this time drone technology and operational practice had been well refined. While the Model 147SC drones had been designed to survive an average of 2.5 missions, in practice the average was much higher. One example, nicknamed "Tom Cat", performed a record 68 missions. The Lightning Bug program had proven highly successful. A series of fast-track adaptations of an existing target drone resulted in a system whose effectiveness was beyond expectations, even with guidance technology that was extremely crude by 21st century standards. Despite this, Lightning Bugs could not affect the course of
the war. Drone reconnaissance clearly showed that the North Vietnamese were violating their agreement with the Americans on a massive scale, but the U.S. leadership was unwilling to commit to ending its "endless war". When the North Vietnamese began their
last offensive in early 1975 the U.S. did little to stop it;
Saigon fell on April 30, 1975, and the war was over. The Lightning Bug program also came to an end. The last Model 147S low-altitude drone flight occurred on the day Saigon fell. AQM-34R / Model 147TF Combat Dawn flights continued until June 1975, and then most of the surviving drones were stockpiled. ==Post-Vietnam use and Ryan Models 234, 259 and 255==