Douglas B-66

B-66 Destroyer
A Douglas B-66B (53-506) in flight
Role	Light bomber
National origin	United States
Manufacturer	Douglas Aircraft Company
First flight	28 June 1954
Introduction	1956
Retired	1973 (USAF)
Primary user	United States Air Force
Number built	294
Unit cost	US$2.55 million (RB-66B)
Developed from	Douglas A-3 Skywarrior
Developed into	Northrop X-21

The Douglas B-66 Destroyer was a United States Air Force light bomber based on the U.S. Navy's A-3 Skywarrior carrier-based heavy attack aircraft. The B-66 was intended to replace the Douglas A-26 Invader, and an RB-66 photo-reconnaissance version was ordered simultaneously. The USAF B-66 retained the three-man crew from the US Navy A-3, but incorporated ejection seats that the US Navy variant lacked.

At first, the United States Air Force intended the conversion to be an easy matter of removing the carrier-specific features, so no prototypes were ordered, just five pre-production RB-66A models (the reconnaissance mission being considered a high priority). The list of modifications grew, and before long, the supposedly easy conversion became what was substantially a new aircraft. Many of the changes were due to the USAF's requirement for low-level operations, while the Navy version had originally been designed and employed as a high-altitude nuclear strike bomber. Two major differences between the A-3 and the B-66 consisted in the types of jet engines used, and the emergency crew egress systems. The A-3 had two J57 turbojet engines, whereas the B-66 had two Allison J71s. The B-66 was equipped with ejection seats whereas the A-3 was not.

The first RB-66A pre-production aircraft flew in 1954, whereas the first production RB-66B aircraft flew in the beginning of 1955.

The basic B-66 design proved to be a versatile one, and was produced or modified into a variety of other versions, including the EB-66, RB-66, and the WB-66. Likewise, many variants of the A-3 Skywarrior were produced.

Deliveries to the USAF began in 1956, with 145 of this model produced. RB-66s were used as the primary night photo-reconnaissance aircraft of the USAF during this time, many examples serving with tactical reconnaissance squadrons based in the United Kingdom and in West Germany. A total of 72 of the B-66B bomber version were built, 69 fewer than originally planned. A total of 13 B-66B aircraft later were modified into EB-66B electronic countermeasures aircraft for the cold war with Russia, and were stationed at RAF Chelveston with the 42nd Tactical Reconnaissance Squadron who did the conversion in the early 1960s. They would rotate out of an alert pad in Spain during the time that the 42nd had them. These and the RB-66Cs that the 42nd had would eventually be sent to Vietnam. Unlike the U.S. Navy's A-3 Skywarrior, which performed some bombing missions, the Destroyer was not used as a bomber in Vietnam.