As early as 1950 Douglas examined equipping the Sparrow with an active radar seeker, initially known as XAAM-N-2a Sparrow II, the original retroactively becoming Sparrow I. In 1952 it was given the new code AAM-N-3.
The active radar made the Sparrow II a "fire and forget" weapon, allowing several to be fired at separate targets at the same time.

By 1955 Douglas proposed going ahead with development, intending it to be the primary weapon for the F5D Skylancer interceptor.
It was later selected, with some controversy, to be the primary weapon for the Canadian Avro Arrow supersonic interceptor, along with the new Astra fire-control system.
For Canadian use and as a second source for US missiles, Canadair was selected to build the missiles in Quebec.

The small size of the missile forebody and the K-band AN/APQ-64-radar limited performance, and it was never able to work in testing.
After considerable development and test firings in the U.S. and Canada, Douglas abandoned development in 1956.
Canadair continued development until the Arrow was cancelled in 1959.
As early as 1950 Douglas examined equipping the Sparrow with an active radar seeker, initially known as XAAM-N-2a Sparrow II, the original retroactively becoming Sparrow I. In 1952 it was given the new code AAM-N-3. The active radar made the Sparrow II a "fire and forget" weapon, allowing several to be fired at separate targets at the same time.
By 1955 Douglas proposed going ahead with development, intending it to be the primary weapon for the F5D Skylancer interceptor. It was later selected, with some controversy, to be the primary weapon for the Canadian Avro Arrow supersonic interceptor, along with the new Astra fire-control system. For Canadian use and as a second source for US missiles, Canadair was selected to build the missiles in Quebec.
The small size of the missile forebody and the K-band AN/APQ-64-radar limited performance, and it was never able to work in testing. After considerable development and test firings in the U.S. and Canada, Douglas abandoned development in 1956. Canadair continued development until the Arrow was cancelled in 1959.
AIM-7 Sparrow