would allow it to act as a decoy for much of its flight, and then deliberately approach a selected defensive site and attack it. As such, the program was renamed Subsonic Cruise Armed Decoy, retaining the SCAD acronym. For this role, the accuracy of the original INS guidance hardware was not enough. While a similar system was also used in SRAM, its shorter range and much shorter flight times meant the drift rate of the system was not a serious concern as long as the bomber could feed it accurate information just before launch, to "zero out" the drift. In contrast, SCAD was designed to fly over much longer ranges and slower speeds, resulting in longer flight times and increasing the problem with drift; even with the drift "zeroed out" just before launch, subsequent drift during the longer flight would accumulate to an unacceptable error. To provide the accuracy needed to attack the SAM sites with a small warhead, some system was needed to zero out the drift in-flight, and for this need, a radar-based TERCOM system was added. Development was approved in July 1970, and it was given the designation ZAGM-86A, the Z indicating its initial development status. ALCM As SCAD moved from the pure-decoy role to decoy-and-attack, this meant it would be able to carry out the same mission as SRAM, but from much longer range. This would reduce the need for a decoy. Accordingly, in June 1973, SCAD was canceled in favor of a system dedicated purely to the long-range attack mission. The original designation number remained, but the name changed to reflect the new mission, becoming the Air Launched Cruise Missile, or ALCM. The first example, similar to the original SCAD in most ways, flew for the first time in March 1976, and its new guidance system was first tested that September. In January 1977, the missile was ordered into full-scale production. Compared to the models that entered service in the 1980s, the A-model had a distinctive look; the nose tapered sharply to a triangular point giving it a shark-like appearance, compared to the later models which had a more rounded conventional appearance. ERV and JCMP Meanwhile, the Air Force had also issued a requirement for a version with a much longer range. This would allow the bombers to launch their missiles from far off the Russian coast, placing it outside the range of the interceptors