Washington — Although it is still possible to hear AWACS referred to as a ''spy plane'' and an ''intelligence gathering aircraft'' on television newscasts, it manifestly does not perform the same function as the sleek U-2 or the even sleeker SR-71A ''Blackbird'' that the United States employs for strategic surveillance missions.
Airborne Warning and Control System (AWACS) planes, their powerful radar housed in rotating radomes, are designed to provide early warning of enemy air assault and to respond by coordinating the counter-attacks of defending aircraft.
According to Boeing, their manufacturer, when flying at 29,000 feet the AWACS can detect fighter aircraft sweeping in at 200 feet above the land or sea at distances up to 201 miles away. But a recent report by the Senate Foreign Relations Committee claims that the ungainly machines can spot low-altitude intruders 275 miles out.
The Saudis want AWACS to protect their oil facilities and oil shipping terminals from air strikes launched from Iran or even the Soviet Union. Without an airborne capability, they are forced to rely on ground-based radars which only have a range of 30 to 40 miles against low-flying attackers.
When Israeli fears about an AWACS sale to Saudi Arabia are dissected, they seem to consist largely of a conviction that the radar planes could monitor Israel's air exercises and flight training; that they could block its air strikes against individual targets; and that they could alert other Arab nations to any preemptive air attack the Jewish state might launch.
While AWACS will almost certainly be accorded a mention in any history of 20 th century America - particularly if the Senate torpedoes its sale to Saudi Arabia tomorrow - it may be remembered as the most misunderstood aircraft ever to come off US production lines, say some observers.
As the Air Force has never ceased stressing, AWACS cannot collect electronic intelligence or take photographs.