I have refrained from posting a summary of the event since there are so many critical details. I guess in all fairness to Zooby I should. I will convey the details of the report as it is written.
What we have is an intelligence report to the DIA [ Defense Intelligence Agency] from a DAO [Defense Agency Officer], and distributed to the CIA, NSA, White house, CMC, Secretary of State, Secretary of Defense, and a number of other agencies. The report describes events over Tehran, Iran, on Sept 19th, 1976. The credibility of the report is listed as high, with high ranking witnesses, RADAR confirmation, effects on the crews night vision [due to the brilliance of the object], and onboard electronics were affected.
The command center at [Iranian] Shamrokhi AFB – then an ally of the US hence our presence in the area – received a number of calls from citizens reporting unusual lights and objects over the city. From the command center, the officer in charge could see a bright light near the area reported. After it was confirmed that no helicopters were in the air, command scrambled an F-4 to investigate at about 12:30 AM. The object was so brilliant that it could be seen from 70 miles away. On approach and when at 25 NM [Nautical Miles] from the UFO, the plane lost all communication and instrumentation. When the plane turned away, [specifically the statement is made] apparently when the F-4 was no longer a threat, the electronics returned to normal. The first plane returned to base. Another F-4 was dispatched for intercept at 12:40 AM. As the “backseater” with RADAR then approached the object and obtained a lock at 27NM, the UFO began to move away so as to pace the F-4 and maintain a constant distance of 25 NM. . This motion was confirmed on RADAR.
The object yielded the same RADAR return as a 707 tanker. The actual size of the object could not be determined due to its intense brilliance. Blue, green, orange, and red strobe lights are seen arranged in a rectangle and flashing so quickly that all could be seen at once. As the chase ensues to the south of Tehran, another bright object about 1/3 the size of the original came out of the object heading directly towards the F-4. The pilot attempted to fire and AIM missile, but at that exact moment his weapons and communications systems failed. The plane took evasive actions to avoid collision with the smaller orb which then followed the F-4 in the evasive dive at about 3-4 NM, and then cut across the inside chord of the flight path for a “perfect rejoin” with the main object.
Next, the crew regains their electronics and then observes another bright object come out of the other side of the original and head straight down at high speed. An explosion was expected, but the object slowed to a gentle landing and then cast a bright light over a 2-3 km area. After circling the landing zone a couple of time, the planes attempted to return to base. They lost communications every time the plane heading approached 150 degrees [presumably the direction of the UFO wrt their heading to base]. Another civil airliner on approach lost communications at this time as well. On final approach, the F-4 crew observed a cylindrical object in flight – about the size of a T-bird – at about 10 miles, and with bright steady lights on each end and a flasher in the middle. This was not detected on RADAR, but the object was visually confirmed by the tower.
The next day the landing area was inspected by helicopter. A very noticeable beeper sound was heard. [presumably on their radio, this is not indicated] They landed and interviewed some people living near the landing area. The locals reported a very loud noise and a bright light like lightning the night before. The area was being checked for radiation. This information was obtained through a sub-source and the pilot of the second F4
http://www.nsa.gov/docs/efoia/released/ufo/ufo20.pdf
http://www.nsa.gov/docs/efoia/released/ufo/ufo17.pdf