Washington (CNN) -- Among the 90,000 secret U.S. military documents posted on the internet this week by WikiLeaks are more than a dozen reports of possible attacks on Afghanistan coalition aircraft using heat-seeking shoulder-fired missiles.
It was that type of missile that brought down numerous Soviet military aircraft when the Soviet Union tried to occupy Afghanistan in the 1980s.
But among all the reports, one day stands out: May 30, 2007.
In the first of three attacks on that day, an American CH-47 helicopter code named "Flipper" was, according to a leaked report, "engaged and struck with a missile."
"The missile struck the aircraft in the left engine," the report says. "The impact of the missile projected the aft end of the aircraft up as it burst into flames, followed immediately by a nose dive into the crash site."
All seven troops on board died, including five Americans, a Briton and a Canadian.
The report goes onto say, "Based on description of launch, size of round, and impact force of the projectile, it is assessed to be bigger than an RPG (rocket-propelled grenade) and possibly a surface-to-air missile. Witness statements ... suggest Flipper was struck by MANPAD (man-portable air-defense system)."
MANPADs are shoulder-fired missiles that can home in on the heat from an aircraft's engine to destroy it.
A U.S. military official in Afghanistan said the reports don't tell the whole story.
"We're aware of the report on surface-to-air missiles. What's being presented is a pretty broad and somewhat random selection of documents that includes information that in some cases is incomplete or not verified by other sources or studies," the official said. "There's been no recent activity suggesting that these weapons are a threat, as attested by the volume of our daily air activity and the causes of aircraft incidents, which we report."
Within half an hour of the first attack, two Apache helicopter gunships were fired on by what the pilots thought was a missile. The helicopters were not damaged.
Another half hour later, another attack came from the ground on the same Apaches. The report on that incident reads, "This was possibly the second MANPAD engagement against this flight of Apaches in a 30-minute period. Clearly, the Taliban were attempting to down an Apache after downing the CH-47."
Many more reported MANPAD attacks or possible MANPAD attacks were reported in 2007, but none brought down a coalition aircraft.
Perhaps the best known and most effective MANPADs are American-made Stingers, which the United States supplied to Afghan militia to fight the Soviets.
At least two of the reports indicate that a Stinger missile could have been used to attack coalition aircraft, albeit unsuccessfully.
One report details that case of a missile fired at an American F-18 Hornet by what was believed to be a MANPAD. And because the missile blew itself up as it approached anti-missile flares, the report's author suggested it was a Stinger.
"A Stinger Basic would have likely been the only MANPAD (currently known to be in Afghanistan) capable of a proximity detonation onto the dispensed flares," the unidentified commander wrote. The Hornet was not damaged and no one was hurt.
Most of the reports mentioning the specific type of MANPADs refer to older, less sophisticated missiles of Chinese or Soviet design. "The 1st or 2nd generation MANPADs generally encountered in Afghanistan (HN-5, SA-7, SA-14, SA-16) would have had to have made direct contact with one of the flares (in order to) initiate the detonator," the report on the F-18 Hornet attack says.
There's no doubt MANPADs are in Afghanistan. One coalition raid on a weapons cache in 2005 found four MANPADs in storage. And during a meeting between U.S. military leaders and a provincial governor, "the governor reported that a man claiming to have MANPADs for sale has been in touch with his staff, presumably to give CF (coalition forces) an opportunity to buy them and get them out of circulation," one of the leaked reports says. "The governor referred to them as Blowpipe missiles. The seller is going to show the governor a picture to prove that he has them."
It is unclear from the report whether the coalition ever secured the missiles the governor talked about.