| KAL007 took off from New York-JFK on August 31, 1983, bound for Kimpo Airport in Seoul, South Korea. It was a Boeing 747 with 269 passengers and crew on board, and after making a stop at Anchorage, the plane continued on its scheduled route across the Aleutian Islands.
Unbeknownst to the crew, a US Air Force RC-135 reconaissance plane was making a flight east of Kamchatka at the same time that KAL007 was approaching the east coast of the Soviet Union, several miles north of its original course. As the airplane entered Soviet airspace, six MiG-23 fighter jets were scrambled to intercept it and shoot it down.
Before the first wave of fighters could reach KAL007, the aircraft passed over the Sea of Okhotsk and out of Soviet airspace. The MiGs disengaged. Now, the 747 was nearly 100 miles north of where it was supposed to be, and was headed for Sakhalin, a Russian island north of Japan. As they approached Soviet airspace again, this time almost 200 miles off course, two Su-15 fighters were dispatched to head off the 747.
The Soviet defense command ordered the fighters to engage at 3:22 AM local time, and KAL007 was struck by their missiles at 3:26 AM, September 1, 1983, while cruising at 35,000 feet. From the cockpit voice recorder, this frantic conversation between the two Korean pilots can be retold:
Captain: What's happened?
First officer: What?
Capt: Retard throttles.
FO: Engines normal.
Capt: Landing gear... Landing gear!... Altitude is going up. Altitude is going up. Speed brake is coming out.
As the cabin lost pressurization, automated warning systems inside the aircraft started to pipe up amid the dialogue, alternating in English, Korean, and Japanese:
Put the mask over your nose and mouth and adjust the headband.
FO: Tokyo radio, Korean Air zero zero seven.
Put the mask over your nose and mouth and adjust the headband.
Tokyo: Korean Air zero zero seven, Tokyo.
FO: Roger, Korean Air zero zero seven. Ah, we are experiencing...
Put the mask over your nose and mouth and adjust the headband.
Flight engineer: All compression.
Capt: Rapid decompression. Descend to one zero thousand.
Attention. Emergency descent.
FE: Now. We have to set this.
Tokyo: Korean Air zero zero seven, radio check on one zero zero four eight.
Attention. Emergency descent.
FE: Speed. Stand by. Stand by. Stand by. Stand by. Set...
Twenty seconds later, the recording ends: the 747 dove for almost two minutes, powered down and spraying jet fuel, before crashing into the ocean off of Moneron Island.
It is believed that the aircraft was off course because the pilots set the autopilot in "heading mode," which steers the aircraft based on compass readings and would have been inaccurate on a long Great Circle route such as the one KAL007 was flying. Preventing similar accidents was one of many arguments made in favor of the Global Positioning System.
Explaining why the Soviet Air Force attacked KAL007 is a more difficult proposition. For one, its navigation lights were on for the duration of its flight: a photoreconaissance plane wouldn't be using navigation lights, and certainly wouldn't be flying in a bold, straight line over Siberia. In the first few years after the crash, however, many conspiracy theorists and yellow journalists played around with KAL007, posing theories that it was actually a CIA platform in disguise, that it was Ronald Reagan's way of testing Soviet air defenses, and so on. For the most dramatic story postulated yet, Michel Brun published a book in 1996 that detailed KAL007 as the centerpiece of a U.S.-Soviet air battle in which ten American aircraft were downed.
After the fall of the Soviet Union, Boris Yeltsin was more than willing to turn over the Soviet papers on the crash to the International Civil Aviation Organization. It was discovered that the plane was almost 16 miles past the coast of Sakhalin when it was shot down... outside of Soviet airspace, therefore making the shootdown a violation of international law. The debriefing of one of the Su-15 pilots confirmed that neither pilot thought the aircraft was an RC-135, but that they had to go along with the orders of their command anyway, or risk potentially allowing sensitive information to leave Soviet territory.
The moral of this story is: Watch where you fly, especially when there's a cold war going on.
References: http://aviation-safety.net/specials/kal007/ and http://www.jamesoberg.com/russian/kal007.html | 
