Tragedy on the way home
(Korean Airlines B-747 vs. Soviet Sukhoi Su-15)
On Sept. 1, 1983, a civilian B-747 flying with registration HL7442 as Korean Air Lines Flight 007 (KAL 007, KE 007) was shot down by Soviet fighters over the Sea of Japan, in an area located west of the Sakhalin Island. All the 269 people on board (crew comprised) were killed. The plane was enroute from New York to Seoul via Anchorage when it flew into the Soviet airspace due to a navigational error and was fatally intercepted by the local fighters. Initially the Soviets denied the episode and their involvement but, following the international pressures, they admitted they had shot down the liner, suspecting it was conducting spying activities on a prohibited territory under the umbrella of a civil plane. It is worth pointing out how this incident brought to a common anti-Soviet sentiment that spread out all over the world, but also led to dozens of hypothesis, some of them bound to conspiracy theories, more or less based upon real facts and figures. But how did such a tragedy happen?
The analysis conducted by the ICAO stated that the reason that brought the KAL 007 many miles off course was a crew error that failed to set and check correctly the navigational route. However, as underlined each time we discuss an aviation accident, there a long list of factors that contributed to the mishap.
After take off from Anchorage (Alaska), the B747 was instructed by the ATC (Air Traffic Control), to turn and maintain a heading of 220 degrees and thereafter proceed to BETHEL, a waypoint located approximately between the Alaskan and Japanese coasts. In order to better understand the type of navigational error, it is worth explaining how the Boeing 747-200 autopilot works. It is equipped with four basic control modes: HEADING, ILS, INS and VOR-LOC. The HEADING mode maintains the plane flying at a constant nose-pointing direction regardless of geographical start or end points. The VOR/LOC mode maintains the plane flying over a given straight ground course relative to a fixed radio beacon ground station. The ILS mode is similar to the VOR/LOC mode but includes additional vertical guidance for landings. Finally, the INS mode has the capability of maintaining a given route without external aids or references, by continuously calculating the aircraft’s ground track since it begins moving away from an arbitrary start fix. When the INS navigation systems are properly programmed with the filed flight plan waypoints, the pilot can turn the autopilot mode selector switch to the INS position and the plane will then automatically track the programmed INS course line, provided that the plane is headed in the proper direction and within 7.5 nautical miles of the INS course line. Since the Wikipedia page dedicated to Korean Air Lines Flight 007 is quite detailed and, unlike some other Airspace Violations we have already commented on this site, there are many documents available, the in-depth description of the flight that follows is an abstract of the above mentioned Wiki page:
At the time of the incident, Anchorage VOR beacon was out of service because of maintenance. The crew had been properly informed by means of a NOTAM (Notice to Airmen), which was not seen as a problem, as the captain could still check his position at the next VORTAC beacon at Bethel, 346 miles (557 km) away. However, the aircraft required to maintain the assigned heading of 220 degrees, until it could receive the signals from Bethel, then it could fly direct to Bethel, as instructed by ATC, by centering the VOR “to” course deviation indicator (CDI) and then engaging the auto pilot in the VOR/LOC mode. Then, when over the Bethel beacon, the flight could start using INS mode to follow the waypoints comprising route Romeo-20 around the coast of the U.S.S.R. to Seoul. The INS mode was necessary for this route as after Bethel the plane would be mostly out of range from VOR stations. About 10 minutes after take-off, KAL 007, flying on a heading of 245 degrees, began deviating to the right (north) of its assigned route to Bethel; it would continue flying with this heading for the next five and a half hours. International Civil Aviation Organization (ICAO) simulation and analysis of the flight data recorder determined that this deviation was probably caused by the aircraft’s autopilot system operating in HEADING mode past the point where it should have been switched to the INS mode.
According to the ICAO, the autopilot was not operating in the INS mode for one of two reasons: either the crew did not switch the autopilot to the INS mode (shortly after Carin Mountain) or they did select the INS mode, but it did not activate as the aircraft had already deviated off track by more than the 7.5 nautical miles (13.9 km) tolerance permitted by the inertial navigation computer. In both scenarios, the autopilot remained in the HEADING mode, and the problem was not detected by the crew. At 1551 UTC, according to Soviet sources, KAL 007 entered the restricted airspace of Kamchatka Peninsula. The buffer zone extended 200 kilometres (120 miles) off Kamchatka’s coast and is known as a Flight Information Region (FIR). The nearest to Soviet territory – 100 kilometre (62 mi) radius part of the buffer zone had the additional designation of prohibited airspace.
When KAL 007 was about 80 miles (130 km) from the Kamchatka coast, one MiG-23 and three Su-15 Flagon fighters were scrambled to intercept the Boeing 747. Significant command and control problems were experienced trying to vector the fast military jets onto the Boeing before they ran out of fuel. In addition, pursuit was made more difficult, according to Soviet Air Force Captain Alexander Zuyev, who defected to the West in 1989, because Arctic gales had knocked out Soviet radar ten days before. The unidentified jetliner therefore crossed over the Kamchatka Peninsula back into international airspace over the Sea of Okhotsk without being intercepted.
The Commander of the Soviet Far East District Air Defense Forces, General Valeri Kamensky, was adamant that KAL 007 had to be destroyed (even if it was overflying neutral waters) provided it could positively identified as not being a passenger plane. His subordinate, General Anatoly Kornukov, commander of Sokol Air base (later, to become commander of the Russian Air Force), was adamant that there was no need to make positive identification as “the intruder” had already flown over Kamchatka.
Soviet Air Defence Force units that had been tracking the Korean aircraft for more than 1 hour while it entered and left Soviet airspace considered the aircraft as a military target when it re-entered their airspace over Sakhalin Island. After the protracted ground-controlled interception, the three Su-15 fighters (from nearby Dolinsk-Sokol airbase) and the MiG-23 (from Smirnykh Air Base) managed to make visual contact with the Boeing.
In a 1991 interview with Izvestia, Major Gennadi Osipovich, pilot of the Su-15 interceptor that shot the 747 down, spoke about his recollections of the events leading up to the shootdown. Contrary to official Soviet statements at the time, he recalled telling ground controllers that there were blinking lights….” He continued, saying that “I saw two rows of windows and knew that this was a Boeing. I knew this was a civilian plane. But for me this meant nothing. It is easy to turn a civilian type of plane into one for military use…” He furthermore did not provide a detailed description of the aircraft to his ground controllers: “I did not tell the ground that it was a Boeing-type plane; they did not ask me.”
Commenting on the moment that KAL 007 slowed as it ascended from flight level 330 to flight level 350, and then on his maneuvering for missile launch, Osipovich said: “They [KAL 007] quickly lowered their speed. They were flying at 400 kilometers per hour. My speed was more than 400. I was simply unable to fly slower. In my opinion, the intruder’s intentions were plain. If I did not want to go into a stall, I would be forced to overshoot them. That’s exactly what happened. We had already flown over the island [Sakhalin]. It is narrow at that point, the target was about to get away… Then the ground [controller] gave the command: ‘Destroy the target…!’ That was easy to say. But how? With shells? I had already expended 243 rounds. Ram it? I had always thought of that as poor taste. Ramming is the last resort. Just in case, I had already completed my turn and was coming down on top of him. Then, I had an idea. I dropped below him about 2,000 meters… afterburners. Switched on the missiles and brought the nose up sharply. Success! I have a lock on.”
“We shot down the plane legally… Later we began to lie about small details: the plane was supposedly flying without running lights or strobe light, that tracer bullets were fired, or that I had radio contact with them on the emergency frequency of 121.5 megahertz.” At the time of the attack, the plane was cruising at an altitude of about 35,000 feet. Tapes recovered from the airliner’s cockpit voice recorder demonstrate that the crew were unaware that they were off course and violating Soviet airspace. Immediately after missile detonation, the airliner began a 113-second arc upward because of a damaged cross-over cable between the left inboard and right outboard elevators. At 18:26:46 UTC, at the apex of the arc at altitude 38,250 feet, either the pilot was able to turn off the autopilot or the autopilot tripped and the plane began to descend to 35,000 feet. From 18:27:01 until 18:27:09, the flight crew reports to Tokyo Radio informing that KAL 007 to “descend to 10,000” [feet]. At 18:27:20, ICAO graphing of Digital Flight Data Recorder tapes shows that after a descent phase and a 10 second “nose-up”, KAL 007 leveled out at pre-missile detonation altitude of 35,000 ft. Yaw (oscillations), begun at the time of missile detonation, continued decreasing until the end of the minute 44 second portion of the tape. The Boeing did not break up, explode or plummet immediately after the attack; it continued its gradual descent for four minutes, then leveled off at 16,424 feet, rather than continue descending to 10,000 as previously reported to Tokyo Radio, continuing at this altitude for almost five more minutes. The last cockpit voice recorder entry occurred at 18:27:46 while descending. At 18:28 UTC, the aircraft was reported turning to the north. ICAO analysis concluded that the flight crew “retained limited control” of the aircraft. Finally, the aircraft began to descend in spirals over Moneron Island before coming down 2.6 miles (4.2 km) , killing all 269 on board. The aircraft was last seen visually by Osipovich, “somehow descending slowly” over Moneron Island. The aircraft disappeared off long range military radar at Wakkanai, Japan at a height of 1,000 feet.
The ICAO report, after months of harsh investigation, often obstructed by several attempts of red herring, published his final conclusions:
1) The crew inadvertently flew virtually the entire flight on a constant magnetic heading (in the heading mode) due to its unawareness of the fact that ‘heading’ had been selected as the mode of navigation rather the ‘inertial navigation system’ (INS).
2) An undetected 10 degree longitudinal error was made in inserting the ‘present position’ co-ordinates of the Anchorage gate position into one or more of the INS units.
3) Interceptions of KE 007 were attempted by USSR military interceptor aircraft, over Kamchatka Peninsula and in the vicinity of Sakhalin Island.
4) The USSR authorities assumed that KE 007 was an ‘intelligence aircraft’ and, therefore, they did not make exhaustive efforts to identify the aircraft through in-flight visual observations.
5) ICAO was not provided any radar recordings, recorded communications or transcripts associated with the first intercept attempt or for the ground-to-interceptor portion of the second attempt, therefore, it was not possible to fully assess the comprehensiveness or otherwise of the application of intercept procedures, signaling and communications.
6) In the absence of any indication that the flight crew of KE 007 was aware of the two interception attempts, it was concluded that they were not.
On Mar. 10, 1986, two years and half after the tragedy, the ICAO Council adopted the Amendment 27 of the Annex 2 of the Chicago Convention. In particular, some intercepting rules measures were enhanced regarding the visual signals, the intercepting maneuvers, the coordination with ground units and most important the principle of the interdiction of the use of force against civil aerial intruders was strengthened.
On the operations side, as a result of the incident, the interface of the autopilot used on airliners was redesigned to make it more ergonomic.
© David Cenciotti & Simone Bovi