After Banging Up the Airplane and Runway Lights, Corrective Action

Human error can never be reduced to a zero-probability event; therefore, the notion of an accident-free airline transportation system is nothing more than a feel-good myth, especially if corrective action follows rather than precedes a mishap.

The August 5, 2013, nighttime landing of Korean Air Lines flight KAL763 at Niigata Airport on the west coast of Japan is an excellent case in point. After the accident, KAL instituted additional procedures and pilot training to forestall a repeat — the word “prevent” is not used here because the human mind can foul up in an infinite number of ways.

The serious incident investigation report of January 29, 2015, by the Japan Transport Safety Board (JTSB), will serve as documentation of the event.

The KAL aircraft was a B737-900 with 106 passengers aboard, seven flight attendants and a cockpit crew of two pilots. The captain was the pilot flying; the first officer was the pilot monitoring.

It was an uneventful one-hour and 45-minute flight from Inchon, South Korea.

The Niigata tower controller cleared the airplane to land on runway 10, which the KAL 763 crew acknowledged. From the opposite direction, the tarmac is designated runway 28.

The autopilot and autothrottle were disconnected at an altitude of 1,000 feet.

The flight crew made all the necessary call-outs, acknowledgments and read backs. The landing was stabilized; touchdown was at a normal and nominal 143 knots (165 mph).

Thrust reversers were deployed. Brakes were applied at 69 knots (79 mph).

Niigata tower radioed the aircraft: “Korean Air seven-six-three, turn right end of runway Bravo One (B1) and taxi to spot cross runway two-four/two-two (04/22).” This was the instruction to exit the runway and make another right turn and cross 04/22 again while taxiing. Runway 04/22 crosses runway 10/28.

The first officer radioed acknowledgment to the tower: “Cross runway 04/22, end of runway right turn.”

The captain noted, “Cross runway 04/22.”

The first officer wondered, “Cross runway?”

Events rapidly started to go downhill.

Neither pilot had been to Niigata in some months, and it was the first officer’s first night landing at the airport.

The airplane roared through the intersection of runway 10/28 and runway 04/22. Braking was insufficient to stop the airplane from running through the runway 10/28 threshold lights. The airplane tore up a bunch of lights and screeched to a stop with its nose wheel dug into the grass and the main landing gear right at the paved edge.

Not according to plan; it could have been worse

Not according to plan; it could have been worse

No one was hurt, but no doubt there was much embarrassment in the cockpit.

The first officer later said he was confused about whether the red lights looming ahead were the stop bar lights for runway 04/22 or the threshold lights at the far end of runway 10/28.

The captain said he assumed the lights signified the stop bar for runway 04/22; not realizing the lights marked the threshold for runway 10/28, he tried unsuccessfully to brake before running out of pavement.

The air traffic controller had radioed “turn right end of runway Bravo one …” indicating the B737 was to exit runway 10 after crossing runway 04/22, as that exit was right at the end of runway 10 and past the intersection of the two runways.

The first officer had read back the clearance in inverted sequence, indicating the intersecting runway first and then the taxiway exit. The tower controller did not catch that the flight crew might have misinterpreted his instruction to turn off runway 10 at the B1 exit and then cross runway 04/22 on the way to the terminal.

Schematic of runways 10/28 and 04/22, with tire skid marks exceeding 500 ft as the crew tried to stop

Schematic of runways 10/28 and 04/22, with tire skid marks exceeding 500 ft
as the crew tried to stop

As the investigation report theorized, “It is highly probable that the Captain and the F/O did not have enough time to confirm with the Niigata Tower or discuss among them [sic] about the meaning of the instruction of ‘cross runway 04/22′ at this point.” However, the crew had been cleared to use the entire length of runway 10 before landing. In telling the crew that they were cleared to cross runway 04/22 after landing, the tower controller was being doubly assiduous.

There was no illuminated sign indicating the juncture of runways 10/28 and 04/22, nor was there a requirement to have such a sign in place.

The investigation report concluded that the tower instruction had been misinterpreted and that the flight crew was short of the intersecting runway during the landing roll out, at too high a speed to stop before the end of pavement.

For Niigata airport, procedures were subsequently changed to have the tower controller radio “Affirm” upon receipt of a correct read back. For example:

            Upon vacating runway 10

            Controller: (Call Sign), turn right end of runway Bravo One (B1).

            Pilot: (Call Sign), roger, turn right end of runway Bravo One (B1).

            Controller: (Call Sign), affirm.

KAL changed its procedures. Among them, “The aircraft must be decelerated to an appropriate safe taxi speed (maximum 30 kt) before 1,000 ft from the planned runway exit point.”

A few observations are in order.

The wrong comforting assumption or a moment’s unvoiced doubt can have dire consequences.

Intersecting runways are common to many airports. An illuminated sign marking the intersection should be required.

The controller’s confirmation of “Affirm” (or not affirmed) should be the standard procedure at ALL airports worldwide, not just at Niigata.

Decelerating to a minimum safe speed 1,000 feet from the planned runway exit point should, likewise, be a prudent procedure at all airports around the globe.

Here are three latent hazards that combined to produce an overrun (the JTSB report has more). There is no indication that they will be shared among airports or airlines for their universal applicability.

One fears that each airport and each airline must experience similar events to correct after the fact.

Neither the airline industry nor government regulatory bodies take a pro-active approach — that is, before incidents or accidents occur — to safety.