On Tuesday January 2nd Japan Airlines (JAL) Airbus 350 landed on top of a Japan Coast Guard Dash-8 at Haneda Airport, Tokyo, killing all but the Captain on board the Coast Guard aircraft; everyone on the JAL Airbus survived. This accident seems to be a case of a hurried crew correctly understanding their instructions but then, inexplicably, not following those instructions.
In this case the First Officer (FO) on the Coast Guard aircraft was handling the radios and they were cleared to taxi to and hold short of the runway at intersection C5. The FO correctly read back that instruction. Yet, when the aircraft arrived at the C5 intersection holding point, the crew taxied the aircraft onto the runway and faced the plane down the runway in preparation for takeoff. So no doubt, as with almost all aviation accidents, the majority of the problem here lies with the crew. However, the reason that aviation is so safe is that there are a number of safeguards that are supposed to ensure that one (or even multiple errors) are caught and prevent an accident. In this case what could have prevented this accident?
First of all, and as I’ve already pointed out, the crew could have caught it. When they received the clearance the FO clearly understood they were cleared to a holding point. We should assume that the Captain also understood the clearance — he also heard it and he heard the readback. In the standard International Civil Aviation Organization (ICAO) clearances in English, the standard language of aviation, there is a very clear difference in the language for an aircraft to taxi to a hold point and the language used to instruct an aircraft to line up and wait on the runway for a takeoff clearance. However, these operations were being conducted in Japanese, as is customary when both the controller and the crew are using their native language. I have no idea if the Japanese language makes the same distinction in phraseology. But, by the time they arrived at the holding point, the crew had come to believe that they were cleared to enter the runway and wait there for takeoff clearance. The aircraft was being given priority, being sent to the C5 intersection and being told they were number one for take off while a number of other aircraft were sent to the end of the runway for their departure. Why they came to the belief that they were cleared to enter the runway is something the Cockpit Voice Recorder (CVR) may be able to tell us, but at the date of this article the CVR from the Dash-8 had not been recovered.
There is one more way the crew could have been alerted to their error, and that is if they had heard the JAL Airbus being cleared to land on the runway they were either on or about to enter. It’s not been clear to me from the transcripts that the Coast Guard crew was on the tower frequency when the landing clearance was issued.
What else could have prevented this accident? The Tower controllers could have spotted the Coast Guard plane entering the runway. Tower controllers are eyes up for the majority of the time. One of the reasons is to make sure that aircraft on the field are in the places they expected them to be in, so it’s very likely that the controller did check on the Coast Guard plane, but if they saw them taxiing in the right direction they may have just assumed it was all OK. It would be less likely that they would come back and verify the aircraft was at the holding point. This is all much harder at night. Controllers also routinely scan runways to ensure they are clear of aircraft, but again, this is much harder at night.
The Haneda airport is also reported to have some form of ground radar that can be used to show the position of aircraft on the field and should have shown that the Coast Guard aircraft was on the runway for what has been reported as in excess of 30 seconds. It’s also been reported that there is some kind of indicator light when there is a plane on a runway, but as with all lights, they only provide information if you look at them.
The Haneda airport also has lights, known as stop bars, that indicate if a pilot is cleared to enter a runway. There appears to be a Notice to Air Mission (NOTAM) indicating those lights were not operational, and even if they were, there is only a requirement to use them under low visibility conditions, although some airports will use them at other times. However, if those lights were working the Coast Guard pilots would not have crossed them regardless of the clearance they thought they had received. It’s also worth considering that if they didn’t know about the NOTAM, and often these things are hidden in reams of paperwork, and if they assumed the lights were working, then the lack of stop bars would have reinforced their belief that they were cleared to enter the runway.
The last avoidance option we’ll consider is that the arriving JAL aircraft could have seen the plane on the runway. That is very difficult to do, as the runway has a myriad of lights all over it, and the Coast Guard plane would have been lost in those lights. If they had been farther down the runway, out of the sea of touchdown zone lights, maybe they would have been spotted. I expect the investigating authorities will do some kind of re-creation of the view of the JAL pilots on final approach and we’ll get to see just how difficult it would have been for them to see the Coast Guard aircraft.
This is a tragic accident that could have been avoided, but then so can most aviation accidents. The difficulty is in finding all the ways that they could have been avoided, understanding why none of those ways worked as expected, and determining what improvements can be made so that they can be avoided in the future. Note that this accident is similar to an accident in Los Angeles in 1991 when a US Air flight landed on a Skywest Metroliner. So clearly not all the gaps have been closed between the time of this accident and this one at Haneda.
