Norwegian B733 at Amsterdam on Dec 18th 2010, took off over bird patrol vehicle

Last Update: January 30, 2013 / 21:38:26 GMT/Zulu time

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Photo of Norwegian Air Shuttle LN-KKZ, Boeing 737-300 — Norwegian Air Shuttle LN-KKZ, Boeing 737-300 (Photo credit: Deanster1983 / Flickr / License: CC by-nd)

Incident Facts

Date of incident
Dec 18, 2010

Classification
Report

Airline
Norwegian Air Shuttle

Flight number
DY-6347

Departure
Amsterdam, Netherlands

Destination
Copenhagen, Denmark

Aircraft Registration
LN-KKZ

Aircraft Type
Boeing 737-300

ICAO Type Designator
B733

A Norwegian Air Shuttle Boeing 737-300, registration LN-KKZ performing flight DY-6347 from Amsterdam (Netherlands) to Copenhagen (Denmark), had been cleared for takeoff from Amsterdam's runway 24. About 15 seconds after the aircraft became airborne and had overflown their vehicle at about 1000 feet AGL the crew of a bird patrol vehicle on the runway notified ground control they had just vacated the runway, at which point the runway incursion was recognized. The Boeing 737 continued the flight to Copenhagen for a safe landing.

Netherland's Onderzoeksraad (DSB - Dutch Safety Board) released their final report in Dutch concluding the probable causes of the serious incident were:

Direct causes:

the tower controller issued a takeoff clearance to the Boeing 737 after another aircraft had crossed the runway however overlooked a bird patrol vehicle, which had previously been cleared to enter the runway for bird scare duties. The overall situation awareness of the tower controller was reduced as he had no direct contact to all vehicles and aircraft around his runway, when he checked the runway visually he did not see the car near the runway end. The "runway occupied" strip does not distinguish whether one or more vehichles/aircraft are occupying the runway.

- the departing aircraft, crossing aircraft and vehicles operated on different frequencies

- the crossing traffic was not on tower frequency

- the term "active runway" is not unambiguously defined in the procedures

- the "runway occupied" markers do not provide an indication how many vehicles and/or aircraft are on the runway

- in the recommendations for air traffic control there is no procedure for the use of "runway occupied" strip and flight strips. As a result, these tools in combination with the electronic runway occupied panel are not optimally used. (Underlying cause of runway incursions)

Underlying causes of runway incursions

- at Schiphol Airport bird patrols (or tower controllers) must wait and make decisions between safety and runway capacity while conducting runway inspections.

- at Schiphol Airport not all traffic on the runways are on the relevant tower frequency deviating from recommendations by ICAO and EASA as well as from other major European Airports

- at Schiphol Airport bird patrols are expected to monitor a number of frequencies simultaneously while performing runway inspections. This is an unreasonable requirement. In addition, by having bird patrols wait an unbalanced relation with ATC arises, which may adversely affect communication

- the guidelines put in effect for bird partrol how often active runways should be checked are sufficiently clear

- the current tools for tower controllers, the electronic runway occupied indication as well as the runway occupied strip together with flight strips, reduce the risk of runway incursions, however not always

- Safety is one of the biggest concern of Netherland's air traffic control. On the aspect of preventing runway incursions with a bird patrol involved the risks are not adequately controlled however. This is in part the result of lack of cooperation between the two parties and little awareness of the risks. Although all parties to Dutch Aviation cooperate to ensure aviation safety, e.g. in the Schiphol Safety Platform, these activities are insufficient for all parties to take adequate management measures

- the separate investigation into the Dec 18th 2010 runway incursion by Air Traffic Control focussed only on the direct cause of the runway incursion but did not investigate underlying causes. The Schiphol Safety Platform also has no mandate for a thorough investigation of the underlying causes of runway incursions

- the safety management of both Schiphol Airport and Air Traffic Control have not yet led to a runway management that prevents runway incursions with bird patrols being involved or at least leads to a substantial reduction of such runway incursions

- there has been no assessment been undertaken to try vehicles and aircraft on the active tower frequency controlling the active runway, and there is no effort in developing procedures for runway inspections by bird patrol

- Only the Runway Incursion Alerting System Schiphol (RIASS) is available to warn about an active runway incursion, which means a safe guard against human error by the tower controller is effectively lacking

- Runway inspections are not included in the capacity planning by Air Traffic Control. The balance between safety and capacity in conducting runway inspections thus is purely in the hands of bird patrol and controller on duty

- the still limited cooperation between Schiphol Airport and Air Traffic Control in the fields of safety would require the involvement of Netherland's Ministry of Infrastructure and Environment to introduce a systematic and integral approach at Schiphol Airport to adequately address the risk of runway incursions

- Weaknesses in the cooperation of Schiphol Airport and Air Traffic Control have not prompted action by the Inspectorate of Environment and Transport to visibly reduce these shortcomings

- the shortcomings in the cooperation between Schiphol Airport and Air Traffic Control, although both organisations are required to cooperate by their certification, continue to exist despite the cooperation of both with the Schiphol Safety Platform.

- the possibilities of coordination offered by the Ministry of Infrastructure and Environment to ensure quality of cooperation are underused.

The crew of bird patrol vehicle KV2 contacted ground control, assistant 2, at 14:22Z to enter runway 24 for a bird patrol inspection of the runway and was cleared to enter the runway. The vehicle entered the runway at the threshold and drove down the runway at about 40kph.

A minute later a Boeing 747 taxiing from Sierra de-icing platform requested clearance to cross runway 24 at taxiway S2 on a second ground control frequency and was also cleared by air traffic assistant 2 to cross the runway. The tower controller notified the bird patrol vehicle of the crossing 747 using the assistant's microphone, while the assistant was on the phone to perform coordination. The bird patrol vehicle stopped on the runway short of intersection with S2 waiting for the 747 to cross the runway.

About 2 minutes after requesting to cross the runway the crew of the Boeing 747 reported clear of the runway on ground frequency, the bird patrol vehicle continued to drive down the runway.

About 45 seconds after the 747 had reported clear of the runway LN-KKZ reported on tower frequency ready for departure and was subsequently cleared for takeoff from runway 24. The aircraft began its takeoff run 80 seconds after the Boeing 747 had reported clear, at that time the bird patrol vehicle just crossed intersection S1 about 1680 meters down the runway and about 620 meters short of the runway end driving at about 80kph.

6 seconds after the takeoff run began, RIASS activated a runway incursion alert, the system however was active only in test mode, the alert therefore was not detectable by the tower controller. The aircraft had reached a speed of 44 knots at that time.

32 seconds after the takeoff run began the aircraft became airborne, at that time the vehicle was about 1700 meters further down the runway, and climbed out overflying the vehicle near the runway end at about 1000 feet AGL. 15 seconds later the bird patrol crew notified ground control they had vacated the runway at which time the assistant realised the runway incursion.

The DSB analysed that assistant 2 provided two clearances to enter the runway in coordination with the tower controller. First the bird patrol was cleared to enter runway 24 for a runway inspection, the runway occupied marker strip was placed and the electronic runway occupied signal activated. Second a Boeing 747 was cleared to cross the runway. After the Boeing 747 had vacated the runway again the strip marker and electronic indication "runway occupied" were cleared resulting in the tower controller issuing the takeoff clearance to the Boeing 737.

While the runway occupied markers that way provide a safe guard with one aircraft or vehicle cleared onto the runway, the lack of information of how many vehicles and/or aircraft had been cleared onto the runway does not protect against multiple crossing clearances or multiple vehicles on the runway or vehicles on the runway with crossing aircraft.

Eurocontrol recommends that for each traffic permitted onto the runway a separate strip marker "runway occupied" is to be placed. The DSB however annotated that there is no such recommendation for electronic runway occupied indications.

Bird patrol was listening to ground control frequency and Schiphol operations frequency. The vehicle was equipped with a transponder making the vehicle visible on Schiphol's ground radar, and carried strobe lights. However, ground radar was rarely referred to in good visibility as present at the time of the runway incursion. Neither assistant nor controller nor anybody else noticed the vehicle on the runway, despite the active strobe lights, when the takeoff clearance was issued.

The crew of the Boeing 737 did not see the bird patrol too, mainly attributed to the fact that the vehicle was driving in takeoff direction.

The DSB analysed that the situation awareness of tower was compromised when the bird patrol vehicle was not transferred onto the tower frequency before clearing the vehicle onto the runway.

The DSB analysed that situational awareness of tower was further compromised when the Boeing 747, other than prescribed by local procedures, were not transferred onto the tower frequency for crossing runway 24.

This created the undesireable and unfavourable scenario that two aircraft and one car were on the runway, each transmitting on and monitoring a different frequency. Had all three been on the same frequency, each of them could have recognized the pending conflict and could have responded to a possible error by the controller or a pilot. That way an additional safe guard is being established.

The moment LN-KKZ got airborne (Photo: DSB/NustyR Air Team ImagesÂ’ photo stream):

Excerpt Aerodrome Chart (Graphics: DSB):