By Simon Hradecky, created Wednesday, Mar 16th 2016 14:20Z, last updated Thursday, Mar 29th 2018 16:01Z A KLM Cityhopper Embraer ERJ-190, registration PH-EXB performing flight KL-1986 from Basel/Mulhouse (Switzerland/France) to Amsterdam (Netherlands), was taxiing for intersection departure from taxiway D and was instructed to "hold short of runway 33 DELTA", the crew read back "Line up and wait runway 33 DELTA".



A Skyworks Dornier Do-328, registration HB-AEO performing flight SX-521 from Basel/Mulhouse (Switzerland/France) to Bern (Switzerland), was cleared to line up runway 15 from taxiway G and subsequently cleared for takeoff from runway 15, when the Embraer went past the hold short line runway 33 and lined up runway 33. The Dornier rotated and climbed out over the Embraer.



The French BEA reported on Mar 16th 2016, that the occurrence was rated a serious incident (runway incursion) and is being investigated by the BEA.



The distance between taxiways G and D is 1350 meters/4430 feet.



On Mar 29th 2018 the BEA released their final report concluding the probable causes of the serious incident were:



The runway incursion resulted from an incorrect understanding of the ATC instruction by the crew of flight KLM1986 and the ATC not detecting the read-back error. A partial visual check by the crew, prior to entering the runway, and partial ATC surveillance did not prevent the incursion.



The following factors may have contributed to the event:



- an inaccurate perception of the crew regarding the runway in use;



- time pressure and distraction in the cockpit;



- use of a short taxiway to the runway which left little time for the crew to build an appropriate perception of the actual situation;



- simultaneous management by the ATC of a VFR flight and another IFR flight leaving from runway 33.



This serious incident highlights the weakness of safety barriers when they are based solely on:



- crew/ATC communication;

- vigilance of crews and ATCs.



The BEA reported that the Dornier at at 380 feet AGL when crossing over the Embraer about 14 seconds after the Embraer had entered runway 33. When ATC instructed the KLM to stop and hold position, the Dornier crew radoied: "We are airborne, we are airborne, don’t worry!" (time point 11 in the map by BEA below).



The BEA reported a trainee under supervision by an instructor was staffing the tower position at the aerodrome at the time of the occurrence. Traffic volume was rather low.



The BEA corrected their initial (French) report stating the last clearance to the KLM had been "line up runway 33 up after the departing Dornier 328", which was met by the read back "line up for takeoff" - the English version of that preliminary information had read: "Air traffic control asked the pilot of the Embraer 190 to hold short of runway 33. The pilot read back: 'lineup and wait'".



The instructor reported that just prior to the incursion the Dornier had called prompting him to visually locate the aircraft. When he turned his eyes back he noticed the trainee had already detected the incursion and was instructing the Embraer to stop.



The BEA summarized the trainee's most relevant testimony: "After asking the crew of flight KLM1986 (which he could also see) to hold short of runway 33 DELTA, he turned to the right. He did not remember the reason why he looked away from the runway. It was either to see the VFR aircraft calling at point NE or to coordinate with the tower cab coordinator. He specified that he noticed the runway incursion when he looked back to the runway and the "DELTA area”. He then asked the aircraft to stop."



The Dornier crew reported they became aware of the Embraer when they were close to V1/Vr and estimated the distance to the Embraer at 300 meters. They rotated normally and believed there were at least 10 meters between the aircraft. The BEA wrote: "The crew stated that at no moment had they considered aborting the take-off because it seemed to them that the collision would have been inevitable if they had done so."



The BEA summarized the testimonary of the KLM crew:



Neither of the two crew members accurately recalled the sequence of the event, the clearance provided by the LOC ATC or their read back, but explained that they were both convinced at that time that they had received authorisation to line up on runway 33.



The captain stated that he looked towards the threshold of runway 33 to ensure that there were no aircraft on take-off or on short final and then entered the runway. He stated that he did not look to the right as he did not consider it necessary because, according to him, only runway 33 was in use at that particular time.



The BEA analysed the phraseology in use:



At the time of the serious incident, the radio-telephony procedures for the use of general air traffic, in force in France, were different to those recommended by ICAO in terms of the vocabulary used for the hold short clearances. France had notified ICAO of this difference:



ICAO recommends the following phraseology:

 “KLM1986 hold short of holding point DELTA runway 33."



France uses the following phraseology:

 “KLM1986 maintain holding point DELTA runway 33."



The DEL/GND ATC clearance was “KLM1986 maintain 33 DELTA, contact tower 118.3 bye bye."



The hold short clearances given by the LOC ATC were in accordance with those defined in the ICAO texts.



The BEA analysed the situational awareness of the Air Traffic Controllers (trainee and instructor):



In response to the ATC clearance, "KLM1986 bonjour, hold short of runway 33 DELTA," the crew of flight KLM1986 read back, "Line up and wait runway 33 DELTA.”



The LOC ATCs (trainee and instructor) did not detect that the crew had not understood its hold short of holding point clearance and therefore did not correct the crew read-back.



This could have been perceived by the crew as an implicit confirmation to line up on runway 15/33.



The studies cited above mention that listening to the read-back can be affected by an expectancy bias. Thus the ATCs may have perceived only a "correct" part of the read-back ("one one eight decimal three", "runway 33 DELTA") and concluded that the whole message was correct.



Three seconds after the read-back error on the LOC frequency, calls from a VFR pilot and a crew ready to take off on QFU 33 probably caught the attention of the LOC ATCs by bringing new information to be handled, to the detriment of the task of analysing the previous readback and the visual check of the aircraft during taxiing. The ATCs added that in fact they had then looked at the VFR and then the SRK51R then taxiing for take-off. They only detected the presence of KLM1986 when it was too late and had already entered the runway.



The erroneous understanding of the ATC's request, probably due to the crew’s inaccurate situational awareness (active runway, take-off order number) and failure to detect the readback error, led to the serious incident. The lack of a visual check of the two ends of the runway by the crew before entering the runway and the late visual detection by the ATCs did not prevent the runway incursion.



Metars:

LFSB 070900Z 13006KT 100V160 9999 FEW026 SCT110 04/M02 Q1004 NOSIG

LFSB 070830Z 13007KT 9999 FEW026 SCT110 04/M01 Q1004 NOSIG

LFSB 070800Z 15004KT 110V200 9999 SCT033 SCT110 03/M00 Q1004 NOSIG

LFSB 070730Z VRB02KT 9999 SCT033 SCT070 02/M00 Q1004 NOSIG

LFSB 070700Z VRB02KT 9999 SCT033 SCT070 00/M00 Q1004 NOSIG

LFSB 070630Z VRB02KT 9999 FEW033 SCT070 M01/M02 Q1004 NOSIG

LFSB 070600Z VRB02KT 9999 BKN030 SCT083 M00/M01 Q1004 NOSIG

LFSB 070530Z VRB02KT 9999 BKN030 SCT083 00/M01 Q1004 NOSIG

LFSB 070500Z 00000KT 9999 BKN030 BKN083 00/M01 Q1004 NOSIG

LFSB 070430Z 06003KT 010V100 9999 BKN028 OVC080 01/M01 Q1004 NOSIG

LFSB 070400Z VRB02KT 9999 FEW028 BKN030 OVC056 01/M01 Q1004 NOSIG

LFSB 070330Z 06003KT 9999 BKN028 BKN033 OVC056 01/M01 Q1004 NOSIG



Map and Trajectories (Graphics: BEA):





Aerodrome Chart (Graphics: BEA):








The Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile completes its probe into the March 2016 near-miss between two commercial aircraft at Basel/Mulhouse Airport, concluding miscommunication between an air crew and air traffic control was to blame. One aircraft took off over the top of the other one.