Iberia A321 and Jet2 B752 at Tenerife on Nov 12th 2011, loss of separation on runway

Last Update: August 26, 2013 / 13:18:48 GMT/Zulu time

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Photo of Iberia EC-JMR, Airbus A321 — Iberia EC-JMR, Airbus A321 (Photo credit: Andy_Mitchell_UK / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Nov 12, 2011

Classification
Report

Airline
Iberia

Flight number
IB-3415

Departure
Paris Orly, France

Destination
Tenerife Sur Sofia Reina, Spain

Aircraft Registration
EC-JMR

Aircraft Type
Airbus A321

ICAO Type Designator
A321

An Iberia Airbus A321-200, registration EC-JMR performing flight IB-3415 from Paris Orly (France) to Tenerife Sur Sofia Reina,CI (Spain) with 153 passengers and 6 crew, was cleared to land and on a final ILS approach to Tenerife South Airport's runway 08 about 6nm before touchdown at about 232 knots over ground.

A Jet2.com Boeing 757-200, registration G-LSAI performing flight LS-518 from Tenerife Sur Reina Sofia,CI (Spain) to Newcastle,EN (UK) with 208 passengers and 7 crew, was taxiing for departure about 300 meters short of the hold short line of runway 08, when tower cleared the aircraft for immediate takeoff. The aircraft continued taxi without any stop at about 20 knots and conducted a rolling takeoff from runway 08.

The arriving Airbus A321-200 however touched down on the runway before the wheels of the departing Boeing left the runway. The Airbus A321-200 rolled out normally, the Boeing 757-200 continued their flight normally for a safe landing in Newcastle.

Spain's CIAIAC released their final report concluding the probable cause of the incident was:

The incident was caused by the improper handling of the immediate takeoff clearance by ATC. The distance between the aircraft cleared to take off and the runway threshold on the one hand, and ATCâ€™s failure to adjust the speed of the incoming aircraft on the other, resulted in a reduction in the separation such that aircraft IBE3415 touched down on the runway just as aircraft EXS518 became airborne.

The CIAIAC reported that the minimum distance between the aircraft reduced to 1250 meters at touch down of the A321 while the B752 just rotated for takeoff and became airborne. Regulations require that the landing aircraft must not cross the runway threshold before the preceding departing aircraft has either crossed the runway end or has turned away from the runway or the preceding arrival has crossed the hold short line vacating the runway.

The crew of the Boeing 757-200 had computed a Vr of 143 knots, the report did not provide any Vapp for the arriving Airbus A321 only stating a generic Vapp range between 125 and 155 knots.

After receiving the takeoff clearance about 300 meters short of the hold short line runway 08 the crew continued taxi at about 20 knots, crossed the hold short line without any stop, the arriving aircraft was about 3.8nm from touchdown at that point slowing through 210 knots over ground. Another 25 seconds later the Boeing crossed the runway edge and began line up on the runway without any stop, the Airbus was about 2.4nm from touchdown slowing through 180 knots over ground.

The Boeing 757 commenced a rolling takeoff and conducted a steady acceleration rotating at about 145 knots about 1350 meters down the runway, at the same time the Airbus A321-200 touched down about 1250 meters behind the Boeing.

The CIAIAC stated that the Boeing crew did not notice anything unusual, they were aware and had been advised about the arriving traffic that did not look too close to commence the takeoff.

The Airbus crew was also aware of the departing traffic and were considering a go-around, but given the excellent visibility conditions and the Boeing 757 far into the takeoff run they decided to continue the landing. They did not need to deviate from normal procedures.

The controller provided testimony that there were no guidelines as to what distance an arriving aircraft should be from touchdown for an immediate takeoff clearance, immediate takeoffs were usually given up to about 5nm on final approach. The arriving aircraft was noticeably faster on final approach than others, the controller perceived the movements of the Boeing slower than usual. While the Boeing continued taxiing he became doubtful of the suitability of the immediate takeoff clearance, but he could not assess whether the Boeing had already crossed the hold short line and thus chose to not ammend the takeoff clearance.

The CIAIAC analysed that the controller cleared the Boeing for immediate takeoff when the aircraft was still a considerable distance from crossing the hold short line without recognizing this fact. The Boeing needed 35 seconds until reaching the hold short line, during which the Airbus had passed 2nm.

The CIAIAC analysed: "The approach speed is a key parameter when designing instrument approach procedures. That is why aircraft are classified into several groups depending on their reference speed above the threshold. The A321 belongs to an intermediate group. As such, when considering its flight characteristics, its approach speed is not expected to deviate significantly from the average value typical of medium-range transport airplanes.

In addition to considerations regarding the aircraft type, airline policies translate into different ways of conducting the approach and of configuring the aircraft for landing, and thus into different approach speed profiles. Specifically, airlines typically resort to the so-called decelerated approaches as part of their fuel savings policies. Such approaches translate into shorter times to the threshold as compared to conventional approaches. This is the case with Iberia, which not only considers them in its Operations Manual, but recommends their use â€œwhenever possibleâ€. In this regard, and as stated by the crew, it is also common not to fully extend the flaps as part of the landing configuration.

In order to control the separation between approaching aircraft, controllers have the possibility of imposing speed adjustments on them, though with certain limitations.

In this particular incident, the speeds (IAS) recorded for IBE3415 while on final approach reveal values that were considerably higher than expected, even for a decelerated approach profile. Since apparently the tower controller was aware of this circumstance, which could affect the separation with the departing airplane, an action by ATC to limit the speed of the incoming aircraft would have been justified in this case."

The CIAIAC concluded analysis stating that when the Iberia crew recognized the gravity of the situation, they considered a go around but assessed they had the Boeing in sight, the speed of the Boeing was already high enough to render a rejected takeoff dangerous and a go-around with both aircraft airborne and in close vicinity undesireable, hence they continued the landing.