Tunisair A320 at Paris on Mar 12th 2013, runway excursion

Last Update: September 24, 2014 / 13:20:06 GMT/Zulu time

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Photo of Tunisair TS-IMC, Airbus A320 — Tunisair TS-IMC, Airbus A320 (Photo credit: Tab59 / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Mar 12, 2013

Classification
Incident

Cause
Runway excursion

Airline
Tunisair

Flight number
TU-634

Departure
Djerba, Tunisia

Destination
Paris Orly, France

Aircraft Registration
TS-IMC

Aircraft Type
Airbus A320

ICAO Type Designator
A320

A Tunisair Airbus A320-200, registration TS-IMC performing flight TU-634 from Djerba (Tunisia) to Paris Orly (France) with 140 people on board, landed on Orly's runway 08 at 11:15L (10:15Z) and slowed, but veered off the runway while attempting to turn off the runway and came to a stop with the nose gear on soft ground. The passengers disembarked via stairs onto the runway about one hour later.

The runway was temporarily closed.

The BEA is investigating.

On Sep 9th 2014 the BEA released their final report in French (English version released on Sep 24th 2014) concluding the probable causes of the incident were:

The inability to measure the runway friction (slipperiness) in real time did not permit the detection of the inhomogenous runway contamination. This led to the degraded perceiption of braking action at the runway end and the overrun.

The non-implementation of the "loss of braking" procedure may have contributed to the occurrence.

The BEA reported that there was continuous snowfall, the snow depth reached 8cm (3.1 inches). There were winds from 020 degrees at 6 knots, the crew had been aware of wet snow on the runway.

ATIS reported that runway 08 was active, there was dry snow on the runway, the only available exits from runway 08 were either runway 02/20 or taxiway W31 at the end of runway 08. On approach air traffic control reported the runway braking action as medium, but about 20 minutes later needed to downgrade now reporting the braking action as "medium to poor". Before handing the crew off to tower the controller reported the runway was covered with wet snow. On each of those reports the crew computed their required landing distances and verified the landing distance available was sufficient. Tower reported the winds from 040 degrees at 8 knots, the previous crew had reported the braking action as medium, then states braking action being "medium to poor". The crew briefly discussed the risk of an overrun, configured the aircraft for landing (Vref=137 KIAS) with autobrakes set to "medium". The aircraft touched down at 136 KIAS, the thrust reversers deploy and the aircraft experiences stable deceleration of about 0.3G, the captain intends to vacate the runway via runway 02/20. At a speed over ground of 69 knots the autobrakes get disengaged by brake pedal application, the thrust reversers get stowed, while decelerating through 42 knots over ground tower instructs the crew to vacate the runway via W31 at the end of the runway. A slight increase of N1 on the engines is recorded on the flight data recorder and the speed over ground stabilizes at 60 knots. About 480 meters before the end of the track the crew begins to apply brakes again but achieves only 0.12G of deceleration. Additional brakes pressure does not increase the deceleration. The captain applies the park brakes but the deceleration is still 0.12G. The aircraft passes the runway end at 17 knots over ground and stops 4 seconds later. The captain radioed tower of the overrun stating the braking action was poor (later stating braking action was "very, very poor"). 45 minutes later stairs arrived at the left rear door and the passengers disembarked.

No safety recommendation was released as result of the investigation.

Related NOTAMs:
A1312/13 (Issued for LFPO PART 1 OF 2) - DUE TO ANTICIPATED ADVERSE WEATHER, SPECIFIC MEASURES ARE REQUESTED FROM AIRCRAFT OPERATORS SERVING PARIS-ORLY AND PARIS-CDG AIRPORTS :
1-AIRCRAFT OPERATORS ARE REQUESTED TO REDUCE THEIR SCHEDULED FLIGHTS BY 20 PER CENT ON PARIS-ORLY AIRPORT ON TUESDAY MARCH 12TH 2013 FROM 0800 UTC IF OPERATING MORE THAN 10 MVTS ARE SCHEDULED FROM 0800UTC.
2-PARIS-ORLY NOT AVAILABLE FOR DIVERSIONS WITH THE EXCEPTION OF EMERGENCY TRAFFIC
3-AIRCRAFT OPERATORS ARE REQUESTED TO REDUCE THEIR SCHEDULED FLIGHTS BY 25 PER CENT ON ROISSY-CDG AIRPORT ON TUESDAY MARCH 12TH 2013 FROM 0500 TILL 1100 UTC IF OPERATING MORE THAN 8 MVTS ARE SCHEDULED FROM 0500 TO 1100 UTC.
END PART 1 OF 2. 12 MAR 00:00 2013 UNTIL 12 MAR 23:59 2013. CREATED: 11 MAR 17:52 2013

A1312/13 (Issued for LFPO PART 2 OF 2) -
4-EXPECT EXTRA FUEL AND WAITING CIRCUIT POSSIBLE OF 45MIN.
5- PARIS-CDG NOT AVAILABLE FOR DIVERSIONS WITH THE EXCEPTION OF
EMERGENCY TRAFFIC
6-HEL LANDING AREA OF PARIS-CDG CLOSED
7-AIRCFRAT OPERATORS SHALL SEND REMAINING PROGRAM AND CANCELLED
FLIGHTS BEFORE MONDAY MARCH 11TH 1900 UTC TO DGAC/DTA BY MAIL TO :
PROGRAMMES-COMPAGNIES.DTA(AT)AVIATION-CIVILE.GOUV.FR.
8-FLIGHT PLANS EXCEEDING THOSE LIMITATIONS MAY BE REJECTED.
9-AIRCRAFT OPERATORS MUST SYSTEMATICALLY CANCEL ALL FPL
FOR THE FLIGHTS NOT PERFORMED.
10-A RENEWED ATTENTION IS REMINDED TO AIRCRAFT OPERATORS OF THE
NECESSITY TO RESPECT ENVIRONMENTAL MEASURES AT THOSE AIRPORTS
CURFEW AND AIRPORTS SLOTS RESTRICTIONS
END PART 2 OF 2. 12 MAR 00:00 2013 UNTIL 12 MAR 23:59 2013. CREATED: 11 MAR 17:52 2013

Metars:
LFPO 121200Z 02007KT 3000 -SN BR BKN010 OVC014 M02/M02 Q0999 R06/2///79 R08/2///33 R02/2///43 TEMPO 1200 SN OVC007
LFPO 121130Z 01008KT 3000 BR BKN008 OVC013 M02/M02 Q0998 R08/2///33 R02/2///43 TEMPO 1200 SN OVC007
LFPO 121100Z 02006KT 3000 -SN BKN008 OVC012 M02/M02 Q0998 R08/2///33 R02/2///43 TEMPO 1200 SN OVC007
LFPO 121030Z 03010KT 2000 -SN BKN007 OVC012 M02/M03 Q0997 R08/2///33 R02/2///43 TEMPO 0800 SN OVC002
LFPO 121000Z 02007KT 0800 R02/1000V1800D R26/2000D R08/0900V1500N R24/1000V2000D R06/0900VP2000U -SN OVC007 M02/M03 Q0997 R08/2///33 R02/2///43 TEMPO 0800 SN OVC002
LFPO 120930Z 02008KT 0800 R02/1200N R26/1000VP2000U R08/1100V1700N R24/0900VP2000N R06/1100VP2000U SN FG OVC007 M03/M03 Q0997 R08/2///46 R02/2///43 TEMPO 0800 SN OVC002
LFPO 120900Z 02008KT 1100 R02/1400VP2000D R26/P2000 R08/1000VP2000D R24/1700D R06/1500U -SN BR OVC008 M03/M03 Q0996 R08/2///46 R02/2///43 TEMPO 0800 SN OVC002
LFPO 120830Z 02009KT 1100 R02/1800D R26/P2000 R08/1700N R24/1800D R06/1700D -SN BR OVC008 M03/M03 Q0996 R08/2//46 R02/2//43 TEMPO 0800 SN OVC002
LFPO 120800Z 02008KT 1500 SN BR OVC008 M03/M03 Q0995 R08/2//46 R02/2//43 TEMPO 0800 SN OVC002
LFPO 120730Z 02010KT 1500 -SN BR OVC008 M03/M03 Q0995 R08/2//46 R02/2//43 TEMPO 0800 SN OVC002
LFPO 120700Z 02010KT 2000 -SN BR OVC008 M02/M03 Q0994 R06/2///64 R08/2///45 NOSIG
LFPO 120630Z 02010KT 3500 -RASN BR OVC008 M02/M03 Q0994 R06/2///64 R08/2///45 NOSIG
LFPO 120600Z 02010KT 3500 -RASN BR OVC008 M02/M03 Q0993 R06/2///64 R08/2///45 NOSIG