Narrative:SATA Internacional flight S4129 departed Lisbon Airport at 19:06 UTC bound for Ponta Delgada Airport, in the Azorean island of Sćo Miguel. There were 8 crew members and 117 passengers on board. The copilot was Pilot Flying.
After an uneventful flight of approximately two hours, the aircraft was established on ILS, for landing on runway 30 at Ponta Delgada Airport. Final approach was performed with both autopilots engaged in LAND mode and Auto Throttle engaged with SPEED mode selected. The aircraft was stabilized on glide slope and localizer, with an approach airspeed Vapp of 132 kts, for a Vref of 126 kts. Descending through 286ft (Radio Altimeter) the autopilots were disengaged. The aircraft was thereafter flown manually, assisted by the use of flight directors and autothrottle.
Below 20 feet at a slightly high descent rate there was a short flare followed by a light bounce with spoilers extended. The ensuing aircraft's natural aerodynamic tendency was an increase in the pitch attitude in conjunction with a pulling force exerted on the control column with a high pitch rate (3°/s) and increasing high pitch up attitude (up to 14.82°). This manoeuvre, most likely to avoid a hard nose wheel ground contact, made the tail strike the ground. By the time the main landing gear shock absorbers were fully compressed the aircrafts pitch angle had exceeded the ground/ tail clearance of 13.2°.
The aircraft was taxied to the apron and a maintenance preliminary check was performed. The aircraft had sustained serious damage to the underside of the rear fuselage, where the lower skin panels were abraded by contact with the runway surface. In some areas, the skin was buckled through its full thickness and some vertical struts bent the attachment area in the airframe structure.
Probable Cause:CAUSES OF THE ACCIDENT
Inadequate recovery handling of a bounced firm landing (deviation from recommended flying pilot technique).
The following were considered as contributing factors:
a) High sink rate prior to and during flare;
b) Aircraft firm landing followed by a light bounce;
c) Crew momentary unawareness of aircraft position (in the air) and intentional column pulling action, trying to smooth nose wheel contact with ground;
d) The presence of a tailwind component during the flare phase above recommended 10kts limits;
e) Aircraft's center of gravity at a slightly backward position but this factor is of marginal contribution only;
f) The decision to land on damp runway 30, with tailwind component marginal to the maximum permitted (10kts), instead of a circling to land to the actual runway (12) in use or the decision to discontinue the approach via a go-around procedure;
g) A bounce recovery at night (with less visual references) characterized by taking place very close to the ground (less than 20 feet) hence allowing for a very short reaction time from the PF and little control effectiveness of the aircraft (throttle retarded and normal configuration to land);
h) The existing take-off / landing certification standards, which were based on the attainment of the landing reference speeds, and flight crew training that was based on the monitoring of and response to those speeds, hindering crew to detect degraded landing speed and sink rate.
METAR Weather report:
20:30 UTC / 19:30 local time: LPPD 022030Z 15014KT 9999 -SHRA SCT016 14/12 Q0997
21:00 UTC / 20:00 local time: LPPD 022100Z 17013KT 9999 -SHRA SCT015 SCT030 13/12 Q0997
Official accident investigation report
|investigating agency: ||Gabinete de Prevenēćo e Investigaēćo de Acidentes com Aeronaves (GPIAA) - Portugal |
|report status: ||Final|
|report number: ||02/ACCID/2013|
|report released:||2 March 2015|
|duration of investigation: ||2 years |
|download report: ||
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from Lisboa-Portela de Sacavém Airport to Ponta Delgada-Joćo Paulo II Airport, Azores as the crow flies is 1439 km (899 miles).