Description

On 5 June 2007, a McDonnell Douglas MCDONNELL DOUGLAS MD-83 being flown by Austrian charter operator MAP on a domestic non-scheduled passenger flight from Lanzarote to Barcelona for Spanish Airline Air Plus Comet failed to follow a normal trajectory after take off in day Visual Meteorological Conditions (VMC) and developed violent roll oscillations. As speed increased, this stopped and a return to land was made without further event. None of the 146 occupants were injured and the aircraft was undamaged.

Investigation

An Investigation was carried out by the Spanish Accident Investigation Board, the CIAIAC. FDR and CVR data were available to aid reconstruction of the event and a full readout was made.

It was established that the takeoff from Lanzarote had been unintentionally made without the flaps/slats being set to the required position. FDR data showed that roll oscillations in both directions of up to 60° angle of bank had occurred and that with each one, the aircraft had lost altitude, in one case by as much as 140 feet. The oscillations had persisted for the first thirty seconds of the flight, beginning at a speed of 159 knots and continuing until the speed exceeded 200 knots. The aircraft manufacturer advised the Investigation that the stall speed for the aircraft at the prevailing takeoff weight with 0° trailing edge flaps and with the slats retracted would have been 161 knots but that the effect of the oscillations would have increased this figure to approximately 202 knots. Although it was noted that other factors such as the center of gravity and spoiler deflection do affect the stall speed, such subsidiary factors were assessed as of minor relevance to a situation as dynamic as the one that occurred.

The Investigation therefore concluded that the flight crew had lost control of the aircraft after rotation because it had stalled as a consequence of the unapproved configuration following the crew’s failure to comply with Standard Operating Procedures (SOPs) and specifically to properly use normal checklists.

The failure of the TOWS to activate during the take off was attributed to the fact that the circuit breaker for the Left Ground Control Relay, which controlled the left ground-air sensing system, had been tripped prior to the first flight of the day from Madrid to Lanzarote by maintenance personnel but not reset. The incident flight crew had then failed to check the CB panel concerned prior to their first flight. The effect of this was that the information being sent to the TOWS, as well as to all other systems reliant on the left ground-air sensing circuit, was that the aircraft was airborne, when the TOWS is inactive by design.

It was also established that the fact that various aircraft systems other than the TOWS had sensed that the aircraft was ‘in flight’ when it was on the ground had resulted in a number of abnormal indications during the earlier taxi out at Madrid. These had been ignored by the crew and it was noted that they had included an annunciation of a stall protection system fault which was identified by the Investigation as a ‘no go‘ item.

It was also established that the test which had been performed by the ground engineers involving the tripping of the left ground control relay c/b to check strobe light function was not in accordance with guidance provided by the aircraft manufacturer, being not part of the ‘Daily Check’ or the 3 day ‘Service Check’ which specified such a test only as part of a 1A Check at 450 hour intervals. However, such a test was apparently habitual during both these regular line engineering tasks for this operator’s fleet. Minor revisions to the manufacturer’s guidance subsequent to the incident were noted by the Investigation and considered to resolve any perceived ambiguity.

Overall, the aircraft was found to have been fully serviceable and the incident broadly attributable to the fact that “the discipline in the cockpit regarding the performance of operational procedures was deficient”.

The formal statement of causes of the Incident as determined by the Investigation was as follows:

“The crew lost control of the aircraft after the rotation due to the stall of the aircraft just after takeoff, because it was performed in a non approved configuration, that is with the slats retracted and 0° flaps. Thus was caused by a lack of discipline of the crew in complying with standard operating procedure and, specifically, with the checklists.

It also found that the following factors contributed to the incident:

• The shortage of training received by the crew once hired and which did not allow them to gain sufficient knowledge of company procedures; the irregularities that took place during the supervised training flights; and the poor oversight of the flight crew.
• The maintenance practices to check the strobe lights and which were performed due to ambiguity in the task cards issued by Boeing for doing the “Service Check”.
• Both maintenance and flight crews failed to follow written procedures (AMM and FCOM, respectively) since they didn’t reset the left ground control relay c/b prior to flight.
• The lack of cleanliness that made (it) more difficult to identify the c/b condition.
• The failure of the operator to determine why the left ground control relay circuit breaker tripped repeatedly.
• Improper supervision by Austrocontrol of the processes (for) the AOC and which resulted in the lack of compliance with OM and training requirements going unnoticed.

The Final Report of the Investigation was approved by the Comisión de Investigación de Accidentes e Incidentes de Aviación Civil (CIAIAC) on 28 October 2009 and included four Safety Recommendations as follows:

• That MAP more accurately define the tasks to be performed by each flight crew member with regard to flight procedures and checklists, the method for executing them and the phases of flight during which they must be executed, in keeping with the principles of CRM, such that they fulfill their function as a deterrent to mistakes. (REC 26/2009)
• That MAP review its training and supervisory programs for newly-hired crews so as to ensure that new crews receive adequately documented information and that their training leads to an in-depth knowledge of the company’s standard practices and to their proper execution. (REC 27/2009)
• That Austrocontrol verify compliance by charter company operators with EU OPS regulations, particularly in reference to obtaining and maintaining their AOCss with regard to training, especially during periods of heightened demand for flights, where there is an increase in the hiring of technical personnel. (REC 28/2009)
• That EASA evaluate the methods and procederes used by Austrocontrol to issue AOCs and to track the conditions in place at operators required to maintain the AOC. (REC 29/2009)

Further Reading

• Stall