Description

On 6 August 2012 an Embraer Phenom 300 (CN-MBR) being operated by a Moroccan company Dalia Air on a commercial flight from Geneva to St. Gallen-Altenrhein under callsign DLI 211 overran the landing runway 10 after touching down from its second approach at destination in day Visual Meteorological Conditions (VMC) following a very low go around from the first one due to being too fast. It overran the runway and after passing through the aerodrome perimeter fence narrowly avoided a collision with a bus travelling on the public road beyond before coming to a stop in a field containing a tall crop. The aircraft was badly damaged but the sole passenger and the two pilots were not injured and were able to leave the aircraft unaided.

Investigation

An Investigation was carried out by the Swiss AIB. Recorded data relevant to the Investigation was recovered from the Flight Data Recorder (FDR) and the CVDR (Cockpit Voice and Data Recorder). It was noted that although ATC communication took place in English, inter pilot conversation took place mainly in Arabic and French although some English was used. Appropriate translation assistance was accordingly obtained.

The aircraft was found "badly damaged" during the overrun. The right main landing gear had collapsed and pierced the wing surface, causing significant damage to the wing. The fuel tank was also damaged and fuel had leaked from it. The lower fuselage and right wing, including the fuselage-wing fillet was "severely damaged".

The 1500 metre long runway at St. Gallen-Altenrhein was found to have a displaced threshold so that the LDA was 1400 metres. In addition, approximately 60 metres of hard surface was available at both ends. The Runway End Safety Area of at least 90 metres as prescribed by ICAO for aerodromes with reference code number 3 (applicable to St. Gallen-Altenrhein) is not available. It was noted that the ILS GS for the runway 10 approach being flown was 4° which exceeds the maximum ICAO standard of 3.5° but , the published approach is not categorised because the runway does not meet the requirements for instrument approaches.

It was established that the aircraft commander, who was also the Dalia Air Deputy Director of Flight Operations, had been the PF and although an experienced pilot had only 75 hours on the aircraft type. The First Officer, who was also the Dalia Air Quality and Flight Safety Manager, was also an experienced (ex-military transport) pilot but had only 465 hours on type.

The weather conditions for both approaches to runway 10 (the alternative being a break from the 10 ILS to circle visually for runway 28) were assessed by the Investigation to have been "challenging". There was a significant tailwind component and until just before landing off the second approach, significant heavy rain associated with the passage of a cold front which had reduced visibility. However, it was nevertheless considered that "these conditions allowed a direct approach on runway 10 or a circling approach to runway 28".

It was found that during the first of the two Instrument Landing System (ILS)/Distance Measuring Equipment (DME) approaches which the crew had elected to make to runway 10 at destination (applicable DA / DH 1806 feet / 500 feet), the PF had called successively for Flaps 1, Flaps 2 and Full Flaps which had been selected and confirmed accordingly. However, recorded data showed that shortly before the aircraft reached 500 feet agl and between two and three seconds after selection to 'FULL', the selection had been changed to Flaps 3. This action led to a 'SPDBRK SW DISAG' annunciation followed shortly afterwards by an audio warning accompanied by 'FLAP FAIL'. The AP was disconnected at 500 feet and at 400 feet agl, the PM noted (in French) that "we have no flaps…almost" which appeared to take the PF by surprise. The approach continued and at 300 feet agl, the airspeed was 154KIAS and the rate of descent on excess of 1000 fpm. In response to the automatic 200 feet agl call, the PF said (in French) "I see nothing" which was followed immediately by the PM saying (in French) "there's the runway". The PF subsequently remarked (in French) " [deleted], now it's impossible to see anything" and soon afterwards called and commenced a go around. ATC were advised and confirmed a standard missed approach. Thrust was set and the flap lever selection sequenced but the retraction of the landing gear was not called and it remained extended. As the aircraft speed exceeded 180 KIAS in the climb, the 'HIGH SPEED' warning sounded due to the flap position not being fully up.

Radar vectoring to a second ILS approach to runway 10 followed with the 'FLAP FAULT' annunciation remaining and an approach with flaps jammed at around the Flap 1 position accepted and a Reference Speed (Vref) of 130 KIAS bugged based on the Flaps 3 Vref of 112 KIAS used for the first approach. The ILS LOC was captured when still above the GS. Speed control thereafter was made more difficult by interruption to commanded speedbrake deployment associated with a recurrence of the 'SPDBRK SW DISAG' annunciation which had begun following the flaps jamming after the brief attempt to select them to the 'FULL' position during the first approach.

At 2330 feet QNH (equivalent to approximately 1000 feet aal) the airspeed was 162 KIAS and the rate of descent approximately 2000 fpm. An Terrain Avoidance and Warning System (TAWS) 'TERRAIN' Alert sounded followed four seconds later by a 'PULL UP' Warning. No significant response followed but by the 400 feet agl auto callout, the airspeed was 153 KIAS and the rate of descent approximately1000 fpm - prompting the PF to say (in French) "….stabilised at the normal approach speed". A few seconds later an EGPWS 'TOO LOW TERRAIN' Alert was annunciated followed by 'TOO LOW FLAPS' and 'GLIDESLOPE' once below 200 feet agl. Touchdown with both MLG recording weight on wheels occurred at 135 KIAS approximately 450 metres after the runway threshold.

After a 17 second landing roll, the aircraft reached the end of the runway at 44 KIAS and continued across the stopway deviating to the left before breaking through the perimeter fence at 39 KIAS and rolling across a public road into a maize field and coming to a stop after a further 10 metres. The assembled evidence indicated that at the time of touchdown, heavy rain had just ceased and water patches were visible on the runway surface. The crew reported that braking action had initially been normal but that brake application and directional control had then become impossible as the end of the runway was approached. However, FDR data showed that maximum brake pressure had not been applied until "shortly before reaching the runway end and 14 seconds after the weight on wheel signal had confirmed that the aircraft (was) on (the) ground".

In respect of the aircraft crossing a public road during the overrun, the Investigation noted that only "a few seconds previously, a….public service bus licensed to carry 90 persons had travelled along the same road from south to north". The bus driver had later stated that he "had glimpsed an aircraft on his left, approaching the end of the runway at high speed" and had "recognised this as a hazard and therefore applied the accelerator pedal".

In respect of the required landing distance and appropriate Vref at the prevailing ELW for both the expected normal approach onto a wet (although mainly grooved) runway and the actual almost flapless approaches to it, the Manufacturer's Pilots Operating Handbook (POH) carried on board provided a means to calculate both. The Investigation found the range 1438 - 1668 (factored) metres depending on the tailwind component for the intended (i.e.'normal') flap 3 approach flown at 113 KIAS and the range 1142 - 1318 (unfactored) metres for the abnormal case actually flown at 130 KIAS. The data source was conditional on a 3° approach at Vref in landing configuration, crossing the threshold at a height of 50 feet at idle thrust and maximum brake applied immediately after MLG touchdown.

In respect of the flap jam which had occurred during the initial approach, it was established that the 'FULL' position is not certified for use. The effect of this selection had therefore been an invalid signal to the flap control unit which resulted in the flaps becoming jammed at approximately 10° and the FLAP FAIL annunciation being displayed. It was found that a mechanical stop that had been installed at the time of the aircraft delivery and was intended to prevent the use of the 'FULL' position was missing.

The overall view of the Investigation was that there had been a widespread failure of the crew to follow SOPs and it was also considered that "analysis of the CVDR recordings does not in any way indicate cooperation in accordance with CRM principles as contained in the Operations Manual." It was further considered that the fact that the First Officer "was also the operator's Quality and Flight Safety Manager and…..was thus responsible for practical compliance with the procedures laid out and defined in the Operations Manuals" made the crew performance "even more incomprehensible". It was also considered that "the presentation of the published procedures and tables (in the QRH) did not offer pilots optimal assistance".

The formal statement as the Causes of the Accident was as follows:

"The accident is attributable to the fact that the aircraft touched down late and at an excessively high speed on the wet runway after an unstabilised final approach and consequently rolled over the end of the runway."

The following Contributory Factors were also identified:

• The insufficient teamwork and deficient situation analysis by the crew.

• The flaps remained jammed at approximately 10 degrees, a position that is almost consistent with the flaps 1 position.

• Late initiation of full brake application after landing.

Safety Action taken as a result of the event was noted to have included arrangements by Dalia Air for improved pilot training, including Crew Resource Management and corrective revisions by Embraer to the aircraft type QRH and AMM as well as certification of the FULL FLAP position on all Phenom 300 aircraft.

Two Safety Recommendations were made as a result of the Investigation. One, as follows, was made in the Interim Report issued on 31 January 2013:

• that The Federal Office of Civil Aviation (FOCA) should ensure that on all Swiss aerodromes, a hazard identification which includes the endangerment of third parties, at least in the immediate vicinity of the aerodrome, is determined and that appropriate measures will be taken to minimise it. [Safety Recommendation 461]

The second, as follows, was made at the conclusion of the Investigation:

• that The European Aviation Safety Agency (European Aviation Safety Agency (EASA)) together with the Aircraft Manufacturer should examine how the manuals can be amended so as to provide optimal assistance to pilots in abnormal situations. [Safety Recommendation 482]

In respect of Recommendation 461, the Investigation noted that the FOCA had subsequently advised that a process for hazard identification at licensed aerodromes already existed under the obligation to have an SMS and that a similar requirement to undertake systematic hazard identification at unlicensed aerodromes would be disproportionate. It had therefore concluded that the Recommendation was "not necessary….or it has already been implemented".

The Final Report was completed on 23 September 2014 and approved for publication by the Swiss AIB on 6 November 2014.

Further reading

• Stabilised Approach
• Flying Stabilized Approaches, by Airbus
• Quick Reference Handbook
• Emergency and Abnormal Checklist
• SMS in Aerodrome Operation
• Australian CAA: SMS for Aerodromes
• Crew Resource Management
• Certification by EASA
• Tailwind Operations
• Landing on Contaminated Runways