Description

On 25 February 2010, a Bombardier CRJ200 being operated by Air Nostrum on a domestic passenger flight from Bilbao to Vigo carried out an Instrument Landing System (ILS) approach to runway 20 in day Visual Meteorological Conditions (VMC) which culminated in a non standard touchdown during which one wing touched the runway. The ground contact and consequential minor damage was not appreciated at the time and was found during a subsequent ground inspection. None of the 23 occupants were injured.

Investigation

An Investigation was carried out by the Spanish CIAIAC. The accident was only reported to the NAA as an occurrence and the CIAIAC only learned of it upon subsequent sight of the weekly list of occurrences complied by the NAA. The Cockpit Voice Recorder (CVR) record had not been preserved but Flight Data Recorder (FDR) data was available.

It was noted that both pilots were experienced on type and established that the First Officer had been designated as PF for the approach and landing.

The METAR-reported wind velocity at the time of the approach was a mean of 240° varying between 220° and 290° at a mean speed of 22 knots with a maximum gust of 33 knots and advice that there was wind shear along the whole length if the 2500m runway. It was established during the Investigation that the crosswind component from the right had remained within AFM limits throughout the landing.

FDR data showed that the whole of the last 1500ft of the approach had been made at a consistently excessive rate of descent of up to almost double that permitted under the mandatory stabilised approach criterion for descent rate given in Air Nostrum’s Operations Manual.

The crew reported that the aircraft had deviated above the ILS GS and to the left of the ILS LLZ after the PF disconnected the AP at 6nm from the runway but claimed that the aircraft had been back on track and profile by 4nm. However, FDR data showed that the ILS LLZ tracking had also been outside the Air Nostrum stabilised approach criterion for that parameter.

FDR data further showed that an Terrain Avoidance and Warning System (TAWS) Mode 5 Alert had activated from 137 ft agl and that the subsequent initial runway contact had been made by the nose landing gear rather than the main landing gear and been followed by a low but sustained bounce during which a left wing drop to 8° and then a reversal after flight crew input to a 12° right wing drop had occurred. The latter had led to the ground contact and had occurred after both pilots had made simultaneous aileron control inputs to the right. There was other evidence that the aircraft commander had made control inputs whilst the First Officer remained as the designated PF.

The Investigation concluded in respect of Cause that:

“the root cause of this accident is considered to be the brusque actions taken by both crew members to roll the airplane to the right in an effort to counteract a wind-induced roll to the left”

It was further concluded that a Contributing Factor was:

“the fact that a non-stabilised approach was made instead of deciding to go around, as specified in the procedure”

Since it had been “verified” during the course of the Investigation that Air Nostrum has (now) implemented a flight data monitoring system "which allows identifying, studying and proposing corrective actions to, among other, the destabilised approaches” the issuing of a Safety Recommendation in that regard was considered unnecessary.

The Final Report: Report IN-004/2010 was approved on 26 January 2011.

Further Reading

• Loss of Control
• Cross Wind Landings
• Tailwind Operations
• Pilot Perception
• Prioritisation for Pilots