A320, Cochin India, 2011
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Revision as of 13:36, 17 January 2020 by Validator1
|On 29 August 2011, an Airbus A320 which had up to that point made a stabilised auto ILS approach at destination deviated from the runway centreline below 200 feet aal but continued to a night touchdown which occurred on the edge of the 3400 metre runway and was followed by exit from the side onto soft ground before eventually coming to a stop adjacent to the runway about a third of the way along it. The subsequent investigation attributed the event to poor crew performance in reduced visibility|
|Actual or Potential
|Human Factors, Runway Excursion|
|Type of Flight||Public Transport (Passenger)|
|Actual Destination||Cochin International Airport|
|Take off Commenced||Yes|
|Location - Airport|
|Airport||Cochin International Airport|
|Tag(s)||Approach Unstabilised after Gate-no GA|
Plan Continuation Bias,
Procedural non compliance
|Damage or injury||Yes|
|Causal Factor Group(s)|
On 29 August 2011, an Airbus A320-200 being operated by Gulf Air on a scheduled passenger service from Bahrain to Cochin as GF 270 touched down off centre on the destination runway in normal night visibility and then exited the side onto soft ground where it eventually stopped close to the runway where an emergency evacuation led to 7 of the 144 occupants sustaining minor injuries. Significant damage was caused to the aircraft and a number of runway edge lights were broken.
An Investigation was conducted by a Committee of Inquiry set up by the DGCA. Significant damage to the aircraft included a collapsed nose landing gear leg and damage to the right main landing gear assembly and to both engine cowlings as well as internally to the right hand engine.
It was noted that the 34 year-old Captain had 7000 total flying hours which included 1200 hours in command on type. The 37 year-old First Officer had a total of 3000 flying hours total but their hours on type were not recorded.
An auto Instrument Landing System (ILS) approach was made to runway 27 with the aircraft commander as PF. DFDR data showed that the aircraft was stabilised at 1000 feet agl and the AP was subsequently disengaged at 670 feet agl. As the aircraft passed 200’ feet agl, it was banked to the right and the drift angle of 4° left was beginning to reduce. However crossed control inputs were evident and a side slip could be seen to have occurred which caused a deviation to the right of the extended runway centreline. Touchdown estimated at about 570 metres from the threshold subsequently occurred with the right main landing gear making ground contact at the extreme right hand edge of the runway and departing the paved surface soon afterwards. The left main landing gear then also left the runway 100 metres further on as although a corrective left rudder input had been made, it had been ineffective because the aircraft had been on soft ground and the groundspeed was rapidly reducing. It was noted that the armed auto brakes had not operated as the actual deceleration of 0.26 g over 4 seconds exceeded the auto brake target deceleration of 0.17 g. The aircraft had finally come to a stop after a ground roll totalling approximately 670 metres.
An emergency evacuation of all 144 occupants was carried out using all four doors and the two right hand side over wing exits during which only 7 minor injuries occurred.
It was concluded that the PF had not appreciated the induced deviation below 200 feet aal and had continued to maintain a slight right bank as increasing rainfall reduced in flight visibility to 2000 metres. It was also noted that the PM had been calling ‘continue, localiser nice, profile nice and continue’ followed after touch down by a repeated ‘maintain centre line’.
Since the PF had at no point considered initiating a go around, it was concluded that the PM call after touch down of ‘maintain centre line' was “too little too late” - insufficiently assertive and could have stated that the Centre Line was well to the left.
The Investigation concluded that the Cause of the Runway Excursion was “an error of judgment of the PIC which was due to loss of situational awareness during reduced visibility conditions”.
Six Safety Recommendations were made as a result of the Investigation as follows:
- that the DGCA should communicate the Monsoon Conditions Training recommended by in the CAR, Section 8, Series C, Part-I dated 17-08-2011 to international Operators operating in India.
- that the Indian Meteorological Department (should) ensure that NAL (the manufacturer of the installed IRVR equipment) is able to ensure (that the system remains serviceable). This is applicable to all airfields where such equipment is installed.
- that Gulf Air (should) address the issue of CRM (since) appropriate and focused interjection by PM whilst PIC was deviating from the (runway extended centreline) during short finals, may have averted the incident.
- that (since) applying cross control and side slipping inadvertently on short finals, resulting in deviation from (the) runway (extended centreline) is a dangerous occurrence, Gulf Air (should give attention to ) skill levels with reference to this aspect. Correct utilisation of FD to avoid large deviation of LOC, should be advocated.
- that the DGCA ensure that after such (an) incident the aircraft is released at the earliest (opportunity once) preliminary investigation is completed and there is no indication of maintenance or technical failure (noting that) apart from financial loss to the operator, high tech. equipment (Computers, Avionics etc.) exposed to weather for long durations could (suffer) irreparable damage.
The Final Report of the Investigation was made available on 20 June 2012