Description

On 5 January 2014, an Airbus A320 (VT-ESH) being operated by Air India on a scheduled domestic passenger flight from Guwahati to Delhi as AI 889 had to discontinue its ILS approach at destination when the RVR dropped below crew minima. A diversion to Jaipur was then made but by the time the night IMC ILS approach there was commenced, visibility was deteriorating rapidly. The approach was continued below DA without visual reference even in the touchdown and landing roll and it subsequently became apparent that the aircraft had landed alongside the runway. After the main landing gear had been damaged and the left wing partly detached due to tree impact, the remainder of the aircraft was steered back onto the runway and stopped and a MAYDAY was declared. Only one of the 179 occupants sustained a minor injury and, with no signs of fire evident, all passengers were subsequently disembarked to buses and taken to the airport terminal. The aircraft could not be moved and so the airport was closed indefinitely pending that action.

Investigation

An Investigation was carried out by an Indian AAIB Committee of Inquiry. The SFDR and the 2 hour SSCVR were recovered from the aircraft and their data were successfully downloaded. The tape-based QAR, which records the same data as the SSFDR, was accessed but found to be unserviceable with this status not recorded in the aircraft Technical Log.

The 43 year-old Captain had 8,322 total flying hours which included 5,502 hours on type of which 3,039 hours had been in command on type. He was PF for the investigated landing and was Cat III qualified. The 46 year-old First Officer had 2,798 total flying hours which included 2,610 hours on type and was only Cat I qualified.

The Accident Flight

It was established that the aircraft had been operating a four sector trip Delhi - Guwahati - Imphal - Guwahati - Delhi with an STA back at Delhi in mid evening. After a 50 minute stop at Guwahati on the return flight, the Captain loaded 500kg extra fuel because of the known destination congestion due to fog and departed on the night flight to Delhi. On arrival, the aircraft was No. 12 to land and was put in the hold for almost half an hour before being vectored onto the runway 28 ILS LOC. During this approach, the RVR dropped below the Cat I minimum and, after being told by ATC that the reported visibility at Jaipur was 2,000 metres, a diversion was commenced there. Weather at the other FPL alternate Lucknow was not checked and although at that point there was sufficient fuel remaining to reach both alternates, Jaipur was preferred because it was nearer.

During the flight to Jaipur, the crew learned that the visibility there was deteriorating rapidly. After an ILS Cat I approach had been commenced with dual APs engaged, the aircraft ahead then went around after failing to acquire visual reference but as the crew did not at this stage have sufficient fuel to reach any other alternate which they were aware was both open and had better weather, they continued the approach. When the aircraft was at 1,489 feet agl, ATC reported that the RVR had dropped to 50 metres and "cleared the aircraft to land subject to minima". At 200 feet radio height, already (just) below DA, the Captain disconnected both APs and continued descent manually as he was not sure if he could carry out an auto land to a Cat I runway "in actual zero visibility". As the runway neared, the aircraft deviated to the left of the centre line before touching down left main gear first on soft ground 46 metres to the left approximately 1,000 metres beyond the threshold of the 2,797 metre-long / 45 metre-wide runway. During the touchdown and landing roll "the visibility was zero and the crew were unable to see any of the reference cues". They did report having "heard rumbling sound during landing roll" as the aircraft continued to roll/skid along the grass and it was subsequently found that part of the left main gear had rolled alongside and then into the boundary drainage ditch which ran parallel to the runway. The ground track of the aircraft from touchdown until it finally stopped after finally entering the runway is shown in the third illustration below.

Once the aircraft had come to a stop, it was apparent that amongst other consequences of the off-runway landing, part of the left wing was missing after tree impact (see the illustration below) - which FDR data indicated had occurred at 109 KCAS - and the left landing gear had been seriously damaged. It was found that 2,400 kg of fuel remained on board. In the apparent absence of any fire or fire risk, "the flight crew never considered an emergency passenger evacuation" and waited for buses to arrive onto which the passengers could be disembarked. As there was "no disabled aircraft removal plan for Jaipur airport nor was there any appropriate equipment available for removal of disabled aircraft", it was necessary to close the only available runway there until the following day.

The damaged left wing. [Reproduced from the Official Report]

The Investigation found no evidence of any relevant pre-existing airworthiness deficiency or aircraft mis-loading and was therefore focussed mainly on the decision making process followed by the flight crew and the 'system support' for that process. SSFDR data showed that misalignment with the runway had developed after disengagement of the APs when unbalanced crossed-control commands had been made (predominantly left aileron against right rudder).

Flight Crew Performance

It was noted that "the weather trend for Jaipur, Delhi & Lucknow should have been reviewed by the flight crew prior to departing from Guwahati for Delhi". And although 500 kg of extra fuel was uplifted by the Captain in the expectation of weather-related delays at Delhi, there had been no information from either Flight Dispatch or ATC on this. En-route to Delhi, in the absence of any VHF VOLMET, the crew did not listen to ATIS broadcasts or ask ATC for the latest Delhi, Jaipur and Lucknow weather. Also, since Lucknow was not only the first designated alternate but also had a serviceable CAT II ILS facility, it was considered that since the crew was not CAT II/ III compliant and the weather at all these locations may well deteriorate below CAT I during the evening, the first choice for diversion should have been Lucknow and that it was inappropriate to initiate an approach at Delhi "with RVR fluctuating toward the lower end of CAT I conditions for runway 28" and worse on other runways. Delhi ATC were not asked for the Jaipur and Lucknow weather and Air India Flight Dispatch passed the crew a Jaipur METAR which was 2 hours old and which gave the visibility there as 2,000 metres. This on its own was likely to have misled the flight crew and influenced their decision to divert to Jaipur, although even when en route there, the crew "had not made any effort to check the weather with ATC". Then "once the crew was made aware of the rapidly deteriorating visibility/ RVR at Jaipur", no discussions took place between the two pilots about the possibility of diverting to Udaipur, Jodhpur or Ahmedabad or about the use of auto land below CAT I minima once the crew had committed to a landing at Jaipur. They also acted contrary to SOP by continuing to use the landing lights, "which in such low visibility conditions impairs the forward vision [and] probably contributed to their late sighting of the approach and runway lights". It was considered that once committed to a landing below minima, "the decision to disengage the autopilot was the last inappropriate act which caused the aircraft to deviate to left from localiser resulting in the aircraft landing (with both main landing gears) on the soft ground". It was also noted that although the crew had "intimated" to Jaipur ATC that they "were committed to land" off the ILS approach there when 25 nm from the airport, they had not declared 'minimum fuel' to either Delhi ATC or Jaipur ATC while diverting.

System Support for the Flight Crew

It was found that the availability of down-route and en-route weather information to crews like the one involved in the investigated accident was poor. Although Air India narrow body aircraft did not appear to carry HF radios which would have been able to receive scheduled HF VOLMET transmissions, there were no continuous VHF VOLMET broadcasts. Air India Flight Dispatch had shown little interest in the flight once it had departed Delhi on the first of its four sectors despite the winter fog season and had appeared to be somewhat disorganised and without access to relevant expertise to proactively advise Captains on the best options for diversion. Down-route self dispatch by aircraft commanders was also not the subject of any company policy. Insofar as TAFs were issued and available on the ground, only 6 hour TAFs were produced and use of 'TREND' in METAR reports was found to be patchy and no such information was being appended to Jaipur METARs at the time of the accident. However, the Investigation found that opportunities for the accident crew to be aware of airport present weather in flight or on the ground were present but the information was neither requested nor automatically provided by ground agencies.

Specific concerns were identified about the widespread absence of the supposedly required instrumented (automated) RVR readings for all Cat 1 runways and the consequent reliance on 'Converted Meteorological Visibility' (CMV) to 'create' an RVR which could be compared with approach and departure procedure limitations. Jaipur Met Office personnel, who had not been providing RVR from their automated measuring system to ATC at the time of the accident were found to be "not very much conversant with the procedures for giving RVR" and it was stated that "the persons who were trained on the equipment were transferred out of airport office". It was also found that periodic calibration of the equipment was not being carried out due to the lack of an appropriate agreement with the manufacturer at the time of installation. No NOTAM had been issued advising that the RVR equipment had not being calibrated. On a slightly different but directly relevant subject also indicative of poor airport operating standard, it was found that the airport ILS critical areas were not protected nor were there any cautionary notices displayed to help ground personnel avoid these areas.

In respect of flight crew rostering, it was noted that DGCA guidelines for low visibility operations "emphasise that Airlines shall ensure that only those pilots who are adequately trained and certificated […] are rostered to operate flights during low visibility conditions from/to Delhi to ensure [continuity of] aircraft operation during low visibility conditions especially during CAT II and CAT III-A/B conditions" with all airlines expected to plan flights "as per the schedule separately filed for the [pre-defined winter] fog period".

Pilot Training

Evidence that simulator training for Air India pilots on low visibility approaches was inadequate was found, with the Captain reporting that he had last undergone a simulator check including a low visibility approach in September 2011. More generally, although Air India had a DGCA-approved SMS, neither pilot was aware of it or any company safety policy. Noting from CVR data that CRM had been poor during the accident flight, it was discovered that CRM training for Air India short haul pilots was delivered by instructors who had not undergone any specialised training and were not approved as such by the DGCA.

Emergency Response

It was found that despite being made immediately aware of the 'crash landing' of the aircraft in this accident, Company Operations had not activated the Emergency Response Plan (ERP) and "the officials at Jaipur including the Airport Manager were not sure whether they had undergone any training on this ERP or carried out any regular practice drills as stipulated".

Conclusions

The Investigation determined that the Probable Cause of the event was "a combination of organisational factors and human error" as follows:

• The flight crew made an erroneous decision of diverting & continuing to an airfield with reducing visibility.
• The flight crew attempted a manual landing in below minima conditions.
• There was a lack of operational supervision and desirable ground support to flight crew.
• Internal Quality Assurance processes had failed to capture relevant hazards which slipped through due to complacency.
• There was insufficient oversight of flight operations

A total of 33 Safety Recommendations were made as follows:

• that the Operator/All Scheduled Operators should clarify flight dispatch policy for multi sector flights and clearly define the responsibility for the dispatch of flights.
• that the Operator/All Scheduled Operators should ensure that proper training is provided to flight dispatchers by an authorised person including recurrent training as per DGCA requirements for preparing and interpreting the computerised flight plan for briefing purposes.
• that the Operator/All Scheduled Operators should ensure that proper documentation on flight dispatch is maintained.
• that the Operator/All Scheduled Operators should clarify the role of flight dispatch vis-à-vis operations control.
• that the Operator/All Scheduled Operators should depute experienced flight dispatch duties so that in case of emergency, timely (safety related) advice is given to flight crew.
• that the Operator/All Scheduled Operators must implement flight following for every leg of all flights and the necessary resources (equipment & manpower) be clearly defined.
• that the Operator/All Scheduled Operators must, during the period 15 November until 10 February (each year) make a senior pilot available in flight dispatch between the stipulated time (foggy weather) to provide to the flight dispatchers. These pilots must be supported by Met Officers etc.
• that the Operator/All Scheduled Operators must take pro-active decisions well in advance for diverting flights which are due to arrive at fog-bound airports instead of accepting holding over a destination until Reserve Fuel / Minimum Diversion Fuel|minimum diversion fuel (MDF) is reached before diverting to the alternate, which leaves the flight crew to declare "minimum fuel" (as per ICAO) and puts undue pressure on ATCOs.
• that the Operator/All Scheduled Operators must ensure that during the period of inclement weather, flight dispatch contacts the aircraft by available means (VHF/HF/ACARS/SATCOM) and relays the latest weather for destination and alternates. The Operations Controller must give his/her advice regarding weather trend. However the final decision remains with the Commander of the flight.
• that the Operator/All Scheduled Operators must develop a fuel consumption monitoring system to be used in the computerised flight planning systems such as LIDO, NAVTECH etc specific to each aircraft registration or use the seasonal wind flight plan and the aircraft manufacturers data to avoid any error in fuel uplifts.
• that the Operator/All Scheduled Operators must define alternates based on the weather trend (TAFOR).
• that the Operator/All Scheduled Operators should define two designated alternates (which have a defined IAP procedure for both runways) for all flights and ensure fuel for the most distant of these is loaded.
• that the Operator/All Scheduled Operators must ensure that fuel policy is in line with the applicable DGCA requirements based on the statistical data for the last 15 days, which must include fuel for ATC delays, en-route icing, congestion at the destination airport, change of routing etc.
• that all Flight Crew must be vigilant about the weather conditions at destination and alternates by seeking weather updates in flight from their company or ATC so that they can monitor weather trend at both destinations and designated alternates.
• that all Flight Crew must, before operating any flight, be provided with details of watch hours, along with details of fire fighting etc. of all the airports in the area of operation in their pre-flight briefing folders.
• that the DGCA should consider keeping All Weather Operations (AWO) simulator training for all weather operations separate from the normal IR/ PPC training / checks during initial and recurrent training.
• that the DGCA should clarify if Monsoon simulator training is a one-time exercise or needs to be carried out annually for all flight crew. The same may be included in the 'Explanatory Notes of the Civil Aviation Requirements (CAR) for AWO'.
• that the DGCA should consider ensuring that RVR is available below 800 metres for the purpose of take-off and landing at all airports. (Many regulators clearly define that below 800 metres visibility, all take-off minima are defined in RVR and the same matter must be clarified in DGCA requirements for AWO.)
• that the DGCA must ensure that the Airports Authority of India (AAI) defines Low Visibility Procedures for airports where Low Visibility Operations (below 800 metres visibility) take place. The AIP must carry this information.
• that the DGCA should include declaration of fuel emergencies as one of the 'Safety Indicators' used in the State Safety Plan.
• that the DGCA should issue approval/ certification to flight dispatchers.
• that the DGCA should re-examine the process of converting Meteorological Visibility into RVR. A Safety Risk Assessment must be carried out by the DGCA (Air Safety & Flight Standards) and the Airports Authority of India (AAI) to ensure its applicability at Indian airports.
• that the Airports Authority of India (AAI) / Indian Meteorological Department (IMD) must provide VHF VOLMET facilities at airports like Varanasi, Ahmedabad, Nagpur, Bangalore, Guwahati, Calicut etc.
• that the Airports Authority of India (AAI) / Indian Meteorological Department (IMD) must ensure that designated alternate (destination and en-route) weather as mentioned in the CAR Section 8, Series C, Part 1 (Table 9) is provided for 1 hour before and 1 hour after the ETA at an alternate based on appropriate METARs and/or TAFs which indicate that, at the alternate ETA, the ceiling and visibility at that airport will be at or above Table 9 of CAR Section 8, Series C, Part 1 (All Weather Operations) for dispatch purposes. The normal in-flight landing minima will be applicable. This procedure must be clarified in the 'Explanatory Notes' of the referenced CAR.
• that the Airports Authority of India (AAI) must ensure that between 15 November and 1 February (each year), the watch hours of airports around designated alternates are defined / made available as NOTAM‘s and these airfields kept open till the last arrival of aircraft at the destination. This is especially important in the case of northern and eastern sector airports like Amritsar, Jaipur, Udaipur, Varanasi, Lucknow, Bhubaneswar, Agartala etc.
• that the Airports Authority of India (AAI) / Indian Meteorological Department (IMD) must ensure that Delhi and all major airports maintain updated/ latest alternate weather information which can be made available to the flight crew on request especially whenever the weather deteriorates e.g. during a thunderstorm, due to strong surface winds or fog.
• that the Airports Authority of India (AAI) must, based on updated statistical data, define the congestion period for all major airports in India and the information must be included in the AIP. The same information can also be made available on their website.
• that the Airports Authority of India (AAI) / Indian Meteorological Department (IMD) should ensure that Met Offices at airports have all their equipment calibrated as and when required. In the event that such equipment is not calibrated, NOTAM action to that effect must be taken and flight crews informed as to any equipment which should be considered unserviceable.
• that the Indian Meteorological Department (IMD) must ensure that the accuracy of TAFs is improved to help with the efficient planning of alternates.
• that the Airports Authority of India (AAI) / Indian Meteorological Department (IMD) must ensure that instrument RVR capability is available at all airports where Cat I ILS is provided or the airport is available for other operations where this is necessary e.g. take-offs when the visibility is less than 800 metres.
• that the Airports Authority of India (AAI) must ensure that at airports where they have not defined LVPs, take-off minima must be not less than 800 metres visibility.
• that the Airports Authority of India (AAI) must have a system to ensure that not all flights file the same alternate airport during periods of congestion. Alternates must nevertheless be filed keeping flight crew qualifications and aircraft technical status in mind.
• that the Airports Authority of India (AAI) must ensure that, during the winter months (approximately 15 November to 10 February), designated destination alternates have a visibility trend that is not below the lowest available non-precision approach for 1 hour before and after the expected time of arrival at the alternate.

The Final Report was completed on 12 August 2016 and released without restriction on 23 February 2017.

Related Articles

• Controlled Flight Into Terrain (CFIT)
• Low Visibility Procedures (LVP)
• Runway Visual Range (RVR)
• Flight Plan Completion
• Fuel - Diversion to Weather Alternate
• Fuel - Regulations
• Crew Resource Management
• Weather
• Fog
• Weather Forecast
• Weather Observations at Aerodromes
• Meteorological Terminal Air Report (METAR)
• VOLMET
• Flight Watch