Vistara

TRUST your AutoPilot under high stress, learnings from Vistara MayDay Fuel

There are situations when it is advisable to consider the OPTION of executing an AUTOLAND even if visibility conditions do not require it or not specifically prohibited. The Vistara flight from BOM-DEL diverted to LKO. Visibility at LKO dropped by the time the flight arrived and the prevailing thunderstorm conditions reduced the visibility to below the CAT-I landing minima. LKO is equipped with CAT III ILS.

It is the prerogative of the PIC to decide on the final outcome based on the prevailing conditions. However, the investigation report released lately does not analyse human factor aspects and especially crew decision making under high-stress situation thereby losing an opportunity for the aviation community to learn from incidents.

There have been occurrences that could be important from learning objectives. The accident and 3 serious incidents in the discussion are:

  1. VT-EDV 15 Nov 1993 Aircraft diverted from HYD under low visibility and experienced a technical malfunction in the FLAP/SLAT system. The crew elected to divert and carried out belly landing en route to the alternate airfield due to fuel exhaustion.
  2. VT-ESH 05 Jan 2014 Aircraft diverted to JAI, attempted manual landing in low visibility and departed the runway on an unpaved surface damaging the wing structure.
  3. VT-WGR 11 Nov 2019 Aircraft attempted to land at BLR, disconnected autopilot and landed manually in low visibility, departed the runway on the unpaved surface leading to ENG1  STALL.
  4. VT-TNH 15 July 2019 Aircraft diverted to LKO, performed a missed approach, and declared “Mayday Fuel”.

In all the above cases, the crew had the option of carrying out an AUTOLAND under the prevailing conditions. I would like to emphasize the word “Option” since it is the PIC’s responsibility on the final disposition of the aircraft under the prevailing circumstances. 
Having said that, the fact that AUTOLAND was not considered as an option is a shortcoming in the airline training and corporate policymaking.
Airbus, the OEM has recommended that AUTOLAND can be performed in CAT I conditions and on CAT I airfields under the emergency authority of the PIC. There is a need to discuss this issue with the airlines and advise/educate the crew on the possibility of exercising the option of an AUTOLAND.I quote the OEM which clarifies their position on the use of AUTOLAND”to clarify a common misunderstanding, Low Visibility Operations (CAT III)  require Autoland, but the use of  Autoland is not limited to Low Visibility  Operations.  Autolands are also permitted on  CAT  II/CATIII  runway when the  ILS  protection is not activated  (LVP  not in force)  and even on CAT I runways unless explicitly forbidden by local procedures or authorities.

Low  Visibility  Operations  (LVO)  is the most commonly used  (and known) reason for the performance of an automatic landing. But there are many other situations where the use of  Autoland provides operational advantages,  and where the decision to perform an Autoland is a smart flight crew decision.

Here are some examples of the cases for which an Autoland can prove beneficial:

  1. Flight crew fatigue  (e.g. an early-morning landing after a long and tiring night flight).  
  2. Unfavorable operational conditions   (e.g.   Overweight landings. Autoland has been demonstrated with weights much above  “Max Landing  Weight”,  as specified in the FCOM).
  3. Poor visual conditions (e.g. even if the reported weather conditions are  VMC,  a  landing that faces a low-rising or a setting sun, aligned on the runway axis,  can seriously affect and reduce the flight crew’s vision).
  4. Crew Incapacitation (e.g. the unaffected pilot could decide to exercise their emergency authority and use the Autoland function in order to benefit from the potential assistance and relief).”

Consideration of executing an AUTOLAND could have been a safer option in the above few cases.

mindFly analysis

While the crew is the best judge in the prevailing situation when a decision is made and debates in hindsight are purely theoretical, there is an opportunity to learn about human behaviour. The important learning from the Vistara Fuel Emergency is that once again the framing of policies have played an important role in crew decision making. Even though the crew is given the authority to change their decision of the choice of alternate selection, humans remain conformists by nature and corporates remain profit-oriented by nature. The overbearing culture of commercial prevailing over safety is a subconscious phenomenon and keeps playing in the background when the crew is considering all options. Under this situation, an added stress can overload the crew cognitively and prevent task analysis. In this situation, the crew was lucky to have a proactive ATC controller at LKO who coaxed them to change their decision of diverting back to LKO after the crew had diverted from their alternate with a fuel emergency situation.

The use of automation takes the part of focussed attention directly from the crew thereby giving them the space to think of options. The crew can then step back and have a birds-eye view of the situation giving them a much clearer picture of the situation unfolding.

 

2 thoughts on “TRUST your AutoPilot under high stress, learnings from Vistara MayDay Fuel”

  1. As far back as july2011 Airbus safety first issue #12 has highlighted these issues under Automatic landings in daily operations. But unless the Airlines disseminate such information to their pilots they may be hesitant to use it. But in JAI accident there was no decision at all. The crew had option to declare may day and go back to Delhi to avail Cat3 or land in JAI and trust the AP to do the job but attempting manual landing in poor visibility was suicidal. In Bangalore case pilot was flirting with visibility below minima which proved hazardous. Even this aspect has been in one Airbus discussion. Coming to human factors it appears that they are used as an epitaph or obituary. Mostly they are indicated as a guess and no one seems to learn anything from them. How many times do we hear of somatogravic illusion and it happens again and again. Something more and practical needes to be done about them.

     
  2. It is actually very logical to exercise the option of using the Autoland for landing but the Pilot has such a mindset regarding post landing enquiries by the regulators and Flight Safety, that he is always hesitant to use this option!!

     

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top
%d bloggers like this: