Why does a flight end up in a catastrophe sometimes? What can possibly go so wrong?
Over the last 50 plus years we have seen many aircraft accidents occur in this world for a variety of reasons. Often it is a chain of several things that come together to create that final catastrophic moment so it is never an easy task for investigators to simply point to a single cause of accident. Sometimes, it is very obvious and the reason for a plane crash can be quite quickly blamed onto a certain element, however most of the times, an investigation will require carefully studying the black boxes (Flight Data Recorder and Cockpit Voice Recorder) to analyse further and deeper to the cause. As travellers, we are fearful about air crashes as most of the time the chances of survival in one are close to zero!
An aircraft can come down for many reasons. These could be a single or combination of things like: sabotage, weather, human error, mechanical problems, ATC, engineering, training, culture, suicide, etc.
Decades ago, aircraft technology was not as advanced as it is today and so mechanical faults played a larger role in many aircraft accidents. Today we have the opposite shift as we see technology improve constantly. A study done some years ago by NASA concluded that almost 70% of air accidents were directly or indirectly caused by human error. As humans, we are going to be vulnerable to the very rapidly changing technology and the use of complex computerised machines. Many of the possible causes of accidents above can be no doubt avoided if the correct human action or procedure is carried out. Flying intentionally into bad weather, operating when unfit or medically not advised, carrying out tasks in a haste to simply meet deadlines or ATC slots, lack of training or a dangerous company culture, work complacency, negative training methods, lack of CRM as a whole, etc. can all contribute to things going wrong and an accident becoming inevitable.
As Pilots, we have a number of non technical skills that play a crucial and important role in our everyday flight operations. These include things like, team-work & leadership, communication, threat & error management, CRM, etc. If we apply such skills in moments that really require them at optimum, then we can find solutions and answers to possible problems ahead of the flight or aircraft. Flying an approach when weather is marginal or close to limits, avoiding thunderstorms, icing conditions, aircraft performance analysis, terrain, operating with an inoperative item, known procedural changes, etc. are all examples of tasks and items that require teamwork and good crew co-ordination in order to find the safest and acceptable options. Flight crew training and experience plays a large role in the above and sometimes this can be challenging in the real world. You might often have a newly promoted Captain flying with a completely new First-Officer. This does not mean it is dangerous, but in fact shows the application of the above skills becomes even more vital. Every company makes this easier by having SOP's (Standard Operating Procedures) for crew to follow in their operations. I am not saying by following all of the above, human errors can be definitely avoided, however it does allow to eliminate the possibilities of it and puts crew better prepared and ready if any thing was to go wrong. A good example is the importance of Pilots briefing for both departures and arrivals. If we were to fly an approach into a gusty limited airport runway, we know as crew this could possibly be a day where things can go wrong during the approach. On such a day, we think about taking extra fuel for a second attempt at landing and diversion to a suitable alternate airport, briefing about wind-shears and pilot actions in these cases, going around if a safe landing can't be carried out, etc. This way we are not surprised by such events and are ready to take the appropriate safe actions.
Other reasons for aircraft crashing include mechanical faults or problems. Unfortunately there is not much a Pilot can do if the aircraft was to become uncontrollable. Certain mechanical problems can occur and the aircraft is designed to continue flying safely, e.g. single engine failures (even with a dual engine failure, a safe landing may be possible), electrical or hydraulic problems with enough redundancy remaining, minor or single system faults, etc. Pilots are trained regularly to deal and manage such failure events and so an aircraft accident should not be the end result at all. Time to time, mistakes have regrettably been made in applying the correct analysis/procedures and the aircraft has crashed in the past but as professional aviators, we can learn from such events and add to it through training and information so that the same mistakes are not repeated. Mechanical faults can be linked to a number of factors which can include, maintenance, manufacturer and design. This is very rare these days however quite recently we saw it occur with the Boeing 737 MAX variant. This doesn't mean the aircraft is unsafe as a whole however some modifications have been needed in order for the aircraft to be signed airworthy again.
In terms of sabotage, there is unfortunately not much we can do to solve this except to put extra security and safety measures in place. These including better and more tightened security technology and measures to stop terrorism, psychological interviews and analysis of airline pilots and crew, closed cockpit doors, crew training in dealing with unruly and disruptive passengers and even having security staff on board flights just in case. Airlines and operators also have their own security teams these days to analyse potential national and international threats in order to advice crew and put appropriate measures where necessary.
This was just a breakdown of how and why sometimes aircraft crash and there could be a lot more added to this. It is never as simple as a single cause! An acci