human factors

COVID-19: Safe to fly again?

A human factors perspective

The current news headlines of COVID-19 vaccines bring the possibility of routine air travel in 2021. The impact of the pandemic on airlines has been devastating – the International Civil Aviation Organization (ICAO) estimates a global loss of passenger revenue from Jan to Nov 2020 of approximately US$358 billion; with similar impacts on tourism and exports. Successful vaccines will provide a much-needed boost to the aviation industry. However, even with successful vaccination programs, consumer confidence may remain low for some time.

The airline industry is reporting that the risk of coronavirus transmission in-flight is extremely low. However, air travel will require multiple layers of protection: managed queuing, contactless processing, face masks, sanitizer and COVID-19 testing will be part of the landscape for some time to come.

Besides the risk of virus transmission during air travel, there are several human factors issues to consider as aviation activity returns. During the COVID-19 pandemic, up to 64% of the global aircraft fleet has been in storage (around 17000 aircraft) and tens of thousands of pilots have also been grounded for many months. The human factors implications of this are significant.

Recent incidents

The International Air Transport Association (IATA) issued an Operations Notice in June 2020 to highlight an increased number of “Unstable Approaches”. These are precursors to high-impact events, such as runway excursions and hard landings.

IATA Unstable Approaches 2018-2020 -
IATA data shows an increase in Unstable Approaches per 1000 operations over the first half of 2020,
when compared to the previous two years

15 September 2020: Runway excursion

An Airbus A330, flight number LNI208 operated by Lion Air, was travelling from Jakarta to Medan with 11 crew and 307 passengers. On landing at Medan during bad weather, the aircraft partially left the runway, with the left wheels veering onto the grass, breaking two runway lights.

The initial investigation report highlights difficulties in maintaining pilot proficiency and experience during the COVID-19 pandemic. The Pilot in Command had flown a total of only 2hrs 56mins in the previous 90 days; the Second in Command had not flown at all in the previous 90 days – his last flight was 1 February 2020. The Indonesian Directorate General of Civil Aviation (DGCA) issued an exemption from the usual competency and experience requirements, due to limitations on both travel during the pandemic and limited access to training simulators. Authorities in many other countries have issued similar exemptions or extensions.

22 May 2020: Crash after failed landing

PIA gear retracted landing - 22 May 2020 -
PIA flight PK8303 – attempted landing with wheels retracted, 22 May 2020 (prior to Go-Around and subsequent crash)

Just days after Pakistan resumed commercial flights when coronavirus restrictions were eased, Pakistan International Airlines (PIA) Flight PK8303 crashed into a residential area of Karachi, killing all but two of those on-board. The Airbus A320 with 91 passengers and eight crew, flying from Lahore, crashed on a second landing approach to Jinnah International. On the first attempt at landing, the aircraft briefly touched down with landing gears retracted (i.e. with wheels up), damaging both engines.

The preliminary report states that the crew did not follow standard callouts and did not observe Crew Resource Management (CRM) aspects during most parts of the flight. During the approach to landing, the aircraft was too high, but the crew ignored the Air Traffic Control advice to Go-Around so that the aircraft could approach on the required descend profile. The landing gears were lowered, but then raised again on approach to landing. The Cockpit Voice Recorder shows that there were several warnings and alerts for over-speed, landing gear not down and ground proximity alerts. There is concern that the crew were distracted:

“The pilots were discussing corona throughout the flight. They were not focused. They talked about corona […] their families were affected”.

Pakistan Aviation Minister Ghulam Sarwar Khan, 24 June 2020
PIA PK8303 crash site -
PIA Flight PK8303 crash site in residential area of Karachi

Air Traffic Control noticed the failed landing and the impact of the engines with the runway, but did not convey this to the aircraft crew. Shortly after the first attempted landing, both engines failed leading to the crash. There were no technical faults in the aircraft, both pilots were medically fit to fly and were reported to be qualified and experienced. European Union Aviation Safety Agency (EASA) Executive Director Patrick Ky said that “The pilots did not seem to be as fluent in the way they were conducting their flights as they should have“.

Maintenance issues

The European Union Aviation Safety Agency (EASA) has warned that they have noticed an alarming trend in the number of reports of unreliable speed and altitude indications during the ‘first flight’ following aircraft storage due to the COVID-19 pandemic. This has led to a number of Rejected Take-Off (RTO) and In-Flight Turn Back (IFTB) events. In most cases, the unreliable speed and altitude indications were caused by insect nests in the pitot system, which provide critical air data to the aircraft. This is extremely concerning – the Air France Flight AF447 crash, and loss of all 228 passengers and crew, was initiated by these pitot probes being disabled.

Other issues arising from prolonged storage of aircraft include fuel system contamination, loss of charge in emergency batteries, bacterial contamination of the potable water system and outdated aircraft software. If aircraft have been stored for long periods on runways and taxiways, there may be an increased risk of surface damage.

Human Factors issues as flying resumes

As airlines resume commercial flights, there will be several challenges to overcome from a human factors perspective. If these issues are not adequately addressed, incidents may be more likely and passenger confidence in air travel will be impacted. I’ve briefly considered some of these challenges through the lens of selected human factors topics outlined elsewhere on this website.

“Extended absence of a significant number of flight deck crew can lead to diminished skills, less effective situational awareness, and can lead to deviation from established Standard Operating Procedures (SOPs). Additionally, as a result of the pandemic, crew will have to educate themselves with multiple temporary revisions to operational policies and procedures designed to operate in the current environment”

International Air Transport Association (IATA), 28 August 2020

Competence and Procedures

The certifications of flight crew have been extended during the COVID-19 pandemic, as opportunities to maintain the currency of their experience have been limited, and travel to attend training on simulators has been impacted. This will lead to a backlog of retraining and the need for exemptions for flight crews. Physical distancing measures may reduce the number of attendees in classroom and simulator training, adding to the backlog. Any extensions to license validity (both medical certificates and technical licenses) may need to also be approved by destination authorities. There will be particular concerns about the approaches to airports and landings, which statistically, are the high-risk phases of flights. Similar competence concerns also apply to maintenance crews, Air Traffic Controllers and other personnel.

Not only have many of the world’s flight crew been grounded along with the aircraft fleet, they will have to adjust to several changes that arise in post-COVID-19 flying. For example:

  • There may be a significant reduction in the weight of aircraft if physical distancing measures are in place (i.e. fewer passengers). Flight crew will need to understand and account for the impact of this on aircraft handling and performance – particularly during highly-manual flying activities such as takeoff and landing. Return-to-work simulator training may include practicing the different flight characteristics of lighter aircraft (such as the potential for tail-strike on takeoff or excessive vertical speeds).
  • There may be temporary runway closures at some airports, to allow parking of grounded aircraft.
  • In order to reduce the likelihood of coronavirus transmission between passengers during the flight, there may be changes to cabin air-conditioning settings; to be made manually from the flight deck.


If crew are wearing face masks on the flight deck, these may interfere with verbal communications between the flight crew, or with Air Traffic Control personnel. Prior to flight, the wearing of masks has the potential to interfere with communications between pilots and ground staff (such as aircraft engineers). Pre-flight walkarounds by the flight deck crew may be prohibited by local regulations and may be undertaken by ground crew. Misunderstandings during pre-flight checks and during the flight have the potential for loss of the aircraft.

A large number of operational or procedural changes may reduce Crew Resource Management (CRM) effectiveness on the flight deck. Team awareness and decision-making may be impacted.


If duty times are outside the normal flight-time limitations, there is a potential for increased fatigue of flight crew. Exemptions to usual limits may be agreed, to allow for logistical issues due to COVID-19 controls – such as extended cleaning of aircraft, slower onboarding of passengers or additional maintenance/monitoring as aircraft are returned to service. The quarantine requirements in different destinations may also impact on flight-time limitations, and lead to roster planning deficiencies.

Management of change

Throughout the COVID-19 pandemic, there have been numerous changes to operational and administrative procedures; some of these may be country, company or airport-specific. For example, given the number of aircraft that may still be “parked”, some runways will be closed. Flight crew may be unaware of key changes due to the high volume of changes, or poor return-to-work briefings. The almost-constant changes and updates can result in a misalignment between crew, or increase the workload of crews.

Besides the resuming of flights following COVID-19, the situation is complicated by the return-to-service of the Boeing MAX 737 fleet, which was grounded in March 2019 following two catastrophic crashes.

Human Computer Interfaces

Airlines have increased the cleaning and sanitization of flight decks, which introduces the risk of switches and controls being inadvertently moved during the cleaning process. This will require extra vigilance by the crew and a thorough check prior to take-off.


There may be additional operational tasks for the first flight when returning an aircraft to service. Flight crew will need to be aware of these tasks and undertake them correctly to prevent significant accidents. Additional fuel planning may be required should the route be changed due to unforeseen closure of airspace or closure of the destination airport at short notice.

Additional passenger announcements may be required to alleviate passenger concerns. Furthermore, an increase in disruption from unruly passengers may be expected in the COVID-19 operating climate (for example, disputes relating to non-compliance with precautions, poor hygiene, or exemptions from face coverings).


The current uncertain environment may reduce the reporting of concerns, non-compliances, near-misses or degraded safety levels. NASA hosts a voluntary aviation safety reporting system (ASRS) where pilots, controllers, mechanics, flight attendants and dispatchers submit incident reports. Several recent reports discuss the issue of pilot complacency when resuming operations after a prolonged break due to COVID-19.

Mental wellbeing

Crew may have concerns around job security, or the potential for infection whilst working. They may have suffered bereavement, or have concerns about the health of family members (such as in the PIA Flight PK8303 incident discussed above). The Air Line Pilots Association (ALPA) reported that increased stress is leading to a greater frequency of pilot-to-pilot conflicts on the flight deck.

Due to quarantine requirements, crew may experience negative changes to their diet or exercise routines. In order to reduce coronavirus transmission, airlines may stipulate reduced contact between flight crew and cabin crew; which will lead to shorter breaks from the flight deck.


The above isn’t a complete analysis. It does demonstrate that the list of key human factors topics can be a useful prompt to help assess a scenario or major change. If you’re restarting activities following the COVID-19 pandemic, (or making changes to how you undertake activities), it may be helpful to use this list of key topics as a basis for assessing whether there are new or different risks emerging. This approach will be valuable for all safety-critical or high-risk industries, not just aviation.

First of all, describe the scenario that you are considering in a short sentence, so that you are clear of the problem statement and the scope of your assessment. For example, it might be “resuming international commercial passenger flights following a six-month period of aircraft and flight crews being grounded“.

Second, consider the relationship of this scenario with each of the human factors topics, one at a time. For example, taking the topic of Competence; you may think about the following:

  • whether people have been trained on new or updated systems, procedures or legislation?
  • have informal or non-technical skills been lost during the COVID-19 pandemic?
  • do staff need refresher training on key technical skills?
  • if there have been staff cuts, are there sufficient staff available for coaching and mentoring?
  • are people carrying out new or additional activities previously undertaken by staff made redundant?
  • how will competence and confidence in new skills be monitored and assessed?
  • is there a balance of competence between team members?

Take a systems perspective – consider the compounding effect of risks from different topics, and the interactions of issues across different personnel groups.

Finally, for any new or emerging risks during this review, identify appropriate mitigations or control measures – ideally focusing on controls with the highest level of protection and reliability. Any assessments should be reviewed in order to ensure that they remain current and appropriate, as the coronavirus situation continues to evolve.

This is essentially a human factors risk assessment. More information on this process can be found in the Human Reliability topic page.