With experience in aviation comes wisdom. But experience does not guarantee safety.
The people involved in the accidents described here were skilled, experienced aviators. Their loss is still deeply felt by families and colleagues. These examples are included here only to help all pilots better recognise how human factors can quietly erode safety, even among expert aviators.
In March 2015, a Cessna 185B Skywagon departed Wānaka, VFR for a country station near Coronet Peak.
In the front seat were two pilots with more than 10,000 hours’ flying experience between them. Both were trained and experienced mountain flyers. One of the pilots had just attended an AvKiwi weather seminar.
Despite this experience, the MetService forecast wasn’t checked before departure. After take-off, the aircraft encountered poor weather conditions.
None of the four occupants in the aircraft survived the subsequent impact with a valley spur, as the Cessna turned away from the deteriorating weather.
The CAA report noted that, as the pilots were only 10 minutes from their destination, a certain amount of plan continuation bias1 was likely involved.
“Inexplicable”?
In 2015, Vector argued this accident was “inexplicable”. But A-cat and Director of Dragonflight Aviation, Penny Mackay, says there’s a phenomenon which she calls the “trap of experience”.
“Sometimes I’ve had to talk myself out of risky behaviour with low flying in mountainous terrain, or pushing a weather window.
“The temptation is there because I’m pretty experienced and have never had an accident. Therefore, I think that with my experience I can get away with it.
“I’ve never done this with a student, but sometimes by myself I’ve definitely had moments where I’m arguing about whether to push things.”
Penny says there are pilots with much more experience than her who’ve done the same thing.
“Some of them tell me about their risky behaviour. If you asked them they’d probably admit to it.
“Not all of them are still here to talk about it though.”
Sense of invulnerability
Max Stevens, Executive Officer of Gliding New Zealand, says if a pilot isn’t current, even an experienced one may not survive their mistakes.
“Get-there-itis and overconfidence are also common among glider competition flyers.
“It contributes to a sense of invulnerability among experienced pilots.”
Martyn Cook, National Operations Officer of Gliding New Zealand, says the trap of experience was a factor in a fatal accident in 2022, involving an experienced tow pilot and an experienced glider pilot at Feilding.
During the take-off roll, the glider wing contacted the ground, leaving the glider out of position. As the glider attempted to correct, the tow rope de-tensioned.
As the tow rope quickly re-tensioned, the glider appeared to kite up, causing a lateral high upset of the tow plane. The result was an uncommanded yaw, roll, and nose pitch down of the tow plane. It was unable to regain control in the height available and crashed, the tow pilot later succumbing to his injuries.
The glider was able to land safely because the tow rope broke under the stress caused it by the diverging aircraft.
The report into the accident noted that both expectation bias2 and plan continuation bias were likely involved. It said, “It is likely that the glider pilot continued with the plan rather than release from the tow plane due to his expectation that he could safely recover the situation and continue on to achieve the intended aims of his flight.”
Martyn says this accident demonstrates that if a pilot has performed a task successfully again and again, it can be hard for them to recognise an emergency if it does occur.
“It also shows how experience can be a trap, where the seriousness of the potential hazards is lost.
“It’s then difficult for a pilot to ‘flip the switch’ into emergency manoeuvres.”
Alaska White, CAA Principal Advisor of Human Factors, agrees.
“Pilot experience can lead directly to both confirmation bias and plan continuation bias.
“If those biases go unchecked and unchallenged, the pilot might disregard their instruments, the forecast, or any other warnings and cautions.
“Maybe they’ve done this thing before, or watched someone else do it, and it seemingly worked out okay.”
Breaking the rules
A 1985 study showed that US Navy pilots over the age of 38 had accidents, due to loss of control, at a rate of 0.75 per 100,000 flight hours. However, accidents due to regulation violations in that age bracket occurred at a rate of 3.25 per 100,000 flight hours.
In comparison, a younger cohort, 26-year-olds, scored much higher in loss of control accidents. Their rates were 2.25 per 100,000 flight hours.
However, their accidents due to regulation violations were just 0.5 per 100,000 hours, showing that older pilots were more likely overall to have an accident.
Penny Mackay says accidents involving older pilots tend to be caused either by procedural errors, inadequate flight preparation, or regulation violations.
“Higher levels of experience can lead to ego and impulsivity. It’s really prominent among older pilots.
“But no one is bullet-proof.”
Alaska White says experienced pilots can often overestimate their abilities.
“At the same time, they’ll underestimate just how formidable and unforgiving New Zealand’s meteorological conditions can be.
“Pilots need to have an honest conversation with themselves – and others – about how easily these biases can affect judgement and decision-making.”
Footnotes
1 We all use ‘biases’ or rules of thumb to quickly judge a situation or make decisions. Biases enable the brain to shortcut the processing of information. For instance, at a supermarket we don’t stand for ages taking in information about each product – we usually grab the one we’ve used before. But such shortcuts can also lead to errors in decision-making or judgement. ‘Get-there-itis’ is another name for plan continuation bias. The Australian Transport Safety Bureau regards this as a major hazard to safety, because it pressures pilots to get to their destination, despite changing conditions.
2 According to SKYbrary, expectation bias is a term to describe a pilot hearing or seeing something they expect to hear or see, rather than what actually may be occurring. It’s often driven by experience or repetition.
Photo: CAA