Many of us would be familiar with the Gimli Glider incident involving Air Canada’s flight 143 in the year 1983. It is a classic example that showcases why verification should be done from various angles, not just repeating the same procedure twice or more. That’s key in effective verification.
Double-checks are good. ‘Are we sure?’ questions are great, but they are not sufficient. Let’s look at the Gimli Glider incident and see why it is so.
Flight 143 of Air Canada was to be loaded with fuel. As the automated fuel information system was malfunctioning, the airport crew had to manually do the fueling. Canada had just changed from imperial system to metric system, but crew was nonchalant about the change, and loaded the plane with pounds as units in mind. The chart would have instructed say 1000, with kgs as units presumed, but the crew loaded 1000 pounds. That is less than half the capacity intended to be fueled!
The plane took off, and the pilot realized that the plane has run out of fuel, and had to do land in emergency. They located an abandoned airstrip at Gimli, Manitoba, and landed the flight there with few minor injuries for some passengers.
The above incident highlights the importance of cross-checking from various angles while testing and making quality checks. We would miss the error even if we had counted twice (1000 is correct!). We would have missed even if we asked ourselves, “Are we sure?” Oh yes, of course we are sure that it’s 1000!
The key lies in checking multiple things:
- Is the fuel gauge showing tank as full?
- Is the checklist specifying the units fully – 1000 kgs?
- Are multiple personnel involved in the checks, not just one?
- Is an automated check available apart from human check?
Because lives are at stake. Especially so in these days of GenAI where information shared or leaked is of prime importance for safety and security. As Software Testing engineers, we have a lot of responsibility, testing in various ways, and in effective verification.
If your organisation is looking for an experienced leader in imparting the importance of Software Testing and Quality to your teams, please feel free to get in touch with me.
Cheers, and happy testing!
Image Source: https://arc-refuellers.be/aircraft-ground-refueling/
Image used for illustration purposes only.