In praise of the Empirical

There’s a lot of people busying themselves and tying themselves up in knots trying to work out how to ensure that new aviation developments fly safely. Making possible the safe introduction of new air vehicles into an already complex system occupies meeting after meeting across the globe.

Advanced Air Mobility (AAM)[1] will mean full time aviation activities in unfamiliar places. There’s a such a complex maelstrom of interacting bits and pieces that it’s not easy to see the light at the end of the tunnel. This is driving innovation and a fresh look at how the business of safety assessment and assurance is done.

Since the first days of my working in an engineering department, I’ve been a supporter of a systematic approach. Over the decades this has paid handsome dividends. I don’t think there would ever have been a civil fly-by-wire aircraft in service if it was not for systematic engineering.

This does require a great deal of characterising and parameterising of measurable items. This is to distinguish, down to a fine level, technical attributes that can be verified and validated. In fact, the concept of verification and validation (abbreviated as V&V[2]) is upheld with almost religious passion.

The emphasis coming from the advocates of AAM is often on flexibility, openness to latest ideas and speed of working. The emphasis coming from public authorities is on maintaining or enhancing existing levels of flight safety[3]. Both are right and bridging the gap is quite doable.

What is most dangerous is to see this equation as purely binary. That is to discard a systematic approach in favour of a more try it and see, empirical approach. Innovation isn’t about throwing away the past. It’s about building on the past. All aviation activities involve safety risk. There are 3 things that can be done with risk: eliminate it, mitigate it, or live with it. To do any of these 3 things it’s first necessary to understand it.

So, I’m putting my finger on the greatest difficulty and that’s anticipating the future. To understand AAM[4] risks requires an appreciation of the combinations and permutations of different interactions that can exist in an aviation system with fast vehicles in dense environments. This is where classical V&V has limitations. It because of the vast, and I mean vast number of different live scenarios that can exist. Afterall the flight operations of AAM are supposed to be wide-ranging and unconstrained.

Hence my title. Not only do we need empirical means of proving systems, but existing means need to be improved. Going off and doing a bit of flying just doesn’t cut it.


[1] https://skybrary.aero/articles/advanced-air-mobility-aam

[2] These are critical components of a quality management system such as ISO 9000

[3]https://publicapps.caa.co.uk/docs/33/Advanced%20Air%20Mobility%20Taking%20a%20Use%20Case%20Approach.pdf

[4] https://www.faa.gov/uas/advanced_operations/urban_air_mobility/

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s