The Shearing Layers of the NAS
I hope to share, over the next few editions, a synthesis of writings of a few systems thinkers I admire by applying it to the NAS.
A fundamental insight of Stewart Brand’s pace layering for complex systems is that “fast learns, slow remembers” and that the layers can “slip” past each other - change in the upper layers can occur at a faster pace without negative impacts. Today, I fear that in the increasingly frenetic pace of change, the memory offered by the slow layers are either being degraded or ignored. Building expertise takes time but losing it can happen in an instant. This can lead to catastrophic outcomes.
Adopting Stewart’s model to the NAS and simplifying it to a few layers (three, to Brand’s six) :
Fashion/Commerce (Fast): New entrants like Advanced Air Mobility (AAM), drones, and commercial space launches. They are experimental and push boundaries.
Infrastructure (Medium): The ground-based radar, satellite constellations (GPS/ADS-B), airspace design, and communication links. These change over decades.
Governance/Culture (Slow): Safety regulations, ICAO standards, and the "Pilot-in-Command" culture. These provide the necessary friction to ensure the "Fast" layers don't compromise safety.
Stewart points out:
Fast learns, slow remembers. Fast proposes, slow disposes. Fast is discontinuous, slow is continuous. Fast and small instructs slow and big by accrued innovation and by occasional revolution. Slow and big controls small and fast by constraint and constancy. Fast gets all our attention, slow has all the power.
In the NAS, slow did (does?) indeed have all the power — in fact almost a stranglehold. The slow layers are slow for a reason and any temptation to accelerate changes in that layer without forethought will have unanticipated consequences. Fast and small is meant to influence changes in the slow layer by accrued innovation - and when the slow layers don’t change, an occasional revolution forces the change. FAA’s proposed SMART is a small revolution in the making. I hope the slow and big does indeed provide the necessary checks and balances, and constancy to the NAS.
All models are wrong but some are useful. Stewart Brand’s pace layering for complex systems is profoundly useful. The article linked above is really short and pithy - I cannot restate the arguments there any more eloquently than Brand. NAS is not the only place where this applies - you will see this play out in a variety of other cases. I would dearly love to know what you think - please email me your comments and questions.
An occasional reminder that we live in a scary world
I had plans to land FIFA26 tickets and then this happened. Some knuckleheads stole some agricultural drones and that sent the FBI into a tizzy. This is one of those times where I wished dearly that I had access to internal FAA information and insights. This news gave me pause.
When people complain about how slow regulations are ( we need pizza delivery by drones, right now, damn it) we forget that it is the careless, clueless, and the criminals that usually hamstring the regulators. Mercifully, this particular incident seems to have had a reasonably happy ending - though I don’t know any of the details of the investigation. The cynic in me says that this is not the last one of this kind we will have to worry about.