Ahead of NBAA in 2017, ShowNews spoke with Eric Stuck, the product manager at Satair in Atlanta who manages that company's program in partnership with Honeywell to carry out ADS-B Out upgrades to Primus II-equipped business aircraft in the U.S.

He painted a disturbing picture of how ill-prepared operators were, and suggested as many as 1,000 Primus jets would fail to be compliant by the Dec. 31, 2019, deadline – meaning those aircraft would effectively be grounded. A year on, the situation is different.

"Oh, it's changed," Stuck says. "For the worse."

How so?

"Even as we enter the fourth quarter of 2018, with less than 15 months to go, the operators are still complacent," he says. "The uptake rate has picked up – we're at about three times the number of ADS-B conversions that we did last year. But it will take something closer to 10 times if there is to be any chance of everyone getting done."

With an estimated 7,000 business jets – a quarter of them Primus II jets – still to be converted, the issues remain the same ones that were worrying Stuck a year ago. He says around 4,000 aircraft will not make the deadline.

"There's capacity with Honeywell and at Satair – we have exchange boxes and new hardware on the shelf," Stuck says. "But the industry just does not have the capacity to process 7,000 airplanes in one year.

"One of the reasons is hangar space," he explains. "The 70-80% of aircraft that are equipped ahead of the mandate will continue to need maintenance, and those operators aren't going to give up their maintenance slots so that the stragglers can get ADS-B done. Following very closely behind that is the number of available technicians to perform the upgrades. Avionics technicians are in short supply globally."

To the outsider, the reluctance to carry out this mandatory work appears baffling. The costs are nontrivial – Stuck puts the figure for most turbofans as being in the $100,000-$150,000 range – and the work means the aircraft will be on the ground for some time. But there is no way around installing the equipment, and the program was announced with the longest lead time of any FAA mandate – some 10 years before the deadline – so the work could have been scheduled to take place in tandem with major checks or other scheduled maintenance.

Stuck acknowledges that owners of some older aircraft may not intend to fly them beyond the end of next year. As many as half of types such as the Learjet 30 and 35, for instance, are expected to be retired in the next 10 years, and ADS-B may well be one expense too far for owners of some of them. But these only account for a minority of aircraft yet to be converted.

Of around 4,000 business jets in the U.S. that won't make the mandate, Stuck expects 1,000 might part-out and retire “but I don't see 3,000 of them doing that."

There will be opportunities amid the chaos, provided owners of charter fleets have converted their jets. Surprisingly, Stuck's soundings suggest the charter sector includes many operators yet to schedule the work.

"I always explain to the fleet guys – the Part 135s that operate 20, 30, 40 airplanes – that if you get your airplanes equipped you're going to be able to name your price for two years, because there's going to be such a need for charter," he says. "Seventy-four percent of private jets in the U.S. are owned by companies that have only one private jet. So, when that goes down, they're going to look to charter. Yet the charter operators are oftentimes even more reluctant to spend money than the owner of an individual aircraft."

For those still to schedule the work, Stuck's message is simple, and stark.

"We are at the 11th hour," he says. "Mr. Pilot, Mr. Operator: If you want to keep your job, you probably have Q4 of this year – which we're in now – to secure a slot before the mandate. By the time we get into 2019, there will be very few slots available; and, by the end of Q1 2019, as an industry, we will be scheduling airplanes into 2020, after the mandate has come into effect."