U.S. aircraft operators are required to have digital position reporting (ADS-B Out) installed, working and certified by Jan. 1, 2020.
There are over 100,000 airplanes in the USA …
But with only a year to go, there’s some very interesting wrinkles per AVweb reader comments:
- aircraft owners are electing to do panel upgrades rather than ADS-B alone, which take weeks to months, not days. There are not nearly enough aircraft shops for that by the FAA deadline. An airplane on the ground is less than worthless, so I suspect a lot of owners will be walking away from their aircraft.
- ATC may not see any difference since FAA computers would require upgrades which take decades
- the low-cost vendors like uAvionix are being sued for patent infringement by Garmin. How can an FAA equipment requirement get tangled in patents?
- just like WAAS, what provides the GPS signal matters more than you’d expect. WAAS and ADS-B Out are supposed to be independent, but you get better resolution with a WAAS-compliant GPS source.
- the US military is ambivalent about ADS-B because they are designing M-code. They are also doing panel upgrades.
- If you think US aircraft owners will have a hard time meeting the mandate, apparently Airbus owners have even fewer options. Also, most airliners are leased, so upgrading would usually fall on the lessor.
- In some countries, 1090ES is required.
I think the lessons are:
- If you plan to upgrade your airplane, decide what you need (ADS-B Out only, a panel upgrade, or 1090ES for international flights or above 18,000′)
- If you’re buying a used airplane, let somebody else upgrade the panel for you
The ADS-B NPRM has a fascinating economic analysis of the roll-out cost for operators. The FAA was well-aware of the significant costs involved to re-equip aircraft. If you like horror movies, check it out. 
See SmartSky Air WiFi Promo
avweb.com: ADS-B Apocalypse
cincinnatiavionics.com: What’s the difference between 1090 and 978?
ainonline.com: FAA To Mandate ADS-B Equipage by 2020 (2007)
faa.gov: NPRM for Automatic Dependent Surveillance – Broadcast (ADS-B) Out performance requirements to support Air Traffic Control (ATC) service