The new rule was part of an overhaul of currency requirements and rules for logging flight time that was published on June 27. There were varying effective dates for the different sections that were modified. The requirement for instrument currency, which must be met every six months, now allows IFR pilots to track radials and fly the required instrument approaches and holding procedures in basic simulators classified as Aviation Training Devices (ATDs). With a starting cost of a little more than $5,000, these devices are affordable enough to keep in the home. Basic ATDs can be purchased from Redbird, Fly This Sim and Elite Simulation Solutions. Previously, pilots had to conduct currency flights in devices classified as either Full Flight Simulators (FFS) or Flight Training Devices (FTD), which are unaffordable to most pilots, and an instructor had to observe the flight for it to count toward currency, a rule that added to the expense and need for planning to keep current.