Private Pilot Flight Training and Instruction Flight Training Article Library | Back To 4VFR.COM ATC Problems in Decending Order Non-adherence to clearance, FAR's, or published procedures. Erroneous penetration of airspace - TCA's, ARSAs, or control zones. Airborne conflict Altitude deviations Equipment problem Written by Gene Whitt Flight Training Article Library | Back To 4VFR.COM