AIM ¶ 4-1-21 — Airport Reservations and STMPs
AIM 4-1-21 explains slot-controlled airport reservations, Special Traffic Management Programs (STMPs), and Prior Permission Required (PPR) procedures for pilots.
AIM 4-1-21 covers three reservation systems pilots may encounter when flying into busy or specially managed airports.
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Slot Controlled Airports: The FAA limits unscheduled operations at certain high-density airports. The Airport Reservation Office (ARO) uses the Enhanced Computer Voice Reservation System (e-CVRS) at fly.faa.gov/ecvrs to allocate slots. Reservations open 72 hours in advance, no standby lists exist, and declared emergencies don't need a reservation. Details are in 14 CFR Part 93, Subpart K.
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Special Traffic Management Programs (STMPs): Temporary programs for events like the Super Bowl, Oshkosh, or SUN 'n FUN, or reduced capacity from construction. Reservations are made via e-STMP (fly.faa.gov/estmp), and a domestic notice publishes the airports, dates, time windows, and contact info.
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Prior Permission Required (PPR): Used when traffic doesn't justify an STMP but operations are limited (ramp space, runway construction, snow removal, GA into military fields). PPRs are published via NOTAM or in the Chart Supplement remarks. Pilots — not controllers — are responsible for compliance, and an issued ID number must go in the flight plan Remarks.
Knowing which system applies prevents you from being turned away or creating a ground safety hazard.
Five FAA-written-style questions. Instant explanations, every answer cites its source — no account needed.
You are flying VFR in Class E airspace at 8,500 feet MSL during the day. What are your minimum visibility and cloud clearance requirements?