New Advisory standardizes non-towered flight operations


A new Advisory Circular standardizes traffic pattern altitudes and procedures at airports without operating control towers.

Advisory Circular (AC) 90-66B, Non-Towered Airport Flight Operations, replaces two advisories: One from 1993 that addressed traffic patterns, and another from 1990 that provided communication guidance, according to officials with the National Business Aviation Association.

“No matter what a pilot flies – turbine, piston, parachute, glider, ultralight, lighter-than-air or unmanned aircraft system – they should read this AC, because it clearly presents the standards for operating at a non-towered airport,” said Richard Boll, a member of the NBAA Access Committee. “Not only does it guide the operation of a pilot’s particular aircraft, it gives the expectation of how pilots of other aircraft using the non-towered airport will operate.”

Standardizing the traffic pattern altitude was a primary focus of the members of the FAA’s Aeronautical Charting Forum, said Boll.

Noting the age of the previous guidance, he said the old standard was 800′ to 1,000′ above ground level (AGL). To eliminate that 200′ of confusion, the ACF set the standard at 1,000′ AGL, with left-hand turns, unless terrain or obstacles mandate otherwise.

Large and turbine-powered airplanes should enter the traffic pattern at an altitude of 1,500′ AGL, or 500′ above the established pattern altitude.

A recent change to the Aeronautical Information Manual introduced this standard, and the AC expands on it.

Cessna 172 Skyhawk. (Photo courtesy Cessna)

Entering the non-tower traffic pattern and self-announcing a flight’s position and the pilot’s intentions received equal detail and attention. It makes clear that airplanes terminating an instrument procedure with a straight-in approach do not have the right of way over VFR traffic in the pattern, said Boll. And when circling to land, left-hand turns are standard, unless otherwise documented.

The committee’s goal was to improve safety for all by standardizing operational practices and getting everyone who uses non-towered airports on the same 18 pages of the new advisory circular, Boll said.

“Everyone seems to focus on towered airport operations, but most of America’s more than 5,000 public-use airports do not have a tower, so safety depends on the pilots flying into them,” Boll said.

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