The US Federal Aviation Administration (FAA) will tighten requirements for aircraft making visual approaches to parallel runways starting in September based on a Eurocontrol-developed risk tool.
Controllers after 28 September must ensure that aircraft being vectored onto final approaches to parallel runways with 4,300ft (1,311m) or more separation have an intersection angle to the extended runway centreline of no more than 30º, allowing for relatively small turns to line up with the final approach course. Previously the angle requirement only applied to more closely spaced runways having a lateral separation between 2,500ft and 4,300ft.
The risk analysis process (RAP) tool, which the FAA adopted from Eurocontrol as part of its air traffic organisation's safety management system, is a forensic aid that sets a "level of risk present after any traffic incident" that results in loss of separation criteria, according to the FAA.
"A review of risk analysis events (RAEs) in the [national airspace system] indicated that approach clearances were being issued to aircraft at questionable times, such as high and fast on the downwind or base leg, which resulted in an overshoot of the extended runway centreline," says the FAA in the order, issued 19 July. "This caused a conflict with aircraft on approach to the other runway with both aircraft in a side-by-side belly-up situation." A belly-up orientation indicates roll angles large enough to prevent pilots from visually seeing the other aircraft on a parallel approach path.