Honolulu is home to one of the busiest airports in the US. It's the only hub for Hawaiian Airlines, and sees hundreds of daily flights from neighboring islands, Asia, North America, and the South Pacific. Traffic congestion here isn't just limited to airlines; flight schools, military operations, and cargo carriers all use PHNL around the clock.

A Unique Procedure Found Almost Nowhere Else

With two sets of intersecting parallel runways in use simultaneously, Honolulu isn't an airport you'll want to fly into unprepared.

One of the most unique features about this airport is a series of reversed hold short markings between Runways 4R and 4L. At most airports, you land, exit the runway on a taxiway, and ensure you've passed the hold short markings. Not in Honolulu. You'll need a clearance to exit this runway!

Because of the close proximity between 4R and 4L, there is no room to clear your runway and hold short of the parallel. For instance, if you're landing on 4R and want to taxi across 4L, you must stop before first set of hold short markings and receive a clearance to cross the parallel runway. During this time, you're still occupying the active runway and haven't cleared it.

The reason this procedure is so notable is because it stands contrary to your natural instincts as a pilot. At nearly every other airport, you're supposed to taxi across that first set of hold short markings as soon as you can. That way, the runway is clear for any traffic behind you.

You don't want to forget which side of the hold short markings you're on. If you're on the solid-lined side, you need a clearance. If you're the dashed-line side, you don't need a clearance to cross.

Fortunately, the controllers in Honolulu are more than used to this procedure, and when able, the tower clears aircraft to cross as soon as possible.

Runway Incursion Risks

It goes without saying that procedures like this increase your risk of a runway incursion. The second you cross that first set of hold short lines between the parallels without a clearance, you've created a runway incursion. It's an easy mistake to make, especially when you've never seen anything like it and are taxiing off the runway.

Expectancy is the risk here. Pilots unfamiliar with the airport have an expectation about how exiting a runway works and in which direction hold short markings are painted. In all of their previous flying experience, they may never have encountered something like this, because who would think you'd need a clearance to exit a runway?

If you're flying into an unfamiliar airport, remember that there might be local procedures contrary to the norm. If you ever see something that doesn't look or feel right, stop, and ask ATC before you go any further. It could be the one thing that prevents a runway incursion.