IFR Fix: 'Pay attention!'

August 2, 2013

The Cessna 310 was in a holding pattern at 8,000 feet when the controller called with a beef.

“Returned to 7,500 feet," the flight instructor later explained in an Aviation Safety Reporting System account, chiding himself, "Pay attention!”

What was so distracting that it caused a 500-foot altitude bust?

Instead of a simple clearance to a holding pattern neatly depicted on a chart, the flight had been given an uncharted VOR hold with instructions to proceed to the 7-DME fix on the 110-degree radial, and hold west.  

Got all that? 

Neither did the twin’s occupants. A “discussion” began in the cockpit as the student set up the nav radios for the procedure. That’s when the crew stopped paying attention and the aircraft climbed.

How many clearances will you have to copy, digest, and fly on your next IFR trip?

At least one, your route—probably received comfortably before departure. A perfectly routine matter, assuming you can read it back without error, fly in glorious sunshine, and cancel near the destination for an easy VFR arrival.

Possibly two clearances: You continue IFR to the destination, and then shoot an approach.

It wouldn’t take much, however, for the trip to become more complicated. The Aug. 2 "IFR Fix To avoid confusion" recounted the narrative of an air-taxi checkride that—while descending toward minimums—was cleared to an alternate missed approach fix via an unpublished route, prompting a pilot’s protest.

A clearance to an uncharted hold would be a similarly rude surprise, requiring quick visualization, precise setup of nav instruments, and rapid compliance. That’s a scenario worth some practice.

To review, the Aeronautical Information Manual 5-3-8 gives six types of information that will be provided to a pilot cleared to an uncharted hold. In brief, they include direction; the holding fix; radial or course; leg length; direction of turns (if left turns); and an expect-further-clearance (EFC) time.

At armchair altitude, that seems mentally manageable, but at 7,500 (or 8,000) feet, perhaps it’s not such a slam dunk.

And that’s not the whole drill. What if detailed clearance information isn’t forthcoming as you approach the assigned fix? (Enter a standard hold, the AIM chapter explains, also discussing altitudes and EFC procedures.)

Bottom line: Having to copy, comprehend, and comply with a partly unpublished clearance can take a big bite out of a pilot’s attention.

Perhaps too big. Visualizing such scenarios ahead of time will give you an edge.