A current instrument pilot flying a VFR cross-country with two passengers aboard observes that the solid cloud deck below is getting higher, the broken layer above is getting lower, and it’s thickening. No matter, he can still file IFR—right?
Maybe. Radio communications with the center have been scratchy at this altitude, and unfamiliarity with the names of local intersections is making the clearance a complicated thing to copy. The ride is getting bumpy, and the cloud decks appear to be merging.
What to do?
The solution was to request diversion to a nearby towered airport with a straightforward, no-curveballs ILS approach that had been reviewed in advance in case the airport might have been useful as a fuel or rest stop.
Refreshed, refueled, and rerouted, the flight proceeded to the final destination.
Requesting a pop-up clearance, that is, filing in flight, as the process is officially defined in the Instrument Flying Handbook (page 10-2) works as a sure-fire safety valve if the pilot doesn’t make the request at too low an altitude, enter clouds before receiving clearance, or try to file in congested airspace. (The handbook reminds pilots to “be aware that traffic saturation frequently prevents ARTCC personnel from accepting flight plans by radio. In such cases, a pilot is advised to contact the nearest FSS to file the flight plan.”)
In some scenarios, such as requesting instrument approaches in the local area, getting a clearance may hinge on air traffic control’s workload; flying your session under VFR remains an option.
What’s important is to avoid scenarios when popping up will mark you as an unwanted presence at an invitation-only party. During the recent holiday period, with the coronavirus pandemic ongoing and a rush of traffic pressuring ATC operations, the FAA worked to head off what it knew some pilots might try to do to skirt delays, cautioning that pilots should not count on being able to air-file IFR flight plans or receive clearances along the East Coast.
As with any prescription solution, air-filing is a remedy to take only as directed.