xkcd.WTF!?

Explanation ➲

The "ANC" Pilot Priority Checklist is a list of three guidelines, sorted by priority, that pilots should follow to prevent them from being distracted. Failing to follow it might make the aircraft crash or suffer other problems. As a mnemonic device, all the activities end in -ate.

1. Aviate means keeping the aircraft in control. If the pilot fails to do this the aircraft might crash, so this should be the highest priority for the pilot.
2. Navigate means knowing where you are and where you're going. Failing to follow this might make the aircraft go into restricted airspace, for example, make the journey take too long, or cause the flight to crash into terrain obscured by clouds.
3. Communicate means talking with air traffic control (ATC) and your company's people through the radio. In the standard list, this is the lowest priority because talking through the radio might distract the pilot from other more important tasks.

By deferring less important activities until the prior need is deemed satisfied, the immediate dangers of flight into terrain (uncontrolled and controlled flight into terrain) are reduced — as the pilot's current circumstances allow — and yet can provide for addressing other hazards.

Randall humorously "extends" this standard list with other -ate checklist items that pilots could do if they're not too busy aviating, navigating and communicating. These extra tasks range from somewhat hilarious to physically impossible or dangerous; see the table below for explanations. These actions should generally not be taken, as they could distract the pilot and prevent them from reaching the cabin in case of an emergency, or vaporize everyone inside along with portions of the airframe.

Airspace classes in the United States

The title text adds another -ate item to the checklist: Celebrate, whereupon congratulatory cakes are served to the passengers. The "inverted tiers" refers to the airspace class diagram used in the United States, used by planes circling over airports. The class diagram starts with a small circle over the airport and then becomes wider in one or two steps at higher altitudes. When depicted graphically, this looks like an inverted tiered cake, as opposed to a regular tiered cake. Randall suggests that after having congratulated yourself for flying an aircraft, you could then celebrate by serving the passengers cakes in this inverted shape. It would, however, be unsuitable for an aircraft to serve cakes that are smaller at the bottom than at the top because of turbulence.

Table of extended priority items

Checklist item	Description	Explanation
Decorate	Make the cockpit fancy	Interior design of aircraft cockpits is usually starkly utilitarian and could conceivably benefit from enhancements if they aren't distracting. See for example this comparison of SpaceX and Boeing space capsule cockpits.
Accelerate	See how fast you can go	While pilots are often keenly interested in the extents of their aircraft flight capabilities, maximum speed is inefficient in jet aircraft, and probably best explored during testing rather than passenger flights. Exceeding VNE might even destroy an airplane, see [1]
Roller skate	Zoom down the aisle	Passengers would probably not appreciate this,[citation needed] although fellow crew members might be amused. Or possibly vice versa.
Exfoliate	Scrub away dead skin	Emery boards and pumice are used to prevent flaking and the development of calluses but dermatologists caution exfoliation is very often unnecessary and can have unwanted consequences. Volcanic ash has an exfoliating but unwelcome effect on aeroplanes.
Sublimate	Turn directly into a vapor	To the contrary, one of the most important duties of aircraft pilots is to prevent passengers and crew from vaporizing because the ANC checklist is impossible to perform in gaseous form.[citation needed]
Pollinate	Fly low to stir up pollen	Low-flying helicopters can assist in plant pollination,[2] and are offered as a commercial service by helicopter pilots. It is unlikely that airliners flying at much higher altitudes would be able to do the same, however.
Congratulate	You're doing a good job flying a plane!	This item suggests that the pilot should praise themself for "doing a good job flying a plane", when ironically, if they did all of the above items, they would not be doing a good job of this.
Celebrate (title text)	Serve passengers tiered cakes shaped like the airspace class diagram	See discussion of the title text above.