The diversion to an alternate airport and the three minutes where most checkride applicants fall apart

The diversion to an alternate airport trips up more checkride applicants than almost any other single task on the private pilot practical test — not because the skill is hard, but because most pilots never practice it the way the examiner actually presents it. The key to passing is understanding that the Airman Certification Standards (ACS) require “reasonable” estimates of heading, time, and fuel, not perfect ones. Fly the airplane first, make sound decisions, and communicate clearly, and the diversion becomes one of the most straightforward tasks on the checkride.

Why Does the Diversion Scenario Trip Up So Many Applicants?

The diversion sounds simple on paper: pick a new airport, figure out a heading, estimate time and fuel, and go there. Four steps. But when you’re already task-saturated in the airplane, with the examiner watching and your sectional chart folded to the wrong panel, those four steps can feel like forty.

The root cause is almost always the same. Applicants try to replicate their kitchen-table flight planning in the cockpit. They grab the sectional, pull out the plotter, and start measuring a precise course — and while they’re doing that, nobody is flying the airplane.

The examiner is not looking for a perfect course line. The ACS says you must “select an appropriate airport” and “make a reasonable estimate of heading, time, and fuel required.” The word reasonable is doing the heavy lifting in that sentence.

What Should You Do First When the Examiner Calls for a Diversion?

The first thing you do is nothing new. Keep flying the airplane. Aviate first. Confirm your wings are level, your altitude is holding, and your engine instruments look normal. Then take a breath. That breath isn’t wasted time — it’s you being pilot in command.

How Do You Pick the Right Alternate Airport?

Your sectional chart knowledge pays off here. You should already have a general awareness of airports near your route — not memorized, just a sense from following along on the chart during the cross-country. You should be able to identify a reasonable alternate within about 30 seconds.

The alternate doesn’t need to be the closest or the biggest airport. It needs to be a reasonable choice: a runway long enough for your airplane, with services if the scenario calls for it.

A common mistake is picking the technically closest airport that sits inside a Class C surface area with a control tower you’ve never talked to, adding unnecessary complexity to an already stressful moment. If there’s an uncontrolled field ten miles farther away with a nice long runway, that’s often the smarter pick. The examiner wants to see judgment, not just math.

How Do You Estimate a Heading Without a Plotter?

You do not need a heading to the nearest tenth of a degree. Here’s a technique that works well:

1. Find the airport on the chart
2. Put your thumb on your current position
3. Look at the nearest line of longitude or latitude between you and the airport
4. Estimate the angle relative to that line

This gives you a heading within about ten degrees, which is close enough. You can correct as landmarks come into view. This is pilotage and dead reckoning in real time — exactly what the examiner wants to see.

Use a VOR radial if one is handy. Use your GPS if the examiner allows it (most do for situational awareness), though they’ll still want to see you reference the chart. Point the airplane in roughly the right direction and refine as you go.

How Do You Estimate Time and Fuel Without a Flight Computer?

This is where applicants get bogged down the worst, pulling out the E6B and trying to calculate groundspeed and fuel burn with flight-plan-worksheet precision while the airplane drifts off heading and the altimeter winds down.

Here’s what “reasonable” looks like using numbers you already know:

• Groundspeed: You’ve been flying the cross-country, so you know your approximate groundspeed — say, 110 knots
• Distance: The airport is roughly 30 miles away
• Time: 30 miles at 110 knots is approximately 16–17 minutes
• Fuel burn: At 8 gallons per hour, 17 minutes requires just over 2 gallons
• Fuel remaining: You have plenty — done

No flight computer required. The examiner is checking whether you can make a sound aeronautical decision under pressure, not whether you can operate an E6B while flying.

What Are the Most Common Mistakes During the Diversion Itself?

Once you’re established on a heading, the diversion isn’t over. Four mistakes consistently cost applicants:

Failing to identify the airport environment. As you get closer, you should be matching landmarks on the sectional — a town, highway, lake, or railroad near the airport. If you fly the heading but never look outside or cross-reference the chart, the examiner will question how you’d find any airport without a magenta line on a screen.

Forgetting to get weather. If the scenario is deteriorating weather, the examiner expects you to check conditions at your alternate. Tune in the AWOS or ATIS frequency if available. If neither is available, say so — and tell the examiner you’d call Flight Service on 122.2. Thinking out loud scores points.

Neglecting descent planning. If you’ve been cruising at 4,500 feet and the airport is 8 miles ahead, when do you start down? A 500 fpm descent starting about 10 miles out at cruise speed gets you down comfortably. Brief the traffic pattern direction, know the runway, know the pattern altitude, and fly a normal pattern entry.

Forgetting to communicate. If you were on flight following, tell approach you’re diverting. If you filed a VFR flight plan, update Flight Service. If the diversion airport has a tower, make contact. Communication is its own area of operation on the ACS, and applicants who focus solely on navigation often forget this entirely.

What Does a Good Diversion Look Like Start to Finish?

Here’s the full sequence as it should flow in the airplane:

You’re on the second leg of your cross-country. The examiner says your destination has gone below VFR minimums.

1. “I’m going to keep flying the airplane and find us an alternate.” Maintain heading and altitude.
2. Glance at the sectional. You spot an uncontrolled airport about 25 miles to the southwest with a 4,000-foot runway.
3. Estimate heading: looks like about 220 degrees. Turn to 220.
4. Estimate time: 25 miles at 100 knots groundspeed = approximately 15 minutes.
5. Estimate fuel: three hours remaining, so fuel is not a concern. Say all of this out loud.
6. Tune the AWOS for the new airport. Winds are 180 at 8 — expect Runway 18, left traffic.
7. Begin descent about 8 miles out.
8. Enter the pattern on a 45 to downwind for Runway 18. Make your calls on CTAF.

Fly it calmly, communicate clearly, and make reasonable estimates — that’s a passing diversion.

How Should You Practice the Diversion Before Your Checkride?

Don’t pre-plan a diversion to a specific airport. Have your instructor pick a random moment during a practice cross-country and throw the scenario at you cold. Do it three or four times. By the third attempt, it won’t feel nearly as overwhelming, and by the fourth, it’ll feel almost routine. That’s exactly where you want to be when the examiner springs it on you.

Key Takeaways

• Fly the airplane first — no chart work until you’ve confirmed wings level, altitude holding, and engine instruments normal
• Pick a reasonable airport in 30 seconds using your sectional awareness, prioritizing judgment over proximity
• Eyeball your heading using latitude/longitude lines on the chart — ten degrees of accuracy is plenty
• Use mental math for time and fuel based on numbers you already know from the cross-country
• Don’t forget the “after” tasks: get weather, plan your descent, and make all required radio calls