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Commercial pilot · ACS CA.VI.D · lesson pack

Lost Procedures

Why this one matters

Being lost isn't the danger; what pilots do while lost is: wandering at low altitude, burning fuel, flying into weather or darkness, too embarrassed to ask for help. A commercial pilot with passengers has more reason, not less, to call ATC early. Radar can find you in seconds.

1 · Know these cold

  • •Fly the airplane first: steady heading and altitude, no wandering in search of landmarks.(PHAK (FAA-H-8083-25C), Navigation)
  • •Climb if you can safely: you'll see farther and get better radio, navigation and radar coverage.(PHAK (FAA-H-8083-25C), Navigation)
  • •Start from the last known position and time: heading, groundspeed and elapsed time give a circle of probable position.(PHAK (FAA-H-8083-25C), Navigation)
  • •Use every tool: GPS, VOR cross-bearings, prominent landmarks, ATC radar.(PHAK (FAA-H-8083-25C), Navigation)
  • •The Five Cs, after flying the airplane: Climb (see farther, better radio and radar); Communicate and Confess (tell ATC or Flight Service you're lost); Comply (follow their vectors and instructions); Conserve (reduce to maximum-endurance power and lean per the POH).(AIM, Chapter 6, Emergency Procedures)
  • •Declare an emergency when fuel, weather, daylight or your own state is deteriorating: priority now, paperwork later.(AIM, Chapter 6, Emergency Procedures)
  • •Any one of low fuel, fading daylight, weather or terrain is enough: land at a suitable airport. If you'd land with less than the 91.151 reserve (30 minutes by day, 45 at night), land now.(Risk Management Handbook (FAA-H-8083-2A); 14 CFR 91.151)

2 · The lesson

Finding your position
  • Recorded checkpoint times are your lifeline: from the last known point, heading, groundspeed and elapsed time give a circle of probable position.(PHAK (FAA-H-8083-25C), Navigation)
  • Look for large, unmistakable features (a lake, a highway interchange, a river bend, a city) and match them to the chart, not the other way round.(PHAK (FAA-H-8083-25C), Navigation)
  • Use GPS if it's working. With VORs: tune and identify each, center the needle with a FROM flag to read the radial, note the time, and take the second radial promptly (or circle a landmark while you plot), because radials taken minutes apart cross where you were, not where you are.(PHAK (FAA-H-8083-25C), Navigation)
  • Hold a steady heading while you start working the position, or deliberately circle over an identifiable landmark while you plot and talk. The mistake is pressing on along a guessed heading or turning aimlessly.(PHAK (FAA-H-8083-25C), Navigation)
Getting help
  • Call the nearest approach control or center (frequencies on the chart), or Flight Service; ATC radar can identify you and give vectors, and Flight Service can give direction-finding help. If you're already talking to ATC, stay on that frequency and keep your assigned code with Mode C.(AIM, Chapter 6, Emergency Procedures)
  • The call: "Pan-pan" three times for urgency, "Mayday" three times for distress; then your call sign and type, the problem, your last known position and time, heading since, altitude, fuel remaining, people aboard and the help you want.(AIM, Chapter 6, Emergency Procedures)
  • Can't raise anyone promptly, or it's distress or urgency? Use 121.5 MHz and squawk 7700. Being unsure of your position alone doesn't require leaving a frequency where ATC is already helping you.(AIM, Chapter 6, Emergency Procedures)
  • Declare an emergency when fuel, weather, daylight or your own state is getting worse; you get priority and help immediately.(AIM, Chapter 6, Emergency Procedures)
Staying safe while lost
  • Being lost pulls your eyes to the chart and the screen: keep scanning for traffic and terrain, and keep the airplane level and trimmed.(AC 90-48, Pilots' Role in Collision Avoidance)
  • Stress narrows attention: slow down, fly the airplane, then work the position methodically, then decide.(Risk Management Handbook (FAA-H-8083-2A))

Want it all on one page, with scenarios? Read the full lesson.

On the flight

ACS standards

  • Use an appropriate method to determine position; maintain an appropriate heading and climb as necessary; identify prominent landmarks.(Commercial Pilot ACS (FAA-S-ACS-7B), CA.VI.D.S1-S3)
  • Use navigation systems or contact ATC for assistance; select an appropriate course of action.(Commercial Pilot ACS (FAA-S-ACS-7B), CA.VI.D.S4-S5)

What your instructor is watching for

Your instructor watches for steady control first, a climb if appropriate, a methodical position fix from the last known point, use of every navigation aid, and an early, clear call to ATC.

3 · Say it out loud

Answer each one out loud, then check yourself and mark how it went.

  1. Remember Recall it

    “What are the Five Cs, and the emergency frequency and code?”

  2. Understand Explain why

    “Why climb when lost?”

  3. Apply Use it on a flight

    “Lost, 45 minutes of fuel left, sunset in 30 minutes, passengers aboard. What do you do?”

4 · Common mistakes

  • Wandering in circles.

    It burns fuel and makes the position harder to work out.

    Instead: Hold a heading and work methodically.

  • Waiting to ask for help.

    Options shrink with fuel and daylight.

    Instead: Call ATC early.

  • Forcing a landmark to fit the chart.

    It confirms a wrong position.

    Instead: Find a feature that only fits one place.

5 · Quick check

Answer, then reveal. Flag anything you want to see again.

  1. 1. What should you do first when lost?

  2. 2. How do two VOR radials help?

  3. 3. Who can help a lost pilot?

  4. 4. When should you declare an emergency?

  5. Scenario5. Lost with low fuel near a suitable airport. What do you do?

Trained it? Now prove it: practice lost procedures out loud with our examiner.

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Connect it

One situation that runs across this lesson and its neighbors in the same ACS area. Decide first, then check.

Connect it · Navigation

A night cross-country. Headwinds are stronger than forecast and your groundspeed is down 25 knots.

How do your checkpoint times feed a diversion decision? Decide, then see the worked answer

Compare the actual time at each checkpoint with the plan. A 25-knot shortfall stretches every leg, so recompute the fuel to the destination at the actual groundspeed. Keep the reserve separate: 91.151(a)(2) requires enough fuel at night to reach the destination and then fly 45 more minutes at normal cruising speed, so add 45 minutes at normal cruise on top of the destination fuel. That's the legal floor; a personal minimum can raise it but never lower it. If you'd land with less than your minimum, divert now, while you still know exactly where you are. At night, choose the alternate with the Chart Supplement: runway lighting and how it's activated, runway length and surface, and whether fuel is actually available at that hour. Note the time and heading as you turn, estimate heading, time and fuel to the new airport, then refine. Leaving it late, at night, is how being short of fuel turns into being lost.

14 CFR 91.151; PHAK (FAA-H-8083-25C), Navigation; Chart Supplement

Brings together: Pilotage and Dead Reckoning · Diversion

Teaching this? The instructor lesson plan →

Study aid, not FAA guidance. Sources: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C); Advanced Avionics Handbook (FAA-H-8083-6); Aeronautical Information Manual (AIM); 14 CFR Part 91; AC 90-48 and AC 91-78; Commercial Pilot ACS (FAA-S-ACS-7B). Checked against current sources 2026-11-13.