A student is flying a dual cross-country over the Laikipia plateau in the early afternoon. The planned leg is forty minutes. At the fifty-minute mark the river they expected to cross has not appeared, the instructor has been quiet for a while, and the student has stopped reading out checkpoints. The student has not said "I am not sure where we are". They have simply decided to fly on for five more minutes and see whether things start to look right.
That decision, to wait and hope, is the real hazard. Being unsure of your position is a normal part of VFR flying. Staying quiet about it while fuel burns and daylight shortens is what turns an inconvenience into a problem.
The Short Version
- Uncertain position is common and recoverable. It becomes dangerous when it is hidden, delayed or combined with fuel, weather or daylight pressure.
- The FAA Aeronautical Information Manual names 121.5 MHz as an emergency frequency, notes that it is guarded by direction-finding stations and some other aircraft, and says its range is generally limited to line of sight (FAA AIM, Chapter 6, Section 3).
- The same chapter describes squawking 7700 if you cannot reach an air traffic facility, and giving your last known position, the time, and the heading flown since then (FAA AIM).
- Climbing, where terrain and cloud allow, helps radio and radar contact, and that point is also made in the AIM text above.
- Decide on the ground, before start-up, the point at which you will stop trying to fix it yourself and ask for help.
Uncertain is not the same as lost
It helps to separate three states. On track means you can match the ground to the chart. Uncertain means one or two things do not match, but you still have a good idea of your area. Lost means you cannot say with confidence where you are within a reasonable distance.
Most flights that end up lost spent a long time in the uncertain state first. The discipline is to treat uncertain as the trigger, not lost. If you wait until you are certain you are lost, you have usually already used up the fuel and the daylight that would have made the fix easy.
Kenyan terrain makes the uncertain state easy to slip into. Large parts of the north and the Rift Valley floor offer few distinctive features, dust and haze flatten the view (see our piece on reduced visibility), and afternoon cloud can shade the very ground you are trying to read. The techniques in pilotage and dead reckoning without GPS are the foundation. This article is about what to do when they stop agreeing with each other.
Step one: stop making it worse
The first job is to stop the error from growing. A few simple actions do most of the work:
- Fly the aircraft. Keep a steady heading, altitude and airspeed. A pilot who is staring at the chart and drifting is adding error faster than they are removing it.
- Note the time. Write it down, with your last confirmed position and the heading you have held since. The AIM wording quoted above asks for exactly these three items when you speak to an air traffic facility, so having them ready helps whether you ask for help or not.
- Check fuel and daylight. Work out how long you can fly and how long until last light. Every decision that follows depends on those two numbers. Our fuel planning article covers how to calculate them in advance.
- Do not chase the chart. The urge to bend the ground to match your expectation is strong. If the river is not where you expected, assume your position is wrong, not that the river has moved.
Step two: use what you already have
Before anything else, use the information in the cockpit and on the ground.
- Time and heading from your last fix. This gives you an area, not a point. Draw the area, not a dot.
- Large, unmistakable features. A lake, an escarpment, a main road or a railway line is easier to identify than a small village. Look for the line feature, then decide which way along it you are.
- A known line to fly to. If you are sure you are somewhere east of a long north-south feature, flying west will bring you to it, and you then know where you are along its length.
- A GPS, if you have one. Use it as one source among several, not the only one. Check it against the chart.
Keep the plan simple. A plan that you can fly in one sentence beats a clever one that needs the chart in your lap.
Step three: ask early, and know who to ask
This is the step that student pilots resist, because asking feels like admitting failure. It is the opposite. An early call costs a few minutes of radio time. A late call may come when fuel is short and options are limited.
The order is a matter of judgement, and the FAA's AIM notes that there is no fixed priority on which approach to try first in a communications problem. A sensible sequence for a Kenyan cross-country is:
- Call the unit you last spoke to on the working frequency. Give your last known position, the time, and your heading since.
- If there is no reply, try another unit or flight information frequency you planned for in your briefing.
- If that fails, use 121.5 MHz. The AIM describes it as guarded by direction-finding stations and some other aircraft, with a range generally limited to line of sight, so altitude helps (FAA AIM). Our article on MAYDAY and PAN-PAN calls covers the wording.
- If you cannot reach anyone and you have a transponder, the AIM describes squawking 7700 so that radar can flag your position (FAA AIM).
A word on the 121.5 point. Kenya's own AIP and rules are the authority for local frequencies and procedures, and the FAA manual is an American publication. We cite it because it sets out the principle clearly, not because it replaces Kenyan requirements. Check the current Kenya AIP and your school's operations manual for the frequencies and services that apply to your route.
If you filed a flight plan, the people on the ground already expect you at a given time. That is the quiet strength of the habit described in our flight plan and search and rescue article: it makes asking for help a smaller step, because someone is already watching the clock.
Step four: choose a landing, not a hope
If you are still uncertain and the fuel or daylight number is getting uncomfortable, stop planning to find your route and start planning to land safely. That means choosing a suitable aerodrome, airstrip or, in the worst case, a field while you still have options. Our forced landing site selection article explains how to judge a site from the air.
A precautionary landing on a good surface with fuel in the tanks is a far better outcome than a forced landing when the engine stops. If you carry an emergency locator transmitter, our piece on emergency equipment for remote flying sets out what Kenyan rules require.
Why pilots stay quiet
The reasons are almost always human, not technical:
- Embarrassment. Students worry that an instructor will think less of them. A good instructor thinks more of a student who speaks up.
- Get-there-itis. The wish to reach the destination makes five more minutes of hoping feel reasonable. See our article on get-there-itis.
- Plan continuation. Having flown this far on one plan, abandoning it feels like a loss.
- Workload. A pilot who is busy does not notice the time passing.
The fix is not more willpower. It is a rule agreed beforehand. Many schools and instructors use a simple one: if you cannot match the chart to the ground within a few minutes of your expected checkpoint, say so out loud.
A briefing line to agree before start-up
- "If a checkpoint has not appeared by [time], we call it uncertain and say so."
- "Uncertain means: steady heading, note the time, check fuel and daylight, and look for a big feature."
- "If we are still unsure after [number] minutes, we call for help. That is a good decision, not a failure."
- "With [amount] of fuel or [time] before last light, we land at the best available site."
Write the actual numbers down on the kneeboard. A number agreed on the ground is much easier to follow than one invented in the air.
Practice it
Lost procedures are a skill, and like any skill they need rehearsal. Instructors can build the scenario into dual cross-country training by asking the student to talk through a simulated uncertain position. A good exercise is to cover the GPS, pick a point on the planned route, and ask: "You cannot see your next checkpoint. What do you do?" The student then walks through the steps above aloud. For AOPA's approach to the same problem, see their student guidance, Lost and unhappy.
AngaBrief's pre-flight assessment helps a student and instructor think about navigation workload, fuel and weather before departure. It is not a dispatch authority: final go or no-go rests with the pilot in command, and so does the decision to speak up when the ground stops matching the chart.
Key Takeaways
- Uncertain position is normal. Hiding it is the hazard.
- Stop the error growing: steady heading, note the time, check fuel and daylight.
- Ask early. Give your last known position, the time and your heading since.
- 121.5 MHz, line of sight, and a 7700 squawk are tools described in the FAA AIM, but check Kenyan AIP procedures for your route.
- Agree your trigger and your landing decision on the ground, with numbers.