Getting a position out of your head and into somebody else’s, intact, over a bad radio, once.
Reading: about 10 minutes · Field drill: about 45 minutes
Bottom Line Up Front
A position you cannot pass is a position only you have. Everything this course has built — the settings, the verification, the decision rule — ends at a moment where somebody else has to receive a number and act on it, often over a marginal radio, often under pressure, usually once.
Three things decide whether that works. The format has to be one they can enter. The precision has to match what you actually know. And the exchange has to close the loop, so both ends know the number arrived intact. The report formats themselves belong to other courses; this lesson is about the position that goes inside them.
Recall Check · L03
From Lesson 03, since every report in this lesson carries one: how many digits of a grid reference should a handheld fix support?
1. What a position is doing inside a report
Position appears in several standard reports, and it does a different job in each.
Report
What the position is for
What that demands
Contact or observation report
Where the thing you saw is, which is often not where you are
Be explicit about which you are giving. This is the most common confusion in the whole set.
Situation report
Where the reporting element is now
Current rather than last confirmed, or say which it is.
Medical evacuation request
Where the aircraft or vehicle is going
The tightest precision you honestly have, plus an elevation with its reference named.
Routine position check
Confirming the plan is holding
Coarse is fine. A grid square is often enough and takes half the airtime.
The distinction in the first row is worth stopping on. “Grid four two three five one seven” passed during a contact report can mean I am here or the thing I am reporting is here, and the difference has sent help to the wrong one of the two more than once. Say which. Every time.
Knowledge Check
A member passes a grid during a contact report. What single addition prevents the most common misreading of it?
2. Precision is a claim, so claim honestly
Lesson 03 covered how grid strings carry precision in their digit count. Here is the operational consequence: the digits you send tell the receiving end how tightly to plan, and they will believe you.
Send ten digits and you have told somebody the point is known to a meter. Nothing about a handheld fix supports that, and the cost is not academic — a team briefed on a one-meter point searches a one-meter point, then widens grudgingly, having been told they should not need to.
Send the precision your fix has earned, and match it to the task. Six digits to confirm a leg. Eight for a rendezvous or a casualty location. Ten only if something other than a handheld produced it. Under-claiming costs a little search time; over-claiming costs trust in every number you send afterwards.
The same logic applies to lat/long. Five decimal places is roughly a meter, which is a claim you cannot back. Four is roughly ten meters and is usually the honest end of what to pass.
Knowledge Check
Why is over-claiming precision worse than under-claiming it?
3. Passing it without losing it
A position is a string of digits with no redundancy in it. Ordinary speech survives a bad radio because a listener can reconstruct a missing word from context; a coordinate cannot be reconstructed from anything. Every digit has to arrive.
Step 1WarnSay a position is coming and what kind. “Grid to follow” or “position, decimal degrees, to follow.” → Step 2Name the frameFormat first, then datum if there is any doubt. The receiving end sets up before the digits start. → Step 3Send in groupsDigits individually, in small groups, with a pause between. Slower than feels natural. → Step 4Get it read backThe receiving station reads the whole position back. You confirm or correct. Not optional.
The read-back is the same principle as Lesson 04’s rule about reading off the device rather than off your notes: the check has to be able to fail independently. A station that says “roger, copy” has told you they heard something. A station that reads the digits back has told you what.
Two habits go with it. Say the format in words the first time, because “three nine decimal seven eight two” and “three nine degrees four six decimal nine five” are different numbers that sound similar at speed. And keep numerals as digits, spoken individually — “four two three” rather than “four twenty-three,” which is heard as two figures about as often as three.
Knowledge Check
Why does a coordinate need a read-back when ordinary radio traffic usually does not?
4. The medical evacuation case
The evacuation request deserves its own note because it is the one where the position has the shortest path to consequences and the least tolerance for a query.
Give the landing area, not your casualty. If they are not the same point, say both and label them. An aircraft is going to the first one.
Pair the position with an elevation and name the reference — aviation works in height above sea level, per Lesson 03. An unlabeled elevation is a query at the worst moment.
Pass obstacles as heights too, with the same reference. Wires, masts, ridge crests. This is the part ground teams most often leave out.
Use the format the receiving service uses, which for civilian air ambulance usually means degrees and decimal minutes rather than a grid.
Verify before you send. This position gets acted on by somebody who cannot check your work, and Lesson 06’s thirty seconds is cheaper here than anywhere else in the course.
Knowledge Check
A ground team passes a landing area position and elevation to an inbound aircraft. What most often gets left out?
What to carry out of this lesson
Say whether a position is yours or the thing you are reporting on. That single word decides where help goes.
Precision is a claim and the receiving end will believe it. Under-claiming costs search time; over-claiming costs trust in every position you send afterwards.
A coordinate has no redundancy, so a corrupted one still looks valid. Close the loop with a read-back, not a “roger.”
For an aircraft: landing area, elevation with its reference named, and obstacle heights. The obstacles are what ground teams leave out.
Field Drill
Two radios, two people, ideally at a distance where the signal is imperfect.
Pass ten positions in each direction using the four-step sequence. Score them: any digit wrong counts as a failed position, not a near miss.
Do it again with one station deliberately saying “roger” instead of reading back. Count how many errors get through.
Practice the same position at three precisions and say aloud which task each one suits.
Write and pass one complete evacuation position: landing area, casualty location if different, elevation with reference, and obstacles with heights.
Add the format and precision decisions to your settings card. Lesson 10 makes them group policy.
Answer all four knowledge checks to unlock Lesson 08