Ground Reference Maneuvers

Not optional. For ASEL or ASES the evaluator must select Tasks E and F — both — along with Task A or B and Task C or D (FAA-S-ACS-25, Area IX note). For AMEL or AMES the required selection is Tasks A and E, so ground reference maneuvers are on every airplane-category CFI checkride.

How many you fly: the evaluator selects at least one ground reference maneuver for the applicant to demonstrate (FAA-S-ACS-25, Task IX.E note). You don't get to pick which one, so you must be able to brief, demonstrate, and narrate the rectangular course, S-turns, and turns around a point.

• Clear the area (AI.IX.E.S1); select a suitable ground reference area, line, or point as appropriate (AI.IX.E.S2)
• Rectangular course — enter a left or right pattern, 600 to 1,000 feet AGL, at an appropriate distance from the reference area, 45° to the downwind leg (AI.IX.E.S3a)
• S-turns — enter perpendicular to the selected reference line, 600 to 1,000 feet AGL (AI.IX.E.S3b)
• Turns around a point — enter at an appropriate distance from the point, 600 to 1,000 feet AGL (AI.IX.E.S3c)
• Apply adequate wind-drift correction during straight and turning flight to maintain a constant ground track (AI.IX.E.S4)
• S-turns: reverse the turn directly over the reference line; turns around a point: either direction, as specified by the evaluator (AI.IX.E.S5)
• Divide attention between airplane control, traffic avoidance, and ground track while maintaining coordinated flight (AI.IX.E.S6)
• Altitude ±100 feet; airspeed ±10 knots (AI.IX.E.S7)
• Analyze and correct common errors (AI.IX.E.S8)

Two purposes, and the second is the one that matters for the rest of the student's life:

• Ground track control — these maneuvers train the pilot to accurately place the airplane in relationship to specific references and maintain a desired ground track (AFH 7-1).
• Division of attention — they develop a pilot's division of attention skill: controlling attitude while tracking a path over the ground, scanning for hazards, preparing for an emergency landing, and scanning flight and engine instruments at regular intervals so that a pending situation, such as decreasing oil pressure, doesn't become an incident (AFH 7-1).

The AFH also names a sensory point worth teaching: while vision is the most used sense, the pressure needed to overcome flight control forces provides tactile feedback about airspeed and aerodynamic load (AFH 7-1).

Start with the fact, not the technique: whenever the airplane is in flight, the movement of the air directly affects its actual ground track (AFH 7-2). The AFH's number: an airplane traveling 90 knots with a 10-knot wind from right to left continues forward at 90 knots but also travels left 10 nautical miles for every hour of flight. Double the speed to 180 knots and it still drifts left 10 nautical miles every hour (AFH 7-2). Airspeed does not reduce drift rate — only the angle you fly does.

Then the correction: in straight-and-level flight, angle the airplane sufficiently into the wind to cancel the sideways drift (AFH 7-2). The required angle depends on the wind's speed, the angle between the wind direction and the airplane's longitudinal axis, and the airplane's airspeed (AFH 7-2). Worked numbers straight from the handbook: an airplane at 100 knots in a 20-knot direct crosswind should turn 12° into the wind; if the wind is 10 knots, the correction is 6° (AFH 7-2).

Close with the AFH's river analogy — a boat crossing a current must angle upstream, and a slower boat speed or a faster current requires a greater angle (AFH 7-2). Students who don't get vectors get boats.

Two follow-ups the examiner will add:

• How much does the wind push you? A wind directly to the right or left (90°) makes the airplane accelerate sideways at the same speed as the wind; a wind halfway between the side and the nose (45°) causes drift up to just over 70 percent of the total wind speed (AFH 7-3). And on groundspeed: as the wind becomes parallel to the longitudinal axis its effect on groundspeed is greater; as it becomes perpendicular, the effect is less (AFH 7-3).
• Does the student calculate the angle? No. Pilots do not calculate the required drift correction angles for ground reference maneuvers; they merely use the references and adjust the airplane's relationship to those references to cancel any drift (AFH 7-3). Teach the theory on the ground so the picture makes sense, then insist on eyes outside in the airplane.

Because the wind changes your groundspeed, and groundspeed sets the radius your fixed bank produces over the ground.

• In a no-wind condition a pilot may make a constant-radius turn over the ground using a fixed bank angle. With wind, that same fixed bank produces a changing radius (AFH 7-3).
• As groundspeed increases, the observed radius of the turn increases; as groundspeed decreases, the radius over the ground decreases (AFH 7-3).
• Therefore: when groundspeed increases, bank more steeply to maintain a constant radius; when groundspeed decreases, use a shallower bank (AFH 7-3).

The clearest way to say it out loud, from the handbook: at a higher groundspeed there is less time to turn the airplane, so increase the bank to increase the rate of turn, and the increased rate of turn offsets the reduced time available. At a lower groundspeed, reduce the bank and the rate of turn to compensate for the additional time taken (AFH 7-4).

Ground reference maneuvers should always be entered from a downwind position — this allows the pilot to establish the steepest bank angle required to maintain a constant-radius ground track right at the start (AFH 7-5). Everything after entry is shallower, so the hardest part of the maneuver is planned rather than discovered.

If it's too steep: immediately exit the maneuver and re-establish a lateral position farther from the ground reference (AFH 7-5). Teach that as a decision, not a failure — and brief the limit: avoid bank angles in excess of 45° due to the increased stalling speed (AFH 7-5). As a general note, a ground reference maneuver should not exceed a bank angle of 45° or an airspeed greater than the maneuvering speed (AFH 7-2).

The rectangular course is a training maneuver in which the airplane maintains an equal distance from all sides of the selected rectangular references, accomplished to replicate the airport traffic pattern that an airplane typically maneuvers while landing (AFH 7-5). That connection is knowledge element K4, so make it explicit in the brief: every leg has a name the student will use for the rest of their flying.

Setup: locate a square or rectangular field or an area with suitable references on all four sides, and fly parallel to and at an equal distance of one-half to three-fourths of a mile from the boundaries, outside the references so they're easily observed from either pilot seat (AFH 7-5). Do not fly close to the references — that forces very steep bank angles, increasing load factor and stall speed, especially in the downwind-to-crosswind turn (AFH 7-5).

The ACS adds the entry: a left or right pattern, 600 to 1,000 feet AGL, 45° to the downwind leg (AI.IX.E.S3a) — the same 45° entry the student will fly at an airport.

Entry is downwind, wind on the tail, groundspeed increased; with a direct tailwind there is no wind correction angle, though real conditions usually demand some (AFH 7-6). Then (AFH 7-6, 7-7):

The unifying rule: each turn requires the bank angle to be adjusted to compensate for changing groundspeed — the higher the groundspeed, the steeper the bank. If groundspeed starts higher and decreases through the turn, the bank should progressively decrease; if it starts slower and increases, the bank should progressively increase until rollout (AFH 7-7).

And the variable students never think of — roll rate: adjust the rate of rolling in and out of turns to prevent drifting into or out of the course. Wind that could drift you into the course calls for a slow banking roll rate; wind that could drift you to the outside calls for a quick one (AFH 7-7). A roll takes time, and during that time the wind gets a free push. This is why failure to execute turns with accurate timing appears in the common errors (AFH 7-7).

A ground track resembling two opposite but equal half-circles on each side of a selected straight-line ground reference (AFH 7-8). It is the practical application of wind correction during a turn (AFH 7-8).

The procedure (AFH 7-9):

1. From the downwind position, cross the reference line at a 90° angle.
2. Immediately begin a 180° constant-radius turn, adjusting roll rate and bank for drift and groundspeed changes.
3. Re-cross the line in the opposite direction just as the first turn completes.
4. Immediately begin the second 180° turn in the opposite direction, with no delay in rolling out of one turn and into the next (AFH 7-9).

Because entry is downwind, the roll into the first turn should be rapid but not aggressive and the bank steepest at initiation, then bank and rollout rate decrease as groundspeed decreases (AFH 7-9). The second half starts upwind, so the roll in should be smooth and gentle and the initial bank shallow, steepening as the airplane turns downwind (AFH 7-9).

The ACS adds the graded detail: reverse the turn directly over the selected reference line (AI.IX.E.S5), entering perpendicular to it (AI.IX.E.S3b).

The AFH admits this is complex and gives you the exact worked case (AFH 7-9). Understand it as degrees turned over the ground versus degrees turned in the air.

Assume the airplane is exactly crosswind — pointed at the position 90° around the ground track — in a left turn with a crosswind from the left requiring a 10° wind correction angle. At the 90° ground reference point the airplane's heading is 10° ahead. So:

• The first 90° of ground track costs 100° of heading change
• The last 90° of ground track costs 80° of heading change

Total is still 180°, but it isn't split evenly. This is why a student who flies by the heading indicator ends up crossing the road at an angle, and why the rollout has to be timed against the nose, wingtips, and ground references so the wings level just as the airplane crosses the line at the proper heading, altitude, and airspeed (AFH 7-9).

It is a logical extension of both the rectangular course and S-turns — a 360° constant-radius turn around a single ground-based reference point (AFH 7-7). What makes it harder: the rectangular course and S-turns limit turns to roughly 90° or 180°, but turns around a point are consecutive 360° turns where the pilot constantly adjusts the bank angle and resulting rate of turn as the airplane sequences through the various wind directions (AFH 7-7). There is no straight segment to catch up in.

Technique (AFH 7-8):

• Select a prominent reference that is easily distinguishable yet small enough to present a precise reference.
• Enter downwind, where groundspeed is fastest, at the appropriate radius and distance.
• Depending on wind speed, roll into the initial bank at a rapid rate so the steepest bank is set quickly to prevent drifting outside the desired radius.
• Gradually decrease the bank until headed directly upwind, then gradually steepen as upwind becomes crosswind and then downwind, reaching the steepest angle back at the entry point.

Fly at least one 360°, but two or more to properly assess wind direction, velocity, and required bank (AFH 7-7).

The crab rule, straight from the AFH (AFH 7-8): during the downwind half, progressively adjust the heading toward the inside of the turn; during the upwind half, progressively adjust toward the outside.

The reason to keep repeating: the goal is a constant-radius turn over the ground, and because the airplane is flying through a moving air mass, the pilot constantly adjusts the bank angle to achieve it (AFH 7-8).

The AFH's lists overlap almost completely (AFH 7-7, 7-8, 7-9). The shared core:

1. Failure to adequately clear the surrounding area, initially and throughout
2. Failure to establish a constant, level altitude prior to entering
3. Failure to maintain altitude during the maneuver
4. Failure to properly assess wind direction
5. Failure to establish the appropriate wind correction angle
6. Failure to apply coordinated aileron and rudder pressure, resulting in slips and skids
7. Failure to manipulate the flight controls in a smooth and continuous manner
8. Failure to properly divide attention between airplane control and orientation with ground references

Plus the maneuver-specific ones: failure to execute turns with accurate timing on the rectangular course (AFH 7-7), and failure to properly execute constant-radius turns on S-turns and turns around a point (AFH 7-8, 7-9).

Error 4 is upstream of errors 5 and 8. When the maneuver is falling apart everywhere at once, check whether the student knows where the wind is coming from.

Teach rate, not position. By visually scanning across several references, the pilot learns to determine the rate of closure to a specific point, and scanning between references reveals relative motion — whether the airplane is maintaining, drifting toward, or drifting away from the desired ground track (AFH 7-1).

The AFH hands you a ready-made analogy: a skilled automobile driver turning through an intersection does not merely turn the wheel some amount and hope. The driver picks several references — an island, a painted lane line, the opposing curb — and uses them to make almost imperceptible adjustments, while adjusting accelerator pressure to join the new lane smoothly (AFH 7-1). Use that in the brief; every student has done it ten thousand times.

Practical build-up: the AFH says a pilot should first be introduced to ground reference maneuvers by correcting for a crosswind over a straight-line reference such as a road or railroad track, choosing a line long enough to give time to understand the concepts. Fly it directly over the line first, then progress to a parallel offset path — not more than three-fourths of a mile from the reference (AFH 7-5). And scan between far ahead and close to the airplane (AFH 7-5).

Brief the illusions too, because not all ground-based references are visually equal and awareness of typical illusions helps a pilot select appropriate ones (AFH 7-1):

• Larger objects may appear closer than they actually are compared with smaller ones
• Prevailing visibility has a significant effect — excellent visibility with clear skies makes an object appear closer than on a hazy day
• Rain can alter the visual image in a way that creates an illusion of being higher than actual altitude
• Brighter objects may appear closer than dimmer ones

The mitigation is a selection rule: using references of similar size and proportion makes ground reference maneuvers easier to execute (AFH 7-1). That is a concrete thing to teach a student to do during preflight planning rather than a caution to nod at.

The AFH gives you a two-part demonstration that makes drift undeniable (AFH 7-4):

1. Choose a straight-line ground reference parallel to the wind. Fly into the wind directly over it, then make a 360° constant medium-banked turn. The airplane returns directly over the reference but downwind of the starting point.
2. Choose a straight-line reference with a crosswind and repeat the same 360° constant medium-banked turn. The airplane drifts away from the reference even though the bank was constant.

The punchline to say out loud: in both examples the path over the ground is not circular, although in reference to the air the airplane flew a perfect continuous radius (AFH 7-4). That single sentence is the entire theory of ground reference maneuvers, and a student who has just watched it happen will never argue with the bank-varies-with-groundspeed rule again.

Order them by the AIH's simple to complex strategy — starting with the simplest builds confidence and makes the student less likely to become frustrated as skills get harder (AIH 9-7) — and by known to unknown, since each new maneuver should relate to a previously learned one (AIH 9-7). The AFH's own structure hands you the sequence:

1. Tracking over and parallel to a straight line — wind correction in straight flight only (AFH 7-5)
2. Rectangular course — straight legs plus turns, and it replicates the traffic pattern (AFH 7-5)
3. S-turns — continuous turning with a reversal, "a practical application for the correction of wind during a turn" (AFH 7-8)
4. Turns around a point — the AFH calls it a logical extension of both the rectangular course and S-turns (AFH 7-7)

Say the relationship out loud each time you move up. A student who is told "this is S-turns with no straight parts" learns turns around a point in one lesson.

The ACS requires narration during the demonstration (FAA-S-ACS-25, Task IX.E), and the AIH says to explain power settings, aircraft attitudes, and other pertinent factors while demonstrating, in the same sequence used in the ground explanation (AIH 9-7). Call the wind before every turn:

• "Cleared. Entering 45° to downwind, 800 feet AGL, about half to three-quarters of a mile off the boundary (AI.IX.E.S3a; AFH 7-5)."
• "Downwind — tailwind, fastest groundspeed of the whole maneuver. Next turn is the steepest and it's more than 90° (AFH 7-6)."
• "Rolling in — bank decreasing through the turn because groundspeed is decreasing (AFH 7-7). Rolling out crabbed into the course on base."
• "Base to upwind is less than 90° because I'm already crabbed (AFH 7-6)."
• "Upwind to crosswind — shallow, rolled in slowly, and I'll crab outside the course (AFH 7-6)."
• "Crosswind to downwind — more than 90°, groundspeed building, hold the bank then roll out quickly (AFH 7-7)."

If the demonstration deviates from what you briefed — and with a shifting wind it will — acknowledge and explain the deviation immediately (AIH 9-5).

Determine which side is wide before you say anything, because the two cases have different causes:

• Wide on the downwind side → the initial bank wasn't steep enough, fast enough. The AFH's fix is in the entry technique: roll into the initial bank at a rapid rate so the steepest bank is set quickly to prevent drifting outside the desired turn radius (AFH 7-8).
• Tight on the upwind side → they never shallowed the bank as groundspeed decayed. Gradually decrease the angle of bank until the airplane is headed directly upwind (AFH 7-8).

Then classify it with the AIH's vocabulary. A slip is an error of action — they know the rule and their hands lagged; a mistake is an error of thought, a gap or misconception in understanding (AIH 3-33). A student who cannot tell you which way the wind is blowing is making a mistake, and more practice will only cement it. A student who says "I know, I was late rolling in" is making a slip, and slips often simply reveal the need for more practice (AIH 3-34).

The tool that separates them is the third step of telling-and-doing, student tells — student does: because the thinking is verbal, you can tell whether the error came from a misconception or a lack of motor skill (AIH 9-8).

And when the maneuver looks clean, change something before you believe it. When you suspect a student performed correctly without understanding the principles, require them to vary the performance slightly, combine it with other operations, or apply the same elements to other maneuvers — those who don't understand the principles probably can't do it successfully (AIH 9-12). Concrete probes:

• Fly the course in the opposite direction (right pattern instead of left). The turn-more-than-90 and turn-less-than-90 logic must be rebuilt on the fly.
• Move to a field oriented differently to the wind.
• Ask them to predict which turn will be steepest before entry, and why.
• Ask what happens to the pattern at an airport in the same wind — that's K4, the relationship of the rectangular course to the airport traffic pattern (AI.IX.E.K4).

If the prediction is right and the flying is right, they understand. If the flying is right and the prediction is a guess, they've memorized a shape.

The AIH's default is restraint: correction of student errors does not include taking over immediately when a mistake is made — safety permitting, it is frequently better to let the student progress part of the way into the mistake and find a way out, because it is difficult to learn a maneuver properly if you seldom have the opportunity to correct an error (AIH 9-12).

But "safety permitting" is narrower here than anywhere else in Area IX, because you are 600 to 1,000 feet AGL (AI.IX.E.S3) with the student's eyes outside and down. Brief hard triggers and say them aloud before the flight:

• Bank approaching 45°, the AFH's stated ceiling for a ground reference maneuver (AFH 7-2, 7-5)
• Any skid in a steep, low, descending turn
• Altitude decaying below your stated floor while the student is fixated on the reference

Then use the words — calmly announce "I have the flight controls" (AIH 9-9) — and take them completely. Students should never be allowed to exceed the flight instructor's limits, and instructors should not exceed their own ability to perceive a problem, decide upon a course of action, and physically react (AIH 9-9).

You must explain and teach these, not recite them (FAA-S-ACS-25, Task IX.E):

• Division of attention (R1) — the whole point of the maneuver is also its principal hazard. The student must control attitude while tracking a ground path, scan for hazards, prepare for an emergency landing, and scan flight and engine instruments at regular intervals (AFH 7-1). Teach the scan explicitly and check it by asking for an altimeter or oil pressure reading mid-maneuver.
• Collision hazards (R2) — you are low, where other airplanes and helicopters operate, near radio towers and wires (AFH 7-2). Clear with two 90° clearing turns, looking left and right as well as above and below (AFH 7-2), and keep clearing throughout (AI.IX.E.S1).
• Low altitude maneuvering, stall/spin, CFIT (R3) — see the next card.
• Distractions, task prioritization, loss of situational awareness or disorientation (R4) — before any maneuver, complete the required checklist items, make any radio announcements (such as on a practice area frequency), and perform the safety clearing turns (AFH 7-2). Doing that on the ground and again before entry keeps the low-altitude phase clean.
• Uncoordinated flight (R5) — every one of the three maneuvers lists failure to apply coordinated aileron and rudder pressure, resulting in slips or skids among its common errors (AFH 7-7, 7-8, 7-9). At this altitude that is the accident, not the deduction.

Altitude — the AFH's answer is a set of tradeoffs, worth walking a student through rather than just naming 600 to 1,000 (AFH 7-2):

• The lower the maneuvering altitude, the faster the airplane appears to travel in relation to the ground
• Drift should be easily recognizable from both sides of the airplane
• The altitude should provide obstruction clearance of no less than 500 feet vertically and 2,000 feet horizontally
• In the event of an engine failure, lower altitudes mean less time to configure the airplane and reduced gliding distance before a forced landing
• What specific altitude or altitude range does the testing standard call for?

For this Task the standard says 600 to 1,000 feet AGL (AI.IX.E.S3), held to ±100 feet (AI.IX.E.S7).