Most of the PGL knowledge test is recall. A handful of it is arithmetic,
and that part has a habit of being taught as a chart to read rather than a relation to
understand — which works until the chart is not in front of you. The
calculations come first, with the working shown. The recall half is
further down: a bank of
questions to drill, one at a time.
The test itself
Test code
PGL
Questions
60
To pass
70%
Time
2.5 hours
Those figures are the FAA's, off the
Airman
Knowledge Testing Matrix, checked on
21 September 2026. They
change from time to time, so check the matrix rather than trusting a date on somebody
else's website — including this one.
The calculations are not FAA questions
The 12 calculation questions were written for this site. They
are in the scope and the shape of the test — three options, the same subjects
— but they are mine, not the FAA's, and nobody should tell you they have seen
them on an exam. The question bank further down is a different thing, and says where
it comes from.
The FAA publishes its
own sample questions for PGL, and the figures those refer to are in
the Airman
Knowledge Testing Supplement (FAA-CT-8080-2H) — the book you are
handed at the testing centre. Work through those as well, and with the supplement
open, because sitting the test is the first time most people meet it.
Score so far
/
(%)
Density altitude
1 of 12
Your field is at 5,000 ft. The altimeter setting is 29.92 in Hg and the outside air temperature is 30 degrees C. What is the density altitude?
A — 7,960 ft
With the altimeter on 29.92 the pressure altitude IS the field elevation, 5,000 ft. Standard temperature there is 15 - 1.98 x 5 = 5.1 degrees C, so the air is 24.9 degrees warmer than standard. At roughly 119 ft per degree of deviation that is 2,960 ft of correction: 5,000 + 2,960 = 7,960 ft.
Why the other answers are there:
5,000 ft is what you get by stopping at pressure altitude and forgetting that the air is hot. 2,960 is the temperature correction on its own.
You are on the ground at a field elevation of 2,500 ft with the altimeter set to 30.42 in Hg. What is the pressure altitude?
A — About 2,040 ft
The setting is 0.50 in Hg above standard, and roughly 1,000 ft of pressure altitude corresponds to 1 in Hg, so the pressure altitude sits about 500 ft below the field: 2,500 - 500 = 2,000 ft by the rule of thumb, and 2,042 ft by the exact standard-atmosphere relation.
Why the other answers are there:
2,960 is the correction applied the wrong way round. A setting HIGHER than standard means the pressure altitude is LOWER than where you are.
You are landing on runway 09. The wind is reported from 130 degrees at 20 knots. What is the crosswind component?
A — About 13 knots
Runway 09 points at 090 degrees, so the wind is 40 degrees off the nose. The crosswind is the sine: 20 x sin 40 = 20 x 0.643 = 12.9 knots. The headwind is the cosine, 20 x 0.766 = 15.3 knots. Note the two do not add to 20; they are the legs of a right triangle whose hypotenuse is 20.
Why the other answers are there:
15 knots is the HEADWIND component -- the cosine rather than the sine. It is the single most common slip on this question.
The surface temperature is 27 degrees C and the dew point is 12 degrees C at a field 1,200 ft above sea level. Roughly where will the cumulus base be, above sea level?
A — About 7,400 ft
The spread is 27 - 12 = 15 degrees C. Temperature and dew point converge at about 2.4 degrees per 1,000 ft, so 15 / 2.4 x 1,000 = 6,200 ft above the field. Add the field elevation: 6,200 + 1,200 = 7,400 ft above sea level.
Why the other answers are there:
6,200 ft is the height above the FIELD -- right number, wrong datum, and the question asked for mean sea level.
You are at 10,000 ft pressure altitude with an outside air temperature of -5 degrees C, indicating 60 knots. What is your true airspeed, near enough?
A — About 70 knots
The rule of thumb is about 2 per cent per 1,000 ft, so 10,000 ft gives roughly 20 per cent and 60 x 1.20 = 72 knots. Worked exactly from the density ratio at that pressure altitude and temperature the correction is 16.3 per cent, giving 69.8 knots -- which is why the rule of thumb is a good first answer and not a precise one.
Why the other answers are there:
52 knots is the correction applied backwards. True airspeed is always HIGHER than indicated as you climb, never lower.
Your glider stalls at 40 knots in level flight. At what speed will it stall in a steady 45-degree banked turn?
A — About 48 knots
Load factor in a level turn is 1 / cos(bank), so at 45 degrees it is 1 / 0.707 = 1.41. Stall speed rises with the SQUARE ROOT of load factor: 40 x sqrt(1.41) = 40 x 1.19 = 47.6 knots.
Why the other answers are there:
57 knots is the answer for 60 degrees of bank, where the load factor is 2.0. At 45 degrees it is 1.41.
Circling at 50 knots true airspeed in a 45-degree bank, roughly what radius are you flying?
A — About 220 ft
R = V squared / (g x tan(bank)), with V as TRUE airspeed in consistent units. 50 knots is 25.7 m/s, and tan 45 = 1, so R = 25.7 squared / 9.81 = 67.5 m, which is 221 ft. The full circle takes 16.5 seconds.
Why the other answers are there:
440 ft is the DIAMETER. Thermals get described by width and circles by radius, and mixing them is how a core gets called twice the size it is.
You want to track 090 degrees at 55 knots true airspeed. The wind is from 180 degrees at 15 knots. What heading and groundspeed?
A — 106 degrees, 53 knots
The wind is 90 degrees off the course, so all 15 knots is crosswind. sin(WCA) = 15 / 55 = 0.273, giving a correction of 15.8 degrees INTO the wind: heading 106 degrees. Groundspeed is 55 x cos(15.8) = 52.9 knots. The loss comes entirely from crabbing, because there is no headwind component at all.
Why the other answers are there:
074 degrees is crabbing the wrong way -- away from the wind instead of into it. 40 knots comes from subtracting the whole 15 knots as if it were all headwind, when it is almost entirely crosswind.
A glider weighs 400 kg as loaded. You move 10 kg of ballast from an arm of 1,000 mm to an arm of 3,000 mm. How far does the centre of gravity move?
A — 50 mm aft
Moving weight already aboard: change in CG = weight x distance / total weight. The distance is 3,000 - 1,000 = 2,000 mm, so 10 x 2,000 / 400 = 50 mm. It moves aft because the weight moved aft, and the total weight is unchanged because nothing came aboard or left.
Why the other answers are there:
20 mm comes from using the arm the weight arrived at rather than the DISTANCE it travelled.
Your glider stalls at 40 knots at 350 kg all-up. You fill the water ballast to 450 kg. What is the new stall speed?
A — About 45 knots
Stall speed goes as the square root of weight: 40 x sqrt(450 / 350) = 40 x sqrt(1.286) = 40 x 1.134 = 45.4 knots. A 29 per cent increase in mass buys only a 13 per cent increase in stall speed, which is why gliders tolerate large ballast changes without the handling falling apart.
Why the other answers are there:
51 knots comes from scaling the speed with the mass ratio directly. It scales with the square root of it, which is a much gentler function.
You are 3,000 ft above the ground in a glider achieving 30:1 in still air. Ignoring any margin, how far can you glide?
A — About 15 nautical miles
30:1 means 30 ft forward for every 1 ft down, so 3,000 x 30 = 90,000 ft. A nautical mile is 6,076 ft, so 90,000 / 6,076 = 14.8 nautical miles. The same 90,000 ft is 17.0 statute miles, which is why the unit matters more than the arithmetic here.
Why the other answers are there:
30 nautical miles comes from reading the glide ratio as a distance in miles. It is a ratio, and the height has to be in the same unit as the distance before you convert.
A sounding gives -2 at 6,000 ft and 0 at 8,000 ft for the forecast maximum temperature. What does that tell you?
A — Lift should work to about 8,000 ft
The thermal index is the sounding temperature minus the temperature of a parcel lifted from the surface. Negative means the parcel is warmer than the air around it, so it is still buoyant and still climbing. At -2 it is going well; at 0 it has run out of buoyancy. The height where the index reaches zero is the top of the usable lift.
Why the other answers are there:
The sign reads backwards to most people's intuition. A more NEGATIVE index is a better day, not a worse one, and zero is the ceiling rather than the best part.
Every calculation above links to the calculator that does that class of problem, so
you can put your own glider and your own airfield into it and see the shape of the
answer change — which is the part of this that outlasts the test.
The recall half: 616 questions
Regulations, airspace, weather, right of way, the instruments: most of the test is
recall, and this is for drilling it. The questions come from the
2017 edition of ASA's Private Pilot Test Prep. These are the
616 of its 1,164 that are marked for
gliders or for every category of aircraft, and the explanations have been rewritten
for this site.
A 2017 bank, not yet checked against today's rules
Some regulations and documents have changed since 2017, and not
every answer here has been checked against the current versions yet. Where a
question and the current rule disagree, the rule wins.
162 of the questions need a figure from the
Airman
Knowledge Testing Supplement, which is not reproduced here; those are marked, and
you can leave them out.
The questions did not load. Check your connection and press Start again.
No questions match those settings.
Question of
right of
(%)
Your score
/
(%)
Neither half will get you through the written on its own, and the FAA's handbooks
remain the thing to learn from.
The guide to learning to fly has
the wider picture of what the licence actually involves, and
the calculators are the part worth keeping
after the test is behind you.
Found one that is wrong?
Every calculation answer is computed by the same code that runs the calculator it
links to, and a test re-derives each one on every build — so a question that
disagrees with its own tool breaks the deploy rather than reaching you. That catches
arithmetic. It does not catch a question that is badly worded, one whose premise an
instructor would argue with, or a bank question whose rule has moved since
2017, and those are the ones I would most like to hear about.