IDAC Private Pilot Airplane (PPA) common mistakes
IDAC Private Pilot Airplane (PPA) · Understand the traps and how to avoid them.
Treating the semi-circular rule as a fixed altitude rather than selecting the correct VFR cruising level for the actual magnetic track, then flying the reciprocal heading's level.
Candidates memorise 'east odd, west even' but forget that the level is set by magnetic track (000-179 vs 180-359), so a change of heading without a level change puts them at the wrong level for their direction.
What to do instead
Before every cruise leg, compute the magnetic track from the plotted course and wind-corrected heading, apply the 0-179/180-359 split, add the 500 ft increments for VFR above 3,000 ft AMSL, and cross-check the altimeter against the quadrantal rule before levelling off.
Reading the altimeter and airspeed indicator as if the subscale setting and the coloured arcs were interchangeable between aircraft, without verifying the current QNH/QFE setting and the POH-derived V-speeds.
Candidates transfer memorised numbers (e.g. 2,000 ft pattern altitude, 70 kt approach) from one training aircraft to another and forget that the pitot-static system and the markings are aircraft-specific.
What to do instead
For each question, identify which pressure setting is being used (QNH, QFE, QNE) and convert explicitly; derive V-speeds from the stated POH figures rather than memory, and check that the altimeter subscale matches the reference datum in the stem.
Computing mass and balance with the basic empty mass and adding fuel and payload, but omitting the moment arm change when baggage or a rear passenger moves the CG aft, or forgetting to convert litres of fuel to kilograms at the correct density.
Candidates treat the CG as a single total rather than a moment sum, and use 1 kg/L for avgas when the stated density is 0.72 kg/L, producing an optimistic mass and a forward CG error.
What to do instead
Build a full moment table: mass x arm for each station, sum moments and divide by total mass, then plot the result against the forward and aft CG limits at the take-off and landing masses; always multiply fuel volume by the density given in the stem.
Answering human-performance items by choosing the 'safe' option (e.g. 'the pilot should get more rest') instead of identifying the specific perceptual or cognitive mechanism named in the stem, such as spatial disorientation in a particular illusion.
Candidates lack a structured model of the senses and rely on general airmanship, so they cannot distinguish somatogravic illusion from the leans, or hypoxia from hyperventilation, when the stem describes the exact symptom.
What to do instead
Learn each illusion and impairment by its trigger and its corrective action (e.g. somatogravic illusion on acceleration -> trust the instruments; hyperventilation -> slow breathing and reassurance), and answer the mechanism asked, not the moral.
Interpreting a METAR or TAF by reading only the visibility and cloud groups while ignoring the trend, the validity period, and the difference between TEMPO and BECMG.
Candidates scan for the worst number and answer with it, missing that a TEMPO group is a temporary fluctuation while BECMG indicates a permanent change within the period, and confusing the issue time with the valid time.
What to do instead
Decode in fixed order: type, time, wind, visibility, weather, cloud, temperature, pressure, then trend; state explicitly whether the change is temporary or becoming, and check the validity window before choosing the forecast condition for the flight time.
Computing a navigation leg with the wind triangle but applying the wind direction as a true bearing to a magnetic heading without correcting for variation and deviation.
Candidates mix true, magnetic and compass references, and use the wind direction as a heading rather than as the direction the wind comes from, producing a track error of tens of degrees on a cross-country leg.
What to do instead
Draw the wind vector as the direction the wind blows from, solve the triangle for a true heading and true groundspeed, then apply variation (east is least, subtract from true to get magnetic) and deviation from the compass card to obtain the compass heading.
Filing or flying a VFR flight plan without checking that the route stays clear of controlled airspace and that the required radio and transponder equipment is serviceable for the class of airspace entered.
Candidates focus on the navigation log and forget that airspace classes impose equipment and clearance requirements, so they plan a route through Class C or D without a clearance or a Mode C transponder.
What to do instead
Before departure, mark every airspace boundary and class along the route on the chart, list the clearance and equipment requirements for each, and confirm transponder, radio and altimeter encoding are serviceable for the whole route.
Explaining lift and drag qualitatively ('the wing deflects air downward') without linking angle of attack, the lift coefficient curve and the stall to the specific condition in the question.
Candidates learn a popular explanation of lift and cannot connect it to the critical angle of attack, so they answer stall questions by reference to speed rather than to angle of attack.
What to do instead
Anchor every answer on the lift equation and the CL-alpha curve: stall occurs at the critical angle of attack regardless of speed, mass or attitude; use the curve to explain load factor, accelerated stalls and the effect of flaps and ice.
Reading back a clearance by repeating only the parts that seem important (e.g. the runway and the squawk) and omitting the initial altitude, the departure frequency or the hold short instruction.
Candidates treat readback as a courtesy rather than a legal confirmation, and under pressure they paraphrase instead of echoing the clearance in the standard order.
What to do instead
Use a fixed readback template: callsign, clearance limit, route, altitude, frequency, squawk; read back hold-short and line-up instructions verbatim, and if any element is unclear, say 'say again' rather than guessing.
Calculating take-off or landing distance from the POH chart using the actual runway length and conditions, but omitting the safety factor and the corrections for wind, slope, temperature and runway surface stated in the question.
Candidates read the chart at the intersection of mass and temperature and stop, ignoring that the chart is based on a dry, level, hard runway at sea level with zero wind, so each factor must be applied separately.
What to do instead
Apply corrections in a fixed sequence (pressure altitude, temperature, mass, wind, slope, surface), then add the regulatory or operator safety factor stated in the stem; state each correction explicitly so the arithmetic can be checked.