BDCA Instrument Rating Knowledge Exam common mistakes
BDCA Instrument Rating Knowledge Exam · Understand the traps and how to avoid them.
Treating the alternate-aerodrome planning minima as identical to the destination approach minima, and picking an alternate that is only just legal on paper.
Candidates memorise a single set of approach minima and apply them everywhere, forgetting that alternate planning minima are raised by a defined increment above the published approach minima and vary with the type of approach available at the alternate.
What to do instead
Build a one-page table of alternate planning minima by approach type and weather requirement, and practise deriving the alternate minima from a published approach plate for five different alternates before every practice paper.
Computing the holding pattern entry and teardrop/parallel offset by eye rather than using the published inbound course and the aircraft's actual heading, then turning the wrong way on entry.
Candidates confuse the outbound/inbound course relationship and forget that entry sector boundaries are defined relative to the inbound course, not the aircraft's track over the ground.
What to do instead
Draw the three entry sectors around the inbound course for every holding clearance received, state the sector aloud, and verify the first turn direction before starting the timer.
Reading the approach plate minimum sector altitude or the initial approach fix altitude as a clearance to descend to that level regardless of terrain or step-down fixes.
The MSA is a 25 nm emergency reference, not a cleared altitude, and step-down fixes on the profile view are frequently skipped when candidates only glance at the plan view.
What to do instead
Trace the vertical profile from the IAF to the MAPt fix by fix, writing each crossing altitude next to the fix name, and state explicitly which altitudes are mandatory versus advisory.
Misidentifying the missed approach point on a non-precision approach, either by timing incorrectly or by using the wrong fix, and beginning the missed approach late or early.
Candidates default to the runway threshold as the MAPt on all approaches, ignoring that many non-precision approaches define the MAPt by timing from the FAF at a specified groundspeed.
What to do instead
For every non-precision approach, write the MAPt definition (fix or time from FAF) at the top of the plate, compute the time for the planned groundspeed, and start the clock at the FAF, not at the IAF.
Applying the standard 200 ft/nm climb gradient to an obstacle departure procedure without checking whether a steeper published gradient is required.
The standard gradient is assumed to be universal, but published departure procedures frequently specify higher gradients, and candidates do not convert the required gradient into a rate of climb for the planned groundspeed.
What to do instead
Convert every published gradient into feet per minute for the planned groundspeed before departure, and compare it against the aircraft's expected climb performance at the departure altitude.
Confusing decision altitude with decision height, or treating a DA on a precision approach as a level-off altitude rather than a point at which a decision must be made.
The two terms are used interchangeably in casual speech, and candidates lose the distinction between a barometric altitude referenced to mean sea level and a radio height referenced to the threshold.
What to do instead
Write the definitions side by side, then for three different approach plates identify whether the published minimum is a DA or a DH and what it is referenced to.
Assuming the attitude indicator or heading indicator is reliable after a partial panel failure, and continuing to fly by reference to a failed or uncaged instrument.
Candidates learn the instrument failure drill as a memorised sequence but do not practise recognising the failure, so they cover the instrument only after the aircraft has already entered an unusual attitude.
What to do instead
Practise partial-panel recognition and cover-up drills under a view-limiting device with an instructor, including cross-checking each instrument against its backup before covering anything.
Misinterpreting a METAR or TAF trend group, particularly TEMPO and BECMG, as a forecast of conditions at the expected time of arrival.
Candidates read the trend group as a standalone forecast rather than as a modifier of the prevailing conditions, and do not account for the validity period of the trend group.
What to do instead
Decode ten METARs and TAFs by hand, writing the prevailing conditions and the trend separately, and note the start and end time of each TEMPO or BECMG group.
Treating a forecast of embedded cumulonimbus or severe turbulence as a go/no-go decision based only on the area forecast, without checking the significant weather chart and upper winds.
Candidates rely on a single product and do not cross-check the significant weather chart, upper wind and temperature chart, and PIREPs, so they miss the vertical extent and movement of hazardous weather.
What to do instead
For each planned route, produce a one-page weather brief that lists the significant weather chart hazards, the freezing level, the tropopause height, and the upper winds at planned levels before making the go/no-go call.
Reading back a clearance partially or in the wrong order, omitting the altitude or the frequency, and failing to challenge an ambiguous instruction.
Candidates rehearse the read-back as a memory exercise rather than as a verification loop, and they are reluctant to query an instruction that seems inconsistent with the aircraft's position or performance.
What to do instead
Use a fixed read-back order (callsign, clearance limit, route, altitude, speed, frequency), and practise challenging at least one deliberately ambiguous clearance in each simulator session.