You've been working hard preparing for your practical test and your big day with the designated pilot examiner (DPE) is fast approaching. You have the confidence of your instructor although you can't help but ask yourself, "Is there anything else I could be doing to more fully prepare?" If that sounds like you, congratulations! Always seeking that higher level of learning throughout your entire aviation career is an essential ingredient to becoming the pilot you truly wish to become.
So, how do you get to that next level? First, it would be good to realize that throughout your flight training experience, your CFI has been working to consistently observe you achieving all four levels of learning as described in the CFI's bible, the Aviation Instructor's Handbook (FAA-H-8083-9). These levels are rote, understanding, application, and correlation. If we consider these to be the building blocks of learning, the final structure of your training is not complete until all four blocks are in place. Just as instructors have the responsibility to train each of their students to the correlation level, DPEs--per practical test standards mandate--have a shared responsibility to test all applicants at the correlative level as much as possible. They do this by asking the why and what if questions, usually in a scenario format.
Let's examine how a DPE might assess these four levels of learning by asking a few what, when, how, and why/what if questions about the carburetor heat system. The answers that follow would be indicative of an applicant who is well prepared in this area.
- Rote--What is carburetor heat? Heat from the exhaust manifold that is transferred to the air entering the carburetor to prevent or eliminate ice formation within the carburetor.
- Understanding--When would you apply carburetor heat? To prevent engine power loss, carburetor heat is applied in accordance with pilot's operating handbook instructions whenever the formation of carburetor ice has either occurred or is likely. The formation of carburetor ice is most likely to occur when relative humidity is above 80 percent where the outside air temperature is below 70 degrees Fahrenheit, and especially during periods of reduced power, as in a descent or during an approach to land.
- Application--How would you know if carburetor ice was present, and how would you cope? Carburetor ice might be suspected if a pilot observed an unexplained engine roughness and/or a gradual rpm drop or reduction in manifold pressure. If ice is suspected, the pilot should apply full carburetor heat until all ice is fully melted.
- Correlation--Why does the engine rpm drop when carburetor heat is applied? The density of the engine's induction air is reduced when heated, thus producing a relatively richer fuel mixture, causing the rpm or manifold pressure to drop when carburetor heat is applied.
- Correlation, continued--What if you noticed your engine's rpm drop around 300 rpm, accompanied by engine roughness, at the moment you applied carburetor heat during an approach to a high-altitude airport? First, a pilot should not turn the carburetor heat off since the excessive rpm drop and engine roughness might be the result of some carburetor ice that is melting. If true, turning off the heat before the ice is fully melted could allow the ice to refreeze, possibly causing a subsequent total power failure. However, since combining the application of carburetor heat with a fully rich mixture at a higher altitude might be responsible for the engine roughness, the pilot should consider leaning the mixture with the carburetor heat still on and expect to observe an increase in rpm and a smoother-running engine even if no ice had been present.
An applicant who has reached the fourth learning level of correlation for all of the required topics in the PTS would be much better prepared to deal with any tough "why" or "what if" questions a DPE might dish out during a practical test. Answering these types of questions as you prepare for your practical test will help you achieve that readiness.
When testing correlative learning, DPEs frequently encounter applicants who have not considered why a particular action is accomplished, why that action produces certain results, or what to do if the desired results are not observed. For example, when I observe applicants running their fingers along the prop blade during the preflight, I might begin a series of questions by asking first, "Why are you doing that?" Of course, the applicants always know they are checking for nicks in the prop. Most will know that a nick would need to be filed (dressed) by an aviation maintenance technician before flight. Some will know that by not dressing the prop, there would be an increased potential for a crack to form in the prop, possibly leading to a prop tip breaking off in flight. But rare is the applicant who has reached that final level of "what if" learning (correlation) by knowing that a prop tip breaking off would result in extreme engine vibration or that the correct immediate actions would be to shut down the engine and slow toward stall speed to fully stop the prop's rotation before establishing the subsequent best glide speed to an emergency landing.
As an example of how you might apply this technique to your own checkride preparations, here is a sample of the sort of what, when, how, and why/what if questions you could ask yourself regarding a slightly more challenging topic--Class D operations, as they pertain to the national airspace system (see "5 Great Questions,").
- What is Class D airspace, and what are the rules associated with it?
- When is Class D airspace effective?
- How would you obtain a special VFR clearance at a Class D airport, and how would this affect your operation?
- Why is a non-instrument-rated pilot restricted from obtaining a special VFR clearance in Class D airspace at night?
- What if you were inbound to a Class D airport and discovered your communications radios were not operating?
By asking yourself these types of questions as you review the many subject areas covered in your practical test, you will be able to more fully assess your various levels of learning, allowing you to become even more prepared and confident for a successful checkride experience on your big day.
Bob Schmelzer is a Chicago-area designated pilot examiner and a United Airlines Boeing 777 captain /line check airman. He has been an active flight instructor since 1972.
5 great questions
1. What is Class D airspace and what are the rules associated with it?
Answer: It is ATC controlled airspace at towered airports from the surface up to about 2,500 feet above the airport elevation, usually within a radius of about 4 nm of the airport, as depicted by the blue dashed circle around the blue colored airports on sectional charts. Before entering the boundaries of the Class D airspace, the pilot must be in two-way radio communications with the air traffic control tower and, except for Special VFR operations, the pilot must maintain at least 3 miles flight visibility and be at least 1,000 feet above, 500 feet below, and/or 2,000 feet away from any cloud formation, with the reported weather at the airport being a at least a 1,000-foot ceiling and three miles' visibility while operating within the airspace.
2. When is Class D airspace effective?
Answer: It is effective whenever the tower is operating as noted on the sectional chart communications tab listing or in the A/FD (Airport/Facility Directory).
3. How would you obtain a special VFR clearance at a Class D airport and how would this affect your operation?
Answer: A noninstrument-rated pilot can only obtain a special VFR clearance to operate within Class D airspace during daylight hours by contacting the tower before entering the Class D airspace and then maintaining at least one statute mile flight visibility and clear of clouds upon entering the airspace after the clearance has been received.
4. Why is a noninstrument-rated pilot restricted from obtaining a special VFR clearance in Class D airspace at night?
Answer: VFR operations at night require at least three miles' visibility and the Class E cloud clearance requirements in order to safely maintain control of the aircraft using outside visual references. Anything less would demand the additional training and skills required of a current, instrument-rated pilot in an aircraft equipped for IFR flight to safely operate at night.
5. What if you were inbound to a Class D airport and discovered your communications radios were not operating?
Answer: While operating at a Class D airport without two-way radio communications, a pilot should be prepared to comply with ATC light gun signals as appropriate. However, unless that pilot was in an emergency situation or had already communicated with that ATC tower facility, he should remain clear of the Class D airspace and divert to a Class G or E airport where two-way radio communications are not required.
