Systems and Equipment Malfunctions

You must determine the appropriate action for simulated emergencies from at least three of the elements or sub-elements in K1 through K5, and complete the appropriate checklist(s) (S1, S2).

The menu the examiner draws from:

• Powerplant power loss
• Electrical
• Vacuum/pressure and associated flight instruments
• Pitot-static
• Electronic flight deck display
• Landing gear or flap malfunction
• Inoperative trim
• Smoke or fire
• Any aircraft-specific system (oxygen, deice)
• An inadvertent door or window opening

There is no numeric flight tolerance on this task — it is judgment and checklist discipline (FAA-S-ACS-7B, Task IX.C).

Less time than most pilots assume. Battery endurance falls off sharply with load: a 25 amp-hour battery could supply 5 amps for 5 hours, but at a 10-amp load it "might last only 2 hours," and a 40-amp load "might discharge the battery fully in about 10 or 15 minutes" (AFH ch. 18). An aged battery has less than nameplate capacity, and if you were slow to catch the failure, some is already gone.

The response:

1. Shed non-essential loads immediately
2. Notify ATC and request vectors to the nearest suitable airport
3. Plan the arrival early — electric gear and flap motors draw far more than most equipment, and selecting them on a partly depleted battery "may well result in an immediate total loss of electrical power"

Expect a no-flap landing and a manual gear extension.

Because it is insidious — it "may go unrecognized until a critical phase of flight" (AFH ch. 18). Takeoff, climb, and level-off can all look normal; the lie starts on the descent.

In a descent with a restricted static line, the altimeter reads higher than actual (static pressure lags), the VSI under-reads the descent rate, and the ASI reads faster than actual. The picture you get is "too high, too fast, descending slowly" — which invites you to descend more. Level off and climb and the altitude still lags, while indicated airspeed "may begin to decrease at an alarming rate," creeping toward apparent stall speed on the slightest pitch-up.

Confirm it by opening the alternate static source while climbing or descending. If the needles move significantly, you have a static problem — use the alternate source for the rest of the flight.

Three reasons the AFH calls out (AFH ch. 18):

• Shared inputs. Many light glass airplanes feed the backup instrumentation from the same pitot-static system as the primary display. A blocked pitot tube or static port can take out both. Some manufacturers combine the ADC and AHRS functions, so a blocked air data input can also corrupt the attitude display
• No standardization. Conventional six-pack failures look the same across airplanes, so you can cross-compare and diagnose. "Electronic systems failure indications are not standardized" — primary and backup displays may respond differently to the same interruption, and both may behave unlike conventional instruments
• Untrainable modes. Complex systems and the difficulty of simulating failures impose real training limits

The obligation is equipment-specific study before you fly the airplane. 14 CFR 23.2615(b)(2) requires essential information to remain available after any single failure — but that is a certification promise, not a guarantee against a common-mode blockage.

Plan for substantially more runway: the increase in required landing distance "could be as much as 50 percent" (AFH ch. 18).

• Fly the pattern in a relatively nose-high attitude to hold altitude without flap drag, and consider a wider, longer pattern so you are not diving to lose altitude
• Expect the nose-high final to degrade forward visibility and to feel close to a stall — do not respond by abruptly lowering the nose onto the nosewheel
• The airplane is slightly less stable in pitch and roll, and will float considerably in the roundout. Do not force it on, and do not over-flare — without flaps, an excessive flare can strike the tail

One flap deploys or retracts while the other stays put, indicated by a pronounced roll toward the wing with the least flap deflection during extension or retraction (AFH ch. 18).

• Counter the roll with opposite aileron; the drag from the extended flap requires substantial opposite rudder, producing a cross-control condition
• Almost full aileron may be needed to hold wings level at approach speed — so do not land with a crosswind from the side of the deployed flap, because the roll authority to handle it may not exist
• Fly the approach faster than normal, and do not flare excessively — fly it onto the runway at a speed with a safe margin above flaps-up stall speed

Once alternate extension has failed, a gear-up landing is inevitable — and the choice is situational (AFH ch. 18):

• Choose an airport with crash and rescue facilities and ask for equipment to stand by. A smooth hard surface usually causes less damage than a rough grass strip, but sparks on pavement can ignite fuel — request foam if available
• Burn off excess fuel to reduce landing speed and fire potential; with one main gear affected, burn fuel from that side to lighten the unsupported wing
• Landing on one main makes the airplane veer strongly toward the failed side after touchdown. On a narrow runway with ditches or obstacles at the edges, landing with all three retracted may be safer
• If you do land on one main: nose-high, wings level, hold the unsupported wing up with aileron as long as possible, then expect a strong yaw and be ready with full opposite rudder and aggressive braking

Fly the airplane. "A cabin door that opens in flight seldom if ever compromises the airplane's ability to fly" — there may be roll or yaw effects, but they are easily overcome (AFH ch. 18).

• Do not rush to land. Climb to normal pattern altitude, fly a normal pattern, make a normal landing
• Do not unfasten belts to reach the door. Leave it alone
• Most doors bang open and then settle partly closed. A slip toward the door may open it wider; a slip away may push it closed
• Complete all landing checklist items

"Accidents are almost never caused by an open door. Rather, an open door accident is caused by the pilot's distraction or failure to maintain control." That is the startle-response item (R4) in one sentence.

Kill the power, then deal with the smoke (AFH ch. 18):

• Master off to remove the source — but understand that materials already ignited may keep burning
• Use the fire extinguisher if there are flames; only then open the cabin air to purge smoke and fumes. If smoke increases when the vents open, close them immediately — the airflow is feeding it, or the fire is in the heating system or nose baggage compartment
• If electrical power is absolutely essential, isolate the circuit deliberately: master OFF, all individual switches OFF, master back ON, then add switches one at a time with a pause after each, watching for odor, smoke, or sparks
• Recognize that this procedure "has the effect of recreating the original problem." The most prudent course of action is to land as soon as possible.

Most power losses are not catastrophic. The AFH's inventory approach (AFH ch. 13, applied to any piston airplane):

• Fuel starvation is the leading recoverable cause — "restoration of power may be made with the selection of another tank"
• Take an orderly inventory of gauges and switches
• Select carburetor heat or alternate air
• The engine may run smoothly on one magneto or at a lower power setting
• Alter the mixture
• If fuel vapor is suspected, run the boost pump to eliminate flow and pressure fluctuations

The judgment rule: "the engine should be left running if there is any doubt as to needing it for further safe flight." Conversely, heavy vibration, smoke, blistering paint, or large trails of oil indicate a critical situation — secure it, divert to the nearest suitable airport, and declare an emergency for priority handling.

Unless the AFM/POH directs otherwise (AFH ch. 18):

• Mixture to idle cutoff and the fuel selector/shutoff to OFF — starve the compartment of fuel
• Leave the ignition ON to burn off the fuel remaining in the lines between the shutoff and the engine
• If the flames go out, make no attempt to restart
• If the fire is oil-fed — thick black smoke, versus the bright orange flames of a fuel-fed fire — consider stopping propeller rotation by feathering, or with a constant-speed prop by going to minimum rpm and raising the nose until it stops. That halts the engine-driven pump from feeding flammable fluid to the fire
• Think twice about the master switch: unless the fire is electrical or a crash landing is imminent, killing the electrical system costs you the radios for a distress call and makes ATC lose your transponder returns

Because the airplane may already be compromised in ways you cannot see. The AFH is blunt (ch. 18):

• The airplane may be severely structurally damaged to the point that control could be lost at any moment
• It may still be on fire and susceptible to explosion — fire can continue to burn under the wing or cowling out of the pilot's view
• Fires that appear extinguished "have been known to rekindle with changes in airflow pattern and airspeed"
• "The airplane is expendable and the only thing that matters is the safety of those on board"

A twin pilot may elect to continue to the nearest airport, but should weigh the possibility that a wing has been seriously impaired: "even a brief but intense fire could cause dangerous structural damage."

Most elevators use a separate up and down cable, so a single break usually produces partial pitch control, not total loss (AFH ch. 18).

Loss of up-elevator control (yoke moves aft easily but does nothing):

• Apply considerable nose-up trim
• Push the yoke forward past neutral to set attitude; increase forward pressure to lower the nose, relax it to raise the nose
• Release forward pressure to flare

Loss of down-elevator control (forward yoke does nothing):

• Apply considerable nose-down trim
• Pull aft to set attitude; release back pressure to lower the nose, increase it to raise the nose
• Increase back pressure to flare

If the cabin-to-elevator linkage fails entirely and the elevator weathervanes free, the trim tab can still raise or lower it within limits — less effective at low airspeed, but usually enough for a safe landing. A fully jammed elevator leaves only power and flap combinations for limited pitch control, and the AFH concedes such a landing "can be problematic."

Frame it as a control-force endurance and configuration problem. Trim failure does not remove pitch control; it removes your ability to relieve pressure, so every configuration change you make — flaps, gear, power — arrives as a force you must hold with your hand.

• Note the direction it failed in and what airspeed leaves you neutral
• Make configuration changes slowly and one at a time, so you can feel each force change coming
• Reduce trim-force excursions by planning a stable, minimally reconfigured approach
• Land as soon as practical — the risk is fatigue and a distracted, one-handed roundout, not aerodynamics

Contrast this with the multiengine case: on an OEI approach, some pilots deliberately reset rudder trim to neutral on final and hold the pressure, precisely so there is no trim change to chase as the throttle closes in the roundout (AFH ch. 13).

Pressurization is limited by the maximum cabin differential pressure the fuselage was designed to withstand (PHAK ch. 7). The cabin air pressure safety valve is a combination of three functions:

• Pressure relief — prevents cabin pressure from exceeding the design differential above ambient
• Vacuum relief — lets outside air in when ambient exceeds cabin pressure
• Dump valve — flight-deck actuated; positioning the switch to ram opens a solenoid valve that dumps cabin air

Monitor the cabin differential pressure gauge, the cabin altimeter, and the cabin rate-of-climb indicator. Decompression is defined as the system's inability to maintain the designed differential — caused by a system malfunction or by structural damage. The response is an emergency descent (Task IX.A).

Practical systems knowledge the examiner may probe (PHAK ch. 7):

• A pressure drop can be a temperature effect, not a leak — a bottle stored in an unheated area reads low. Mark high-pressure containers with their psi tolerance (e.g., 1,800 psi) before filling to that pressure
• Oxygen must meet or exceed SAE AS8010, Aviator's Breathing Oxygen Purity Standard
• Select 100 percent at high altitude if the system is demand or pressure-demand
• Fire hazard: materials that are nearly fireproof in ordinary air are not in an oxygen-enriched atmosphere

Regulator oxygen blend by approval ceiling:

Regulatory requirements are in 91.211 — covered under Task IX.A.

Four behaviors, and they matter more than any individual system answer:

• R1 — checklist usage. Memory items first where the AFM/POH designates them, then the printed checklist to verify. "Certain immediate action items (such as a response to an engine failure in a critical phase of flight) are best committed to memory. After they are accomplished, and as work load permits, the pilot can compare the action taken with a checklist" (AFH ch. 13)
• R2 — task prioritization. Aviate, navigate, communicate. Airplanes "have been lost at altitude due to apparent fixation on the engine problem to the detriment of flying the airplane"
• R3 — undesired aircraft state. Recognize and correct the deviation before continuing the troubleshooting
• R4 — startle response. Absorb the surprise, then act deliberately. "There is a distinct possibility of actuating an incorrect switch or control if the procedure is rushed"