Multi Engine Study Guide Flashcards
What is climb performance dependent on?
Excess power needed to overcome drag
Climb performance is significantly affected by the relationship between available power and drag.
What percentage of Power & Performance is lost when you lose an engine in a multi-engine aircraft?
It loses 50% of Power and 80% of Performance
What must an increase in drag be offset by?
Additional power
This additional power is taken from the excess power, impacting climb performance.
What are the two key actions to achieve optimum single engine climb performance?
- Maximizing thrust - full power
- Minimizing drag - flaps & gear up, feather prop
These actions enhance the aircraft’s performance after an engine loss.
Impact on Climb FPM
- Critical engine inoperative
- Wind-milling propeller
- Landing gear extended for the DA42?
-600 fpm
Impact on Climb FPM
- Flaps LDG
-600 fpm
Impact on Climb FPM
- Flaps APP
-400 fpm
Impact on Climb FPM
- Landing Gear Extended
-300 fpm
Impact on Climb FPM
- Critical engine inoperative
- Wind-milling propeller
-300 fpm
What is a twin engine aircraft with both propellers rotating in the same direction called?
A conventional twin
What effect do the same left-turning tendencies of a single engine airplane have on a multi-engine airplane?
They affect the multi-engine airplane similarly
What is the purpose of counter-rotating propellers in multi-engine airplanes?
To help combat left-turning tendencies
How do counter-rotating propellers affect p-factor and torque?
They cancel each other out
What is the result of using counter-rotating propellers in terms of rudder usage?
Less rudder is needed to oppose left-turning tendencies
Fill in the blank: A conventional twin aircraft has both propellers rotating _______.
the same direction
True or False: Counter-rotating propellers are designed to increase the amount of rudder needed.
False
What are the three main changes that occur when an engine fails?
Changes occur in Yaw, Roll, and to a lesser extent, Pitch.
What direction will an aircraft yaw and roll towards when an engine fails?
Towards the dead engine.
What causes the aircraft to roll towards the dead engine?
Loss of accelerated propwash and lift.
What happens along the Longitudinal Axis when an engine fails?
The aircraft will roll toward the dead engine due to loss of accelerated propwash.
Pronounced yaw towards the inoperative engine known as _________________ is caused by what two reasons?
*Asymmetric Thrust
* Loss of Thrust
* Drag created by the wind-milling propeller.
What happens along the Vertical Axis when an engine fails?
You will experience a pronounced yaw towards the inoperative engine.
What happens along the Lateral Axis when an engine fails?
You will experience a pitch down due to loss of accelerated propwash.
Why is the pitch down less noticeable in the D4A2 aircraft?
Because the tailplane is located high and out of the propwash (t-tail design).
What is the Twin Engine Pilot’s Mantra for determining which engine failed?
DEAD FOOT, DEAD ENGINE!
What is the main issue with using rudder alone to maintain direction?
It puts the aircraft into a sideslip, creating a large amount of drag.
What is the solution to minimize drag while maintaining heading?
Achieve a zero sideslip condition.
What bank angle should the aircraft be at to achieve zero sideslip?
2°- 5° toward the operating engine.
What does the dihedral of the wing create when the aircraft is banked?
A horizontal component of lift.
What does the inclinometer indicate when the appropriate amount of rudder deflection is applied?
The ball being halfway deflected toward the operating engine.
What is a mnemonic to remember the rudder deflection related to zero sideslip?
RAISE THE DEAD!
What is the service ceiling of an aircraft?
The maximum density altitude where Vx will produce a 100 fpm climb with both engines at max continuous power.
What factors affect the service ceiling of an aircraft?
Weight loading, temperature, and pressure.
What is the absolute ceiling of an aircraft?
The maximum density altitude that the airplane can attain or maintain at max gross weight in clean configuration and max continuous power.
What happens to Vx and Vy as altitude increases?
Vx increases while Vy decreases.
At what point do Vx and Vy converge?
At the absolute ceiling.
What is the single engine service ceiling?
The maximum density altitude at which the aircraft can maintain a 50 fpm climb with one engine operating at full power and one engine with a feathered propeller.
Why is the single engine service ceiling important?
It is critically important when flying over mountainous terrain.
What happens if an aircraft is above the single engine service ceiling during an engine failure?
The aircraft will slowly drift down to its single engine service ceiling.
How should the single engine service ceiling be determined?
During flight planning using the single engine service ceiling chart from the POH.
What is Vyse?
Best rate of climb single engine, identified by the blue radial on the airspeed indicator.
What should you pitch for when an engine fails?
Pitch for Vyse (blue line) to achieve the best single engine performance.
What is Vxse?
Best angle of climb single engine, used to clear obstacles with an engine failed.
What should you do after clearing obstacles with an engine failed?
Pitch for Vyse.
What is Vsse?
Minimum speed at which an intentional engine cut can be performed, providing a safety margin from Vmc.
Why do MEI candidates need to know Vsse?
It provides a safety margin for safe engine cuts while training.
Fill in the blank: The single engine service ceiling is determined using the _______.
single engine service ceiling chart from the POH.
True or False: Vyse provides the best single engine performance.
True.
Fill in the blank: If the single engine absolute service ceiling is 6,000’ and Ian aircraft has an engine failure at 12,000’, it will drift down to _______.
6,000’.
What altitude is indicated as MEA in the example provided?
9,500’.
What are the 4 Engine Failure Steps that need to be Memorized
- Maintain Aircraft Control
- Configure the Aircraft for Best Peformance
- Identify, Verify, and Fix or Secure
- Run Appropriate Checklist
Engine Failure Steps
What the Process for Step 1 - Maintain Aircraft Control
- Pitch Attitude should be reduced to maintain speed
- User Rudder Input to stop the Yaw
- Always use rudder to identify before using ailerons - Bank into the operating engine 2-3 degrees
Engine Failure Steps
What the Process for Step 2 - Configure the Aircraft for Best Performance
- Power to 100%
- Flaps Up (Reduces Drag)
- Gears Up (Reduces Drag)
Engine Failure Steps
What is the Process for Step 3 - Identify, Verify, Fix or Secure
- Identify - Dead foot, dead engine
- Verify - Reduce Dead engine power and verify no change
- Fix or Secure - Decide whether or not to troubleshoot
Engine Failure Steps
When should you just Secure & Land and not Attempt an Engine Fix
- Below 3000’ AGL
- Or during an Instsrument Approach
What is the first action to take when an engine fails in flight?
Maintain Aircraft Control
This involves reducing pitch attitude to maintain airspeed and using rudder input to stop yaw.
What should be done to stop yaw during an engine failure?
Use rudder input
This is crucial before adding aileron input to identify the failed engine.
What is the recommended bank angle into the operating engine during an engine failure?
2 - 3 degrees
This small bank is usually sufficient to assist in maintaining control.
What configuration should the aircraft be in for best performance after an engine failure?
- Power 100%
- Flaps UP
- Gear UP
Reducing drag is essential for optimal performance.
How do you identify a failed engine during flight?
Dead foot, dead engine
This is a common mnemonic to help pilots identify engine failure.
What should be done to verify the dead engine after identification?
Reduce dead engine power lever and verify no change
This confirms that the engine is indeed inoperative.
What decision must be made after identifying and verifying the dead engine?
Decide whether or not to troubleshoot
This step is crucial for determining the next course of action.
What is the purpose of running an appropriate checklist after an engine failure?
To verify that the above flow was correctly accomplished
Checklists help ensure all necessary steps were followed.
What should be done below 3000 feet or during an instrument approach after an engine failure?
Secure the inoperative engine and land as soon as practicable
This is vital for safety during critical phases of flight.
What is a critical engine?
The engine which, if lost, will most adversely affect the performance and handling characteristics of the aircraft.
When is the effect of the critical engine most significant?
When operating at low airspeeds with a high power setting.
On conventional twins with clockwise rotating propellers, which engine is the critical engine?
The left engine.
In aircraft with counter-rotating propellers, is there a critical engine?
No, due to the turning tendencies cancelling each other out.
What is the critical engine on the DA42?
The left side engine (when viewed from the cockpit).
What can also classify an engine as a critical engine?
If important systems are operated off that engine (i.e. landing gear, pressure system).
What are the four factors used in determining a critical engine?
- P-factor
- Accelerated Slipstream
- Spiraling Slipstream
- Torque
What is P-factor?
The descending propeller blade is producing more thrust than the ascending blade.
What happens if the left engine fails in terms of P-factor?
The p-factor from the right engine creates a yawing moment due to being farther from the longitudinal axis of the aircraft.
What is Accelerated Slipstream?
The air being forced over the wing by the operating engine creates extra lift.
How does Accelerated Slipstream affect the aircraft if the left engine fails?
It creates a rolling moment due to more induced flow farther away from the longitudinal axis.
What is Spiraling Slipstream?
The effect of the propeller creating a spiraling stream of air, which hits the rudder to enhance its effectiveness.
What happens to the spiraling slipstream from the right engine if the left engine fails?
It spirals away from the rudder.
What is Torque in relation to propeller rotation?
The opposite reaction to the action of the turning propeller, trying to roll the airplane opposite of the propeller’s direction.
If the left engine fails, how does torque affect the aircraft?
It tries to roll the aircraft to the left, making it more difficult to raise the dead engine.
What are the four factors that affect climb performance?
- Airspeed
- Drag
- Power
- Weight
How does lower airspeed affect climb performance?
The generally lower the climb performance.
What is the effect of drag on climb performance?
If it creates drag, it lowers climb performance.
How does power affect climb performance?
Less power results in lower climb performance.
What effect does weight have on climb performance?
The higher the weight, the lower the climb performance.
Acronym for how the manufacturer determine Vmc?
COMBATS
What is Vmc?
Vmc is the calibrated airspeed at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the airplane with the engine still inoperative.
Vmc is essential for ensuring the aircraft can continue flying safely after an engine failure.
What conditions must be met to maintain control at Vmc?
To maintain control at Vmc, the following conditions must be met:
* Maintain straight flight at the same speed
* Angle of bank not more than 5 degrees
These conditions are crucial to ensure the aircraft does not lose directional control.
What happens to rudder effectiveness as airspeed decreases?
As airspeed decreases, the rudder becomes less effective, requiring full rudder deflection to maintain directional control at Vmc.
Beyond Vmc, any further reduction in airspeed will lead to a loss of directional control.
How is published Vmc indicated?
Published Vmc is defined by the red radial on the airspeed indicator.
This visual cue helps pilots identify the critical Vmc speed during flight.
What factors affect Vmc?
Vmc decreases as density altitude increases due to:
* Engines developing less power
* Propellers being less efficient
Pilots must be aware of these factors when operating at high density altitudes.
What does Vmc guarantee?
Vmc guarantees directional control only.
It does not ensure overall flight safety without considering other factors.
What does the acronym COMBATS stand for in determining Vmc?
COMBATS stands for:
* C - Critical engine failed and windmilling
* O - Operating engine at maximum takeoff power
* M - Maximum gross weight
* B - Bank of no more than 5 degrees
* A - Aft center of gravity
* T - Takeoff configuration (gear up, flaps up)
* S - Standard temperature (15°C) and pressure (29.92” Hg)
Each component of COMBATS is essential for accurately determining Vmc.
What effect does a windmilling propeller have on drag compared to a feathered propeller?
A windmilling propeller creates much more drag than a feathered propeller
If the airplane is equipped with an autofeather system, the propeller is feathered automatically.
How does operating the engine at maximum takeoff power affect Vmc?
It increases Vmc due to more lift and a greater yawing tendency about the longitudinal axis.
What is the relationship between maximum gross weight and Vmc?
While a heavier airplane is more stable, it requires the wing to produce more lift, affecting Vmc.
What is the maximum bank angle required for standardization regarding Vmc?
No more than 5°.
How does an aft center of gravity (CG) influence the effectiveness of the rudder?
It decreases the distance between the CG and rudder, reducing leverage and effectiveness.
What is included in the takeoff configuration for Vmc?
Flaps in normal takeoff position and landing gear retracted.
What effect does landing gear and flaps being down have on aircraft stability?
It creates drag but also provides a keel effect that stabilizes the aircraft.
What conditions are the published Vmc and red line on the airspeed indicator based on?
Standard temperature and pressure at sea level.
How does density altitude affect Vmc?
As density altitude increases, Vmc decreases, making the red line less reliable and bringing Vmc closer to stall speed.
What is Vmc?
Vmc is defined using a very specific set of conditions.
How do published Vmc and actual Vmc compare?
Published Vmc and actual Vmc can be two very different numbers.
What does Vmc address?
Vmc only addresses directional control and is not related to aircraft performance.
What is equally important alongside controllability?
Single engine performance is just as important.
What must be balanced to prevent a serious situation from getting out of control?
Both controllability and performance must be balanced.
True or False: An increase in controllability can sometimes hurt performance.
True
Fill in the blank: Vmc is important for _______.
[directional control]
What is a key consideration when dealing with Vmc?
Controllability and performance must be managed together.
What does Vmc stand for?
Vmc is the minimum control speed with one engine inoperative.
How does Vmc change?
Vmc changes with any combination of variables.
What is the maximum allowable Vmc for certification?
Vmc cannot be greater than 1.2 times stall speed with flaps in takeoff position and gear retracted.
What are the warning signs that Vmc is occurring or about to occur?
- Loss of directional control
- Stall warning horn or buffeting of the controls
- Rapid decay of control effectiveness
What happens when you experience loss of directional control?
The rudder pedal is depressed to its fullest travel, but the airplane still yaws or rolls toward the inoperative engine.
What is a potential consequence of a single engine stall?
A single engine stall is very dangerous and could result in a spin.
What should you do to recover from Vmc?
You must simultaneously reduce power on the operating engine and pitch down.
Why is it important to reduce power on the operating engine during Vmc recovery?
Reducing power on the operating engine reduces the asymmetric airflow.
What does pitching down accomplish during Vmc recovery?
Pitching down lowers the nose of the aircraft to get air flowing over the control surfaces.
How does density altitude affect normally aspirated engines?
They lose efficiency as density altitude increases.
What remains constant as altitude changes, stall speed or Vmc?
Stall speed remains constant while Vmc changes.
What is the implication if both Vmc and stall speed are reached at the same time?
A spin is almost inevitable.
How to these factors Impact VMC
Increase power on good engine
Increases Vmc- More yaw and roll
How to these factors Impact VMC
Increase temperature
Lowers Vmc- less dense, less power, less yaw
How to these factors Impact VMC
Increase pressure
Lowers Vmc- less dense, less power, less yaw
How to these factors Impact VMC
Increase altitude
Lowers Vmc- less dense, less power, less yaw
How to these factors Impact VMC
Reducing bank
Increases Vmc- less AOA on rudder=less
effectiveness
How to these factors Impact VMC
Windmilling propeller
Increases Vmc- more drag=more yaw
How to these factors Impact VMC
Feathered propeller
Lowers Vmc- less drag=less yaw
How to these factors Impact VMC
Aft CG
Increases Vmc- less distance between rudder &
CG
How to these factors Impact VMC
Heavier weight
Lowers Vmc- more lift needed in turn=helps
prevent turn
How to these factors Impact VMC
Flaps down
Lowers Vmc- more drag-creates stability
How to these factors Impact VMC
Gear down
Lowers Vmc- more drag-creates keel effect/stability
How to these factors Impact VMC
Critical engine fails
Increases Vmc- more yaw, more roll
How to these factors Impact VMC
In ground effect
Increases Vmc- less drag= more yaw and roll
What is the Vso speed for the Diamond DA42?
62 KIAS
Vso is the stalling speed in a specified configuration.
What is the Vs1 speed for the Diamond DA42?
69 KIAS
Vs1 is the stalling speed in a specified configuration with flaps up.
What is the Vmc speed for the Diamond DA42?
73 KIAS
Vmc is the minimum control speed with the critical engine inoperative.
What is the rotation speed (Vr) for the Diamond DA42?
- 76 KIAS - Flaps APP
- 80 Flaps UP
Vr is the speed at which the aircraft is rotated for takeoff.
What is the Vy speed for the Diamond DA42?
- 85 KIAS Flaps APP
- 90 KIAS Flaps UP
Vy is the best rate of climb speed.
What is the Vx speed for the Diamond DA42?
82 KIAS
Vx is the best angle of climb speed.
What is the Vyse speed for the Diamond DA42?
85 KIAS
Vyse is the best rate of climb speed with one engine inoperative.
What is the Vfe Flaps Landing speed for the Diamond DA42?
113 KIAS
Vfe is the maximum flap extension speed.
What is the Vo speed for the Diamond DA42 at maximum weight?
- 112 KIAS - Below 3748
- 119 KIAS - 3748 to 3986
- 122 KIAS - Above 3986
Vo is the maximum operating maneuvering speed.
What is the Vno speed for the Diamond DA42?
151 KIAS
Vno is the maximum structural cruising speed.
What is the Vne speed for the Diamond DA42?
188 KIAS
Vne is the never exceed speed.
What is the Vloe speed for the Diamond DA42?
188 KIAS
Vloe is the maximum landing gear extension speed.
What is the maximum landing gear retraction speed (Vlor) for the Diamond DA42?
152 KIAS
Vlor is the maximum speed for retracting the landing gear.
What is Vfe Flaps APP for the Diamond DA42?
133 KIAS
This is the maximum speed at which landing flaps can be safely deployed.
What is the maximum demonstrated crosswind component for the Diamond DA42?
25 KIAS (flaps up), 20 KIAS (flaps app)
This indicates the maximum crosswind condition for safe operations.
What does the bottom of the white arc indicate?
Stall speed with flaps LDG
This is the stall speed when landing flaps are deployed.
What does the bottom of the green arc indicate?
Stall speed with flaps UP
This is the stall speed when flaps are not deployed.
What does the red line represent on the airspeed indicator?
Never exceed speed (Vne)
Operating above this speed can result in structural damage.
What does the blue line indicate on the airspeed indicator?
Best single engine rate of climb speed (Vyse)
This speed is crucial for performance during engine failure scenarios.
What does CAS stand for?
Calibrated Airspeed
CAS is the indicated airspeed corrected for installation and instrument errors. It equals TAS at standard atmospheric conditions (ISA) at MSL.
What is KCAS?
CAS in knots
What does KIAS represent?
IAS in knots
Define IAS.
Indicated Airspeed as shown on an airspeed indicator
What is TAS?
True Airspeed. The speed of the airplane relative to the air. TAS is CAS corrected for errors due to altitude and temperature.
What is vA?
Maneuvering Speed. Full or abrupt control surface movement is not permissible above this speed.
What does vFE stand for?
Maximum Flaps Extended Speed. This speed must not be exceeded with the given flap setting.
What is the definition of vLO?
Maximum Landing Gear Operating Speed. This speed may not be exceeded during the extension or retraction of the landing gear.
What does vLE indicate?
Maximum Landing Gear Extended Speed. This speed may not be exceeded if the landing gear is extended.
Define vMC.
Minimum Control Speed. Minimum speed necessary to be able to control the airplane in case of one engine inoperative.
What is vNE?
Never Exceed Speed in smooth air. This speed must not be exceeded in any operation.
What is the Maximum Zero Fuel Weight for DA42NG?
3891 lbs
What is the Maximum Takeoff Weight for DA42NG?
4189 lbs
What is the Maximum Landing Weight for DA42NG?
3979 lbs
True or False: Landings at weights above the Maximum Landing Weight are allowed.
True
Landings above the MLW, but not exceeding MTOW, are allowed as an Abnormal Procedure. See your AFM for complete details.
What is the Cardinal Rule for single-engine procedures?
Maintain control and airspeed at all times
This is critical to ensure safety and manage the aircraft effectively.
What action should be taken regarding the operating engine during single-engine procedures?
Apply max power to operating engine (Assuming you are currently well above Vmc)
Vmc is the minimum control speed in the air.
What should be done to minimize drag during single-engine procedures?
Reduce drag to an absolute minimum
This helps maintain performance and control.
What is the first step in handling a failed engine?
Secure failed engine and related sub-systems
This is essential for safety and to prevent further complications.
Why is a takeoff briefing important?
Takeoff is the most critical time for a multi-engine airplane
A standard briefing helps prepare for emergencies.
What is the consequence of attempting to continue a single-engine takeoff and crashing at 70 knots?
Will result in up to four times greater impact G-forces than running off the runway and hitting a fence at 35 knots
This highlights the dangers of improper engine failure management.
What should be done before rotation in case of engine failure?
Power levers idle
This is part of the emergency procedure to manage the situation.
What is the immediate action if insufficient runway remains during an engine failure before rotation?
Avoid obstacles, Engine Master Switches OFF, Fuel selectors OFF
These steps are crucial to secure the aircraft.
What should be done after rotation if there is an engine failure?
Power levers idle and land straight ahead
This approach maximizes safety during an emergency landing.
What should be verified after rotation if the decision is made to continue?
Verify gear UP, flaps UP
Ensures that the aircraft is configured correctly for climb.
How do you identify a dead engine during flight?
Dead foot = dead engine
This is a mnemonic to help pilots recognize engine failure.
What is the next step after identifying a dead engine?
Power lever IDLE, no performance change
This helps in confirming the engine’s status.
What should be done to secure a dead engine?
Engine Master switch OFF
This action is necessary to prevent fuel flow and potential fire.
What atitude should you climb at after an engine failure?
Climb at blue line
The blue line indicates best rate of climb speed on single engine.
What should you declare after an engine failure?
Declare an emergency
This is crucial for getting priority handling from air traffic control.
What is the final action to take after declaring an emergency?
Return for landing
This is a critical step in ensuring the safety of the flight.
What is the first step in the engine failure procedure?
Maintain Aircraft Control
This involves reducing pitch attitude to maintain airspeed and using rudder to stop yaw.
How should the bank angle be adjusted when an engine fails?
Bank into the operating engine (2 - 3° bank is usually sufficient)
This helps maintain control of the aircraft.
What is the best performance configuration for an aircraft after an engine failure?
Power 100%, Flaps UP, Gear UP
This configuration reduces drag.
What does ‘Identify’ refer to in the engine failure procedure?
Dead foot, dead engine
This is the first part of Step 3.
What is the purpose of the ‘Verify’ step in the engine failure procedure?
Reduce dead engine power level and verify no change
This confirms which engine has failed.
What action should be taken below 3000’ or during an instrument approach?
Secure the inoperative engine and land as soon as practicable
This is to ensure safety during critical phases of flight.
What should be considered above 3000’ AGL after an engine failure?
Consider troubleshooting if time and workload permit
This allows for potential recovery if feasible.
What should be done to maintain airspeed after an engine failure?
Pitch for blue line, even if you must descend to do so
Maintaining airspeed is crucial to prevent loss of control.
What is the consequence of losing airspeed below Vmc?
The aircraft will roll toward the inoperative engine, resulting in a loss of control
Vmc is the minimum control speed.
What is Accelerate-Stop Distance?
The distance required to accelerate to liftoff speed, abort takeoff due to an engine failure, and stop the airplane using only brakes.
Defined by FAA citation: 14 CFR 23.55.
What does the FAA define as the Accelerate-Go Distance?
The distance required to accelerate to liftoff speed, continue the takeoff after an engine failure, and climb to at least 35 feet AGL.
Defined by FAA citation: 14 CFR 23.57.
What is the significance of the Takeoff Weight chart?
It determines if the aircraft can maintain a positive single engine rate of climb at liftoff based on weight and balance.
If unable to climb, the pilot must abort the takeoff.
True or False: The DA42 TwinStar is required to define Accelerate-Stop and Accelerate-Go distances.
False.
These definitions are not required for the DA42 due to its MTOW being less than 6000 pounds.
What should you know before attempting a takeoff in the DA42?
Whether you can maintain control and climb out if you lose an engine with the gear still down.
This is crucial for safe operation during takeoff.
Fill in the blank: The _______ distance is crucial for determining whether to abort a takeoff after an engine failure.
Accelerate-Stop
Fill in the blank: The _______ distance involves continuing the takeoff after an engine failure and climbing to a specified height.
Accelerate-Go
What is the regulation for operating a civil aircraft at cabin pressure altitudes above 12,500 feet up to 14,000 feet?
The required minimum flight crew must be provided with and use supplemental oxygen for any part of the flight at those altitudes lasting more than 30 minutes.
This is outlined in 91.211(a)(1) of the Supplementary Oxygen regulations.
What must be provided to the flight crew at cabin pressure altitudes above 14,000 feet?
The required minimum flight crew must use supplemental oxygen during the entire flight time at those altitudes.
This is specified in 91.211(a)(2).
At cabin pressure altitudes above 15,000 feet, what is required for each occupant of the aircraft?
Each occupant must be provided with supplemental oxygen.
This requirement is stated in 91.211(a)(3).
What is required for civil aircraft operating with a pressurized cabin above flight level 250?
At least a 10-minute supply of supplemental oxygen must be available for each occupant in case of loss of cabin pressurization.
This is outlined in 91.211(b)(1)(i).
What must one pilot do when operating at flight altitudes above flight level 350?
One pilot must wear and use an oxygen mask that is secured and sealed, supplying oxygen at all times or automatically when cabin pressure altitude exceeds 14,000 feet.
This is specified in 91.211(b)(1)(ii).
Under what condition can one pilot at flight level 410 not wear an oxygen mask?
If there are two pilots at the controls and each has a quick-donning type of oxygen mask that can be put on within 5 seconds.
This is part of the exception in 91.211(b)(1)(ii).
What should the remaining pilot do if one pilot leaves the controls above flight level 350?
The remaining pilot must put on and use an oxygen mask until the other pilot returns.
This is detailed in 91.211(b)(2).
