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High Altitude Training

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Altimeter Settings

Transition Altitude• Set altimeter to 29.92 (QNE) – when climbing through Transition Altitude.• In the U. S. the typical transition altitude is 18,000’ • Referred to as Flight Levels.

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Altimeter Settings

Transition Layer• Airspace between transition level and transition altitude. • No cruise flight is typically granted in the transition layer.

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Altimeter Settings

Transition Level• Set altimeter to local altimeter setting (QNH) when descending through the

transition level

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Class A Airspace

• Positive controlled airspace.• FL 180 feet to FL 600.• IFR flight plan and ATC communication required.• Mode C transponder required.

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FL 180 to FL 290 (non-RVSM airspace)• 0 – 179 degrees magnetic heading - any odd flight level.• 180 - 359 degrees magnetic heading - any even flight level.

FL 290 to FL 600 (RVSM Designated airspace)• 0 – 179 degrees - any odd flight level at 2,000 foot intervals. • Ex: FL 290, FL 310 etc.• 180 - 359 degrees - any even flight level, at 2000 foot intervals. • Ex: FL 300, FL 320 etc.

Class A Airspace Cruise Altitudes

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• FL 290 to FL 410.• Allows 1,000 feet vertical separation between aircraft.• Increases airspace capacity and fuel efficiency.• Additional altitude reporting equipment. • Additional crew training.• FAA certification required.

Reduced Vertical Separation Minimum (RVSM airspace)

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Above FL 250 • At least a 10-minute supply of oxygen for each occupant in the

event cabin pressure is lost. FL 350 to FL 410

• Single pilot at the flight controls - Must wear oxygen mask at all times.

• Two pilots at the flight controls – both pilots must have access to a quick donning mask.

Above FL 410 • One pilot must wear an oxygen mask at all times.

Oxygen requirements in Pressurized Aircraft

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• Lies between the troposphere and the stratosphere.

• Base ranges from 30,000 at higher latitudes to 50,000 feet, at the equator.

• Little or no temperature change with altitude.

• Relatively little moisture

The High Altitude EnvironmentTropopause

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• Strong winds that generally run west to east.

• Formed by adjacent air masses with large temperature differences.

• Velocities up to 200 knots.

• Strongest near the base of the tropopause.

• Most prominent in winter.

• Northern U.S. - Polar jet.

• Southern U.S. - Subtropical jet.

• Clear air turbulence considerations.

Jet Stream

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• Airframe icing conditions are rare in the tropopause.

• Typically no visible ice on airframe.• Associated with mature convective

activity that has currently or previously penetrated the tropopause.

• Most common FL 200 – FL 350 / -10 C to -40 C.

• Ice crystals aggregate within the engine core.

• Slow decrease in power and rise in ITT.

• Possible rollback/non-responsive engine.

• Avoid flying near or over active or dissipating thunderstorms.

• Utilize and monitor aircraft/engine anti-ice and de-ice equipment and procedures.

Icing ConsiderationsIce Crystal Icing

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Valid for all weights, load factors and configurations.

• Red Arc - .85 AOA = stick shaker, to 1.0 AOA = Stall /Critical Angle of Attack

• Yellow Arc - Caution range• White Arc - .6 AOA

• 1.3 Vso (Vref)• Maximum Lift vs. Drag (L/D max)• Minimum drag speed (Vmd)• Maximum endurance (ENDmax)• Maximum angle of Climb (Vx / Vxse / V2)• Minimum sink rate / Best glide speed (Vg)

.35 AOA • Maximum velocity vs. drag (V/Dmax)• Maximum range• Best rate of climb 2 engines (Vy)• Best rate of climb with one engine inoperative

(Vyse/Venr)

Aerodynamic ConsiderationsAngle of Attack

Indicator

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• Aircraft speed through the air mass.

• Typically increases as altitude increases.

• TAS accounts for decreasing air density and non-standard (relative to ISA) temperatures.

• Utilized for navigation and when combined with wind component = groundspeed of the aircraft .

Airspeed ConsiderationsTrue Airspeed (TAS)

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• The speed of sound is (Mach 1) is 667 knots at sea level and 15 degrees C.

• The speed of sound decreases as temperature decreases.• Mach number is the aircraft speed in relationship to the local speed of

sound (Mach 1.0).• Mmo – Maximum Mach Number: Expressed as a percentage, it is the

maximum aircraft speed relative to the local speed of sound.

Ex: .737 mach = 73.7% of the local speed of sound.• Mmo provides a reference to critical airframe and engine elements

that are associated with the transonic / supersonic flight range.

Mach Number

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• As altitude increases the Speed of sound typically decreases while stall speed increases.

• The diminishing envelope between stall speed and the speed of sound could ultimately result in a stall.

• Heavy weight aircraft with lower power capabilities at greatest risk .

Coffin Corner

**Avoid airspeeds below Vmd (the back side of the power curve) due to the rapid increase of drag and increased risk of stall.

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• Recognize stall and initiate recovery at first indication.

Ex: Stick shaker, aural warning, tactile/pre-buffet indications.

• Execute recovery methodically to avoid inducing deep stall.

• Increase pitch down angle and time in order to increase the relative wind component and reduce the angle of attack sufficient for recovery.

• Utilize AOA, airspeed indicator and airspeed trend vector.

• Expect 2000 to 4000 feet altitude loss.

High Altitude Stall RecoveryReduced flight control effectiveness = Slower recovery from stalls

and upsets.

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• Provides lower cabin altitude relative to aircraft cruise altitudes.

• Psi(d)

• Air is sourced from the engines.• Constant rate.• Introduced through aircraft environmental

system.

• Outflow valves allow air to escape.• Constantly modulating• Pressurization controller.

PressurizationPressurization

System

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• Sudden and rapid depressurization.

• Immediate use of quick donning mask / supplemental oxygen.

• Emergency descent to 10,000 feet or less.

• Time of useful consciousness: • A few minutes at FL 250.• A few seconds above FL 400.

Emergency Depressurization

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• You Tube audio – “Pilot Declares Emergency Because of Extreme Hypoxia.”

• Lear 35

• Gradual pressurization loss at FL 320.

• Co-pilot reportedly disengaged the autopilot while flailing his arms in an unsuccessful attempt to don his mask before he became unconscious.

Hypoxia – “Kalitta Flight 66”

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Gradual onset:• Often insidious. • Signs may be best recognized by an

observer. • Indications may include:

• Slurred speech, delayed brain or motor functions, euphoria, tiredness, hyperventilation, blue lips or fingertips, unusually cold or hot.

Sudden onset: Indicated by aircraft warning systems or pilot observations.

• Ex: Rapid or explosive depressurization.

Indications of HypoxiaA lack of oxygen in body tissues

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Hypoxic Hypoxia • Decreased oxygen in the bloodstream at

increased altitudes.

Anemic Hypoxia • The bloods oxygen carrying capability is

dramatically reduced. Ex: Carbon monoxide poisoning.

Stagnant Hypoxia • Circulatory restrictions that may occur during

high-G force maneuvers.

Histoxic Hypoxia • The ability to absorb oxygen in the

bloodstream is limited by certain substances, such as alcohol, narcotics or poisons.

Aviation Related Forms of Hypoxia

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Check the mask for:• Setting (100%), proper inflation, plugged in properly and a

green flow indication on hose. **Breathing through mask is the only way to insure proper

flow. • Oxygen bottle gauge and valve.• Cockpit gauge.• Oxygen blowout disk.

PreflightConduct a thorough preflight inspection of the oxygen system

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• Don oxygen mask immediately.• Descend immediately.• Advise ATC. • Consider terrain factors.• Provide supplemental oxygen to passengers.• Consider fuel vs. altitude limitations.

In-Flight response to Loss of Pressurization or Hypoxia