Study sheet: Aviation Atmosphere Weather and Regulations

📋 Course Outline

1. Aviation Terminology and Communication
2. Aerodynamics and Flight Controls
3. Aircraft Structure and Systems
4. Airports, Balance, and Atmosphere
5. Atmosphere and Gas Expansion
6. Weather Fronts and Clouds
7. Turbulence and Volcanic Ash
8. Icing and Aviation Organizations
9. Flight Information Regions and Separation
10. EASA Regulatory Framework
11. Safety Management and Crew Authority
12. Normal Cabin Operations
13. Passenger Briefings and Cabin Preparation
14. Flight Phase Safety Duties
15. Emergency Evacuation Procedures
16. Survival and Decompression Response
17. Aircraft and Operator Training
18. Differences and Familiarisation Training

📖 1. Aviation Terminology and Communication

🔑 Key Concepts & Definitions

• Aircraft : a vehicle that can travel through the air
• Control surface : a movable aircraft surface that controls motion around one of the three principal axes
• Flight level : the nominal altitude of an aircraft referenced to a standard pressure datum rather than its real altitude above mean sea level

★ Must-know

• The aviation phonetic alphabet represents the letters A to Z with the words Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliet, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, and Zulu.

📐 Formula — Pressure satisfies $P = \frac{F}{S}$, where P is pressure, F is force, and S is surface area.

Further detail

• One nautical mile equals 1.852 kilometers, and one knot equals one nautical mile per hour.

💡 Memory Hook

ATC: aviation terminology, terminology codes, communication

📖 2. Aerodynamics and Flight Controls

🔑 Key Concepts & Definitions

• Aircraft axes : The three aircraft axes are the longitudinal axis from nose to tail, the lateral axis from wing tip to wing tip, and the vertical axis from top to bottom.
• Flaps : high-lift devices on the trailing edges of wings that increase lift at a given airspeed

★ Must-know

• The four forces acting on an aircraft in flight are:
  • weight
  • lift
  • thrust
  • drag

📌 In straight and level flight at constant speed without turning moments, an aircraft is in equilibrium when thrust equals drag and weight equals lift.

📌 Ailerons control roll around the longitudinal axis, elevators control pitch around the lateral axis, and the rudder controls yaw around the vertical axis.

Further detail

• Seventy-five percent of an airfoil's total lift results from decreased pressure over its upper surface, while the remaining 25% results from air impacting its lower surface.

💡 Memory Hook

Lift rises upward, drag acts backward; ailerons roll, elevators pitch, rudder yaws

📖 3. Aircraft Structure and Systems

🔑 Key Concepts & Definitions

• Airframe : The airframe consists of the wing, fuselage, landing gear, horizontal stabilizer, and vertical stabilizer or drift.

★ Must-know

• The landing gear permits taxiing, absorbs stresses during initial runway contact, and retracts in flight to reduce drag.

📌 A turbojet produces all its thrust by ejecting a high-energy gas stream, whereas a turboprop is a jet engine optimized to drive a propeller.

• To use the pilot oxygen mask, the pilot squeezes and holds the red knobs, pulls the mask from its container, places it over the mouth and nose, adjusts the harness, and releases the knobs.

• The three main aircraft circuits are:

  • electrical
  • hydraulic
  • pneumatic

Further detail

• A protective breathing equipment hood operates as a closed circuit, neutralizes exhaled carbon dioxide with a soda lime cartridge, and provides 15 minutes of operating time.

💡 Memory Hook

Airframe → engines → oxygen → water → communication → circuits

📖 4. Airports, Balance, and Atmosphere

🔑 Key Concepts & Definitions

• Taxiway : an airport path connecting runways with aprons, hangars, terminals, and other facilities

★ Must-know

• Runways are used for aircraft landing and takeoff and are oriented along the dominant wind axis of their region.

📌 A forward center of gravity increases stability and decreases maneuverability and fuel consumption, whereas an aft center of gravity decreases stability and increases maneuverability and fuel consumption.

• The standard atmosphere has a sea-level pressure of 1013.25 hPa, a sea-level temperature of 15 °C, a temperature gradient of 2 °C per 1000 feet, and a lowest temperature of −56.5 °C.

Further detail

📐 Formula — Mach number is the ratio of an aircraft's speed to the speed of sound, expressed as $M = \frac{V}{a}$.

• For a one-liter helium balloon at sea level with pressure 1000 hPa and pressure 250 hPa at 35,000 feet, Boyle's law gives a volume of 4 liters at 35,000 feet.

💡 Memory Hook

Higher altitude → lower pressure → gas expansion

📖 5. Atmosphere and Gas Expansion

🔑 Key Concepts & Definitions

• Differential pressure : the pressure increase created when expanding gases are confined in a sealed body whose volume cannot increase

★ Must-know

• Standard atmospheric pressure at sea level is 1013.25 hPa and standard temperature at sea level is 15 °C.

• Water vapour is excluded from the otherwise nearly constant atmospheric gas proportions because it varies from around 4% by volume in humid air near the equator to almost 0% in dry, cold air near the poles.

📐 Formula — For a gas at constant temperature, Boyle's law gives the new volume as $V' = \frac{P \times V}{P'}$.

Further detail

• The standard atmospheric temperature gradient is 2 °C per 1000 ft, or 6.5 °C per 1000 metres, and the lowest standard-atmosphere temperature is −56.5 °C.

• A one-litre helium balloon at sea level with a pressure of 1000 hPa would have a volume of 4 litres at 35,000 ft where the pressure is 250 hPa, assuming the envelope does not burst and its elasticity is negligible.

💡 Memory Hook

Sea level pressure → altitude expansion → differential pressure

📖 6. Weather Fronts and Clouds

🔑 Key Concepts & Definitions

• Tropical cyclone : an intense circular storm originating over warm tropical oceans and characterized by low atmospheric pressure, high winds, and heavy rain

★ Must-know

📌 A cold front is the changeover region where colder air replaces warmer air, while a warm front is the region where warmer air replaces colder air.

• In the Intertropical Convergence Zone near the equator, intense solar heating warms humid air, trade winds converge, and the buoyant air rises, cools, and releases moisture through frequent thunderstorms.

• The stated cyclone-formation conditions are:

  • An upper-ocean temperature of 26.5 °C
  • A tropical depression
  • Cumulus congestus or vigorous cumulonimbus
  • Abundant moisture in the troposphere
  • Regular winds at all altitudes

• Clouds form when rising warm air cools and its water vapour condenses into water droplets or ice crystals.

• High clouds form above 20,000 feet, middle clouds between 6,500 and 20,000 feet, low clouds below 6,500 feet, and vertical clouds can span several levels.

Further detail

• Tropical cyclones can produce winds exceeding 119 km per hour, with extreme cases exceeding 240 km per hour and gusts surpassing 320 km per hour, while storm surges can reach 6 metres above normal sea level.

• The ten main cloud types are:

  • Cirrus
  • Cirrocumulus
  • Cirrostratus
  • Altostratus
  • Altocumulus
  • Nimbostratus
  • Stratus
  • Stratocumulus
  • Cumulus
  • Cumulonimbus

💡 Memory Hook

Cold front: colder, drier air; warm front: warmer, more humid air

📖 7. Turbulence and Volcanic Ash

🔑 Key Concepts & Definitions

• Cumulonimbus : a dense cloud with considerable vertical extent, often shaped like a mountain or tower, associated with heavy rainfall, lightning, thunder, and anvil-shaped tops when mature
• Clear air turbulence : normally occurs outside clouds above 15,000 feet MSL and is caused by strong wind shear in the jet stream
• Wind shear : a difference in wind speed and direction over a relatively short distance and may have vertical or horizontal components

★ Must-know

• The formation requirements and triggers are:

  • A deep layer of unstable air
  • Warm and moist air
  • Surface heating
  • Orographic uplift
  • A front forcing air upward

• Cumulonimbus hazards include:

  • Severe turbulence and wind shear
  • Moderate to severe icing
  • Electrical disturbances
  • Hail
  • Contaminated runways
  • Severe downdrafts
  • Microbursts
  • Tornadoes

📌 The only sensible defense against the hazards of cumulonimbus is to avoid flying into it, using planning, awareness, weather radar, and diversion or holding when necessary.

• Volcanic ash can melt inside engines and adhere to internal components, potentially causing engine failure, while fine ash particles can damage windscreens and reduce pilot visibility.

Further detail

• Wingtip vortices can remain in the air for up to three minutes after an aircraft passes, whereas jetwash is extremely turbulent but short-lived.

💡 Memory Hook

Airflow disturbance or ash ingestion → reduced aircraft safety

📖 8. Icing and Aviation Organizations

🔑 Key Concepts & Definitions

• Flight Information Region : a defined area of airspace managed by a controlling authority responsible for providing air traffic services to aircraft within it

★ Must-know

• Aircraft are de-iced on the ground in freezing conditions because frozen contaminants degrade aerodynamic properties and dislodged ice can damage engines.

• In-flight ice accretion can cause:

  • Loss of lift
  • Loss of thrust
  • Increased drag
  • Altered longitudinal stability and pitch trim
  • Degraded control-surface effectiveness
  • Uncommanded control deflections

📌 For aircraft without airframe ice-protection systems, icing should be avoided by operating in VMC without freezing precipitation or in IMC with temperatures above freezing and no freezing precipitation.

📌 Aircraft contaminated by ice, frost, sleet, or snow must be de-iced before takeoff, and aircraft exposed to freezing precipitation that may adhere during takeoff must be anti-iced.

• A final inspection by suitably qualified personnel must confirm that all critical aircraft surfaces are free of contamination before release in icing conditions or after de-icing or anti-icing.

• ICAO was established by States in 1944 to administer and govern the Chicago Convention and develops international Standards and Recommended Practices with its 193 Member States.

📌 An ICAO airport code is a four-letter location indicator used for air traffic control and airline operations, whereas an IATA code is used for commercial identification; Malta's codes are LMML and MLA respectively.

• 🔄 The SAR phases progress as follows:

  1. Uncertainty phase (INCERFA)
  2. Alert phase (ALERFA)
  3. Distress phase (DETRESFA)

• The phraseology for SAR alert messages begins with PAN PAN, while distress messages begin with MAYDAY.

Further detail

• Ground de-icing fluids typically contain a glycol-water solution, dye, and agents protecting the metal surface, and protection time can range from 2 minutes to 2 hours depending on the fluid and weather conditions.

• IATA was founded in Havana in April 1945 and in 2009 comprised 230 companies representing 93% of world passenger traffic.

• The current ICAO regions are:

  • Africa-Indian Ocean
  • Asia
  • Caribbean
  • European
  • Middle East
  • North American
  • North Atlantic
  • Pacific
  • South American

📖 9. Flight Information Regions and Separation

🔑 Key Concepts & Definitions

• Flight Information Region : A designated volume of airspace managed by a controlling authority responsible for ensuring that air traffic services are provided to aircraft flying within it.
• Aircraft separation : The maintenance of a minimum distance between aircraft, terrain, obstacles, or controlled airspace to reduce collision risk and prevent accidents such as those caused by wake turbulence.
• Flight plan : A flight plan is a document providing air traffic service units with specified information about an intended flight or part of a flight, including aircraft identification, departure and destination, timing, route, flight level, flight rules, flight type, aircraft and wake turbulence information, and equipment and capacity.

★ Must-know

📌 Controlled airspace requires aircraft to follow air traffic controller instructions, whereas uncontrolled airspace does not mandate air traffic control services but allows aircraft to request services such as flight information, alerting, and distress assistance.

• Vertical separation is 1,000 feet (300 m) from the Earth’s surface to 29,000 feet (8,800 m), and 2,000 feet (600 m) above 29,000 feet except where Reduced Vertical Separation Minima (RVSM) applies.

Further detail

• The present regional structure comprises:
  • Africa-Indian Ocean (AFI)
  • Asia (ASIA)
  • Caribbean (CAR)
  • European (EUR)
  • Middle East (MID)
  • North American (NAM)
  • North Atlantic (NAT)
  • Pacific (PAC)
  • South American (SAM)

💡 Memory Hook

Controlled airspace requires ATC instructions, whereas uncontrolled airspace only offers optional services.

📖 10. EASA Regulatory Framework

🔑 Key Concepts & Definitions

• European Union Aviation Safety Agency : Established in 2002, works to provide the highest common level of safety protection for European citizens and a level playing field for the aviation industry within the European Single Market.

★ Must-know

• EASA assists the European Commission with common safety rules and international agreements, issues certification specifications and guidance, certifies aviation products, approves certain organizations, authorizes third-country airlines to fly into the EU, monitors Member State application of safety requirements, and cooperates with aviation authorities and international organizations.

📌 The Basic Regulation (EU) 2018/1139 establishes the foundational civil aviation safety and environmental protection framework, whereas implementing regulations provide detailed rules for particular aviation domains.

• Part-CC contains requirements for cabin crew attestations, training, and related competence standards, including minimum age 18, attestation issue after examination, unlimited validity subject to conditions, and specific aircraft type qualification.

• Cabin crew medical checks are required before starting work and then every 5 years, and qualified medical professionals must conduct them.

Further detail

📌 Acceptable Means of Compliance (AMC) illustrate ways to demonstrate compliance and create a presumption of compliance when followed, whereas Guidance Material (GM) provides explanations and practical clarification for applying regulations and AMCs.

💡 Memory Hook

Basic Regulation establishes the framework → implementing regulations provide detailed requirements.

📖 11. Safety Management and Crew Authority

🔑 Key Concepts & Definitions

• Safety Management System : A structured organizational approach to managing safety through hazard identification, risk assessment, risk controls, and continuous monitoring and review of safety performance.
• Risk assessment matrix : Evaluates risk by combining the likelihood of an event with its consequences, with their intersection determining the overall risk level and helping prioritize controls.

📝 Essential Points

• Organizations identify hazards and risks through observation, risk assessments, incident reports, employee input, and industry standards and regulations, then regularly review whether the risks are being effectively managed.

📌 A just culture avoids automatically assigning blame to individuals and instead focuses on systemic causes and corrective action, whereas a blame-focused culture attributes incidents primarily to individual fault.

• Duty is prohibited when the crew member is affected by:
  • psychoactive substances
  • injury
  • fatigue
  • medication
  • sickness
  • unfulfilled medical requirements
  • uncertainty about fitness
  • suspected fatigue endangering the flight

📌 The Captain is responsible for the safety of crew members, passengers, and cargo on board and may issue commands, take safety actions, disembark hazardous persons or cargo, and refuse transportation when safety is threatened.

💡 Memory Hook

Hazard identification → risk assessment → controls → continuous safety monitoring.

📖 12. Normal Cabin Operations

★ Must-know

• 🔄 The phases of flight occur in this order:

  1. pre-flight
  2. taxi-out
  3. takeoff
  4. climb
  5. cruise
  6. descent
  7. approach
  8. landing
  9. taxi-in
  10. post-flight

• Critical phases typically include:

  • taxi
  • takeoff
  • ascent
  • descent
  • landing
  • periods when the seatbelt sign is illuminated

• Before the first flight, the cabin crew briefing covers safety awareness, take-off and landing position assignments, and duties during ground handling with passengers on board, while the cabin pre-flight check verifies safety equipment and its locations.

• Exit-row seats may not be occupied by: passengers unable to hear, understand, or act on instructions, persons with reduced mobility, incapacitated passengers, infants or children under 12, passengers unable or unwilling to assist, deportees or persons in custody, passengers with service animals or pets

📌 During refuelling or defuelling with passengers on board, two assigned passenger doors must remain clear, aisles must be unobstructed, passengers must remain seated with seatbelts unfastened, emergency exits must be identifiable, no meal or drink service may occur, and qualified crew must continuously man the assigned doors.

Further detail

• A clear area used during refuelling or defuelling must measure at least 4 × 11 metres.

💡 Memory Hook

Pre-flight → boarding → departure → flight phases → refuelling precautions.

📖 13. Passenger Briefings and Cabin Preparation

📝 Essential Points

📌 Before each departure with embarking passengers, a passenger safety briefing must be given and normally completed immediately after the doors are closed, the fasten-seatbelt sign is switched on, and all doors are armed.

• The passenger safety briefing covers:
  • smoking regulations
  • hand-luggage stowage
  • upright seat backs
  • stowed tray tables and footrests
  • portable-electronic-equipment restrictions
  • seatbelt use
  • oxygen masks
  • life vests when applicable
  • emergency exits and cabin-aisle lighting
  • the safety-on-board card

📌 A life-vest demonstration is required when flying more than 50 nautical miles (93 km) from shore or when the take-off or approach is over water such that ditching might be likely.

• Cabin preparation includes: securing luggage and loose objects, closing luggage bins, securing infants and seatbelts, placing seats and portable electronic equipment correctly, stowing tables and service equipment, collecting glassware, opening curtains and panels, securing galleys, containers, and trolleys

📌 The Purser reports “Cabin ready” to the flight crew as soon as possible after taxiing has started, but not during pushback or engine starting.

💡 Memory Hook

Brief, secure, check, report

📖 14. Flight Phase Safety Duties

🔑 Key Concepts & Definitions

• Sterile cockpit : rule applies around Flight Level 100, or 10,000 feet above mean sea level, and requires pilots and cabin crew to minimize non-essential activities and communications

★ Must-know

📌 During taxiing, cabin crew must guard their assigned exits and ensure that passengers remain seated with their seatbelts fastened.

• 🔄 During moderate or severe turbulence, cabin crew:
  1. stop service
  2. stow trolleys and galley equipment
  3. secure loose items and cots
  4. take their seats
  5. fasten their seatbelts

Further detail

• Lavatories should be checked regularly, preferably every 60 minutes, for fire-prevention and security reasons.

• The cabin crew member working in the galley area closest to the cockpit must check the flight crew at least once every 30 minutes by interphone.

💡 Memory Hook

Above Flight Level 100: services may resume; below it: cockpit remains sterile

📖 15. Emergency Evacuation Procedures

★ Must-know

📌 The Captain normally initiates an evacuation by commanding “EVACUATE, EVACUATE, EVACUATE” and switching on the evacuation signal, but the Purser may initiate it when evacuation is unmistakably necessary and no cockpit information is available.

• 🔄 During an evacuation, cabin crew: open their seatbelts, stand up and shout commands, check outside conditions and door configuration, open the door when appropriate, use the manual inflation handle if automatic inflation fails

📌 If an exit is unsafe, cabin crew must redirect passengers to the nearest usable exit, guard the unusable exit when possible, and shout “EXIT BLOCKED - GO THAT WAY”.

Further detail

• 🔄 After evacuation, crew should: assemble people upwind at a safe distance, search for missing or shocked persons, check injuries and provide first aid, evaluate the situation, establish temporary shelter with slides if immediate help is unlikely

💡 Memory Hook

Command, open, redirect, evacuate

📖 16. Survival and Decompression Response

★ Must-know

• 🔄 When decompression occurs, cabin crew:

  1. take a nearby oxygen mask
  2. put it on demonstratively
  3. sit down immediately

• A rapid or explosive decompression may produce loud noise, severe cold, flying debris, and dense fog, whereas a slow decompression may first be indicated by the oxygen masks dropping.

• 🔄 After decompression, cabin crew: use the overhead oxygen system to reach a portable oxygen cylinder, activate its 4-litre-per-minute outlet for personal use, assist passengers with their masks, provide first-aid oxygen where required

Further detail

📌 If the flight crew does not visibly react or does not begin a descent, the Purser or cabin crew must notify the flight crew that the oxygen masks have deployed and verify that all flight crew members are wearing them.

💡 Memory Hook

Pressure loss → oxygen masks → immediate descent

📖 17. Aircraft and Operator Training

★ Must-know

• Aircraft type-specific training must use a representative training device or the actual aircraft and cover the aircraft description, safety equipment and systems, operation of normal and emergency doors and exits, other exits, fire and smoke protection equipment, evacuation slides where fitted, and equipment used for pilot incapacitation.

• Operator conversion training must cover:

  • the operator’s standard operating procedures
  • cabin configuration
  • portable safety and emergency equipment
  • normal and emergency procedures
  • passenger handling and crowd control
  • fire and smoke procedures
  • evacuation procedures
  • pilot incapacitation procedures
  • security requirements
  • crew resource management

Further detail

📌 Each cabin crew member should descend an evacuation slide from a height representative of the aircraft main deck sill height, and must make a further descent when qualifying on an aircraft type whose main deck exit sill height differs significantly from a previously operated type.

• Operator conversion fire and smoke training requires each cabin crew member to extinguish an actual aircraft-interior fire, with an alternative agent permitted for halon extinguishers, and to practise using protective breathing equipment in an enclosed simulated smoke-filled environment.

💡 Memory Hook

Type-specific training concerns the aircraft; operator conversion concerns the operator’s procedures.

📖 18. Differences and Familiarisation Training

🔑 Key Concepts & Definitions

• Flight Duty Period : the period beginning when a crew member reports for duty and ending after the post-flight activities following the final flight’s block time

📝 Essential Points

• Differences training is required before assignment to an aircraft variant or to an aircraft type or variant with different safety equipment, equipment locations, or normal and emergency procedures.

• The differences training programme must be determined by comparing the cabin crew member’s completed aircraft type-specific and operator conversion training with the relevant differences, and it must include practice in a representative training device or the actual aircraft as appropriate.

• A new entrant cabin crew member without comparable operating experience should complete both an aircraft familiarisation visit and familiarisation flights, whereas a cabin crew member moving to a subsequent aircraft type with the same operator may complete either a familiarisation flight or a familiarisation visit.

• A crew member must stop flying and consult the Captain or Purser when: applicable medical requirements have not been fulfilled, assigned duties cannot be accomplished, a condition or diagnosis may endanger the flight

📌 No alcohol should be consumed less than 8 hours before the specified reporting time or standby, the blood alcohol level must not exceed the lower of national requirements or 0.2 per thousand at the start of a flight duty period, and no alcohol may be consumed during the flight duty period or standby.

📌 Crew members must not use party drugs, soft drugs or hard drugs, and must not take prescription or non-prescription medication or undergo treatment unless they are completely sure it will not adversely affect safe performance; doubts require advice from the corporate doctor.

• The operator must ensure that cumulative duty hours do not exceed 1,800 hours in any 12 consecutive calendar months, 190 hours in any 28 consecutive calendar days, or 60 hours in any 7 consecutive calendar days; the annual limit may rise to 2,000 hours for crew members with a significant share of contracted non-flying office duties.

• The maximum basic daily Flight Duty Period is 13 hours, reduced by 30 minutes for each sector from the third sector onward, with a maximum sector-based reduction of 2 hours.

• The maximum planned Flight Duty Period is 16 hours with an augmented crew, limited to 4 landings, and 18 hours with a double crew, limited to 6 landings, provided the required rest facilities are available.

• An augmented crew has a maximum planned flight duty period of 16 hours, irrespective of the reporting time, with a maximum of 4 landings.

• The conditions for an augmented crew are: a comfortable reclining seat above economy class for each resting crew member, a shared seat row used only by another crew member, rest seats separated from the flight deck and screened from passengers

• The permitted FDP increase is: no increase for 0 to 2 hours 59 minutes, half the break for 3 to 6 hours 59 minutes, two-thirds of the break for 7 to 10 hours 59 minutes, one and a half times the break when at least 7 hours fall between 20:00 and 08:00 local time

• Flight block time for an individual operating crew member must not exceed $100\text{ hours}$ in 28 consecutive calendar days, $280\text{ hours}$ in 90 consecutive calendar days, or $900\text{ hours}$ in 12 consecutive calendar months.

📌 Before an FDP, rest must be at least the preceding duty period or 12 hours at home base, whichever is greater, and the preceding duty period or 10 hours away from home base, whichever is greater.

• The company must provide either 36 consecutive hours including 2 local nights within 7 consecutive days or 60 consecutive hours including 3 local nights within 10 consecutive days.

💡 Memory Hook

Difference first, then familiarisation before or during assignment.

📊 Synthesis Tables

Aircraft Control Surfaces

Control surface	Axis	Movement
Ailerons	Longitudinal	Roll
Elevators	Lateral	Pitch
Rudder	Vertical	Yaw

ICAO and IATA

Organization	Main role	Identification
IATA	Commercial coordination between air transport companies and agents	Commercial codes such as MLA
ICAO	International civil aviation standards, policies, and oversight	Operational codes such as LMML