I- User Environment

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I- User Environment
Aviation meteorology, session 2
ENM Sep 2008 Franck PITHOIS ENM/PAM
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I- User Environment

1. International Context
2. Aircraft
3. User Organization
4. Measurement Units
5. Altimetry Basics

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Aviation course blended learning- I/ User
Environment
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1. International Context

• International Civil Aviation Organization
• Dec. 7, 1944 Chicago Conference (52 states)
• Wrote a convention covering international civil
  aviation
• Founded ICAO (190 member states in 2008)

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ICAO's purposes

• Setting out the principles and techniques of
  international air navigation
• Promoting and planning the development of safe,
  reliable, efficient and cost effective air
  transport.

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2. Aircraft
Engine cowling
Leading edge
Wing
Wing tip
Aileron
Flaps
Trailing edge
Elevator
Trim tab
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Aerodynamic forces
Lift
Drag
Thrust
Relative airflow
Weight
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Relative airflow VR
Leading edge
Upper surface underpressure
VR
Lower surface overpressure
Trailing edge
Link http//www.av8n.com/how/htm/airfoils.html,
for further explanations
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Dynamic study of the forces in presence
R Aerodynamic resultant
Fz
P Weight T Thrust (engine)
Fx
Vr
T
? Density of air S Reference surface Vr
Aircraft/Air speed Cx Coefficient of drag Cz
Coefficient of lift
P
Lift
Drag
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Various aircraft
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3. User Organization

• Airspace structure (introduction)
• Different categories of users
• Two types of flight rules IFR/VFR
• Flight safety

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a- Airspace structure UIR/FIR
In-flight information
In France 1 UIR 5 FIR
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Vertical structure
There are two categories of controlled
airspace Control area CTR
CTR Control region CTA TMA, AWY,
LTA UTA
U I R
UTA
F I R
AWY
CTR
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Airspace classifications

• - Controlled airspace (classes A, B, C, D E)
• Uncontrolled airspace (class F G)
• Regulated airspace (marked as R)
• Dangerous airspace (marked as D)
• Prohibited airspace (marked as P)

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Examples
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b. Different categories of users

• What flies (in France)
• General aviation traffic
• Military aviation traffic
• Operational military aviation traffic
• Flight tests and aircraft acceptance
• Airport operations (in France)
• Airport services Air navigation
• Airport operators Chambers of Commerce
  Industry, companies

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General Aviation Traffic

1. Commercial aviation
2. Government and military aviation
3. Business and recreational aviation

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Commercial aviation
Flights operated by international, domestic and
regional airlines carrying passengers and cargo.
Performance by type of propulsion
Jets (major airlines) Operational ceiling 8,000 to 12,000 m Speed mach 0.9 to mach 2.2Range 1,000 to 15,000 km Turboprops (regional airlines) Operational ceiling 3,000 to 6,000 m Speed 200 to 300 knots Range 500 to 3/5,000 km
Piston engines (small operators) Operational ceiling 4 to 5,000 m Speed 100 to 250 knots Range 500 to 5,000 km
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Government and military aviation

• Presidential or ministerial flights
• Customs service
• Civil protection
• SFACT (Aeronautical training and technical
  inspection service)
• Carrying passengers and cargo

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Business and recreational aviation
Private flights public transport other than
scheduled flights and express cargo Recreational
aviation motorized (airplanes helicopters),
gliders, free flight, ULM, skydiving and
ballooning.
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c. Two types of flight rules IFR/VFR
Defined in line with IMC/VMC weather
conditions IFR Instrument Flight Rules VFR
Visual Flight Rules
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IFR

• Suitably equipped aircraft
• Qualified crew (professional)
• Aircraft guidance using radio navigation
  equipment
• Procedures to follow (air traffic control)
• Radio communication equipment fitted

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IFR

• Commercial aviation type flights, implying
• Safety and reliability
• Different weather conditions during different
  phases of the flight take off, cruising, landing

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VFR

• Less sophisticated aircraft equipment
• Generally a relatively less qualified crew
  (amateur)
• More restrictive visibility and ceiling
  conditions
• Subject to weather conditions

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Different types of VFR

• "Regular" VFR
• Special VFR excluding VMC conditions, low
  altitude
• Night VFR specific qualifications
• VFR on TOP flight above the clouds

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d. Flight safety International statistics

Since 1999, the ICAO only keeps records on
accidents involving aircraft with a certified
maximum take off weight in excess of 2,250 kg The
total of death is quite egal despite a bigger
trafic every year
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Passenger fatalities on scheduled flights
Years 1997 1998 1999 2000 2001 2002 2003 2004
Passenger fatalities per 100 million Pax/km 0.04 0.035 0.02 0.025 0.02 0.025 0.015 0.005
Excluding accidents due to illicit intervention
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Aircraft categories involved in accidents
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Occurrences
Source DGAC
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4. Measurement Units
Horizontal distances Nautical Mile (NM
1852 m) Horizontal speeds Knots (KT) Vertical
distances Feet (FT0.3048 m) Standard Flight
Levels 850 (FL050), 700 (FL100), 500 (FL180),
300 (FL300), 250 (FL340), 200 (FL390).
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5. Altimetry basics

1. Principle
2. A Reminder on Altitudes
3. ICAO standard atmosphere
4. Altimeter
5. Altimeter settings

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a. Principle

• Defining the altitude-pressure relationship in
  the vertical distance or elevation sense
• Resolving problems relating to determining
  vertical distances from pressure measurements.

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b. Reminder Altitudes
Height The vertical distance between any point
or level taken in relation to a reference point.
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b. Reminder Altitudes
Altitude The vertical distance between any point
or level Above Mean Sea Level (AMSL)
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c. ICAO standard atmosphere (1/4)

• A fictitious atmosphere defined up to an altitude
  of 32 km
• Air is a perfect gas with an invariable chemical
  composition
• Air is dry (Tv T)
• Gravity acceleration is constant g
  9.80665m/s²

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c. ICAO standard atmosphere (2/4)

• - A vertical temperature gradient that is
  constant for each of the following intervals
• 0 to 11 km gradient of T -0.65C/100 m
  or 2C /1000 ft
• 11 to 20 km gradient of T 0 (T - 56.5C)
• 20 to 32 km gradient of T 1C/1000 m

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c. ICAO standard atmosphere (3/4)

• Pressure at sea level is 1013.25 hPa
• Temperature at sea level is 15C or 288k

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c. ICAO standard atmosphere (4/4)
Graphic representations
Z f(P)
Z f(T)
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d. Altimeter Operation
The instrument itself comprises aneroid capsules
that are sensitive to pressure variations. The
measured pressure level is directly translated
into a vertical distance in line with the
standard atmospheric rule.
Graduated in feet, 1 ft 0.3048 m
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d. Altimeter Description
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e. Altimeter settings Why they were created
Height
Altitude
Reference altitude
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e. Altimeter settings

• QFE
• QNH
• 1013

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QFE
Equivalent atmospheric pressure at the
aerodrome's official altitude. For a pilot this
is the setting pressure that corresponds to a
ZERO indication on their altimeter when their
wheels touch down.
The setting reference is the runway.
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Calculating QFE
The pressure measured by the barometer brought
back to the official runway altitude thanks to an
altitude correction. QFE P(Station reference
altitude) dP
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Using QFE
During takeoff or landing phases for aerodromes
located above 600 meters. The altimeter provides
the height in relation to the runway. It is used
less and less. Advantage when the plane touches
the runway, the altimeter indicates ZERO.
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QNH
Station pressure returned to sea level by
applying a standard correction.For pilots, this
setting gives them the flight or runway altitude
in relation to sea level.In a standard
atmosphere, the setting reference for QNH is the
sea.
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Calculating QNH
QNH P(station reference altitude)dP Correction
calculated just like QFEin standard atmosphere
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Using QNH

• More and more often used for it offers many
  advantages
• Routes through mountain ranges.
• Takeoff and landing from aerodromes.
• Precise position at the auto-information stage.
• A good approximation of the plane's true
  altitude.
• Used under the transition altitude.

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Setting 1013
Used to separate aircraft at their cruising
altitude.
Isobar surfaces
Fl 65
Fl 60
Fl 55
1013
Fl 50
0 ft
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Setting to use Uncontroled airspace
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Setting to use Controlled airspace
FL 90
FL 80
1013 settings, flight level indications
FL 70
FL 60
Transition zone
FL 50
QNH settings, Z indications
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Exercise

• What is the lowest flight level that can be
  chosen to overfly an obstacle at an elevation of
  3800 ft?
• When QNH is
• 1033 hPa
• 993 hPa
• 1013 hPa
• Remember to add a safety margin of 500 ft!
• 1 hPa 28 ft