property of lear siegler. physics of the atmosphere
TRANSCRIPT
Property of Lear Siegler
PHYSICS OF THE ATMOSPHERE
Property of Lear Siegler
TERMINAL LEARNING OBJECTIVE
At the completion of this lesson, the student will:
ACTION: Demonstrate an understanding of theatmosphere’s physical properties and their impacton the operation of the TH-67 pressure instruments.
CONDITION: In a classroom environment giveninformation on the pressure instruments and the atmosphere.
STANDARD: Answer questions pertaining to theatmosphere’s physical properties and their impact on the operation of the TH-67 pressure instruments. Receive a “GO” by correctly answering the required number of questions on criterion referenced examination 011-0050.
A: Enabling Learning Objective
Action: Identify the characteristics of the standard atmosphere
Condition: Given information about the standard atmosphere
Standard: IAW FM 3-04.240 and FAA-H-8083-25A,Pilot’s Handbook of Aeronautical Knowledge.
Property of Lear Siegler
The “Standard Atmosphere”
“A hypothetical vertical distribution of atmospheric temperature, pressure, and density which by
international or national agreement is taken to be representative of the atmosphere for the purpose
of altimeter calibrations, aircraft design, performance calculations, etc.”
Property of Lear Siegler
29.9
2”
Property of Lear Siegler
53,000
18,000Sea Level 50%
90%
Sea Level
MSL 29.92”Hg
1000’ 28.92”Hg
2000’ 27.92”Hg
3000’ 26.92”Hg
4000’ 25.92”Hg
5000’ 24.92”Hg
Standard Pressure Lapse Rate
1” Hg per 1000’
Property of Lear Siegler
7500’ 22.42”Hg
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
Standard Temp Lapse Rate
2°C per 1000’
Property of Lear Siegler
7500’ 0°C
29.92”Hg 15°C
AIR DENSITY
29.92”Hg 15°C29.92”Hg 15°C 28.92”Hg 15°C29.92”Hg 23°C
Property of Lear Siegler
AIR DENSITY
Press
Hum
Temp
Good Bad
H
L
L
L
H
H
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
B: Enabling Learning Objective
Action: Identify the pressures used in the pitot static system
Condition: Given information about the pitot static system pressures
Standard: IAW FM 3-04.240
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
Weight of a column of airStatic Pressure --
Impact Pressure -- Static + Dynamic
Property of Lear SieglerProperty of Lear Siegler
Dynamic Pressure – Additional pressure caused by air in motion
Stagnation point
Property of Lear Siegler
Static pressure only
Impact pressure = Static + Dynamic
Property of Lear Siegler
Note: Impact = Ram = Total = Pitot Pressure
LEFT
PITOT TUBE
RIGHT
STATIC VENTS
Property of Lear Siegler
HEATER
Construction of the Pitot System
Construction of the Pitot System
Notice that the Pitot Tube goesonly to airspeed indicator!
The Static Pressure is ventedto all three instruments.
Construction of the Pitot System
The diaphragm in the Airspeed Indicatoris connected to the Pitot Tube. It
only senses Pitot Pressure. The caseis vented to Static Pressure.
Construction of the Pitot System
The diaphragm in the Vertical Speed Indicator is vented to Static Pressure.The case is vented to Static Pressure
through a calibrated leak.
Construction of the Pitot System
The aneroids in the Altimeter are sealed. The case is vented to Static Pressure.
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
C: Enabling Learning Objective Action: Identify the operational characteristics of the airspeed indicator
Condition: Given information about the airspeed indicator
Standard: IAW FM 3-04.240
Property of Lear Siegler
AIRSPEED INDICATOR
Property of Lear Siegler
LEFT
PITOT TUBE
RIGHT
STATIC VENTS
Property of Lear Siegler
STATIC VENTPITOT TUBE
Property of Lear Siegler
Property of Lear Siegler
Impact pressure = Static + Dynamic
Property of Lear Siegler
Property of Lear SieglerProperty of Lear Siegler
??
?? ?
?
?
D: Enabling Learning Objective Action: Identify the uses of the airspeed indicator
Condition: Given information on the uses of the airspeed indicator
Standard: IAW FM 3-04.240
Property of Lear Siegler
Uses for the airspeed indicator
Property of Lear Siegler
1: Keep aircraft within “Never Exceed Speed"
2: Determine best operational speed for best climb, best endurance, and best range
3: Determine rate of movement for navigation
4: Aircraft attitude
Airspeed fast-Pitch attitude low
Airspeed low-Pitch attitude high
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
E: Enabling Learning Objective
Action: Identify the errors associated with the airspeed indicator
Condition: Given information about airspeed indicator errors
Standard: IAW FM 3-04.240
Property of Lear Siegler
ERRORS
Instrument Error – Minor, caused by friction
Property of Lear Siegler
Installation Error – Caused by misalignment of the pitot tube and/or the static vents with the relative wind
Density Error – Caused by changes in air density
Property of Lear Siegler
TRUE AIRSPEED (TAS) IS THE SAME,AIR IS LESS DENSE AT ALTITUDE,
THEREFORE, CALIBRATEDAIRSPEED (CAS) IS LESS THAN TAS.
Property of Lear Siegler
CAS IS THE SAME, AIR ISLESS DENSE AT ALTITUDE, THEREFORE,
TAS IS MORE THAN CAS AT ANYALTITUDE ABOVE
ZERO FEET DENSITY ALTITUDE.
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
F: Enabling Learning Objective
Action: Identify the types of airspeed
Condition: Given information about types of airspeed
Standard: IAW FM 3-04.240
Property of Lear Siegler
Types of Airspeed
TAS – True Airspeed - Calibrated Airspeed corrected for density error
CAS – Calibrated Airspeed – Indicated Airspeed corrected for installation error
Property of Lear Siegler
IAS – Indicated Airspeed – read from the airspeed indicator
Airspeed Indicator in Review…
Property of Lear Siegler
Can you identify the pressures used, the errors and the types of airspeed?
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
G: Enabling Learning Objective
Action: Identify the operational characteristics of the vertical speed indicator
Condition: Given information about the operation of the vertical speed indicator
Standard: IAW FM 3-04.240
Property of Lear Siegler
Vertical Speed Indicator
Property of Lear Siegler
LEFT
PITOT TUBE
RIGHT
STATIC VENTS
Property of Lear Siegler
PITOT TUBE
STATIC VENTS
Property of Lear Siegler
Property of Lear Siegler
CalibratedCalibratedLeakLeak
Property of Lear Siegler
CalibratedCalibratedLeakLeak
Property of Lear Siegler
CalibratedCalibratedLeakLeak
Property of Lear Siegler
CalibratedCalibratedLeakLeak
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
H: Enabling Learning Objective
Action: Identify the uses of the vertical speed indicator
Condition: Given information about the uses of the vertical speed indicator
Standard: IAW FM 3-04.240
Property of Lear Siegler
Uses of the vertical speed indicator
Property of Lear Siegler
1: Determine rate of climb or descent
2: Trend instrument-shows attitude changes immediately when in level flight
Vertical Speed IndicatorPreflight Check
Property of Lear Siegler
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
I: Enabling Learning Objective
Action: Identify the errors associated with use of the vertical speed indicator
Condition: Given information about vertical speed indicator errors
Standard: IAW FM 3-04.240
Property of Lear Siegler
Errors of the vertical speed indicator
Property of Lear Siegler
1: Six to nine second lag when leveling off from a climb or descent caused by the calibrated leak
Property of Lear Siegler
CalibratedCalibratedLeakLeak
Property of Lear Siegler
CalibratedCalibratedLeakLeak
Errors of the vertical speed indicator
Property of Lear Siegler
1: Six to nine second lag when leveling off from a climb or descent caused by the calibrated leak
2: Erratic in rough air
Vertical Speed Indicator in Review…
Property of Lear Siegler
Can you identify the pressures used, the errors and preflight procedures?
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
J: Enabling Learning Objective
Action: Identify the operational characteristics of the altimeter
Condition: Given information about the operational characteristics of the altimeter
Standard: IAW FM 3-04.240
Property of Lear Siegler
ALTIMETER
Property of Lear Siegler
LEFT
PITOT TUBE
RIGHT
STATIC VENTS
Property of Lear Siegler
PITOT TUBE
STATIC VENTS
Property of Lear Siegler
Property of Lear Siegler
Aneroid wafers sealed at factory
Dial – three pointers
10,000’ IndicatorTick marks in increments of 2000’
1,000’ IndicatorTick marks in increments of 200’
100’ IndicatorTick marks in increments of 20’
1,040’
8,000’
18,980’
Kollsman window – corrects for atmospheric pressure changes
28.10”Hg to 31.00”Hg
Set field elevation
ATIS – “Altimeter setting three zero two four”
AIMS Counter Drum Pointer
ATC Radar Beacon System
Identification Friend or Foe
MARK 12
SYSTEM
Property of Lear Siegler
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
K: Enabling Learning Objective
Action: Identify the uses of the altimeter
Condition: Given information about the uses of the altimeter
Standard: IAW FM 3-04.240
Property of Lear Siegler
Uses of the altimeter
Property of Lear Siegler
Terrain clearance
Vertical separation
Attitude control
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
L: Enabling Learning Objective
Action: Identify the types of altitude
Condition: Given information about the types of altitude
Standard: IAW FM 3-04.240
Property of Lear Siegler
Identify the types of altitude
a. Indicated
b. True
c. Absolute
d. Pressure (PA)
e. Density (DA)
Property of Lear Siegler
Indicated Altitude
Read from instrument with correctly set Kollsman window (sea level pressure).
Property of Lear Siegler
True Altitude – Altitude above Mean Sea level
MSL
1000’
Property of Lear Siegler
MSL
Absolute Altitude– Altitude above the surface (AGL)
Property of Lear Siegler
MSL
Pressure Altitude (PA) – Altitude above the standard datum plane
29.92 Standard datum plane
1000’
Property of Lear Siegler
MSL 29.92 Standard datum plane
Standard Day
TrueAltitude
PressureAltitude=
1000’
1000’
Pressure Altitude
Property of Lear Siegler
Max torque available, max gross weight,and performance are all
affected by Density Altitude
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
Density Altitude (DA) : Is the densitycorresponding to a given altitude
in a standard atmosphere.
Density Altitude (DA) : Pressure Altitude corrected for non standard temperature
Property of Lear Siegler
DA = PA + (120 Tv )
PA = Pressure AltitudeTv = Temperature Variation
Mean Sea Level (MSL)MSL 29.92”Hg 15°C
1000’ 28.92”Hg 13°C
2000’ 27.92”Hg 11°C
3000’ 26.92”Hg 9°C
4000’ 25.92”Hg 7°C
5000’ 24.92”Hg 5°C
7500’ 22.42”Hg 0°C
Property of Lear Siegler
29.92”Hg 15°C 29.92”Hg 32°CMSL
2040’ PA
Property of Lear Siegler
29.92”Hg 15°C 29.92”Hg 32°CMSL
2040’
Property of Lear Siegler
PA = 0’
OAT = 36°DA = 2500’
Property of Lear Siegler
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C PA = 6000’
OAT = 5°C
OAT is Higher than standardDA is Higher than PA
Property of Lear Siegler
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
PA = 4000’
OAT = 5°C
OAT is Lower than standardDA is Lower than PA
Property of Lear Siegler
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
PA = 5000’
OAT = 5°C
DA = PA +120’
Property of Lear Siegler
One hour later
OAT = 6°C
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
M: Enabling Learning Objective
Action: Identify the errors associated with the use of the altimeter
Condition: Given information about altimeter errors
Standard: IAW FM 3-04.240
Property of Lear Siegler
Altimeter errors
a. Instrument Error
b. Pressure Error
c. Temperature Error
Property of Lear Siegler
MSL
TrueAltitude
1000’
Property of Lear Siegler
Instrument Error
1000’
FieldElevation
Caused by friction inside instrument
MSL
TrueAltitude
1000’
Property of Lear Siegler
Instrument Error
30.24 hg”
“Altimeter three zero two four”
30.26-30.24
= .02= 20 foot error
1000’
FieldElevation
Maximum Error + / - 70 ft
Property of Lear Siegler
Pressure Error – caused when flying intoareas that have different altimeter settings than those set in the Kollsman window.
TRUE ALT
TRUE ALT
IND ALTIND ALT
Property of Lear Siegler
Pressure Error
Temperature Error
MSL MSL
1000’ 1000’
Sta
ndar
d te
mp
29.92
28.92
29.92
28.92
Col
der
29.92
28.92
War
mer
Property of Lear Siegler
TRUE ALT
TRUE ALT
IND ALTIND ALT
Property of Lear Siegler
Pressure Error
Sta
ndar
d te
mp
28.92
28.92
War
mer
29.92 29.92 29.92
28.92
Col
der
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
Indicated Altitude = 6000’
OAT = 20°C
True Alt. is Higher than Indicated
Property of Lear Siegler
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
Indicated Altitude = 4000’
OAT = 5°C
True Altitude is lower than Indicated
Property of Lear Siegler
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
Indicated Altitude = 5000’
OAT = 5°C
Indicated Altitude = True altitude
Property of Lear Siegler
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
N: Enabling Learning Objective
Action: Identify pitot static system malfunctions
Condition: Given information about pitot static system malfunctions
Standard: IAW FM 3-04.240
Property of Lear Siegler
STATIC VENT PITOT TUBEProperty of Lear Siegler
Pitot Static System Malfunctions
STATIC VENT PITOT TUBEProperty of Lear Siegler
Pitot Static System Malfunctions
Property of Lear Siegler
STATIC VENT PITOT TUBEProperty of Lear Siegler
Pitot Static System Malfunctions
STATIC VENT PITOT TUBEProperty of Lear Siegler
Pitot Static System Malfunctions
Altimeter – No change in indication
VSI – Level off at zero
Property of Lear Siegler
Airspeed Indicator – opposite of clogged pitot tube
Property of Lear SieglerProperty of Lear Siegler
MMMMMMMMOVING
The endThe end
STOPSTOP
Abandon hope all ye who enter hereAbandon hope all ye who enter here
You are entering the hidden slide ZoneYou are entering the hidden slide Zone
0C H 0 2
M N
248.2GD
TX
LEFT
PITOT TUBE
RIGHT
STATIC VENTS
Property of Lear Siegler
HEATER
PA = 6000’
OAT = 5°C
DA is Higher than PAProperty of Lear Siegler
Is the DA higher or lower than PA
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
Standard temperatures
PA = 4000’
OAT = 5°C
DA is lower than PAProperty of Lear Siegler
Is the DA higher or lower than PA
MSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
Standard temperatures
Property of Lear Siegler
Temperature Error
MSL MSL
1000’ 1000’
Sta
ndar
d te
mp
29.92
28.92
29.92
28.92
Col
der
29.92
28.92
War
mer
Property of Lear Siegler
Indicated Altitude = 6000’
OAT = 20°C
True Alt. is Higher than Indicated
Property of Lear SieglerMSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
Standard temperatures
Indicated Altitude = 4000’
OAT = 5°C
True Altitude is lower than Indicated
Property of Lear SieglerMSL 15°C
1000’ 13°C
2000’ 11°C
3000’ 9°C
4000’ 7°C
5000’ 5°C
6000’ 3°C
Standard temperatures
TRUE ALT
TRUE ALT
IND ALTIND ALT
Property of Lear Siegler
Pressure Error