1. Flight Instrumentation

2. Lesson Objectives Describe the operation of an airspeed indicator
Identify different types of airspeed readings
Describe the operation of an altimeter
Describe the effects of barometric pressure and temperature of altitude readings
Describe the operation of attitude indicators
List the data elements a pilot can gain from a horizontal situation indicator
Chapter 4, Lesson 4

3. The Operation of an Airspeed Indicator
An airspeed indicator determines airspeed by measuring the difference between dynamic air pressure and static air pressure
It gets its data from a system called the pitot- static system
Pitot tube captures dynamic as well
as static pressure
Pitot tube’s pressure chamber sends
the total pressure to the airspeed indicator
Static port sends static pressure to the airspeed indicator
When the dynamic pressure changes, airspeed indicator shows either increase or decrease

4. Airspeed Readings Indicated — Airspeed shown on the airspeed indicator
Calibrated — Indicated airspeed corrected for installation error and instrument error
Equivalent — As a plane flies faster than 200 knots, the air being squeezed into the pitot tube becomes more compressed. This leads to an error that indicates the plane is flying faster than it really is. This error grows particularly large near the speed of sound. Pilots can correct for error at speeds exceeding 200 knots using a chart to find the equivalent airspeed
True — Calibrated airspeed corrected for altitude and temperature. Because air density changes at different altitudes and temperatures. The pilot uses a flight computer that calculates the true airspeed when the pilot enters the calibrated airspeed, pressure altitude, and temperature..

5. Airspeed Indicator Markings
Airspeed indicator has color-coded markings
White arc— Aircraft’s operating range for approaches and landings
Green arc—Aircraft’s normal operating range
Yellow arc—Range in which a pilot should be cautious
Red line—Pilot should never exceed this speed
Chapter 4, Lesson 4
Reproduced from US Department of Transportation/Federal Aviation Administration

6. The Operation of the Altimeter
The most common type of altimeter is the pressure altimeter
The major component is a stack of sealed aneroid wafers; an aneroid is a sealed flat capsule made out of thin metal disks and emptied of all air
The pressure inside the sealed wafers is inches of mercury.
A static port captures static pressure and introduces it into the sealed altimeter case.
"Reproduced from US Department of Transportation/Federal Aviation Administration"

7. The Operation of the Altimeter
The wafers expand or contract because of changes in the static pressure in the surrounding atmosphere due to change of altitude.
Mechanical parts connect the wafers’ movements to needles on the altimeter’s face.
When the wafers contract, the needles show a decrease in altitude.
When the wafers expand, the needles indicate an increase in altitude.
"Reproduced from US Department of Transportation/Federal Aviation Administration"

8. Effect of Barometric Pressure on Altitude Reading
The altitude shown on the altimeter face is correct only when certain standards are met:
Sea level barometric pressure of inches of mercury
Temperature of 59 degrees F (15 degrees C)
A standard rate of decrease in pressure and temperature with an increase in altitude
Since barometric pressure and temperature generally don’t remain constant; pilots must adjust their altimeters
If flying from high-pressure area to a low-pressure area without adjusting the altimeter, the aircraft’s
actual height would be lower than
the altimeter indicates

9. Effect of Temperature on Altitude Readings
Similarly when flying in temperatures that are colder than standard, the actual altitude will be lower than the altimeter indicates
When the air is warmer than standard, the aircraft will be higher than the altimeter says
Pilot can correct for temperature with the help of a computer
Chapter 4, Lesson 4
Reproduced from US Department of Transportation/Federal Aviation Administration

10. The Operation of Attitude Indicators
Displays an aircraft’s attitude which can alert the pilot to possible changes in airspeed, altitude, and direction
Works according to gyroscopic rules; features a fixed aircraft on its face and a freely moving horizon bar
If an aircraft pitches or banks, the horizon bar of the altitude indicator remains in its original horizontal plane. This is because the bar is fixed to the gyroscope so it can maintain its horizontal plane even as the aircraft moves about its lateral or longitudinal axis.
Chapter 4, Lesson 4
Reproduced from US Department of Transportation/Federal Aviation Administration

11. Attitude Indicator
An attitude indicator generally has limits as to how much pitch and roll it can indicate
Banking limits are usually from 100 to 110 degrees.
Pitch limits are from about 60 to 70 degrees.
Chapter 4, Lesson 4
Reproduced from US Department of Transportation/Federal Aviation Administration

12. The Functions of a Horizontal Situation Indicator
HSI is a flight instrument that indicates an aircraft’s position and direction in relation to the desired route
Information includes:
magnetic heading
course the pilot has selected
deviation from the intended course
glide slope indicators
deviation from the intended descent
red warning flags when HSI isn’t working properly
Chapter 4, Lesson 4
Reproduced from US Department of Transportation/Federal Aviation Administration

13. Lesson Objectives Describe the operation of an airspeed indicator
Identify different types of airspeed readings
Describe the operation of an altimeter
Describe the effects of barometric pressure and temperature of altitude readings
Describe the operation of attitude indicators
List the data elements a pilot can gain from a horizontal situation indicator
Chapter 4, Lesson 4

14. Activity 1: Calculating True Airspeed
Read the information about corrections to indicated airspeed on the airspeed indicator
Examine the example on how to calculate true airspeed and then solve the problems
Chapter 4, Lesson 4

15. Activity 2: Airspeed Indicators
Review the textbook information on airspeed indicator markings
Answer the questions about the airspeed indicator in your own words
Chapter 4, Lesson 4

16. Activity 3: Altimeters and Temperature
Determine the air or ground temperature or altitude
Examine the examples and solve the problems
Chapter 4, Lesson 4

17. Activity 4: Functions of the Horizontal Situation Indicator
Review the textbook information on the functions of a horizontal situation indicator (HSI)
Describe in your own words the functions of some features on the HIS and what they tell a pilot
Chapter 4, Lesson 4

18. Activity 5: Attitude Indicator Readings
Review the textbook information on the functions of attitude indicators
Answer the questions about the attitude indicator and determine the readings
Chapter 4, Lesson 4

19. Activity 6 Flight Simulator: Flight Instruments
Identify the different aircraft flight instruments using Microsoft Flight Simulator
Chapter 4, Lesson 4