Chapter 4 Flight Instruments Flashcards
What are the 6 classes of instruments?
Pitot Tube, Magnetic, Gyroscopic, Electrical, Electronic, Self Contained
What are the two types of pitot tube instruments?
Static - Altimeter, Variometer
Dynamic - Airspeed Indicator, Total Energy Probe - separates ascent or descent due to pitch from thermal
Where is the static pitot tube mounted?
Usually on the sides of the fuselage.
Where is the dynamic tube located?
Usually it extends out from the vertical stabilizer.
How does the airspeed indicator work?
It measures the difference between the total pressure and the static pressure to find the dynamic pressure which represents the airspeed.
What are the three types of airspeed?
Indicated IAS, Calibrated CAS , True TAS, Ground speed GS
What is Calibrated Airspeed CAS?
CAS is indicated IAS adjusted for position sensing errors and instrument errors. It is a calculated value.
What is True Airspeed TAS?
TAS is IAS corrected for pressure and temperature. It is a calculated value. True airspeed is always higher than indicated airspeed. TAS increases 2% above IAS for each 1000’ increase in altitude. TAS at 10,000’ will be 20% higher than IAS.
IAS values does not change with altitude for what designated speeds?
Stall speed, Min Sink speed, Best L/D speed.
What happens to Vne as altitude increases?
Vne decreases as IAS as altitude increases. Vne would be constant for TAS.
What is maneuvering speed?
Max speed where full movement of one flight control can safely be used. Also max speed in rough air. Sometimes marked at the top of the green arc.
What arc on the airspeed indicator is used for flap deployment?
White arc
What does green arc represent?
Normal operating range.
What does yellow arc represent?
Safe operating range in smooth air.
What does red line mean?
Vne
What does the triangle on the airspeed indicator mean?
Recommended approach speed.
Regardless of altitude, Indicated airspeed is the same for what?
Stalls. Stall speed does not change.
Biggest difference between IAS and CAS occurs when?
High AOA, Yawing, Low speed, flap/spoiler deployment.
Other airspeeds to know.
Landing gear, tow speed
How does the altimeter work?
A sealed chamber expands or contracts based on the static pressure acting on the outside of it. The chamber is attached to the needle of the altimeter and moves the needle when it contracts or expands.