Aircraft instruments principle and application

1. 09EI205 AIRCRAFT
INSTRUMENTATION
Text Books:
Pallett, E.B.J ., : " Aircraft Instruments -Principles and applications",
Pitman and sons, 1981.
Refer :
www.scribd.com

2. UNIT- V : POWER PLANT INSTRUMENTS
Fuel flow -Fuel quantity measurement, exhaust
gas temperature measurement and pressure
measurement.

3. Fuel flow
• The measurement of the quantity of fuel in the tanks of an aircraft fuel
system is an essential requirement, and in conjunction with
measurements of the rate at which the fuel flows to the engine or engines
permits an aircraft to be flown at maximum efficiency compatible with its
specified operating conditions.
• Furthermore, both measurements enable a pilot or engineer to quickly
assess the remaining flight time and also to make comparisons between
present engine performance and past or calculated performance.

4. operating principle and
construction
• Fuelquantity indicating systems vary in operating principle and
construction, the application of any one method being governed by the
type of aircraft and its fuel system. Two principal methods currently
applied utilize the principle of electrical signal transmission from units
located inside the fuel tanks.
• In one method, mainly employed in the fuel systems of small and light
aircraft, the tank units consist of a mechanical float assembly which
controls an electrical resistance unit and varies the current flow to the
indicating element.
• The second method, employed in high-performance aircraft fuel systems,
measures fuel quantity in terms of electrical capacitance and provides a
more accurate system of fuel gauging.

5. Float-Type Fuel- Quantity lndicating
Systems

6. Capacitance-Type Fuel-Gauge
System

10. Location of tank sensing units.

19. Integrated fuel flowmeter system.

20. pressure measurement

29. Measurement of
temperature