# What are the names and the function of these aircraft components?

These images were taken from a Cessna 150 aircraft containing a Continental O-200 engine.

• Related, in case you don't have all answers: C150 service manual. After 1976, this one. – mins Dec 24 '16 at 13:14
• Are you the pilot, owner or mechanic? – vasin1987 Dec 24 '16 at 13:52

1 - nutplate holding something on the other side of the firewall

2 - starter or master contactor (a relay operated by low-current signal from cockpit switch)

4 - positive heavy-gauge cable to battery or starter

5 and 6 might be the alternator voltage regulator to hold the output voltage at 14.4V

10 - oil filter to remove carbon and other crud from oil

11 and 23 - magneto to provide carefully-timed high voltage pulses at for ignition

12 - alternator to charge battery and run electric instruments / radios

14 - vacuum pump to power gyroscopic flight instruments

15 - carburetor to meter air and fuel

21 - crankcase vent (?) to prevent blow-by gases from forcing oil out of the engine

22 - fuel strainer drain valve to drain water / crud from low point in fuel system

Better pictures would help to identify the other parts!

• Are you sure it's a 12v (14.4) system and not a 28v one? – Ron Beyer Dec 24 '16 at 14:59
• @RonBeyer C150s have 12V systems by design. I suppose someone could change out of r a 28V system if they really wanted to. – J Walters Dec 24 '16 at 15:02
• I believe 2 is specifically the starter solenoid. I believe the master solenoid is below the battery box. – J Walters Dec 24 '16 at 16:16
1 - nutplate holding something on the other side of the firewall

2 - starter or master contactor (a relay operated by low-current signal from cockpit switch)

4 - positive heavy-gauge cable to battery or starter

5 and 6 might be the alternator voltage regulator to hold the output voltage at 14.4V

10 - oil filter to remove carbon and other crud from oil

11 and 23 - magneto to provide carefully-timed high voltage pulses at for ignition

12 - alternator to charge battery and run electric instruments / radios

14 - vacuum pump to power gyroscopic flight instruments

15 - carburetor to meter air and fuel

21 - crankcase vent (?) to prevent blow-by gases from forcing oil out of the engine

22 - fuel strainer drain valve to drain water / crud from low point in fuel system


And to fill in the missing items:

3 - Rubber nipple protecting the energize conductor for the item 1 contactor

6 - Over voltage sensor (shuts off alternator if voltage is too high)

7 - Vacuum hose to cockpit (feeds air powered instruments)

8 - Avionics cooling duct inlet.

9 - static pressure port.

13 - left side exhaust muffler / cabin heat exchanger.

16 - Induction air filter

17 - Induction air box including carb heat valve.

18 - Engine data plate.

19 - Spark plug.

20 - Air inlet for cabin heat system.

23 - Right magneto.

24 - Oil filler cap.

25 - Rubber nipple protecting battery positive wire terminal.

26 - Battery box.

• I believe 6 is not an over-voltage sensor but the radio noise filter. – J Walters Dec 24 '16 at 16:13
• @JonathanWalters You are correct. Thanks – Steve H Dec 24 '16 at 16:23
• 8 may be the AC system intake
• 9 is the static port for the pressure-based instruments

• 15 looks like a fuse box

• 18 is the engine information plate

• 19 is a spark plug
• What kind of Cessna 150 has air conditioning? Probably just cabin air intake – pericynthion Dec 24 '16 at 14:44
• 8 is an avionics vent intake; 15 is the Carburetor; 18 is more properly called the engine data plate; – J Walters Dec 24 '16 at 16:07