Fuel System 2

Question 1

Fuel system function

Answer 1

To store and deliver fuel to carb or fuel injection continuously in adequate quantities and at correct pressures

Question 2

Gravity fed

Answer 2

Tank higher than engine (high wing ac)
No pump
Flow effected by attitude
Susceptible to vapour lock due to low operating pressure
Minimum flow rate requirement 150%?

Question 3

Pump fed

Answer 3

High or low wing
Tank lower than engine
Modern ac
Aux and engine pump
Know fuel system for your aircraft

Question 4

Fuel properties

Answer 4

Avgas 100 green 100ll blue
Calorific value ( amount of energy provided)
Volatility ability to vaporise ( volatile= vapour lock or detonation not volatile= hard to ignite hard starting poor acceleration)
Octane (anti knock rating)
Corrosiveness and tendency to form deposits

Question 5

Hydrocarbon

Answer 5

C1h4
Created petrol

Question 6

Octane rating

Answer 6

100 = iso octane
Lead additives such as tetra ethyl lead increase rating

Question 7

Mogas

Answer 7

No quality control
More volatile
Vapour lock likely
Less power
Spark plug flowing
Detonation

Question 8

Lead additives

Answer 8

Cause spark plug fowling with lead deposits
Engine at low power for extended periods with low CHT
to solve run engine with high CHT or increase power periodically

Question 9

Avtur

Answer 9

Higher grade than recommended leads to plug fouling and corrosion

Question 10

Refuelling

Answer 10

Parking brake
Masters and ignition off no one on board
Bonding wire attached
No taps

Question 11

Preignition

Answer 11

Combustion before spark fires
Caused by high CHT or carbon deposits

Question 12

Detonation

Answer 12

Auto ignition before flame wall
Caused by too high pressure/temp in FA mixture