KDRS

Question 1

Minimum drag and speed Part 61 MOS unit 1.3.2 CADA 2.3.1(a)

2. 3.1 With reference to CL, CD, CL/CD graphs, explain the angles of attack associated with the following
   a) minimum drag – maximum level flight speed;

Answer 1

-To find the total drag we add the values of parasite and induced drag together.
-This is done by laying the solid line and the dashed line end to end for each speed. If we draw a curve joining the total values for each speed we have the total drag curve.
- The total drag curve displays a minimum value near the middle of the speed range
- At low speeds the total drag is higher because of higher induced drag
-At high speed total drag is higher because of high parasite drag
-At the point where induced drag and parasite drag are equal S2 the total drag is at a minimum
If the aircraft is flown straight and level at speed S2 it will achieve :
-maximum range in nil wind
-best air nm per gallon
-least gallon per nm
- best lift / drag ration aeroplane
-best gliding range in nil wind conditions
- Since lift has a fixed value in level flight the lift drag ration is greater when drag is least.

Question 2

Waste gate operation Part 61 MOS unit 1.2.2 PAKC 2.2.3

Answer 2

• A super charger is an engine driven air pump or compressor that provides compressed air to the engine to provide additional pressure to the induction air so that the engine can produce additional power
• It increases manifold pressure and forces the fuel air mixture into the cylinders.
• Higher manifold pressure increased the density of the fuel air mixture and increase the power an engine can produce.

Question 3

Ignition system Part 61 MOS Unit 1.1.1 BACK 3.4.1
For paragraphs (a), (b) and (c), the components are listed in paragraph (d):
(a) describe the cockpit indications which may suggest a malfunction or failure of a component;
(b) state the actions (if any) a pilot should take to rectify a malfunction or failure of a component;
(c) describe the consequences if a malfunction or failure of a component listed above cannot be rectified;

Answer 3

The switch has five positions:
OFF
R (right)
L (left)
BOTH
START
With RIGHT or LEFT selected, only the associated magneto is activated while BOTH uses the two simultaneously
A malfunctioning ignition system can be identified during the pre-takeoff check by observing the decrease in rpm that occurs when the ignition switch is first moved from BOTH to RIGHT, and then from BOTH to LEFT
The permissible decrease is listed in the AFM or POH
If the engine stops running when switched to one magneto, the rpm drop exceeds the allowable limit, or no drop occurs, do not fly the aircraft until the problem is corrected
The cause could be fouled plugs, broken or shorted wires between the magneto and the plugs, or improperly timed firing of the plugs
Following engine shutdown, turn the ignition switch to the OFF position
Even with the ignition, battery, and master switches in the OFF position, if the ground wire between the magneto and the ignition switch becomes disconnected or broken, the engine could accidentally start if the propeller is moved with residual fuel in the cylinder because it requires no external power
If this occurs, the only way to stop the engine is to move the mixture lever to the idle cutoff position
The video below is an example of a magneto check
Always follow the procedures and limits listed in the AFM/POH for your aircraft when performing this check
(i.e., 125 RPM is this aircraft’s maximum drop, yours may be different)

Question 4

Fuel Flow Gauge Part MOS unit 1.2.9 CAKC 2.2.3

Answer 4

The fuel flow gauge measures fuel pressure with a transducer and transmits it to the instrument which is calibrated in fuel flow
This system assumes that a given pressure will produce a given fuel flow rate
The face of the instrument is calibrated in gallons per hours.
They do not measures fuel flow directly a partial blockage in the fuel line or filter will cause an incorrect reading as the pressure will rise while the flow rate will fall.
Fluctuations in the fuel pressure are also a likely indication when fuel vaporisation is occurring
Excessive heat from the engine, exhaust system, and/or outside temperature can cause the fuel to vaporize in the lines

Question 5

Aircraft starting

Answer 5

The function of the ignition system is to provide an electrical spark to ignite the fuel/air mixture in the cylinders. The ignition system of the engine is completely separate from the airplane’s electrical system. The magneto type ignition system is used on most reciprocating aircraft engines. Magnetos are engine driven self-contained units supplying electrical current without using an external source of current. However, before they can produce current the magnetos must be actuated as the engine crankshaft is rotated by some other means. To accomplish this, the aircraft battery furnishes electrical power to operate a starter, which through a series of gears, rotates the engine crankshaft. This in turn actuates the armature of the magneto to produce the sparks for ignition of the fuel in each cylinder. After the engine starts, the starter system is disengaged, and the battery no longer contributes to the actual operation of the engine.

Question 6

How does the ignition system work

Answer 6

The ignition system provides spark to the spark plugs
It includes the
-Magnetos
-Spark plugs
- Wires
-ignition switch
Turning the ignition on to start, then starts the starter motor which engages the crank shaft which starts the engine.
which sends power to the magnetos consists of a rotating magnet that supplies electricity to the spark plugs. The spark that is generated is independent of the aircrafts electrical system.
The magnetos would still be able to generate sparks for the engine if it failed