AVIATION TECHNOLOGY

Paper 2 – PRACTICAL

Oct./Nov. 2007

2^l/₂ hours

• There are ten stations in this examination.
• Candidates are allowed 15 MINUTES at each station.
• Candidates are NOT allowed to either review the previous station’s work or read instructions for other stations.
• Write your NAME and INDEX NUMBER on all projects.
• Attempt ALL exercises in each station.
• All dimensions are in millimetres unless otherwise stated.

STATION 1 – INSTRUCTIONS

The figure below shows an exploded view of an aeropiston engine driven pump. On the drawing paper provided:

(a) Sketch in good proportion a section view of an assembled unit along the vertical plane.

(b) Name four parts which are not visible when the pump is assembled. (10 marks)

STATION 2

Using the tools, materials and equipment provided, make the square head bolt as shown in the
drawing below. (10 marks)

8.5

M12

STATION 3 – INSTRUCTIONS

The beakers labelled 1 to 5 contain samples of oil obtained from various aeropiston engine lubrication systems.

Determine the possible causes of contamination in each sample by visual inspection, viscosity test
and magnetic chip test. Record your observations in the table below. (10 marks)

INSTRUCTIONS

Carry out the following tasks using the tools and materials provided.

(a)      (i)       Hold vertically and at midlength each of the rods labelled K, L, M and N in a bench vice.

(ii)      Using the tube labelled P, bend each rod fore and aft until it breaks. Record the number of bends for each rod.

K……………………………………………….

M……………………………………………….

N……………………………………………….

(iii)     State the mechanical property being tested.

(iv)     Comment on the relationship between the number of bends each rod takes to break to the mechanical property tested. (6 marks)

(b) Cut each of the rod labelled K, L, M and N to determine the hardest material.

Hardest material………………………………………………………………………………………………….. (1 mark)

(c) State one application and one reason of selecting each of the materials labelled K, L and
M in an aircraft.

Application Reason

M                           ……………………………….. (3 marks)

(a)      (i)       Fill the bottle labelled J with water and turn it upside down into the bowl provided. Record your observations.

(ii)      Repeat (a)(i) above with the hole marked Q covered. Record your observations.

(iii)     Relate the observations in (a)(i) and (a)(ii) above to the operation of an aircraft system.

(a) (i) .-.……………………………………………………………………………………………………… (4 marks)

(b)      (i)       Repeat experiment (a)(i) above using the bottle marked K. Records your observations.

(ii)      Lift the bottle slightly above the water level. Record your observations.

(iii)     Relate the observations in (b)(i) and (b)(ii) above to the operation of an aircraft hydraulic system. (4 marks)

(c)      Give one limitation and one remedy of operations of an aircraft in flight in relationship

to the experiments in (a) and (b) above. (2 marks)

Limitation Remedy

(a)……………………………………………………………………………………………………………

(b) ……………………………………………………………………………………………………..

STATION 6 INSTRUCTIONS

Study the components marked A, B, C, D, E and F and carry out the following tasks:

(a)      Identify items A to F and for each item draw the symbol and state its use. (9 marks)

STATION 7

The pilot for the aircraft marked A has been cleared to taxi and encounters each of the scenario 1,2,3,4 and 5 as shown on the aerodrome plan provided.

Study each scenario and in the table below state the expected immediate action and the reason for
the action. (10 marks)

STATION 8 - INSTRUCTION

Study the dial test indicator provided and carry out the following tasks: (a)      Push the plunger gently and describe what happens. (2 marks)

Set the dial indictor plunger on the bar provided at the point marked X and take the reading. Move the bar under the indicator plunger and take the readings at points Y and Z respectively.

X…………………………………………………….

Y……………………………………………………..

Z……………………………………………………..

(ii)      From the results in (b)(i) above determine the state of the surface of the bar.

(c)      (i)       With the dial indicator plunger still at point Z, insert the plate labelled N between
the plunger and the bar. Record the dial indicator reading……………………………

(ii)      Determine the thickness of the plate labelled N from the readings obtained.

(iii)     Using the micrometer screw gauge provided measure and record the thickness of the plate labelled N.

(iv)     Comment on the results obtained in (c)(ii) and (c)(iii)

STATION 9

Using the tools equipment and materials provided, perform the following patch repair activities: (a)      On the perspex piece labelled R;

(i)       trim all the edges

(ii)      chamfer one of the longer edges

(iii)     round all the corners.

(b)      Use the piece labelled R to patch the area painted red on the perspex piece labelled S using the two capscrews provided. (5 marks)

Write your index number on a piece of masking tape and fix it to your workpiece.

STATION 10

Using the materials, apparatus and equipment provided: (a)      By tabulation, determine:

(i)       upthrust of the materials labelled A and B

(ii)      density of the materials A and B

(iii)     volume of the materials A and B (6 marks)

UPTHRUST

A                                 B

DENSITY

A                                  B

VOLUME

A                              B

(b)     State the principle behind your observations in (a). (1 mark)

(c)       State the relevance of this experiment to an aircraft in flight. (1 mark)

(d)      Relate the results of the experiment in (a)(i) and (a)(ii) above to an aircraft during take-off
and landing. (2 marks)