Aviation Technology Paper 1 Questions and Answers - KCSE 2021 Past Papers

 Solution

1.  Assessing design requirements, maintenance.
2. Measuring and improving the performance of aircraft, components and systems, repair.
3. Assembling the aircraft or fitting components, manufacturing.
4. Testing evaluating, modifying and retesting products/components.
5. Writing reports, manuals and documentation i.e. tech log.
6. Provide technical advice.
7. Pre-flight checks.                                                                          Any 3 x 1 

(3marks)

 Factors to consider in the location of fire extinguishers:

1. Extinguishers should be sited on escape routes on all floors at what is called fire points (exit points).
2. They should be fixed in a location where they can be reached quickly. The best place is near a door leading to a place of safety(accessibility)
3. They should be fixed where they can be easily seen. Fixing them
   inside cupboards or behind doors will waste valuable time, in case
   of a fire i.e open place.
4. Extinguishers must not be placed in places of extreme temperatures, hot or cold (conducive environment)
5. Extinguishers should not be fixed at an elevated height, so that the handle is easily accessible from the floor for heavier units.
6. They should be within reasonable distance from any fire risk areas
                                                                                     Any 4 x 1 

(4marks)

1. Class airspace
   • All flights are provided with air traffic control service and are separated from each other(IFR only)
2. Class B airspace
   • All flights are permitted and are provided with air traffic control service and are separated from each other(Both IFR and VFR)
3. Class C airspace
   • All flights are permitted and provided with air traffic control service. IFR flights are separated from other VFR flights (Any 4x=2 marks)

(2marks)

 Advantages of composite materials:

1. High strength to weight ratio
2. Longer life than metals (durable)
3. High corrosion resistance
4. High tensile strength than steel or aluminum (v) Easily repairable
5. Eliminates joints and fasteners                                      Any 3 x ½

Disadvantages of composite materials:

1. Difficult to conduct inspections
2. Very expensive processing equipment
3. Product often toxic and hazardous
4. Lack of standardized methods for construction and repair
5. General lack of repair knowledge and expertise in using composites (vi)
6. Expensive in cost as compared to metals       Any 3 x ½

 1½

 1½
(3marks)

1.   
   • Autogyro is a form of aircraft with freely rotating horizontal blades and a propeller. It differs from a helicopter in that blades are not powered but rotate in the strip stream, propulsion being by a
     conventional mounted engine.
     (autogyro-non powered, helicopter-powered)
   • Glider is a light aircraft designed to fly without using an engine, whereas an ornithopter is a machine designed to achieve flight by means of flapping wings                                                  2 x 2
2.  
   • Skin friction drag is the result of the aircraft's surface being rough/ sharing effect of successive layers fair).
   • Form drag is the result of an object's general shape in relation to the relative word
   • Interference drag is generated by the mixing of airflow
     streamlines between airframe components eg wing & free lance 
     3 x 1
3.  
   1. He laid down the principles of heavier than air aircrafts and defined a modern aircraft comprising of a fixed wing, fuselage & tail assembly
   2. Conducted demonstrations of manned, gliding flight
   3. Conducted experiments demonstrating drag and streamlining on an aircraft
   4. Set out principles of power-to-weight ratio in sustaining flight (v) Invented glides
   5. Designed helicopter, airships, aeroplane.  4 x ½

(4marks)

(3marks)

(2marks)

1.   
   1. Machmeter - an instrument in an aircraft indicating airspeed as a mach number (airspeed in relation to speed of sound)
   2. Twin and slip indicator - an instrument that shows the rate of turn of an aircraft in degrees per second or coordinated turn
   3. Artificial horizon - an instrument that indicates to the pilot the aircraft orientation relative to the earth's horizon and gives an immediate indication of the smallest orientation change (pitching moments) 3x1
2. Sources of fuel contamination:
   
   1. Water-these include free water on low spots in a pipeline, rain water leaking past the seals in floating-roof tanks
   2. Microbial growth-micro-organisms found in fuels include bacteria and fungi
   3. Particulates-This include air-bone solids that enter through tank vents or slip past the seals of floating roof tanks(dust and pollen) (iv)
   4. Petroleum products-mixing two grades of fuel in the tank. (v)
   5. Abrasives                                                                  Any 2 x 1

(3marks)

(2marks)

1. Hardening involves heating of steel, keeping it at an appropriate temperature and then quenching it rapidly in water or oil.
2. Tempering involves heating steel that has been hardened and
   quenching for an adequate period of time.
3. Annealing involves heating steel up-to a high temperature, and then cooling it very slowly to room temperature.
4. Normalizing involves heating steel, and then keeping it at that temperature for a period of time, then cooling in air. Any 4 x 1 

(4marks)

1. Very light and thin lines used to construct layout work.
2. Long and short dash lines used to indicate center of holes, circles. 
3. Thin and dark line used to show the starting and ending (extend) of
   dimensions.
4. Medium live with arrowhead to shows notes or label for size or special information about and features.                                       4 x 1

(4marks)

 Copying the figure                                           - 1 mark
 Drawing the plan                                             - 1 mark
 Dividing plan into 12 divisions                         - 1 mark
 Complete projection of points from plan         - 1 mark
 Projector from F points from FE to plan          - 1 mark
 Plotting of points of transaction to plan           - 1 mark
 Joining the points with a smooth curve           - 1 mark
 Hatching the face which is cut                        - 1 mark
                                                                           8 marks

 b. 
 Projecting points from F.E. to E.E.                 - 1 mark
 Projecting points from F.E. plan to E.E.         - 1 mark      
 Joining points to obtain E.E. outline               - 1 mark
 Plotting points to obtain the cut face              - 1 mark
 Joining the points to obtain the cut face         - 1 mark
 Hatching the cut face                                      - 1 mark
                                                                         14 marks

1.  
   
                                                                         Sketching 6 x ½ = 3 marks
                                                                         Naming 6 x ½ = 3 marks
                                                                                    TOTAL = 6 MARKS
2.  
   

   1	Reservoir
   2	Power pump
   3	Fitter
   4	Pressure regulator
   5	Accumulator
   6	Check values
   7	Hard pump
   8	Pressure gauge
   9	Relief valve
   10	Selector valve

                                                                                                     10 x 1⁄2
3.  
   • Winglet - a winglet is a vertical option of the wing's tip resembling a vertical stabilizer. It is an aerodynamic device designed to reduce the drag created by long tip vertices in flight
   • Vortex generators-vortex generators are airfoils usually attached to the upper surface of a wing. They are designed to promote positive linear flow over the wing and control surfaces
   • Stall fence - a stall fence is a chord divide barrier on the upper surface of the wing used to halt the span-wise flow of air. During low speed flight, this can maintain proper chord wise airflow reducing the tendency for the wing to stall.                     3 x 1     

(6marks)

(5marks)

  (3marks)

1. At the intake, a large amount of air getting inside the engine is drawn into the rotating compressor
2. At the compressor, the pressure of air increases by passing it through a series of rotating and stationary blades
3. At the combustor, fuel is being injected into the conclusion chamber by the burner where the compressed air gets mixed and whole air
   fuel mixture ignited to produce a high amount of heat energy in the combustion chamber
4. At the turbine, the heated gas of the combustion chamber passes through the turbine it rotates the shift and it consumed very less energy
5. At the nozzle, it restricts the flow-------before allowing gas to expand and thus it creates additional pressure that results in additional thrust.
                                                      Sketching 1 x 11⁄2 = 11⁄2 marks
                                                       labelling 5 x 1⁄2 = 21⁄2 marks
                                                       cycles 5 x 2 = 10 marks

(14marks)

1.  
   1. Clean the component to be inspected
   2. Remove paint
   3. Dry the component
   4. Apply penetrant
   5. Allow time for penetrant to sink
   6. Respect and interpret
   7. Wipe off the penetrant
   8. Apply developer
   9. Allow time for the developer to sink
   10. Remove the applied penetrant and developer
   11. Clean and restore the component
   12. Fill in the appropriate paperwork                                         12 x 1⁄2
2.  
   1.  
      • Proper use of logbooks and worksheets
      • Ensure that maintenance personnel discuss exactly what has been and needs to be completed to the next shift
      • Never assume that the work has been completed
      • Do a proper handover
      • Ensure radio communication
      • Briefings
      • Meetings
      • Good listening skills                                                      4 x 1⁄2
   2.  
      • Be aware of the symptoms of fatigue and look out for them
      • Forfeit complex task if you know you are exhausted
      • Eat healthy foods at regular intervals
      • Exercise during free time
      • Get enough sleep/rest                                              Any 4 x 1⁄2)
   3.  
      • Only fix parts that you are trained for
      • Ensure that the maintenance manual you are using is up to date If you don't know how to fix something ask for help
      • Countercheck your work particularly on tasks you are not sure about
      • Research/studying                                                  Any 4 x 1⁄2
   4.  
      • On returning on the job go back through all of the steps to ensure where you left off
      • Use a detailed checklist
      • Never leave tools or parts lying around
      • Secure your area before leaving even if for a short while
      • Alertness                                                                   4 x 1⁄2

(6marks)

(2marks)

(2 marks)

(2 marks)

(2 marks)

1.   
   
2.  
   
3.  
   • Immediately get the person away from the source of heat
   • Cool the burn with cool or lukewarm water for 20 minutes 
   • Remove any clothing or jewelry that is near the burnt area of skin
   • Make sure the person keeps warm
   • Cover the burn by placing a layer of clean film over it
   • Use painkillers such as paracetamol or ibufen to treat the pain
   • If the face or eyes are burnt sit up as much as possible, rather than lying down to reduce swelling                                    Any 4 x 1 

 (5marks)

(2½ marks)

(4 marks)