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GCAA AME Licence Exam study materials
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GCAA AME Licence Exam practice questions

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Question 1Aviation Legislation and Regulatory Framework

Which body issues aircraft maintenance engineer licences under the UAE civil aviation regulatory framework?

  1. The UAE Ministry of Interior
  2. The General Civil Aviation Authority Correct answer.
  3. The International Civil Aviation Organization
  4. The European Union Aviation Safety Agency

Explanation

The GCAA is the national civil aviation authority of the UAE and is empowered to issue personnel licences, including aircraft maintenance engineer licences, under the national civil aviation law and its implementing regulations. ICAO sets international standards but does not issue national licences.

Question 2Aviation Legislation and Regulatory Framework

Under the Chicago Convention, which Annex contains the international Standards and Recommended Practices for Personnel Licensing?

  1. Annex 8
  2. Annex 6
  3. Annex 1 Correct answer.
  4. Annex 14

Explanation

Annex 1 to the Convention on International Civil Aviation covers Personnel Licensing, including maintenance personnel. The other Annexes address different subject areas such as operations, airworthiness and aerodromes.

Question 3Aviation Legislation and Regulatory Framework

An aircraft maintenance engineer licence is primarily intended to certify that the holder is competent to:

  1. Operate the aircraft during commercial flights
  2. Dispatch aircraft and calculate loading
  3. Certify maintenance and release of aircraft after maintenance Correct answer.
  4. Design aircraft modifications and repairs

Explanation

The maintenance engineer licence attests that the holder has met the knowledge and experience requirements to certify that maintenance has been carried out and to issue a certificate of release to service within the scope of the licence. Flight operations and design are separate disciplines.

Question 4Aviation Legislation and Regulatory Framework

In the context of maintenance certification, what does a Certificate of Release to Service signify?

  1. That the aircraft has completed a full design review
  2. That the operator has paid all applicable regulatory fees
  3. That the maintenance recorded has been properly carried out and the aircraft is fit for release Correct answer.
  4. That the aircraft has been permanently withdrawn from service

Explanation

A Certificate of Release to Service is issued after maintenance to confirm that the recorded work has been completed to the required standard and that the aircraft or component is fit to return to service. It does not relate to fees or design review.

Question 5Aviation Legislation and Regulatory Framework

Which of the following is normally a condition that must be met before an aircraft maintenance engineer licence is issued?

  1. Ownership of a maintenance facility
  2. Demonstrated knowledge, practical experience and a medical fitness declaration Correct answer.
  3. A commercial pilot licence
  4. Membership of a pilot association

Explanation

Licensing regulations require applicants to demonstrate the required knowledge through examinations, the required practical experience, and compliance with medical fitness requirements where applicable. Association membership or facility ownership are not conditions.

Question 6Aviation Legislation and Regulatory Framework

Which document type issued by the GCAA typically sets out detailed binding requirements that support the national civil aviation law?

  1. Civil Aviation Regulations Correct answer.
  2. Aircraft sales brochures
  3. Annual financial statements
  4. Airport duty rosters

Explanation

National civil aviation law establishes the authority and framework, while the Civil Aviation Regulations contain the detailed binding requirements that licensed personnel and organisations must comply with. The other documents are administrative or commercial in nature.

Question 7Aviation Legislation and Regulatory Framework

An engineer holds a licence with a type rating for a specific aircraft type. Which statement best describes the effect of the type rating?

  1. It replaces the need for any further training
  2. It authorises certification of maintenance on that type within the licence scope Correct answer.
  3. It permits flight instruction on that type
  4. It authorises certification on every aircraft type in the same category

Explanation

A type rating extends the licence scope to a specific aircraft type, allowing the holder to certify maintenance on that type subject to the licence category and any limitations. It does not grant blanket authority across all types or flight instruction privileges.

Question 8Aviation Legislation and Regulatory Framework

An engineer's licence has lapsed. What is the most accurate statement about certifying maintenance during the lapse?

  1. Certification may continue if the aircraft is not commercial
  2. Certification may continue because experience is unchanged
  3. Certification must not be made until the licence is renewed and valid Correct answer.
  4. Certification may continue with verbal approval from a colleague

Explanation

Certification privileges exist only while the licence is valid. Once the licence lapses, the holder may not exercise certification privileges until it is renewed in accordance with the regulations. Experience or informal approval does not restore the privilege.

Question 9Aviation Legislation and Regulatory Framework

Which of the following best describes the role of a maintenance organisation approval in relation to individual licensed engineers?

  1. The organisation removes the need for any certification
  2. The organisation issues the engineer's licence on behalf of the authority
  3. The organisation replaces the engineer's licence entirely
  4. The organisation provides the approved procedures and facilities within which engineers certify Correct answer.

Explanation

An approved maintenance organisation establishes procedures, facilities and quality systems under which licensed engineers perform and certify work. It does not replace the individual licence, which remains issued by the authority.

Question 10Aviation Legislation and Regulatory Framework

Under the international framework, a Contracting State that finds a Standard in an Annex impractical to comply with must:

  1. Amend the Annex itself
  2. Notify ICAO of the difference from the Standard Correct answer.
  3. Ignore the Standard without any action
  4. Immediately suspend all aviation activity

Explanation

Under Article 38 of the Chicago Convention, a State that cannot comply with an international Standard must notify ICAO of the difference. The State cannot unilaterally amend the Annex or simply ignore the requirement.

Question 11Aviation Legislation and Regulatory Framework

A licensed engineer is asked to certify work performed by an unqualified person without supervision. What is the correct regulatory response?

  1. Certify the work and note the issue later
  2. Refuse to certify until the work is properly performed and verified Correct answer.
  3. Ask the unqualified person to sign instead
  4. Certify the work to avoid delaying the aircraft

Explanation

Certification asserts that the work was carried out by qualified personnel to the required standard. Certifying unverified or improperly performed work would be a false certification and a breach of the regulations.

Question 12Aviation Legislation and Regulatory Framework

Continuing airworthiness requirements are primarily aimed at ensuring that:

  1. The operator's marketing material is accurate
  2. The aircraft is repainted at regular intervals
  3. The aircraft remains in a condition that meets its type design and is safe to operate Correct answer.
  4. The aircraft is always operated at maximum weight

Explanation

Continuing airworthiness is about keeping the aircraft in conformity with its approved type design and in a condition for safe operation throughout its service life. Cosmetic or commercial matters are not the objective.

Question 13Aviation Legislation and Regulatory Framework

Which of the following is the best example of an airworthiness directive?

  1. A recommendation from a manufacturer's sales team
  2. An internal company newsletter item
  3. A voluntary suggestion from a pilot union
  4. A mandatory action issued by the authority to correct an unsafe condition Correct answer.

Explanation

An airworthiness directive is a legally binding instruction issued by the authority to address an unsafe condition in a type design. It is mandatory and must be complied with within the stated timeframe.

Question 14Aviation Legislation and Regulatory Framework

An engineer discovers that a required inspection was signed off but not actually performed. What action is most consistent with regulatory obligations?

  1. Report the discrepancy through the established occurrence reporting system Correct answer.
  2. Correct the record silently and continue
  3. Wait for the next audit to mention it
  4. Record the finding in a personal notebook only

Explanation

Regulations require that errors, omissions and unairworthy conditions be reported through the established reporting system so that safety action can be taken. Silent correction or non-reporting undermines the safety management system.

Question 15Aviation Legislation and Regulatory Framework

Which statement best describes the relationship between a licence and the privileges it confers?

  1. Privileges depend only on the engineer's years of service
  2. Privileges are set by the engineer's employer alone
  3. Privileges are unlimited once the licence is issued
  4. Privileges are defined by the licence category and any limitations endorsed on it Correct answer.

Explanation

The privileges of a licence are defined by its category and any limitations or endorsements recorded on it. Employers cannot extend privileges beyond what the licence authorises.

Question 16Aviation Legislation and Regulatory Framework

A component is removed from an aircraft and maintained by an approved organisation. What document is normally required before the component can be fitted to an aircraft?

  1. A purchase invoice for the component
  2. A verbal confirmation from the storekeeper
  3. An authorised release certificate for the component Correct answer.
  4. A photograph of the component

Explanation

Components must be accompanied by an authorised release certificate confirming that maintenance was performed in accordance with approved data before installation. Commercial or informal documents do not establish airworthiness status.

Question 17Aviation Legislation and Regulatory Framework

Which of the following best explains why the regulatory framework requires records of maintenance to be retained?

  1. To increase the administrative workload of engineers
  2. To serve as marketing evidence of quality
  3. To replace the need for physical inspections
  4. To provide traceability of airworthiness status and support later inspections Correct answer.

Explanation

Maintenance records provide the traceability needed to establish the airworthiness status of an aircraft or component and to support future inspections, audits and investigations. They do not replace physical inspections.

Question 18Aviation Legislation and Regulatory Framework

An engineer qualified on a type is asked to certify a modification that requires approved design data not yet available. What is the correct course of action?

  1. Certify only if the aircraft is grounded
  2. Certify and note that data will follow
  3. Do not certify until the approved design data is available and the work is performed accordingly Correct answer.
  4. Certify based on engineering judgement alone

Explanation

Modifications must be performed and certified in accordance with approved design data. Without that data the work cannot be properly certified, regardless of the engineer's experience or the aircraft's status.

Question 19Aviation Legislation and Regulatory Framework

A State adopts a regulation that is more stringent than the corresponding ICAO Standard. How is this treated under the Convention framework?

  1. It requires prior approval from every other Contracting State
  2. It is prohibited because ICAO Standards are maximum limits
  3. It is permissible, and the State notifies ICAO of the difference where the Standard is exceeded or not met Correct answer.
  4. It automatically invalidates the State's membership in ICAO

Explanation

ICAO Standards are minimum standards; States may adopt more stringent requirements. Where a State's practice differs from a Standard, it notifies ICAO of the difference under Article 38.

Question 20Aviation Legislation and Regulatory Framework

An engineer signs a release to service but later realises a required functional test was omitted. What is the most appropriate regulatory action?

  1. Notify the organisation immediately so the aircraft's status can be reassessed and corrected Correct answer.
  2. Amend the record quietly without notifying anyone
  3. Wait until the next scheduled check to address it
  4. Take no action because the signature is already recorded

Explanation

A release to service that was issued without completing required tasks means the aircraft's airworthiness status may be invalid. Prompt notification allows the organisation to quarantine or re-inspect the aircraft and take corrective action.

Question 21Aircraft General Knowledge - Airframe, Systems and Structures

In a semi-monocoque aircraft fuselage, the primary purpose of the stringers is to:

  1. Route electrical looms between the flight deck and tail
  2. Seal the pressurised cabin at the door frames
  3. Carry bending loads and stiffen the skin against buckling Correct answer.
  4. Provide the main attachment points for the wing spar

Explanation

In semi-monocoque construction the skin carries much of the shear and some tension, while longitudinal stringers stiffen the skin and carry bending loads together with the frames. Frames maintain the cross-sectional shape and resist hoop stress in pressurised hulls.

Question 22Aircraft General Knowledge - Airframe, Systems and Structures

A riveted lap joint in an aircraft skin is mainly designed to:

  1. Transfer shear load between the joined sheets Correct answer.
  2. Permit controlled flexing of the skin in flight
  3. Allow thermal expansion of the skin panels
  4. Provide a path for bonding electrical returns

Explanation

Lap joints connect overlapping sheets and the rivets transfer shear load from one sheet to the other. The joint is not intended as a flexible hinge or an electrical bonding feature.

Question 23Aircraft General Knowledge - Airframe, Systems and Structures

The function of a wing spar is to:

  1. House the flap actuation motor only
  2. Carry the primary bending and shear loads of the wing Correct answer.
  3. Provide the aerofoil shape at the trailing edge
  4. Support the wingtip navigation light

Explanation

The spar is the main structural member of the wing, reacting bending moments and shear forces from lift. Ribs form the aerofoil contour and stringers stiffen the skin.

Question 24Aircraft General Knowledge - Airframe, Systems and Structures

In a typical transport aircraft hydraulic system, the purpose of the reservoir pressurisation is to:

  1. Prevent pump cavitation at altitude Correct answer.
  2. Filter particulate contamination
  3. Increase system operating pressure
  4. Cool the hydraulic fluid during cruise

Explanation

Pressurising the reservoir maintains a positive head at the pump inlet, which prevents cavitation when ambient pressure falls at altitude. It does not set system pressure, cool the fluid or filter it.

Question 25Aircraft General Knowledge - Airframe, Systems and Structures

Aircraft tyres are inflated with dry nitrogen rather than air primarily because nitrogen:

  1. Increases the tyre's load rating
  2. Reduces the risk of internal combustion and pressure change from moisture Correct answer.
  3. Has a lower density giving less wheel weight
  4. Provides better grip on contaminated runways

Explanation

Dry nitrogen is inert and moisture-free, reducing the risk of an internal fire from hot brakes and avoiding pressure variation caused by water vapour condensing or freezing. It does not change tyre load rating or runway grip.

Question 26Aircraft General Knowledge - Airframe, Systems and Structures

The primary purpose of a fuselage frame (former) in a pressurised aircraft is to:

  1. Carry the longitudinal bending loads of the fuselage
  2. Transmit torsional loads to the empennage
  3. Provide attachment for the engine pylon
  4. Maintain the cross-sectional shape and react hoop stress Correct answer.

Explanation

Circumferential frames hold the skin to the required cross-section and carry hoop stresses generated by cabin pressure. Longitudinal bending is carried mainly by skin and stringers.

Question 27Aircraft General Knowledge - Airframe, Systems and Structures

Aircraft brake discs are commonly made from carbon-carbon because it:

  1. Requires no wear inspection
  2. Retains strength and low weight at very high temperatures Correct answer.
  3. Is cheaper than steel for all aircraft types
  4. Has the highest coefficient of friction at low temperature

Explanation

Carbon-carbon maintains structural strength and low weight at high brake temperatures and can absorb large amounts of energy. It is expensive and its friction behaviour at low temperature requires specific brake design.

Question 28Aircraft General Knowledge - Airframe, Systems and Structures

The function of a vortex generator on an aircraft surface is to:

  1. Act as a mounting point for antennas
  2. Energise the boundary layer to delay flow separation Correct answer.
  3. Provide static discharge from the skin
  4. Reduce the aircraft's radar cross-section

Explanation

Vortex generators create small vortices that add energy to the boundary layer, delaying separation and improving control effectiveness or reducing buffet. They are aerodynamic devices, not electrical or stealth features.

Question 29Aircraft General Knowledge - Airframe, Systems and Structures

In a landing gear shock strut, the metering pin's function is to:

  1. Lock the gear in the down position
  2. Control the rate of oil flow between the chambers during compression Correct answer.
  3. Provide the pneumatic spring force
  4. Indicate gear extension to the cockpit

Explanation

The metering pin varies the orifice area as the strut compresses, controlling oil flow and thus the damping force through the stroke. Spring force comes from the compressed gas, and locking is by down-locks.

Question 30Aircraft General Knowledge - Airframe, Systems and Structures

Aircraft hydraulic fluid is specified by its viscosity index. A high viscosity index means the fluid:

  1. Has a higher flash point
  2. Changes viscosity less with temperature Correct answer.
  3. Contains more anti-wear additive
  4. Is more compressible

Explanation

Viscosity index describes how little viscosity changes with temperature; a high index indicates more stable viscosity across the operating range. It does not directly describe flash point, compressibility or additive content.

Question 31Aircraft General Knowledge - Airframe, Systems and Structures

A pressure relief valve in an aircraft hydraulic system is fitted to:

  1. Prevent reverse flow through the pump
  2. Limit maximum system pressure by returning fluid to the reservoir Correct answer.
  3. Maintain a constant pump output flow
  4. Indicate low pressure to the cockpit

Explanation

The relief valve opens at a set pressure and bypasses fluid back to return or reservoir, protecting components from overpressure. Flow control and non-return functions are performed by other valves.

Question 32Aircraft General Knowledge - Airframe, Systems and Structures

In a busbar-based DC electrical distribution system, the essential bus is designed to:

  1. Provide a ground path for the aircraft structure
  2. Supply critical loads that must remain available after loss of a main generator Correct answer.
  3. Distribute power only to the galley equipment
  4. Convert AC to DC for battery charging

Explanation

The essential bus remains powered by the battery or emergency source to keep flight-critical equipment running after generator loss. It does not serve non-essential loads, and conversion is done by transformer-rectifiers.

Question 33Aircraft General Knowledge - Airframe, Systems and Structures

The purpose of a fuel crossfeed valve in a twin-engine aircraft is to:

  1. Allow either engine to draw fuel from either tank Correct answer.
  2. Prevent fuel from entering the vent system
  3. Dump fuel overboard in an emergency
  4. Balance cabin pressure between tanks

Explanation

Crossfeed connects the left and right fuel manifolds so that either engine can be supplied from either tank, useful for correcting imbalance or following an engine failure. It does not dump fuel or balance cabin pressure.

Question 34Aircraft General Knowledge - Airframe, Systems and Structures

Aircraft cabin pressurisation is normally controlled by:

  1. Opening the safety relief valves
  2. Varying the bleed air temperature
  3. Modulating the outflow valve to regulate cabin pressure Correct answer.
  4. Adjusting the engine compressor speed

Explanation

Cabin pressure is regulated by controlling the rate at which air leaves the cabin through the outflow valve, while inflow from the bleed system remains roughly constant. Safety relief valves are non-return protection devices and do not control normal pressure.

Question 35Aircraft General Knowledge - Airframe, Systems and Structures

A 'wet wing' fuel tank design means that:

  1. Fuel is carried in external pods
  2. A flexible bladder is installed inside the wing
  3. Fuel is stored in the fuselage only
  4. The sealed wing structure itself contains the fuel Correct answer.

Explanation

In a wet wing, the wing box structure is sealed and used directly as the fuel tank, saving the weight of separate tanks. Bladder tanks and external tanks are different arrangements.

Question 36Aircraft General Knowledge - Airframe, Systems and Structures

The function of a torque link (scissors) on a landing gear leg is to:

  1. Transmit steering torque to the wheel while allowing vertical travel Correct answer.
  2. Damp shimmy oscillations only
  3. Act as a drag brace in the down position
  4. Provide the main vertical load path to the airframe

Explanation

Torque links connect the upper and lower strut sections so that steering inputs and wheel orientation are maintained while the strut extends and compresses. They are not the primary load path or the drag brace.

Question 37Aircraft General Knowledge - Airframe, Systems and Structures

An anti-skid system prevents wheel lock-up by:

  1. Increasing hydraulic system pressure
  2. Disabling the brakes below a set groundspeed
  3. Applying continuous maximum brake pressure
  4. Modulating brake pressure when wheel deceleration is excessive Correct answer.

Explanation

Wheel speed sensors detect rapid deceleration approaching a skid, and the control unit commands the anti-skid valve to release then reapply brake pressure. Continuous maximum pressure would cause a locked wheel.

Question 38Aircraft General Knowledge - Airframe, Systems and Structures

In a fly-by-wire flight control system, the purpose of the flight control computers is to:

  1. Provide direct mechanical linkage to the control surfaces
  2. Convert pilot inputs into commands to the hydraulic actuators according to control laws Correct answer.
  3. Reduce the aircraft's structural weight only
  4. Supply electrical power to the hydraulic pumps

Explanation

In fly-by-wire, pilot inputs are processed by computers that apply control laws and send commands to actuators; there is no direct mechanical linkage. The computers do not power hydraulic pumps.

Question 39Aircraft General Knowledge - Airframe, Systems and Structures

Aircraft structural inspection programmes use 'fail-safe' design philosophy, which means that:

  1. The structure will never fail under any load
  2. Failures are prevented by over-designing every part
  3. All primary members are single load paths
  4. The structure can sustain a failure of a primary member until it is detected at inspection Correct answer.

Explanation

Fail-safe design provides alternate load paths so that a crack or failure in one member does not cause immediate loss of the structure, allowing detection by inspection. It does not mean the structure is indestructible.

Question 40Aircraft General Knowledge - Airframe, Systems and Structures

Aircraft skin panels are often bonded with adhesive rather than riveted because bonded joints:

  1. Allow easy disassembly for maintenance
  2. Require no surface preparation
  3. Are always stronger than riveted joints in tension
  4. Distribute load over a larger area and reduce stress concentrations Correct answer.

Explanation

Adhesive bonding spreads load over the whole overlap, reducing stress concentrations and improving fatigue life. Bonded joints are not necessarily stronger in all modes and require careful surface preparation.

Question 41Aircraft General Knowledge - Airframe, Systems and Structures

An aircraft has a hydraulic system with a pump delivery of 20 litres/min and an actuator that requires 15 litres/min at full extension. If a priority valve supplies the flight controls first, the effect on the actuator during simultaneous demand is that:

  1. The pump delivery increases to meet demand
  2. The actuator receives full flow and the flight controls are starved
  3. The actuator receives reduced flow and moves more slowly Correct answer.
  4. System pressure rises above the relief valve setting

Explanation

A priority valve gives the essential users precedence, so under simultaneous demand the non-essential actuator gets only the surplus flow and operates more slowly. Pump delivery is fixed by pump displacement and speed, and pressure is limited by the relief valve.

Question 42Aircraft General Knowledge - Airframe, Systems and Structures

During a landing gear retraction test, the gear retracts fully but the 'gear up' indication remains illuminated. The most likely cause is:

  1. A faulty up-lock proximity switch or its associated circuit Correct answer.
  2. A leaking actuator seal
  3. An incorrectly set tyre pressure
  4. A failed hydraulic pump

Explanation

Full retraction with no up indication points to the position sensing circuit, such as the proximity switch or wiring. Hydraulic faults would affect movement, and tyre pressure is unrelated to gear position indication.

Question 43Aircraft General Knowledge - Airframe, Systems and Structures

An aircraft fuel system uses ejector (jet) pumps instead of electric boost pumps in the main tanks. The advantage of ejector pumps in this application is that they:

  1. Deliver higher pressure than electric pumps
  2. Require no fuel as a motive source
  3. Can be controlled by the flight computer
  4. Have no moving parts and use motive fuel flow to transfer fuel Correct answer.

Explanation

Ejector pumps use a venturi effect with motive fuel from a boost pump to move fuel, with no moving parts to wear. They do not produce higher pressure than electric pumps and do rely on motive fuel.

Question 44Aircraft General Knowledge - Airframe, Systems and Structures

Aircraft cabin altitude is maintained at a set value by the pressurisation controller. If the outflow valve sticks partially open, the immediate effect is that:

  1. Cabin altitude rises because less air is retained Correct answer.
  2. Cabin altitude falls because more air escapes
  3. Cabin differential pressure increases
  4. Cabin temperature falls sharply

Explanation

The outflow valve controls how much air leaves the cabin; if it sticks open, more air escapes than commanded and cabin pressure falls, so cabin altitude rises. Differential pressure would decrease, not increase.

Question 45Aircraft General Knowledge - Airframe, Systems and Structures

In a semi-monocoque fuselage, a crack is found at a rivet hole in a skin panel. From a damage-tolerance perspective, the most important immediate consideration is whether the crack:

  1. Lies in a primary load path and can propagate to a critical length before detection Correct answer.
  2. Exceeds 1 mm in length
  3. Is located near a passenger window
  4. Is visible from outside the aircraft

Explanation

Damage tolerance assesses whether a crack in a primary load path can grow to a critical size within the inspection interval. Visibility, absolute size and proximity to windows are secondary to load-path significance and propagation rate.

Question 46Aircraft General Knowledge - Airframe, Systems and Structures

The main structural role of the stringers in a semi-monocoque wing is to:

  1. Seal the integral fuel tank bays
  2. Carry bending loads along the span and stabilise the skin against buckling Correct answer.
  3. Provide attachment points for the passenger seats
  4. Transmit engine thrust directly into the fuselage

Explanation

Stringers run spanwise and work with the skin to resist bending and to keep the thin skin from buckling under compression. They are secondary members that stiffen the skin and support it between ribs and spars.

Question 47Aircraft General Knowledge - Airframe, Systems and Structures

In a typical multi-plate disc brake assembly on a main wheel, the function of the automatic adjuster is to:

  1. Retract the pistons fully when the brake is released
  2. Increase hydraulic pressure during heavy braking
  3. Maintain correct clearance between the discs and pads as the linings wear Correct answer.
  4. Balance braking effort between left and right wheels

Explanation

As friction material wears, the running clearance between discs and pads would otherwise grow and increase pedal travel. The automatic adjuster takes up this wear so that clearance stays within design limits.

Question 48Aircraft General Knowledge - Airframe, Systems and Structures

An aircraft has a 28 V DC bus supplied through a 200 A contactor. During a ground check the contactor coil is energised but the main contacts remain open. Which of the following is the most probable cause?

  1. The main contact faces are contaminated or pitted Correct answer.
  2. The generator field is de-energised
  3. The contactor coil circuit is open
  4. The bus tie breaker has tripped

Explanation

If the coil is energised, the coil circuit is intact and the armature should pull in; failure to close then points to the main contact faces. Pitted or contaminated faces prevent a low-resistance connection even when the armature moves.

Question 49Aircraft General Knowledge - Airframe, Systems and Structures

A pressurised fuselage is designed so that the skin carries hoop stress and the frames carry the pressure reaction at the cut-outs. During a cabin pressure test, a crack is found growing from a small undetected manufacturing defect at a frame-to-skin attachment. Which design philosophy is best described by the structure being able to tolerate this crack until it is found at the next inspection?

  1. Safe-life design
  2. Fail-safe (damage-tolerant) design Correct answer.
  3. Corrosion-prevention design
  4. Ultimate load design

Explanation

Damage-tolerant (fail-safe) design accepts that cracks can exist and requires that the structure retain adequate residual strength until the damage is detected by inspection. Safe-life instead retires the component before a crack is expected to initiate.

Question 50Aircraft General Knowledge - Airframe, Systems and Structures

In a typical aircraft pneumatic (bleed air) system, the primary purpose of the pressure regulator valve is to:

  1. Reduce and hold engine bleed air at a constant delivery pressure to the system Correct answer.
  2. Shut off bleed air automatically whenever the landing gear is extended
  3. Prevent reverse flow of air from the manifold back into the engine
  4. Limit the maximum temperature of bleed air entering the manifold

Explanation

Bleed air is tapped from the engine compressor at a pressure that varies widely with engine speed, so a pressure regulator valve reduces and holds it at a constant value suitable for the system. Temperature control and reverse-flow prevention are handled by separate components such as precoolers, temperature control valves and check valves.