AM Installation Techniques 3 — Questions and Answers
Question 1: What type of safety wire is required when safety-wiring a set of three closely-spaced bolts in a triangular pattern?
- Each bolt is wired individually with separate pieces
- A single strand threaded through all three in sequence
- Two bolts are wired together and the third wired separately
- A double-strand twisted wire linking all three in a daisy-chain pattern (Correct answer)
Correct answer: A double-strand twisted wire linking all three in a daisy-chain pattern
Three bolts in close proximity are safety-wired with a single continuous double-strand twisted wire connecting all three in sequence.
Question 2: A technician is installing a new fuel selector valve. After installation, what is the FIRST check to perform?
- Perform a full fuel system pressure test
- Verify correct safety wiring on all fittings
- Confirm the valve operates through all positions without binding (Correct answer)
- Check for fuel leaks with the system pressurized
Correct answer: Confirm the valve operates through all positions without binding
Valve freedom of movement must be verified before any pressure is applied to ensure no binding or interference that could prevent proper fuel selection.
Question 3: When torquing a nut on an AN bolt, what should the technician do if the torque wrench reaches the specified value before the cotter pin hole aligns?
- Back off the nut until the holes align and then insert the cotter pin
- Continue tightening beyond the specified torque until the holes align (Correct answer)
- Replace the bolt with one that has a correctly positioned hole
- File the cotter pin hole until it aligns at the specified torque
Correct answer: Continue tightening beyond the specified torque until the holes align
Torque specifications are a minimum; the nut may be tightened further within the maximum limit to achieve cotter pin hole alignment, but never backed off.
Question 4: Which statement is correct regarding the installation of Dzus fasteners on an access panel?
- Dzus springs must be installed with the open end facing forward (Correct answer)
- The Dzus stud should protrude no more than 0.010 inch above the panel surface
- Quarter-turn fasteners should be installed so they rotate counterclockwise to lock
- Dzus springs should be mounted perpendicular to the airflow direction
Correct answer: Dzus springs must be installed with the open end facing forward
Dzus fastener springs must be installed with the open end facing forward (into the airflow) to prevent the spring from scooping air and potentially detaching.
Question 5: What type of fitting is used to connect flexible hydraulic hose to a rigid tube when both are part of the same hydraulic system?
- A reducing fitting must always be used
- An AN bulkhead union connector
- A compatible AN or MS flared or flareless fitting (Correct answer)
- Only JIC fittings are acceptable for this connection
Correct answer: A compatible AN or MS flared or flareless fitting
Compatible AN or MS fittings are used to connect flexible hose to rigid tubing, ensuring pressure integrity and system compatibility.
Question 6: When installing a battery in an aircraft, why must the battery be secured with the specified hold-down hardware?
- To ensure proper battery venting
- To maintain correct battery orientation for electrolyte level
- To prevent movement that could short battery terminals or damage structure (Correct answer)
- To allow easy removal for scheduled maintenance
Correct answer: To prevent movement that could short battery terminals or damage structure
Battery hold-down hardware prevents movement under dynamic loads, which could cause terminal shorts, structural damage, or loss of electrical power.
Question 7: What is the effect of installing a thicker gasket than specified between an engine accessory and its mounting pad?
- No effect as long as the fasteners are properly torqued
- The gasket may provide better sealing than the original specification
- Drive shaft or coupling misalignment may result (Correct answer)
- The accessory mounting bolts will be placed in excess shear
Correct answer: Drive shaft or coupling misalignment may result
An oversized gasket changes the spacing between mating flanges, causing misalignment of drive shafts or couplings that can lead to component failure.
AM Installation Techniques 3
What type of safety wire is required when safety-wiring a set of three closely-spaced bolts in a triangular pattern?