A&P - AIRFRAME ORAL EXAM Questions
and Answers Latest Updates 2025
GRADED A+
What are the dimensions of a properly formed rivet head? - answer The head should be 1-1/2 times the
shank diameter in width and 1/2 the shank diameter in height.
Describe the markings found on the heads of A, B, D, AD, and DD rivets? - answer A rivets are plain, B
rivets have a cross, D rivets have a raised dot, AD rivets have a dimple, and DD rivets have a double dash.
What happens to the stem of a self-plugging (friction lock) rivet when the rivet is installed? - answer The
stem is pulled until it snaps off and the remaining projecting part is trimmed flush with the head.
Name at least three types of self-plugging mechanical lock rivets. - answer CherryMAX, CherryLOCK,
OLYMPIC-LOK, and HuckLok.
What is the difference between the tools required to pull a CherryLOCK rivet and a CherryMAX rivet? -
answer CherryLock rivets require a tool for each different size and head shape, while one pulling tool will
set and size CherryMAX rivet.
Which of the five stresses is the most common cause of rivet failure? - answer Shear.
If a 2024 rivet must be replaced with a 2117 rivet, how do you determine the size to be used? - answer
For 5/32" or smaller diameter, use the next larger size 2117 rivet, assuming that the edge distance and
spacing meet the minimum requirements.
Describe the process for determining the total length of a solid rivet for a particular installation. - answer
Add the grip length (thickness or the materials being joined) plus 1-1/2 times the rivet diameter.
,What minimum edge distance and spacing should be used for a single row of protruding head rivets? -
answer Not less than two rivet diameters from the edge and not less than three rivet diameters apart.
How can a mechanic determine whether the countersink for a flush rivet should be dimpled or drilled? -
answer By the thickness of the top sheet; thin sheets are dimpled while thick sheets may be
countersunk.
What action is taken to prevent cracks from forming while dimpling magnesium or some hard sheet
metals? - answer Hot dimpling equipment is used to preheat and soften the metal before the dimple is
formed.
What type of damage can occur when using a rivet set that does not properly fit the rivet? - answer If
the radius of the set is too small, the rivet head may be damaged, whereas a set with an over-sized
radius may cause damage to the sheet metal.
Why is it important to use the proper size and weight bucking bar when performing sheet metal riveting?
- answer If a bucking bar is too large or heavy it may be difficult to control and may cause damage to the
surrounding structure, whereas a bucking bar that is too light will not properly upset the rivet before
work hardening occurs.
What procedures should be followed to properly remove a solid-shank rivet? - answer Center punch the
rivet and then drill just to the base of the rivet head with the same size or one size smaller drill. Once
drilled, use a pin punch to tip off the rivet head and drive the remaining shank out of the hole while
supporting the surrounding metal.
What are the two special calculations that must be made bending sheet metal? - answer Bend allowance
and setback.
What factors must be considered in order to determine setback? - answer The thickness of the metal
and the bend radius.
What is done to a corner where two bends intersect to prevent cracking? - answer Relief holes are drilled
in the corner.
,What are the two reasons for installing a lightening hole in the sheet metal? - answer Lightening holes
reduce the weight and increase stiffness.
Describe a joggle and explain its function. - answer A joggle is an offset formed at an intersection of two
or more sheets of metal to allow the multiple sheets to be stacked flat against each other.
When repairing an all-metal aircraft, how do you determine what metal should be used? - answer Always
use metal of the same type and thickness as the original structure.
What are three forms of wood commonly used in aircraft construction? - answer Solid, laminated, and
plywood.
What type of wood should be used when splicing or reinforcing plywood webs? - answer The same type
of plywood as originally used.
Name at least four different types of defects found in wood? - answer Knots, checks, splits, pitch pockets,
cross grain, curly grain, decay, dry rot, etc..
Can a section of wood containing a hard knot be used? - answer Yes, within specified limits.
What type of glue may have been used in older wooden aircraft construction that requires careful
inspection to detect deterioration? - answer Casein glue.
What are the three types of glue uses in modern aircraft construction and repair? - answer Resorcinol
glue, Phenol-formaldehyde glue, and epoxy resin glue.
Is compression wood acceptable for structural repairs? - answer No.
Why should the various pieces of wood being joined be kept in the same room for at least 24 hours prior
to joining? - answer To allow the moisture content to equalize, thereby minimizing dimensional changes
in the wood.
, Why is it important to consider the open-assembly time when gluing wooden structures? - answer If the
maximum open-assembly time is exceeded, the joint may fail since the glue may begin setting up before
the joint is assembled.
Why is it important to apply the proper clamping pressure to a glue joint? - answer Clamping forces air
out of the joint, brings the wood surfaces together evenly and is, in part, responsible for the strength of
the glue line.
Describe some of the methods used to apply pressure to glue joints. - answer Clamps, nailing strips,
power presses, brads, nails, and small screws.
What minimum curing temperature should be observed when joining wood with various adhesives? -
answer 70 degrees Fahrenheit or as specified by the glue manufacturer.
When inspecting wood structues, why might it be important to consider stains and discolored area? -
answer Stains and discoloration usually accompany decay and/or rot.
Describe the acceptable methods used to repair elongated bolts holes found in wooden wing spar. -
answer Remove the section containing the elongated holes and splice in a new section or replace the
entire spar.
What type of joint is used to splice a solid or rectangular wood spar? - answer A scarf joint.
In what are splices to a wood spar prohibited? - answer Under an attachment fitting for the wing root,
landing gear, engine-mount, lift, or inter-plane strut.
What is the maximum number of splices allowed for any single spar? - answer Two.
Describle the characteristics of a scarf joint. - answer The pieces to be joined are tapered or beveled on a
slope of 1 to 10 or 1 to 12.
Why must the beveled cut be accurate on both pieces of wood being repaired with a scarfed joint? -
answer The two pieces must match exactly to ensure a tight joint.
and Answers Latest Updates 2025
GRADED A+
What are the dimensions of a properly formed rivet head? - answer The head should be 1-1/2 times the
shank diameter in width and 1/2 the shank diameter in height.
Describe the markings found on the heads of A, B, D, AD, and DD rivets? - answer A rivets are plain, B
rivets have a cross, D rivets have a raised dot, AD rivets have a dimple, and DD rivets have a double dash.
What happens to the stem of a self-plugging (friction lock) rivet when the rivet is installed? - answer The
stem is pulled until it snaps off and the remaining projecting part is trimmed flush with the head.
Name at least three types of self-plugging mechanical lock rivets. - answer CherryMAX, CherryLOCK,
OLYMPIC-LOK, and HuckLok.
What is the difference between the tools required to pull a CherryLOCK rivet and a CherryMAX rivet? -
answer CherryLock rivets require a tool for each different size and head shape, while one pulling tool will
set and size CherryMAX rivet.
Which of the five stresses is the most common cause of rivet failure? - answer Shear.
If a 2024 rivet must be replaced with a 2117 rivet, how do you determine the size to be used? - answer
For 5/32" or smaller diameter, use the next larger size 2117 rivet, assuming that the edge distance and
spacing meet the minimum requirements.
Describe the process for determining the total length of a solid rivet for a particular installation. - answer
Add the grip length (thickness or the materials being joined) plus 1-1/2 times the rivet diameter.
,What minimum edge distance and spacing should be used for a single row of protruding head rivets? -
answer Not less than two rivet diameters from the edge and not less than three rivet diameters apart.
How can a mechanic determine whether the countersink for a flush rivet should be dimpled or drilled? -
answer By the thickness of the top sheet; thin sheets are dimpled while thick sheets may be
countersunk.
What action is taken to prevent cracks from forming while dimpling magnesium or some hard sheet
metals? - answer Hot dimpling equipment is used to preheat and soften the metal before the dimple is
formed.
What type of damage can occur when using a rivet set that does not properly fit the rivet? - answer If
the radius of the set is too small, the rivet head may be damaged, whereas a set with an over-sized
radius may cause damage to the sheet metal.
Why is it important to use the proper size and weight bucking bar when performing sheet metal riveting?
- answer If a bucking bar is too large or heavy it may be difficult to control and may cause damage to the
surrounding structure, whereas a bucking bar that is too light will not properly upset the rivet before
work hardening occurs.
What procedures should be followed to properly remove a solid-shank rivet? - answer Center punch the
rivet and then drill just to the base of the rivet head with the same size or one size smaller drill. Once
drilled, use a pin punch to tip off the rivet head and drive the remaining shank out of the hole while
supporting the surrounding metal.
What are the two special calculations that must be made bending sheet metal? - answer Bend allowance
and setback.
What factors must be considered in order to determine setback? - answer The thickness of the metal
and the bend radius.
What is done to a corner where two bends intersect to prevent cracking? - answer Relief holes are drilled
in the corner.
,What are the two reasons for installing a lightening hole in the sheet metal? - answer Lightening holes
reduce the weight and increase stiffness.
Describe a joggle and explain its function. - answer A joggle is an offset formed at an intersection of two
or more sheets of metal to allow the multiple sheets to be stacked flat against each other.
When repairing an all-metal aircraft, how do you determine what metal should be used? - answer Always
use metal of the same type and thickness as the original structure.
What are three forms of wood commonly used in aircraft construction? - answer Solid, laminated, and
plywood.
What type of wood should be used when splicing or reinforcing plywood webs? - answer The same type
of plywood as originally used.
Name at least four different types of defects found in wood? - answer Knots, checks, splits, pitch pockets,
cross grain, curly grain, decay, dry rot, etc..
Can a section of wood containing a hard knot be used? - answer Yes, within specified limits.
What type of glue may have been used in older wooden aircraft construction that requires careful
inspection to detect deterioration? - answer Casein glue.
What are the three types of glue uses in modern aircraft construction and repair? - answer Resorcinol
glue, Phenol-formaldehyde glue, and epoxy resin glue.
Is compression wood acceptable for structural repairs? - answer No.
Why should the various pieces of wood being joined be kept in the same room for at least 24 hours prior
to joining? - answer To allow the moisture content to equalize, thereby minimizing dimensional changes
in the wood.
, Why is it important to consider the open-assembly time when gluing wooden structures? - answer If the
maximum open-assembly time is exceeded, the joint may fail since the glue may begin setting up before
the joint is assembled.
Why is it important to apply the proper clamping pressure to a glue joint? - answer Clamping forces air
out of the joint, brings the wood surfaces together evenly and is, in part, responsible for the strength of
the glue line.
Describe some of the methods used to apply pressure to glue joints. - answer Clamps, nailing strips,
power presses, brads, nails, and small screws.
What minimum curing temperature should be observed when joining wood with various adhesives? -
answer 70 degrees Fahrenheit or as specified by the glue manufacturer.
When inspecting wood structues, why might it be important to consider stains and discolored area? -
answer Stains and discoloration usually accompany decay and/or rot.
Describe the acceptable methods used to repair elongated bolts holes found in wooden wing spar. -
answer Remove the section containing the elongated holes and splice in a new section or replace the
entire spar.
What type of joint is used to splice a solid or rectangular wood spar? - answer A scarf joint.
In what are splices to a wood spar prohibited? - answer Under an attachment fitting for the wing root,
landing gear, engine-mount, lift, or inter-plane strut.
What is the maximum number of splices allowed for any single spar? - answer Two.
Describle the characteristics of a scarf joint. - answer The pieces to be joined are tapered or beveled on a
slope of 1 to 10 or 1 to 12.
Why must the beveled cut be accurate on both pieces of wood being repaired with a scarfed joint? -
answer The two pieces must match exactly to ensure a tight joint.
