Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
114 Cards in this Set
- Front
- Back
|
What is the difference between plywood and laminated wood?
|
The grain layer of laminated wood runs in the same direction, but the grain layers in plywood runs at 90 or 45 degrees to each other.
|
|
|
What kind of glue is recommended for making a repair to a wooden aircraft structure?
|
Synthetic Resin Glue.
|
|
|
How much pressure must be applied to a glue joint in a piece of softwood to produce a strong joint?
|
125 to 150 pounds per square inch.
|
|
|
What is the correct repair to a wooden aircraft wing spar if the wing attach bolt holes in the spar are elongated?
|
Splice in a new section of the spar and drill new holes.
|
|
|
What kind of repair is recommended for a hole in the plywood skin of an aircraft wing?
|
a SCARF patch.
|
|
|
What is the recommended taper for a SPLAYED patch in a plywood aircraft skin?
|
5 to 1
|
|
|
What is the recommended taper for a SCARF patch in a plywood aircraft skin?
|
12 to 1
|
|
|
Why should sandpaper never be used when preparing a scarf joint in a wing spar for splicing?
|
Because DUST caused by sanding will plug the pores of the wood and the GLUE cannot get in to form a good BOND.
|
|
|
What is the largest hole in a plywood wing skin that can be repaired with a FABRIC patch?
|
1 inch in diameter
|
|
|
Why are light steel bushings often used in bolt holes in a wooden wing spar?
|
The bushing keeps the spar from being crushed when the nut on the bolt is tightened.
|
|
|
Are MINERAL streaks in a piece of wood reason for rejection of the wood?
|
No, as long as their is no evidence of wood decay.
|
|
|
How is compression of wood identified?
|
It has a high specific gravity, it appears to have excessive growth of summer wood, and little contrast between spring wood and the summer wood.
|
|
|
What is done to a splice in a wooden aircraft wing spar to strengthen the splice?
|
Reinforcement plates are glued to both sides of the splice.
|
|
|
Why must abrupt changes in the cross sectional area of a wooden structural member be avoided?
|
This can concentrate stresses and cause failure.
|
|
|
What are 3 types of fabric that can be used to cover an aircraft?
|
1) Cotton 2) Synthetic 3) Glass fabrics.
|
|
|
What paperwork must be completed if an aircraft that was originally covered with Grade A cotton fabric is re-covered using a synthetic fabric?
|
Done in accordance with the (STC) Supplemental Type Certificate, and a form 337 must be executed stating that all materials and processes complied with the requirements of the STC.
|
|
|
What type of rib lacing cord is recommended for attaching cotton fabric to an aircraft structure?
|
Wax LINEN cord.
|
|
|
How wide should the surface tape be that is used to cover the trailing edge of an aircraft wing?
|
3 inches wide.
|
|
|
Why is the surface tape used on the trailing edge of the control surfaces of some aircraft notched?
|
Since the edges of this tape faces into the wind, it is possible that it could start to lift and form a very effective spoiler. If the tape is notched, it will TEAR OFF AT A NOTCH.
|
|
|
What is the purpose of the reinforcing tape that is used between the fabric and the rib lacing on an aircraft wing?
|
The REINFORCING tape keeps the rib lacing cord from pulling through the fabric.
|
|
|
Should a sewed seam in the fabric used to cover an aircraft wing run spanwise or chordwise?
|
Both are acceptable but chordwise seams are preffered.
|
|
|
What is the preferred seam used for machine sewing pieces of aircraft fabric together?
|
French Fell Seam.
|
|
|
What type of material is used for inter-rib lacing in a fabric-covered aircraft wing?
|
A modified SEINE knot.
|
|
|
What determines the spacing of the rib lacing stitches on a fabric-covered aircraft wing?
|
The NEVER-EXCEED speed of the aircraft.
|
|
|
When is the finishing tape applied to a fabric-covered wing when it is being recovered?
|
After the 2ND coat of dope has dried and the nap of the fabric has been sanded off.
|
|
|
What is the recommended type of repair to a fabric covered aircraft surface when it has an L-Shaped tear with each of the legs of the tear more than 14 inches long?
|
If the NEVER EXCEED speed of the aircraft is less than 150 mph, a doped on repair can be made.
|
|
|
What type of HAND-sewing stitch is used when sewing in a panel of new fabric on an aircraft fabric-covered wing?
|
A baseball-stitch, locked every 8 to 10 stitches.
|
|
|
What is the minimum strength to which aircraft fabric is allowed to deteriorate before it is considered to be unairworthy?
|
To 70% of the strength of the fabric required on the aircraft.
|
|
|
What is an anti-tear strip, and when are they required on a fabric-covered aircraft?
|
An anti-tear strip is a strip of the same type of fabric as is used for covering the wings. It is laid over the rib between the reinforcing tape and the fabric. an anti-tear strip is required for aircraft that have a never-exceed in excess of 250 MPH.
|
|
|
When are drainage grommets applied when an aircraft is being re-covered?
|
They are laid into the 3rd coat of dope, at the same time the surface tape is applied.
|
|
|
When are drainage grommets located on a fabric covered aircraft wing?
|
At the lowest point in each bay. It is customary to install a grommet on each side of a wing rib, on the underside of the wing, at the trailing edge.
|
|
|
How is the strength of the fabric on an aircraft structure determined?
|
An approximate strength test can be made with an FAA approved fabric punch tester, but the only way to know for sure that the fabric has sufficient strength is by pull-testing a one inch wide sample of the fabric.
|
|
|
What is done to cotton and linen fabric to protect it from mildew?
|
The 1st coat of dope that is used on cotton and linen fabric has a mildewcide mixed in it.
|
|
|
How is polyester synthetic fabric shrunk on an aircraft structure?
|
It is shrunk with heat from an iron or from a heated blower.
|
|
|
Why is retarder used in dope when the dope is being sprayed in humid conditions?
|
The retarder slows the drying of the dope and keeps it from blushing.
|
|
|
What is used as a protective finish for the inside of steel tubing?
|
Hot linseed oil.
|
|
|
How THICK should a coat of wash primer be that is used on an aluminum alloy aircraft structure?
|
It should be THIN enough that it doesn't hide the surface of the metal.
|
|
|
What happens to an enamel finish when paint remover is applied to it?
|
The enamel softens and swells so that it pulls away from the surface of the metal.
|
|
|
what should be done to an aircraft surface that is covered with paint remover to give the remover the max amount of time to soak into the old finish?
|
Cover the surface with a polyethylene sheeting such as a paint drop cloth. This keeps the solvents from evaporating before it has time to penetrate the paint film.
|
|
|
When mixing epoxy paint, should the converter be added to the resin or the resin to the converter?
|
The converter should ALWAYS be added to the resin. Never resin to converter.
|
|
|
What can be done to remedy blushing that has formed on a doped surface that has just been sprayed?
|
Spray a very light mist coat of a mixture of 1 part retarder to 2 parts of thinner over the blushed area. Allow it to dry and spray on another coat. If this does not remove the blush, the blushed dope will have to be sanded off and new dope applied.
|
|
|
How can a vinyl film decal be removed from an ALUMINUM alloy surface?
|
Place a cloth saturated with MEK over the decal until it is softened, and scrape it off of the surface with a PLASTIC scraper.
|
|
|
What safety precaution must be observed when sweeping a paint room that has dried dope or lacquer overspray on the floor?
|
The floor must be wet down with water to prevent static electricity which can start a fire.
|
|
|
What will happen if dope is sprayed over an enameled surface?
|
The thinner in the dope will penetrate the enamel surface and cause it to swell.
|
|
|
What are 3 types of primer used when painting an aircraft?
|
1) Zinc chromate 2) Wash 3) Epoxy primers.
|
|
|
How is the finish removed from a fiberglass aircraft component that is being repaired?
|
The finish must be sanded off. Paint remover can soften the resin of which the component is made.
|
|
|
What are the 2 basic types of dope that are used on fabric covered aircraft?
|
Nitrate dope or butyrate (CAB) dope.
|
|
|
What kind of dope is used on polyester synthetic fabric that has been heat-shrunk on an aircraft structure?
|
Nontautening butyrate dope.
|
|
|
What type of thinner is used with Zinc Chromate Primer?
|
Toluol or Toluene
|
|
|
What are 3 requirements for a repair to a piece of sheet metal aircraft structure?
|
The repair must restore the lost strength and rigidity, and it must not change the aerodynamic shape of the part.
|
|
|
When making a riveted repair to an aircraft sheet metal structure, which should be stronger, the shear strength of the rivet, or the bearing strength of the metal sheet?
|
The 2 strengths should be close to each other, but the bearing strength of the sheet should be the greater.
|
|
|
What stress is in the upper skin of an aircraft wing in flight?
|
Compression
|
|
|
What is the purpose of a sight line when laying out sheet metal to be bent in a cornice brake?
|
The SIGHT LINE allows the jaws of a cornice brake to be positioned so the bend made by the brake will start at the bend TANGENT LINE.
|
|
|
What kind of metal forming is done by a slip roll former?
|
SIMPLE curves with a large radius.
|
|
|
What kind of metal forming is done by bumping?
|
COMPOUND curves in sheet metal.
|
|
|
What is meant by the BEND ALLOWANCE used in making a bend in a piece of sheet metal?
|
The bend allowance is the amount of metal that is actually used in making the bend in a piece of sheet metal.
|
|
|
What determines the minimum BEND RADIUS that can be used with a piece of sheet metal?
|
The thickness of the material and its hardness.
|
|
|
What is meant by SETBACK when bending a piece of sheet metal in a cornice brake?
|
SETBACK is the distance the jaws of the brake must be set back from the mold line to form the bend.
|
|
|
Why are lightening holes in a sheet metal wing rib flanged?
|
Flanging the lightening holes gives the rib rigidity. (A lightening hole is a opening cut into a strengthening member that decreases its weight)
|
|
|
When hand forming a piece of sheet metal that has a concave curve, should the forming be started in the center of the curve, or at its edges?
|
Start at the EDGES and work toward the center.
|
|
|
What is meant by a joggle in a piece of sheet metal?
|
A joggle is a small offset near the edge of a piece of sheet metal that allows the sheet to overlap another piece of sheet metal. __/---
|
|
|
When drilling stainless steel, should the drill be turned fast or slow?
|
The drill should be turned slowly.
|
|
|
What is the minimum EDGE distance allowed when installing rivets in a piece of sheet metal?
|
2D Two times the DIAMETER of the rivet.
|
|
|
What is the recommended TRANSVERSE pitch to use when making a riveted 2 row splice in a piece of sheet metal?
|
3/4 (three fourths) of the pitch of the rivets in the rows.
|
|
|
Why should aluminum alloy rivets be driven with as few blows as possible?
|
Excessive hammering will work harden the rivets and make them difficult to drive.
|
|
|
What determines whether a piece of sheet metal should be dimpled or countersunk when installing flush rivets?
|
The thickness of the metal sheet. Countersinking should be done only when the thickness of the sheet is GREATER than the thickness of the rivet head. Dimpling creates a seat for the rivet.
|
|
|
What type of metal should be hot dimpled?
|
7075-T6, 2024-T81 aluminum alloys, and magnesium alloys.
|
|
|
What kind of repair can be made to a small damage of the core material and one face sheet of a piece of aluminum alloy honeycomb structure?
|
A potted compound repair.
|
|
|
What special precautions must be taken when repairing a radome?
|
Nothing that will affect the electrical transparency or its aerodynamic strength. A radome is a weatherproof enclosure that protects a microwave (e.g. radar) antenna.
|
|
|
How is the point of a twist drill ground that is to be used for drilling transparent acrylic material?
|
The cutting edge should be dubbed off to zero rake angle, and the included angle of the tip should be ground to 140 degrees.
|
|
|
What causes crazing in a piece of transparent acrylic material?
|
Uneven stresses in the material, usually caused by heat.
|
|
|
What is the purpose of anodizing a piece of aluminum alloy, and how is it applied?
|
Anodizing is a protective oxide film that is de-posited on the surface by an electrolytic process.
|
|
|
Why is TIG welding preferred over oxyacetylene welding for building and repairing welded steel tube aircraft structure?
|
The heat is concentrated in the weld and does not cause as much distortion as gas.
|
|
|
What are 2 types of electric resistance welding used in aircraft construction?
|
SPOT welding and SEAM welding.
|
|
|
Why is it important that the pressure of the gas in an acetylene cylinder be kept low?
|
Acetylene gas becomes UNSTABLE when it is kept under pressure of more than about 15psi.
|
|
|
What is the difference in the appearance of an oxidizing, neutral, and a reducing flames produced by an oxy-acetylene torch?
|
The OXIDIZING flame has a pointed inner cone, and the torch makes a hissing noise. A NEUTRAL flame has a rounded inner cone, and there is no feather around the inner cone. A REDUCING flame has a definite feather around the inner cone.
|
|
|
What is a TACK weld?
|
A tack weld is the use of a small welded spot to hold the material together until the final bead is run.
|
|
|
Why must thick plates of metal be preheated before they are welded?
|
Preheating controls the expansion and contraction of the metal that is being welded. It also minimizes the stresses caused by welding thick metal.
|
|
|
Why is it important that all traces of the welding flux be removed after a piece of aluminum or magnesium is welded?
|
Welding flux is corrosive and it must be removed to keep the metal from corroding.
|
|
|
what is the function of the inert gas that is used in TIG and MIG welding?
|
It forms a shield to keep oxygen away from the weld puddle so oxides cannot form and weaken the weld.
|
|
|
What is the difference between brazing and welding?
|
In BRAZING, the base metal is NOT melted, but is covered with a low-melting point alloy. In WELDING, the base metal is melted.
|
|
|
What is used the ELECTRODE in TIG welding?
|
A small diameter TUNGSTEN wire.
|
|
|
Is a HEAT-TREATED steel part normally repairable by welding?
|
No, welding destroys the heat treatment.
|
|
|
What kind of solder is recommended for soldering electrical wires?
|
60/40 resin-core solder.
|
|
|
What kind of flame should be used when gas welding aluminum?
|
A SOFT, NEUTRAL oxy-hydrogen flame is recommended.
|
|
|
What is an acceptable acetylene line pressure to use when welding with an oxyacetylene rig?
|
About 5psi
|
|
|
What kind of flame should be used when gas welding stainless steel?
|
A slightly CARBURIZING flame.
|
|
|
How much should the bead penetrate the material when welding 2 pieces of steel with a butt weld?
|
The joint should have 100% penetration.
|
|
|
What is meant by a soft flame?
|
A flame made when the pressures of the gases are low enough that the flame does not make a noise and does not BLOW THE PUDDLE.
|
|
|
What must be done to an aircraft fuel tank before it can be repaired by welding?
|
Purge with steam for 30 minutes, soak it in hot water, or by filling it with nitrogen or carbon dioxide.
|
|
|
Why is it important that the leading edge of a wing and the upper surface of the forward half of the wing be kept free of dents and any dirt or contamination?
|
The air flowing over this portion of the wing must be smooth to produce the max amount of lift. If the surface is rough or dirty, the air flow will be distorted and the lift will be lost.
|
|
|
What is meant by the ANGLE OF ATTACK of an airplane wing?
|
The acute angle that is formed between the chord line of an airfoil and the direction of the air that strikes it.
|
|
|
4 basic forces acting on an aircraft are?
|
Lift, drag, thrust, and gravity.
|
|
|
What is meant by the ANGLE OF INCIDENCE of an airplane wing?
|
The acute angle that is formed between the chord line of an airfoil and the longitudinal axis of the aircraft on which it is mounted.
|
|
|
Does the lift produced by the horizontal tail surfaces of an airplane act upward or downward in normal flight?
|
Downward
|
|
|
What is the function of lateral dihedral in the wings of an airplane?
|
Lateral dihedral gives the aircraft ROLL stability, or stability about the longitudinal axis.
|
|
|
What is the purpose of a stall strip on an airplane wing?
|
Stall strips distort the air flowing over the top of the wing in the root area at high angles of attack. They cause the root of the wing to stall out at a lower angle of attack than the portion of the wing ahead of the ailerons.
|
|
|
What is the function of a servo tab on an aircraft control surface?
|
It produces an aerodynamic force on a control surface that aids the pilot in moving the surface.
|
|
|
Why do most high performance aircraft use slotted flaps?
|
They can be deflected to a greater angle than other types of flaps before the airflow over their surface breaks away.
|
|
|
What is the purpose of a movable slat on the leading edge of some airplane wings?
|
The moveable slat remains flush with the leading edge of the wing during all low-angle-of-attack flight conditions. When the angle of attack becomes high, the slat automatically moves out of the wing and forms a duct which FORCES the air back over the upper surface of the wing. This DELAYS the STALL.
|
|
|
What causes dissymetry of lift produced by the rotor of a helicopter?
|
The forward speed of the helicopter produces this. The rotor blade which is travelling forward as the helicopter is flying produces more lift than the blade that is travelling rearward.
|
|
|
Why is it important that the leading edge of a super sonic airplane wing be kept free from dents and damage?
|
A sharp leading edge allows an oblique shock wave to attach to the airfoil in supersonic flight. If the leading edge is dented or blunt, a normal shock wave will form and slow the air immediately behind it to a subsonic velocity.
|
|
|
What is the purpose of vortex generators on the wing of a high speed airplane?
|
They pull high-energy air down to the surface of the wing and keep shock induced separation from occuring.
|
|
|
Why are control cables of large airplanes normally equipped with automatic tension regulators?
|
The large amount of aluminum in the aircraft structure contracts so much as its temperature drops in flight that the control cables could become dangerously loose. The automatic tension regulators keep the cable tension CONSTANT as the dimensions of the aircraft change.
|
|
|
Why is it important that the blades of a helicopter rotor system be in track?
|
If the blades are not in track, vertical VIBRATION can develop.
|
|
|
Why is it important that any repairs to the control surfaces of an airplane not change their original condition of balance about their hinge line?
|
A control surface that is out of static balance can FLUTTER in certain flight conditions. Flutter normally tears the surface off the aircraft.
|
|
|
Where can you find the recommended statement to use for recording the approval or disapproval of an aircraft return to service after a 100-hour inspection?
|
in 14 CFR 43.11
|
|
|
What determines whether or not an aircraft must be given a 100 hour inspection?
|
Aircraft that carry persons for hire and an aircraft that are used for flight instruction for hire must be given 100 hour inspections.
|
|
|
What is the difference between an annual inspection and a 100 hour inspection?
|
They are identical. An annual can be performed by an A&P mechanic who holds an Inspection Authorization, while a 100 hour can be performed by an A&P mechanic without and IA.
|
|
|
Where can you find the requirements for inspecting the altimeter and static systems of an aircraft that are operated under IFR's?
|
In 14 CFR Part 43, Appendix E.
|
|
|
Where can you find the requirements for inspecting the ATC transponder that is installed in an aircraft?
|
In 14 CFR Part 43, Appendix F
|
|
|
What takes up the TAXI shocks in an oleo shock strut?
|
Compressed air.
|
|
|
What is the purpose of the centering cam in a nose wheel shock strut?
|
The centering cam forces the nosewheel straight back with the strut before it is retracted into the nose wheel well.
|
|
|
How does a nosewheel shimmy damper keep a nosewheel from shimmying?
|
It acts as a small hydraulic shock absorber between the piston and the cylinder of the nosewheel shock strut.
|
