AM Book Ch 2 Aircraft Construction & Materials Flashcards
What does the airframe of a fixed-wing aircraft consist of?
5 principal units: fuselage, wings, stabilizers, flight control surfaces, and landing gear
What does the airframe of a rotary-wing aircraft consist of?
Fuselage, landing gear, main rotor assembly, and tail rotor.
How many principal structural units are there on a fixed-wing (conventional) aircraft?
9: fuselage, engine mounts, nacelle(s), wings, stabilizer(s), flight control surfaces, and landing gear, arresting gear, and catapult equipment.
What is the main structure or body of the aircraft to which all the units attach?
Fuselage
What provides space for crew, passengers, cargo, most of the accessories, and other equipment?
Fuselage
The monocoque design can be divided into how many classes?
-monocoque design relies largely on strength of of skin or shell to carry various loads.
3: monocoque, semi-monocoque, reinforced shell
How is monocoque reinforced?
Has its only reinforcement vertical rings, station webs, and bulkheads
How is semimoncoque reinforced?
With same monocoque features and with addition with skin is reinforced by longitudinal members, that are stringers and longerons, but no diagonal web members.
How is reinforced shell reinforced?
By a complete framework of structural members.
Cross sectional shape= bulkheads, station webs, and rings,
Longitudinal contour with longerons, formers, and stingers. The skin is fastened to all these members, primarily Carrie’s the shear load and together with longitudinal members Carrie’s loads of tension and bending stresses.
How is the longitudinal contour developed?
Longerons, formers, and stringers
What materials is a semimonocoque fuselage co trusted primarily by?
Aluminum alloy, newer A/C use graphite epoxy composite. Steel and titanium are found in areas subject to high temperatures.
What absorbs primary bending loads?
Longerons
What structure carry concentrated loads where fittings attach other units like what?
Vertical members referred to bulkheads, frames, and formers.
Units that attach to it are wings, engines, and stabilizer.
How many sections are in fuselage in small aircraft compared to larger aircraft?
Small aircraft= 2 or more sections
Larger= 6 sections.
Station markings?
Various points in fuselage located by station number. A station on aircraft may be a rib or frame number
Fuselage Stations (FS)are neasured in?
Station 0 is @ or near nose of aircraft. Other stations are distances measured in inches aft of station 0.
Vibrations originating in the engine are transmitted to aircraft structure through the ___?
Engine mounts
Nacelles are similar in shape and design for the same size aircraft. Larger aircraft require less fairing therefore _____ nacelles.
Smaller
I’m certain cases the ____ is designed to transmit engine loads and stress to the ____ through the engine mounts.
Nacelle,
Wings
Internal structure of wings running spanwise?
Spars and stringers
Spars are main structural members of wing, often referred to as “beams”.
Internal structure is wings running chordwise (leading edge to trailing edge)?
Ribs and formers
What’s a box beam construction?
The stringers and sparlike sections are joined together in a box shaped beam. Remainder of wing is constructed around the box.
How many variations are there for wing construction?
3, monospar, multispar, and box beam
*1. How many principal structural units are there in a fixed wing aircraft?
5,
Fuselage, wings, stabilizers, flight control surfaces, and landing gear
*2. On a semi monocoque fuselage, what component absorbs the primary bending loads?
Longerons
The text also mentions that longerons are supplemented by other longitudinal members called “stringers,” but the longerons are the main components handling those primary bending loads!
2-1: The shimmy damper on a nose landing gear assembly prevents the nosewheel from shimmying during takeoff and landing by what means?
- By actuating a low-rate gear train
- By forcing a rotary bar to move against a
friction plate - By accentuating sudden torque loads ap-
plied to the nose wheel - By metering hydraulic fluid through a
small orifice between two cylinders or
chambers
2-3: When comparing catapult hookup methods on a carrier, the nose gear launch method is superior to the holdback pendant method for all EXCEPT which of the following?
- It saves time
- It cost less to operate
- It requires fewer personnel
- It is the safest method
2-4: Which of the following helicopter components provide(s) lift?
The rotor blades
2-6: The tail landing gear of a helicopter is capable of swiveling how many degrees?
- 45°
- 90°
- 180°
- 360°
2-7: What type of spar is used in the construction of a rotor blade?
Titanium spar
2-8: How many rotor blades are attached to the main rotor head of an H-60 helicopter?
Four
2-9: Which of the following components is NOT a part of the tail pylon of a helicopter?
- The intermediate gearbox
- The tail gearbox
- The horizontal stabilator
- The swash plate
2-14: What high tensile metal is used to manufacture tubes, rods, and wires?
- Aluminum
- Titanium
- Magnesium
- Alloy steel
2-20: What metal property allows a metal to carry heat or electricity?
Conductivity
2-21: When all other metal properties are equal, what method of joining metals structurally has the greatest advantage?
Welding
2-22: The intermediate shape of steel that has width greater than twice the thickness and from which sheets are rolled is known by what name?
Slab
2-25: While holding a piece of metal against a
revolving stone, you see red sparks leave the
stone and turn to straw color. This is what type
of metal?
Cast iron
2-27: An aluminum alloy containing manganese as the major alloying element is identified by what number?
3003
2-38: In various aircraft structural components, what materials are replacing and supplementing
metallic materials?
Composite
*3. What multiengine aircraft structure is designed to transmit engine loads, stresses, and vibrations to the aircraft structure?
A. Fuselage
B. Landing gear
C. Nacelle
D. Tires
Nacelle
*4. A rudder is designed to move an aircraft about (movement around) what axis?
A. Lateral
B. Longitudinal
C. Horizontal
D. Vertical
Vertical
*5. What secondary flight controls are small airfoils recessed in the trailing edge of a primary control surface?
A. Slats
B. Spoilers
C. Trim tabs
D. Wing flaps
Trim tabs
“Trim tabs are small airfoils recessed in the trailing edge of a primary control surface. Their purpose is to enable the pilot to neutralize any unbalanced condition that might exist during flight, without exerting any pressure on the control stick or rudder pedals.”
These clever little devices help reduce pilot fatigue by eliminating the need for constant pressure on the controls
*6. What secondary flight control on some aircraft are long, narrow surfaces hinged at their leading edge to the upper wing skin?
A. Slats
B. Spoilers
C. Trim tabs
D. Wing flaps
Spoilers
“The spoilers on some aircraft are long, narrow surfaces hinged at their leading edge to the upper wing skin. In the retracted position, the spoiler is flush with the wing skin. In the extended position, the spoiler is pivoted up and forward.”
The text also mentions that spoilers work by disturbing the smooth airflow over the wing to reduce lift and add drag!
*7. During strut compression, fluid passes through an orifice into what chamber of a shock strut?
A. Aft
B. Upper
C. Lower
D. Forward
Upper
The upper chamber contains compressed air or nitrogen while lower chamber (piston) is always filled with fluid.
*8. How does the shimmy damper on a nose landing gear assembly prevent the nosewheel from shimmying during takeoff and landing?
A. By actuating a low-rate gear train
B. By forcing a rotary bar to move against a friction plate
C. By accentuating sudden torque loads applied to the nosewheel
D. By metering hydraulic fluid through a small orifice between two cylinders or chambers
By metering hydraulic fluid through a small orifice between two cylinders or chambers
*9. The droop stops of an H-53 main rotor assembly are released when the main rotor speed reaches what percent of power?
A. 25
B. 50
C. 75
D. 90
75
*10.The leading edge of an H-53 tail rotor assembly is protected by what type of abrasion strip?
A. Nickel
B. Copper
C. Titanium
D. Magnesium
Nickel
“The blades are all composite construction of laminated skin over an I-beam and honeycomb core. The leading edge is protected by a nickel abrasion strip.”
*11. What type of stress is produced by two forces pulling in opposite directions along the same straight line?
Tension defined as pull
For example : elevator control cable and pilot at control column there’s a “tug-a-war action”
*12. What force is the opposite of tension?
A. Shear
B. Tension
C. Torsional
D. Compression
Compression
“Compression is the opposite of tension. Tension is a ‘pull,’ and compression is a ‘push.’ Compression is the resistance to crushing, produced by two forces pushing toward each other in the same straight line.”
The text even gives us a practical example: while an airplane is on the ground, the landing gear struts are under constant compression stress!
*13. What type of stress is a combination of tension and compression?
A. Shear
B. Bending
C. Torsional
D. Stretching
Bending
*14. What is the most widely used metal in modern aircraft construction?
A. Aluminum alloy
B. Brass
C. Titanium
D. Steel
Aluminum alloy
*15. What structural metal is lightweight, strong, and corrosion resistant?
A. Nickel
B. Titanium
C. Aluminum
D. Magnesium
Titanium
*16. At what temperature, in degrees Fahrenheit, does transparent plastic become soft and
pliable?
A. 32
B. 115
C. 225
D. 325
225
“Transparent plastic is found in canopies, windshields, and other transparent enclosures. Transparent plastic surfaces must be handled with care because this material is relatively soft and scratches easily.
*17. The strength of all metals is closely related to what other property?
A. Hardness
B. Denseness
C. Brittleness
D. Conductivity
Hardness and strength
*18. What metal property allows a metal to be hammered, rolled, or pressed into various shapes without cracking or breaking?
A. Ductility
B. Elasticity
C. Brittleness
D. Malleability
Malleability
Copper is an example of malleable metal.
Malleability is seen through sheet metal worked in curved shapes such as cowlings, fairings, and wing tips.
*19. At what temperature, in degrees Fahrenheit, does aluminum alloy become a liquid form?
A. 1,000
B. 1,110
C. 1,120
D. 1,130
1,100 for alloys lower melting point compared to pure aluminum.
Pure aluminum is at 1,216
*20. What term is defined as the eating away or pitting of the surface or the internal structure of
a metal?
A. Corrosion
B. Exfoliation
C. Anodizing
D. Intergranular
Corrosion
*21. What property allows two metals to be welded, brazed, or soldered?
A. Weight
B. Joining
C. Strength
D. Working
Joining
*22. The intermediate shape of steel that has width greater than twice the thickness and from
which sheets are rolled is known by what name?
A. Slab
B. Ingot
C. Billet
D. Bloom
Slab
What metal working process involves the forcing of metal through an opening in a die?
Extruding, this causes the metal to take the shape of the die opening
What numerical index is used to identify molybdenum steel?
4xxx = molybdenum steels
For example SAE 4130 is used for parts such as engine mounts, nuts, bolts, gear structures, and support brackets
What type of metal normally does not give off sparks when touched to a grinding stone?
Nonferrous
“Few nonferrous metals give off sparks when touched to a grinding stone. Therefore, the spark test cannot successfully identify these metals.”
Nonferrous metals are those that don’t contain iron as their principal element - like aluminum, copper, and titanium!
What is the principal alloying element of aluminum alloy 2024?
Copper
The first digit of the designation indicates the major alloying element or alloy group… 2xxx indicates an aluminum alloy in which copper is the major alloying element”
Alloy 2024 is actually mentioned specifically as being used for airfoil covering and fittings!
What does the letter “W” following the aluminum alloy number indicate?
Solution heat treated
“The letter W indicates solution heat treated. Solution heat treatment consists of heating the metal to a high temperature followed by a rapid quench in cold water. This is an unstable temper, applicable only to those alloys that spontaneously age at room temperature.”
The text even mentions that Alloy 7075 may be ordered in the W condition!
What is the melting temperature of titanium in degrees Fahrenheit?
3,300
What metal is added to Monel to create K-Monel?
Aluminum
“K-Monel is a nonferrous alloy containing mainly nickel, copper, and aluminum. It is produced by adding a small amount of aluminum to the Monel formula.”
The text also mentions that K-Monel is corrosion-resistant and can be hardened by heat treatment
What measurement must be taken to determine the Brinell number of a metal?
To determine the Brinell hardness number, you must measure the diameter of the impression made by the ball penetrator.
“To determine the Brinell hardness number for a metal, first measure the diameter of the impression using the calibrated microscope furnished with the tester.”
After measuring the diameter of the impression, you then convert this measurement into the Brinell hardness number using a conversion table that comes with the tester
How does a Rockwell tester measure the hardness of a metal?
Measures the depth of impression
“The Rockwell hardness tester measures the resistance to penetration as does the Brinell tester, but instead of measuring the diameter of the impression, the Rockwell tester measures the depth and indicates the hardness directly on a dial attached to the machine. The more shallow the penetration, the higher the hardness number.”
So unlike the Brinell tester that measures diameter, the Rockwell looks at how deep the penetrator goes!
What type of plastic will soften when heated and harden when cooled?
Thermoplastic materials
What type of plastic will harden when it is heated?
Thermosetting
Plastic sheets should be stored in a bin and must be tilted at least how many degrees from vertical?
10 degrees from vertical
-store plastic sheets with the masking paper in place in bins, tilted 10 degrees to prevent “buckling”.
What is the term for small surface fissures that develop in plastic materials?
Crazing
These are tiny cracks very narrow in width and usually not over 0.01 inch in depth.
What is the term for the outer laminated of glass fiber-reinforced honeycomb?
Facings
Are made up of several layers of glass cloth, impregnated and bonded together with resin
What type of composite materials are suitable to create complex contoured parts?
Graphite (carbon)
What type of composite materials have poor compression properties that limit their use to nonstructural access covers?
Kevlar
The shear load on a reinforced shell type fuselage is primarily carried by what structural component(s)?
The skin
What are the internal chord wise structural members of a wing assembly?
Ribs and formers
Internal chord wise is leading edge to trailing edge
What structural member of a wing supports all distributed loads as well as concentrated weights?
Spars
Also referred to as “beams”
Longitudinal control systems control movement of the aircraft about which of the following axis/axes?
Lateral only
“Longitudinal control systems control pitch about the lateral axis of the aircraft.”
This is why when you pull back or push forward on the control stick/yoke (longitudinal control), the aircraft pitches up or down around its lateral axis!
Which of the following types of flaps operate on tracks and rollers?
Fowler type
There are 4 types of flaps: plain, split, leading edge, Fowler.
What is the primary purpose of a spoiler?
Decrease lift
A boundary layer control is used with which of the following secondary flight controls?
Slats
“Opening the slat (extending it forward), creates a slot between the slat and the leading edge of the wing. The slot allows introduction of high-energy air into the air layer moving over the top of the wing. This is known as boundary layer control.”
So slats help control the boundary layer of air flowing over the wing by managing that high-energy airflow! 🛩️💨
Let me know if you need any clarification! 😊
What controls the size of the orifice in a shock strut?
A tapered metering pin
What component is used to hold the arresting hook in the down position to prevent it from bouncing when it strikes the carrier deck?
A snubber (dashpot)
What main landing gear component of a helicopter includes the weight on wheels sensing switch?
Left main landing gear
What component of the h-53 main rotor assembly minimizes the hunting movement of the blades about the vertical hinges as they rotate?
Hydraulic Dampers
Prevent shock to the blades when main rote head assembly is started or stopped
What type of spar is used in the construction of a H-53 rotor blade?
Titanium
What type of stress is produced in an engine crankshaft while the engine is running?
Torsion
“Torsional stress is the result of a twisting force. When you wring out a chamois skin, you are putting it under torsion. Torsion is produced in an engine crankshaft while the engine is running.”
So that rotating crankshaft is experiencing twisting forces (torsion) during operation!
What type of stress is defined as “stress exerted when two pieces of fastened material tend to separate”?
Shear stress
What is the largest portion of metal present in an alloy?
Base metal
What high tensile metal is used to manufacture tubes, rods, and wires?
Alloy steel
What does the core material of advanced composite material consist of?
Honeycomb structure
What property of a metal allows for little bending and deformation without shattering?
Brittleness
What metal property allows a metal to be permanently drawn, bent, or twisted into various shapes without breaking?
Ductility
What metal property allows a metal to carry heat or electricity?
Conductivity
When all other metal properties are equal, what method of joining metals structurally has the greatest advantage?
Welding
What metal working process is used to make wire?
Cold drawing
While holding a piece of metal against a revolving stone, you see red sparks leave the stone and turn to straw color. This is what type of metal?
Cast iron
What is the prime characteristic of aluminum?
Lightweight
What aluminum alloy should be used when the highest strength is necessary?
7178
Alclad is an aluminum alloy with a protective coating of what material?
Pure aluminum
Titanium becomes brittle and worthless after exposure to temperatures above what number in degrees Fahrenheit?
1,000
The use of copper as a structural material is limited by what factor?
Great weight
What is the principal element added to copper to form brass?
Zinc
Which of the following extinguishing agents should be used in a magnesium fire?
Graphite powder
How many different weights does a Rockwell hardness tester have?
2
“The Rockwell tester is equipped with a weight pan and two weights are supplied with the machine. One weight is marked in red, the other weight is marked in black.”
The text explains that:
- No weight = 60 kg load
- Red weight = 100 kg load
- Red + Black weights together = 150 kg load
“Always use the black weight in conjunction with the red weight; never use it alone.”
Each riehle harness tester is supplied with a diamond penetrator and what size, in inches, ball penetrator?
1/16 ball penetrator
You can distinguish a plastic enclosure from a glass enclosure by performing which of the following actions?
Tapping lightly with a blunt instrument
If long and improper storage has caused the adhesive to deteriorate on a sheet of plastic, the masking paper should be moistened with what chemical?
Aliphatic naphtha
