Final Exam Airframe Structures

what does SMAW stand for?

Shielded Metal Arc Welding: stick welding

what is the appropriate description for electrical resistance welding?

spot welding

what is unstable at working pressures greater than 15 psi?

acetylene

is oxygen non-flammable?

yes

how hot can electric arc welding get?

up top 10,000 degrees F

what is a backfire?

loud snap or pop

what is a flashback?

loud hissing

what is also known as GMAW

mig welding

engine mount members should preferably be repaired by using a ______ _______

larger diameter

dents or holes in tubing may be repaired using the welding-patch repair providing the dents are not deeper than _____ of tube diameter, and do not involve more than _____ of the tube circumference and are not longer than tube ______

1/10th, 1/4, diameter

what is the correct Rosette edge weld distance?

1/2th

which polarity setting would better deposition rate but less penetration

DC negative

concerning ratio; a neutral flame will burn 1 part acetylene to how many parts oxygen?

1

when brazing, which joint will yield a strength equal to that of the original base metal?

flanged butt joint

which polarity setting would you use to weld aluminum and magnesium while using GTAW?

AC

which polarity setting would give better penetration but a lower deposition rate?

DC positive

welding joins two metal by a process known as _______. brazing or soldering joins two metals in a process known as ______

cohesion, adhesion

which of the following weld defects does AC43.13-IB list as the worst, and why?

micro fissures (small cracks), because they are hard to detect and produce the worst form of notch effect/stress concentration

3 multiple choice options

the type of flame we will use for the welding stainless steel is a/an ____ flame

slightly carburizing

what are the two basic methods of striking an arc?

tapping and scratching

soft solders are chiefly alloys comprised of what two metals; ______ and _____

tin, lead

which of the following solder alloys is considered general purpose solder

50/50

oxyacetylene welding is the preferred method for welding aluminum (T/F)

false

torch tip #'s are like # drills. generally, the lower the #, the larger the orifice (more heat) (T/F)

false

hoses and regulators connected to an oxygen bottle use left hand threads (T/F)

false

from an airworthiness point of view, it is acceptable to weld wing-brace struts and tail brace struts made of rounded or streamlined tubing (T/F)

true

give the full name of SMAW, is it consumable?

shielded metal arc welding, consumable

give the full name for GMAW, is it consumable?

gas metal arc welding, consumable

give the full name for GTAW, is it consumable?

gas tungsten arc welding, Non-consumable

what head marking will we find on an AN470AD4-4 rivet?

dimple

what are the two major types of aircraft structures, with respect to carrying stresses, or loads?

monocoque and semi- monocoque

what is the head style for an AN426AD4-6 solid rivet?

countersunk

repairs must be strong enough to carry all the loads with the required factor of ______, but they must not have too much ______

safety, extra strength

what is the name for the type of strength that is measured in psi which is calculated by dividing the load required to separate a material by its cross-sectional area?

tensile

what is the diameter of an AN430DD5-6 rivet?

5/32 "

what is the head style for an AN426AD4-6 solid rivet?

countersunk

what does MS20 represent

military standard

what does 426 rivet represent?

countersunk

what does an AD rivet stand for?

dimpled head

what does the 4 in MS20426AD4-8 stand for?

4/32 "

what does the 8 in MS20426AD4-8 stand for?

8/16 "

what does the 5 in MS20426AD4-5 stand for?

5/16 "

what is the length of an AN426B6-8?

8/16"

fasteners can be divided into ____ groups: solid shank rivets and ______ that include ______

2, special rivets, blind rivets

a rivet consists of a smooth conical shaft with a _____ head on one end

factory

what is the preferred formed head dimension for an A rivet?

height: .5 D, width: 1.5 D

what head marking will we find on an AN470AD4-4 rivet?

dimple

what are the considerations where special fasteners are used?

fastener strength, ease of installation, and temperature properties of the fastener

blind rivets shall not be used on?

control surfaces, hinges, hinge brackets, flight control actuating systems, landing gear, fittings

what is brinelling?

occurrence of shallow, spherical depressions in a surface

what is burnishing?

polishing of one surface by sliding contact with a smooth, hard surface

what is chattering?

break down or deterioration of metal surface by vibratory or chattering action

what is galling?

Breakdown (or build-up) of metal surfaces due to excessive friction between two parts having relative motion.

what is inclusion?

presence of foreign or extraneous material wholly within a portion of metal

what is "upsetting"?

a displacement of material beyond the normal contour or surface (a local bulge or bump)

what is negligible damage?

visually apparent, surface damage that does not affect the structural integrity of the component involved

what is damage repaired by patching?

any damage exceeding negligible damage limits that can be repaired by installing splice members to bridge the damage portion of a structural part

aircraft manufacturers use different repair techniques and repairs designed and approved for one type of aircraft. when repairing a damaged component or part, consult the applicable section of the manufacturers _____ ______ manual for the specific aircraft being repaired

structural repair

according to AC 43.13 -1B, all typical methods of repairing cracked leading and trailing edges and rib intersections, the reinforcing plates should be approximately what thickness in comparison to the original skin?

same alloy and approximately one and a half time thicker then original

when repairing cracks or small holes with a flush or scab patch the damage must be ____ and _____

cleaned, smooth

on thin metal or unsupported structures, support the sheet metal with a _____ ______ while driving out the shank

bucking bar

the doubler should be of material _____ gauge ____ than the skin

one, heavier

____ support from the aircraft manufacturer is required for repair techniques and methods that are not described in the aircraft maintenance manual or SRM

engineering

repairs involving a substitution of material are considered a major repair (T/F)

true

round all square corners, remove damaged material so that edge of the completed repair matches existing structure and aircraft lines, remove all distorted skin and structure, remove and incorporate into the new repair any previous repairs joining the area of the new repair, smooth out any abrasions and/or dents

steps for preparing a sheet metal repair

what are the criteria which can be used to help an aircraft technician decide upon the repairability of a sheet metal structure?

type of repair, location of the damage, type of original material, type of damage

to remove countersunk or flush head rivet, you must select a drill size that is ______than the rivet shank diameter

smaller

wing main ribs and compression members are considered a minor repair (T/F)

false

the presence of black residue around rivets is an indication of movement, a condition know as _____

fretting

in a flush patch the filler must be the _____ gauge and ______ as the original skin

same, material

when a repair in a flight control adds additional weight, a balancing check is required. failure to perform this function check could result in flight control ______

flutter

it is critical that in any aircraft sheet metal repair:

maintain original contour, maintain original strength, minimize weight

stressed skin is a form of construction in which the external _____ of an aircraft carries part or all of the main loads

skin

when flight controls are repaired and weight is added, it is very important to perform a ________ check

balancing

skin patches may be classified as two types

scab and flush

Concerning approval of repairs, Title 14 of the Code of Federal Regulation (14 CFR) defines the approval process. 14 CFR part 43, section 43.13(a) sets forth verbiage pertaining to who may perform the task, the practices covered, and the applicable regulations and data for the repair, alterations, preventive maintenance, etc. What form must accompany a Major repair and alteration?

FAA form 337

concerning the heat treatment of aluminum alloy part, if not found in the aircraft maintenance manual, where may an A&P technician look for additional guidance?

AC 43.13-1B pp 4-12

give two attributes of the metal that determine the minimum bend radius of a piece of sheet metal

type of material and thickness of material

what is the bend tangent line in layout and forming?

it is where the bend actually begins and ends

what is a sight line, and where is it located on the unbent piece of sheet metal?

a reference mark used to position the metal correctly before bending

define grain (with respect to sheet metal). what is the significance of grain as it has to do with layout and forming

the structure formed as the metal solidifies from a molten ingot