Practicas estándar TLA 4

Dirt, grime and exhaust residue can be removed from an aircraft structure by using a/an ___________ type cleaner. Water emulsion. Oil emulsion.

Stubborn exhaust stains can be removed from an aircraft by scrubbing the area with an emulsion cleaner mixed with _________ or_________ . Varsol, Thinner. Varsol, Kerosine.

All traces of oil and grease may be removed from an ai rcraft surface prior to doping or painting by wiping it with dope thinner or ___________ . acetone. aromatic.

If a tire is covered with engine lubricating oil, all of the excess oil should be removed by wiping it with a dry cloth, then scrubbing it with a solution of __________. Stoddard solvent. soap and water.

Oil and grease may be removed from acrylic plastics and rubber by wiping them with a rag dampened with ________________________. aliphatic naphtha. aromatic naphtha.

The smallest particle of a chemical element is a/an _ ________ . atom. molecule.

The smallest particle of a chemical compound is a/an _____________ . molecule. atom.

An atom which has more electrons spinning around its nucleus than there are protons in the nucleus is a ____________ ion. negative. positive.

The white powder which forms on the surface of aluminum when it corrodes is a chemical _____________ . salt. sand.

The chief alloying agent in 2024 aluminum alloy is __________. cadmium. copper.

In an alloy of aluminum and copper, the __________ will be eaten away by corrosion. aluminum. titanium.

The three basic requirements for the formation of corrosion are: a. must have an electrode potential difference within the metal b. must have a conductive path between the areas of potential difference c. must be covered with an electrolyte. a. must have an electrode potential difference within the metal b. must have a conductive path between the areas of pressure difference c. must be overcast with an electrolyte.

Three steps that can be taken to minimize damage from corrosion are: a. maximize potential difference b. leaving conductive path c. prevent electrolyte contacting the metal. a. minimize potential difference b. eliminate conductive path c. prevent electrolyte contacting the metal.

Arrange these metals, cadmium. copper. iron. and magnesium in the proper order of their electrochemical activity. Place the most active metal first. a. magnesium b. cadmium c. iron d. copper. a. cadmium b. iron c. magnesium d. copper.

When electrolytic or galvanic corrosion occurs between an aluminum structure and a steel bolt, the ______________ will be the metal that is corroded. aluminum. steel.

Corrosion that forms in riveted joints where there is a slight relative movement is called _______________ corrosion. fretting. oxide.

A green corrosion film forms on ______________ . copper. iron.

An extreme case of intergranular corrosion that forms in extruded metal in which the metal separates in layers is called ____________corrosion. exfoliation. ferrous.

Another name for dry corrosion is ____________ . oxidation or rust. oxide or rust.

The oxide film that forms on aluminum alloy is __________ . porous. nonporous.

The oxide fi lm that forms on iron is __________ . porous. nonporous.

Surface corrosion on aluminum alloy shows up in the form of__________. Pits or Blisters. flat or level.

Corrosion that forms inside a metal along the grain boundaries is called ______________ corrosion. pitting. intergranular.

One of the primary causes for intergranular corrosion is ______________________. improper heat treatment. improper cold treatment.

Intergranular corrosion may often be detected by either of two types of nondestructive inspection, these are____________ and__________inspections. ultrasonic, x-ray. eddy current , gamma-ray.

Exfoliation corrosion usually develops in __________ metal parts. extruded. sheets.

If an unplated copper bonding braid is attached to an aluminum alloy structure and is not protected, the ____________ will corrode. aluminum. copper.

Low oxygen concentration cell corrosion forms ___________ lap joints in the aircraft skin. between. at the edge of.

Stress corrosion occurs when a part is under a __________ stress in a corrosive environment. tensile. compressive.

Fretting corrosion __________ form if there is no relative motion between the surfaces. can. cannot.

Aluminum alloys left in contact with a concrete floor are likely to corrode because of the ______________ that leaches out of the concrete. acid. alkali.

If mercury comes into contact with an aluminum alloy, it will cause the aluminum to_________________ . corrode. oxidation.

The scum that forms inside the fuel tanks of some jet aircraft is caused by __________ and ____________ in the fuel. microbes, bacteria. microbes, virus.

An additive may be used in jet fuel to help prevent corrosion inside the fuel tanks. This additive kills the _________________ and ______________. microbes, bacteria. microbes, battery.

A type of finish used to protect the inside of a battery box against corrosion is ____________ enamel. polyurethane. polyethylene.

A solution of ____________ and water is used to neutralize fumes from a lead-acid battery. bicarbonate of soda. bicarbonate of calcium.

A solution of _____________ and water is used to neutralize fumes from a nickelcadmium battery. boric acid. sulfuric acid.

If blue litmus paper turns pink when it is placed in water which has been used to rinse out a battery box, the area is __________. acidic. alkaline.

The type of corrosion that is likely to form in a spot welded scam is ____________corrosion. intergranular. Pitting.

Corrosion in a spot-welded seam will cause the metal between the spots to __________. bulge. flat.

A piano hinge should be lubricated with a _________ lubricant. water displacing. oil displacing.

Engine mount structures are specially prone to corrosion attack because they carry the __________from the starter. return current. eddy current.

The inside of a welded steel tube engine mount is protected from corrosion by coating the inside of the tube with _____________. hot linseed water. hot linseed oil.

Steel control cables can be protected from corrosion by spraying them with a _____________ lubricant. water-displacing. waster-displacing.

Steel control cables installed in a seaplane can be protected from corrosion by a heavy grease such as __________________ . par-al-ketone. methyl ethyl ketone.

Welding flux may be removed from aluminum by scrubbing it with hot water and a __________ bristle brush. nonmetallic. metallic.

The three steps that are used in the dye penetrant method of inspection are: a. clean the area to be inspected b. apply the penetrant c. wash off surface penetrant and apply developer. a. clean the area to be finished b. spread the penetrant c. wash on surface penetrant and apply developer.

Penetrant inspection ________________ detect subsurface faults. can. cannot.

Penetrant inspection ________________ be used on a steel part to detect a surface crack. can. cannot.

Two methods of ultrasonic inspection appropriate for detecting corrosion are: a. pulse-echo b. resonance. a. ultrasonic b. resonance.

ln an X-ray inspection, areas of corrosion damage show up as a __________ area on the photographic negative. light. dark.

Technicians who work around radiographic equipment should wear _______________________ film badges. radiation monitor. display.

The amount an X-ray penetrates the structure is determined by the amount of ________applied to the X-ray tube. voltage. current.

X-rays used for corrosion inspection are _________________ power. low. high.

Corrosion may be removed from aluminum surfaces by scrubbing them with a/an___________________ . nylon scrubber. rubber scrubber.

Corrosion may be removed from a highly stressed steel part by the use of fine-grit ____________________ . abrasiver. alodine.

The products of corrosion should be removed from magnesium parts by scrubbing them away with a stiff ________ brush. nonmetallic. metallic.

The oxide film produced by anodizing is ____________. airtight. porous.

A damaged anodized coating may be repaired in the field by using a chemical conversion coating material. One well-known treatment of this type is called ____________ . alodine. adhere.

Mild corrosion can be removed from an aluminum alloy surface by scrubbing with a household abrasive that does not contain _________ . chorine. corrode.

Severe corrosion can be removed from an aluminum alloy structure by blasting it with _______________________ . glass beads. carbon beads.

A chemically deposited oxide film on an aluminum surface is called _____________________. acetone film. alodine film.

An electrolytically deposited oxide film on an aluminum surface is called alan ___________ . anodizing. alodine.

A fully formed anodized film is ___________________. hard. soft.

An anodized film is an electrical_____________. conductor. insulator.

The surface of clad aluminum surface be _______________ to allow better adhesion for the primer. roughened. smooth.

A self-etching primer used under acrylic lacquer finishes is called a _________________ primer. wash. water.

One of the best methods for removing the corrosion products from rusted steel patts is alan ___________________________ . abrasive blast. smooth blast.

Highly stressed steel parts should not be cleaned by scrubbing them with a wire brush because of the danger of scratches causing____________ . strength concentrations. stress concentrations.

Cadmium plating protects a steel part from corrosion by a process known as. sacrificial corrosion. sacrificial oxide.

Galvanizing is a method of protecting steel with a coating of __________ . zinc. iron.

Before paint will stick to a cadmium-plated surface, the surface should be etched with a solution of ___________. chromic acid. fusidic acid.

The oxides that naturally form on a magnesium surface _________ protect the surface from further oxidation or corrosion. do. do not.

Corrosion which cannot be mechanically removed from a piece of magnesium may be neutralized by pickling the surface with _________ . chromic acid. sulfuric acid.

The largest soft alumi num tubing that may bent by hand is ________ -inc h outside diameter. 1/4. 3/8.

A piece of %-inch 5052 aluminum alloy tubing with a wall thickness of 0.070-inch has an inside diameter of _____ inch. 0.61. 0.64.

The flare angle to be used with an AN fitting is ________ degrees. 37. 45.

Rigid fluid lines for use in 3,000-psi hydraulic systems should be made of annealed or V4-H __________. oxide-resistant steel. corrosion-resistant steel.

The largest aluminum tube that should be flared with a double n a re has an outs ide diameter of ______________________ inch. 3/8. 1/2.

When rigid n uid lines are installed in an a ircraft, each section of the tubing ___________ have bends in it. should. should not.

If the flare in a rigid fluid line almost reaches the flare cone of the fitting, it ____________ permissible to pull the flare tight against the fitting by tightening the fitting nut. is. is not.

When rigid fluid lines are attached to an aircraft structure with cushion clamps, the clamps should be of the _________ type. bonded. remain.

A fluid line that carries a fluid that is physically dangerous to personnel must be marked with the abbreviation _________. PHDAN. PDHAN.

A flu id line that must be handled with special care is marked with a warning symbol. This symbol is a series of black___________ on a white background. skull and crossbones. skull and bending.

If a fuel line is routed through a compartment parallel with an electrical wire bundle, the fu el line should be installed________ the wire bundle. above. below.

The maximum distance between end fittings to which a straight hose assembly is to be connected is 50 inches. The minimum hose length to make such a connection should be __________ inches. 52 1/2. 51 3/8.

A permanent impression left in a flexible hose by the pressure of hose clamps or supports is called ________________________ . cold flow. heat flow.

Damaged swaged-end fittings on a piece of flexible hydraulic hose _________ be replaced. can. cannot.

Flexible hose has a stripe running along its length. This is called a lay line and is used to determine whether or not the hose has been __________during installation. twisted. straight.

The size of a flexible hose is determined by its __________ diameter. inside. outside.

The type of flex ible fl uid line that is used when high operating strength and resistance to solvents are required is ___________ hose. teflon. nylon.

An A 818-8 nut will fit a tube with an outside diameter of ________ inch. 1/2. 7/8.

AN fittings made of steel are colored __________ . black. white.

AN fittings made of aluminum alloy are colored _________ . blue. red.

The flare-type fitting that has a short unthreaded section between the flare cone and the beginning of the threads is an _______ fitting. AC. AN.

When presetting an MS flareless fitting. tighten the nut by hand until resistance is felt and then, using a wrench, turn _______ to _________ turns. 1, 1 1/2. 2, 1 3/8.

When installing a fluid line equipped with MS tlareless fittings. tighten the nut by hand until resistance is felt. and then turn it _______to______ tum with a wrench. 1/6, 1/3. 3/8, 1/2.

A primary reason why ordinary or otherwise nonapproved cleaning compounds should not be used when washing aircraft is because their use can result in. hydrogen embrittlement in metal structures. hydrogen embrittlement in nonmetallic materials. a general inability to remove compound residues.

How may magnesium engine parts be cleaned?. Soak in a 20 percent caustic sods solution. Spray with MEK (methyl ethyl ketone). Wash wish a commercial solvent , decarbonize, and scrape or grit blast.

When an anodized surface coating is damaged in service, it can be partially restored by. applying a thin coat of zing chromate primer. chemical surface treatment. use of a suitable mild cleaner.

For which of the following reasons would a water break test be conducted?. to make certain that a newly alodized aluminum surface is sufficiently coated. to make certain that a bare metal surface is thoroughly clean. to make certain that an anodizing coating has been sufficiently removed before an electrical bonding connnection can be made.

Select the solvent recommended for wipedown of cleaned surfaces just before painting. Aliphatic naptha. Dry-cleaning solvent. aromatic naptha.

Nickel-cadmium battery cases and drain surfaces which have been affected by electrolyte should be neutralized with a solution of. boric acid. sodium bicarbonate. potassium hydroxide.

Which of the following are acceptable to use when utilizing chemical cleaning agents on aircraft? 1. Synthetic fiber wiping cloths when using a flammable agent. 2. Cotton fiber wiping cloths when using a flammable agent. 3. Atomizing spray equipment. 2 and 3. 1. 2.

Select the solvent used to clean acrylics and rubber. Aliphatic naphtha. Methyl ethyl ketone. Aromatic naphtha.

Fayed surfaces cause concern in chemical cleaning because of the danger of. forming passive oxide. entrapping corrosive materials. corrosion by imbedded iron oxide.

Caustic cleaning products used on aluminum structures have the effect of producing. passive oxidation. improved corrosion resistance. corrosion.

Fretting corrosion is most likely to occur. when two surfaces fit tightly together but can move relative to one another. only when dissimilar metal are in contact. when two surface fit loosely together and can move relative to one another.

The rust or corrosion that occurs with most metals is the result of. a tendency for them to return to their natural state. blocking the flow of electrons in homogenous metals, or between dissimilar metals. electron flow in or between metals from cathodic to anodic areas.

Which of the following are the desired effects of using Alodine on aluminum alloy? 1. A slightly rough surface. 2. Relieved surface stresses. 3. A smooth painting surface. 4. Increased corrosion resistance. 3 and 4. 1,2 and 4. 1 and 4.

Which of the listed conditions is NOT one of the requirements for corrosion to occur?. the presence of an electrolyte. electrical contact between an anodic area and a cathodic area. the presence of a passive oxide film.

The lifting or flaking of the metal at the surface due to delamination of grain boundaries caused by the pressure of corrosion residual product buildup is called. brinelling. granulation. exfoliation.

A nonelectrolytic chemical treatment for aluminum alloys to increase corrosion resistance and paint-bonding qualities is called. anodizing. alodizing. dichromating.

Which of the following are acceptable to use in cleaning anodized surfaces? 1. Steel wool. 2. Brass wire brush. 3. Aluminum wool. 4. Stainless steel wire brush. 5. Fiber bristle brush. 1,3,&5. 2 & 4. 3 & 5.

Intergranular corrosion in aluminum alloy parts. may be detected by surface pitting, and white, powdery deposit formed on the surface of the metal. commonly appears as threadlike filaments of corrosion products under a dense film of paint. cannot always be detected by surface indications.

Which of the following may not be detectable even by careful visual inspection of the surface of aluminum alloy parts or structures?. Filiform corrosion. intergranular corrosion. uniform etch corrosion.

What may be used to remove corrosion from highly stressed steel surfaces?. steel wire brushes. fine-grit aluminum oxide. Medium-grit carborundum paper.

A primary cause of intergranular corrosion is. improper heat treatment. dissimilar metal contact. improper application of primer.

Corrosion should be removed from magnesium parts with a. stiff, nonmetallic brush. silicon carbide brush. carborundum abrasive.

Why is it important not to rotate the crankshaft after the corrosion preventive mixture has been put into the cylinders on engines prepared for storage?. fuel may be drawn into one or mare cylinders and dilute or wash off the corrosion preventive mixture. the seal of corrosion preventive mixture will be broken. engine damage can occur from hydraulic lock.

Which of the following is an acceptable first step procedure to help prevent scratching when cleaning a transparent plastic surface?. Gently wipe the surface with a clean, dry, soft cloth. flush the surface with clean water. Gently wipe the suraface with a clean, soft cloth moistened with de-mineralized or distilled water.

What should be done to prevent rapid deterioration when oil or grease come in contact with a tire?. wipe the tire thoroughly with a dry cloth, and then rinse with clean water. wipe the tire with a dry cloth followed by a washdown and rinse with soap and water. wipe the tire with a cloth dampened with aromatic naphtha and then wipe dry with a clean cloth.

Galvanic corrosion is likely to be most rapid and severe when. the surface area of the cathodic metal is smaller than surface area of the anodic metal. the surface areas of the anodic and cathodic metals are approximately the same. the surface area of the anodic metal is smaller than the surface area of the cathodic metal.

Corrosion caused by galvanic action is the result of. excessive anodization. contact between two unlike metals. excessive etching.

Which of these materials is the most anodic?. cadmium. 7075-T6 aluminum alloy. Magnesium.

The interior surface of sealed structural steel tubing would be best protected against corrosion by which of the following?. charging the tubing with dry nitrogen prior to sealing. Evacuating moisture from the tubing before sealing. A coating of linsee oil.

Which of these materials is the most cathodic?. zinc. 2024 aluminum alloy. stainless steel.

Of the following, when and/or where is galvanic corrosion is most likely to occur?. when an electrolyte (water) covers the surface of an aluminum skin, seeps into the cracks between lap joints, and oxygen is excluded from the area. at the interface of a steel fastener and aluminum alloy inspection plate in the presence of an electrolyte. in an area of unprotected metal exposed to an atmosphere containing battery fumes, exhaust gases, or industrial contaminants.

One way of obtaining increased resistance to stress corrosion cracking is by. relieving compressive stresses (via heat treatment) on the metal surface. crating compressive stresses (via shot peening) on the metal surface. producing nonuniform deformation while cold working during the menufacturing process.

(1) In the corrosion process, it is the cathodic area or dissimilar cathodic material that corrodes. (2) In the Galvanic or Electro-Chemical Series for metals, the most anodic metals are those that will give up electrons most easily. Regarding the above statements,. only No. 1 is true. only No. 2 is true. both No. 1 and No. 2 are true.

Spilled mercury on aluminum. greatly increases susceptibility to hydrogen embrittlement. may cause imparied corrosion resistence if left in prolonged contact. causes rapid and severe crrosion that is very difficult to control.

Which coupling nut should be selected for use with 1/2-inch aluminum oil lines which are to be assembled using flared tube ends and standard AN nuts, sleeves, and fittings?. AN-818-5. AN-818-16. AN-818-8.

Metal tubing fluid lines are sized by wall thickness and. outside diameter in 1/16 inch increments. inside diameter in 1/16 inch increments. outside diameter 1/32 inch increments.

From the following sequences of steps, indicate the proper order you would use to make a single flare on a piece of tubing: 1. Place the tube in the proper size hole in the flaring block. 2. Project the end of the tube slightly from the top of the flaring tool, about the thickness of a dime. 3. Slip the fitting nut and sleeve on the tube. 4. Strike the plunger several light blows with a lightweight hammer or mallet and turn the plunger one-half turn after each blow. 5. Tighten the clamp bar securely to prevent slippage. 6. Center the plunger or flaring pin over the tube. 1,3,5,1,4,6. 3,1,6,2,5,4. 3,1,2,6,5,4.

Hydraulic tubing, which is damaged in a localized area to such an extent that repair is necessary, may be repaired. by cutting out the damaged area and utig a swaged tube fittito join the tube ends. only by replacing the tubing sction run (connection to connection) using the same size and material as the original. by cutting out the damaged section and soldering in a replacement section of tubing.

What is an advantage of a double flare on aluminum tubing?. Ease of construction. More resistante to damage when the joint is tightened. Can be applied to any size and wall-thickness of tubing.

A certain amount of slack must be left in a flexible hose during installation because, when under pressure, it. expands in length and diameter. expands in length and contracts in diameter. contracts in length and expands in diameter.

The term 'cold flow' is generally associated with. the effects of low temperature gasses or liquids flowing is hose or tubing. impressions left in natural or synthetic rubber hose material. Flexibility characteristics of varius hose materials at low ambient temperature.

What is the color of an AN steel flared-tube fitting?. black. blue. red.

Which of the following statements is/are correct in reference to flare fittings? 1. AN fittings have an identifying shoulder between the end of the threads and the flare cone. 2. AC and AN fittings are considered identical except for material composition and identifying colors. 3. AN fittings are generally interchangeable with AC fittings of compatible material composition. 1. 1 and 3. 1, 2, and 3.

Flexible lines must be installed with. a slack of 5 to 8 percent of the length. a slack of at least 10 to 12 percent of the length. enougt slack to allow maximum flexing during operation.

The maximum distance between end fittings to which a straight hose assembly is to be connected is 50 inches. The minimum hose length to make such a connection should be. 54-1/2 inches. 51-1/2 inches. 52-1/2 inches.

Excessive stress on fluid or pneumatic metal tubing caused by expansion and contraction due to temperature changes can best be avoided by. using short, strainght sections of tubing between fixed parts of the aircraft. using tubing of the same material as the majority of the adjoining structure. providing bends in the tubing.

The material specifications for a certain aircraft require that a replacement oil line be fabricated from 3/4-inch 0.072 5052-0 aluminum alloy tubing. What is the inside dimension of this tubing?. 0.606 inch. 0.688 inch. 0.750 inch.

In most aircraft hydraulic systems, two-piece tube connectors consisting of a sleeve and a nut are used when a tubing flare is required. The use of this type connector eliminates. the flaring operation prior to assembly. the possibility of reducing the flare thickness by wiping or ironing during the tightening process. wrench damage to the tubing during the tightening process.

When flaring aluminum tubing for use with AN fittings, the flare angle must be. 37°. 39°. 45°.

Which statement(s) about Military Standard (MS) flareless fittings is/are correct? 1. During installation, MS flareless fittings are normally tightened by turning the nut a specified amount, rather than being torqued. 2. New MS flareless tubing/fittings should be assembled clean and dry without lubrication. 3. During installation, MS flareless fittings are normally tightened by applying a specified torque to the nut. 1. 1 and 2. 3.

Scratches or nicks on the straight portion of aluminum alloy tubing may be repaired if they are no deeper than. 20 percent of the wall thickness. 1/32 inch or 20 percent of wall thickness, whichever is less. 10 percent of the wall thickness.

Flexible hose used in aircraft systems is classified in size according to the. outside diameter. wall thickness. inside diameter.

A scratch or nick in aluminum tubing can be repaired provided it does not. appear in the heel of a bend. appear on the inside of a bend. exceed 10 percent of the tube OD an a straight section.

Which of the following hose materials are compatible with phosphate-ester base hydraulic fluids? 1. Butyl. 2. Teflon. 3. Buna-N. 4. Neoprene. 1 and 2. 2 and 4. 1 and 3.

Which tubings have the characteristics (high strength, abrasion resistance) necessary for use in a high-pressure (3,000 PSI) hydraulic system for operation of landing gear and flaps?. 2014-T or 5052-0 aluminum alloy. corrosion-resistant strrl annealed or 1/4H. 1100-1/2H or 3003-1/2H aluminum alloy.

When installing bonded clamps to support metal tubing,. paint removal from tube is not recomended os it will inhibit corrosion. paint clamp and tube after clamp installation to prevent corrosion. remove paint or anodizing from tube at clamp location.

In a metal tubing installation,. rigid straight line runs are preferable. tension is undersirable because pressurization will cause it to expand and shift. a tube may be pulled in line if the nut will star on the threaded coupling.

The best tool to use when cutting aluminum tubing, or any tubing of moderately soft metal is a. hand operated wheel- type tubing cutter. fine-tooth hacksaw. circular-saw equipped with an abrasive cutting wheel.

Which of the following statements is true regarding minimum allowable bend radii for 1.5 inches OD or less aluminum alloy and steel tubing of the same size?. the minumum radius for steel is greater than for aluminum. the minumum radius for steel is less than for aluminum. the minumum radius is the same for both steel and aluminum.

A gas or fluid line marked with the letters PHDAN is. a dual-purpose pneumatic and/or hydraulic line for normal and emergency system use. used to carry a hazardous substace. a pneumatic or hidraulic system drain or discharge line.

Which statement is true regarding the variety of symbols utilized on the identifying color-code bands that are currently used on aircraft plumbing lines?. symbols are composed of various single colors accrding to line content. symbols are always black against a white background regardless of line content. symbols are composed of one to three contrasting colors according to line content.

If a flared tube coupling nut is overtightened, where is the tube most likely to be weakened/damaged?. along the entire length of the sleeve and tube interface. at the edge of the sleeve and straight portion of the tube. at the sleeve and flame junction.

Which statement concerning Bernoulli's principle is true?. the pressure of a fluid incrases at points where the velocity of the fluid increases. the pressure of a fluid decreases at points where the velocity of the fluid increases. it applies only to gases and vaporized liquids.

(1) Bonded clamps are used for support when installing metal tubing. (2) Unbonded clamps are used for support when installing wiring. Regarding the above statements,. only No. 1 is true. Both No. 1 and No. 2 are true. neither No. 1 and No. 2 are true.

Which statement is true regarding flattening of tubing in bends?. flattening by a maximum of 20 percent of the original diameter is permissible. flattening by not more than 25 percent of the original diameter is permissible. the small diameter portion is the bend cannot excees mare than 75 percent of the diameter of straight tubing.

A 3/8 inch aircraft high pressure flexible hose as compared to 3/8 inch metal tubing used in the same system will. have higher flow capacibilites. have equivalent flow characteristics. usually have interchangeable application.