STRUCTURES MMTB Flashcards by Karla Claudette Roldan

The basic questions of
configuration, arrangement,
size and weight, and
performance are answered

Conceptual Design

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Begins when the major changes are over

Preliminary Design

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Begins in which the actual
pieces to be fabricated are designed.

Detail Design

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Mathematical modeling of the outside
skin of the aircraft with sufficient
accuracy to ensure proper fit between its
different parts designed by different designers.

Lofting

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Structural Weight is between 30 to 35%
of the total weight

PRELIMINARY WEIGHT ESTIMATE

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Total Weight of the aircraft as it begins the mission for which it was designed.

Design Take-off Gross Weight

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𝑊𝐶𝑟𝑒𝑤 + 𝑊𝑝𝑎𝑦𝑙𝑜𝑎𝑑 + 𝑊𝑓𝑢𝑒𝑙 + 𝑊𝑒𝑚𝑝𝑡

𝑊0/ total weight

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Part of the fuel supply that is available for
performing the mission

Mission Fuel

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Fuel which cannot be pumped out of the
tanks

Trapped Fuel

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The firing of gun and missiles, and is often
left out of the sizing analysis

Weapon Drop

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Rate of fuel consumption divided by the
thrust

Specific Fuel Consumption

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A measure of the design’s overall aerodynamic efficiency

Lift-to-Drag Ratio

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Curvature characteristics of most airfoil

Camber

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Line equidistant from the upper and lower surfaces

Mean Camber Line

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Maximum thickness of the airfoil divided by its chord

Airfoil Thickness Ratio

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𝑡/c

Thickness Ratio

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Point about which the pitching moment
remains constant for any angle of attack

Aerodynamic Center

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Ratio between the dynamic and the
viscous forces in a liquid

Reynold’s Number

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Lift coefficient at which the airfoil has the
best 𝐿⁄𝐷

Point in the airfoil drag polar that is tangent to a line from origin and closest
to the vertical axis

DESIGN LIFT COEFFICIENT

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Stall from the trailing edge

Turbulent boundary layer increases with
angle of attack

Fat Airfoils (𝒕⁄𝒄 > 𝟏𝟒%)

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Flow Separates near the nose at a very small angle of attack but reattaches itself so that little effect is felt.

At higher angle of attacks the flow fails to
attach, which almost immediately stalls
the entire airfoil

Moderate Thick Airfoils (6-14%)

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The flow separates from the nose at a
small angle and reattaches almost
immediately

Very Thin Airfoils (𝒕⁄𝒄 < 𝟔%)

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Cause the wing to stall first at the root.

Twisting/Washout

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Drag increases with increasing thickness
due to separation

AIRFOIL THICKNESS RATIO

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For a wing of fairly high aspect ratio and moderate sweep, a larger nose radius provides higher stall angle and greater maximum lift coefficient

AIRFOIL THICKNESS RATIO

Wing structural weight varies approximately inversely with the square root of the thickness ratio

AIRFOIL THICKNESS RATIO

Angle of concern in supersonic flight It is common to sweep the leading edge behind the Mach cone to reduce drag.

Leading Edge Sweep

Sweep most related to subsonic flight.

Quarter-Chord Line Sweep

Aerodynamic Center for SUBSONIC

0.25c

Aerodynamic Center for SUPERSONIC

0.4c

Has tips farther apart making them less affected by the tip vortex and the tip vortex strength is reduced

High aspect ratio wings

Wing weight increasing with___

increasing aspect ratio

will stall at a higher angle of attack than higher aspect ratio wings

Lower aspect ratio wings

If the Aspect ratio is High, the Induced Drag is _______

Low

If the Aspect ratio is High, the Lift-Curve Slope is _______

High

If the Aspect ratio is High, the Pitch Attitude is _______

Low

If the Aspect ratio is High, the Ride in Turbulence is _______

Poor

If the Aspect ratio is High, the Wing Weight is _______

High

If the Aspect ratio is High, the Wing Span is _______

Large

If the Aspect ratio is Low, the Induced Drag is _______

High

If the Aspect ratio is Low, the Lift-Curve Slope is _______

Low

If the Aspect ratio is High, the Pitch Attitude is _______

High

If the Aspect ratio is Low, the Ride in Turbulence is _______

Good

If the Aspect ratio is Low, the Wing Weight is _______

Low

If the Aspect ratio is Low, the Wing Span is _______

Small

Primarily used to reduce the adverse effects of transonic and supersonic flow

WING SWEEP

are wings with one wing swept aft and the other swept forward.

Oblique wings

tend to have lower wave drag

Oblique wings

improves stability

Wing sweep

increases the effectiveness of vertical tails at the wing tips

Wing sweep

Better ride through turbulence characteristics

Wing sweep

Increases Critical Mach Number

Wing sweep

Highly undesirable tendency, upon reaching an AOA near stall, to suddenly and uncontrollably increase AOA

Pitch up

Solution to constant sweep problems

Variable Sweep

Complex and attendant balance problems

Variable Sweep

If there is an increased wing sweep forward, the Lift-Curve Slope is ___

Low

If there is an increased wing sweep forward, the Pitch Attitude in Low Speed, Level Flight is ___

High

If there is an increased wing sweep forward, the Ride through Turbulence is ___

Good

If there is an increased wing sweep forward, the Asymmetric Stall is ___

Best

If there is an increased wing sweep forward, the Lateral Control at Stall is ___

Best

If there is an increased wing sweep forward, the Compressibility Drag is ___

Low

If there is an increased wing sweep forward, the Wing Weight is ___

Highest

If there is an increased wing sweep on none, the Lift-Curve Slope is ___

High

If there is an increased wing sweep (none), the Pitch Attitude in Low Speed, Level Flight is ___

Low

If there is an increased wing sweep (none), the Ride through Turbulence is ___

Poor

If there is an increased wing sweep (none), the Asymmetric Stall is ___

Good

If there is an increased wing sweep (none), the Lateral Control at Stall is ___

Good

If there is an increased wing sweep (none), the Compressibility Drag is ___

High

If there is an increased wing sweep (none), the Wing Weight is ___

Low

If there is an increased wing sweep aft, the Lift-Curve Slope is ___

Low

If there is an increased wing sweep aft, the Pitch Attitude in Low Speed, Level Flight is ___

High

If there is an increased wing sweep aft, the Ride through Turbulence is ___

Good

If there is an increased wing sweep aft, the Asymmetric Stall is ___

Poor

If there is an increased wing sweep aft, the Lateral Control at Stall is ___

Poor

If there is an increased wing sweep aft, the Compressibility Drag is ___

Low

If there is an increased wing sweep aft, the Wing Weight is ___

High

Ratio between the tip chord and the centerline tip chord

Taper Ratio

Affects the distribution of lift along the span of the wing

Taper Ratio

More taper

lesser the weight

Less taper means

more fuel volume

If there is High Taper Ratio, the Wing Weight is ____

High

If there is High Taper Ratio, the Tip stall is ____

Good

If there is High Taper Ratio, the Wing Fuel Volume is ____

Poor

Used to prevent tip stall and to revise the lift distribution to approximate an ellipse

TWIST

Actual change in airfoil angle of incidence, usually measured with respect to the root airfoil

Geometric Twist

Twist angle changes in proportion to the distance from the root airfoil

Linear Twist

Angle between zero-lift angle of an airfoil and the zero-lift angle of the root airfoil

Aerodynamic Twist

If identical airfoil is used root to tip, aerodynamic twist is_____ as the geometric twist

the same

If there is a Large Twist Angle the Induced Drag is,

High

If there is a Small Twist Angle the Induced Drag is

Small

If there is a Large Twist Angle the Tip Stall is,

Good

If there is a Small Twist Angle the Tip Stall is

Poor

If there is a Large Twist Angle the Wing Weight is,

Mildly Lower

If there is a Small Twist Angle the Wing Weight is,

Mildly Higher

The pitch angle of the wing with respect to the fuselage

WING INCIDENCE

Minimizes drag at some operating conditions, usually cruise

WING INCIDENCE

If the WING INCIDENCE IS LARGE, the Cruise Drag is ___

High

If the WING INCIDENCE IS SMALL, the Cruise Drag is ___

Small

If the WING INCIDENCE IS LARGE, the Cockpit Visibility is ___

Good

If the WING INCIDENCE IS SMALL, the Cockpit Visibility is ___

Watch out

If the WING INCIDENCE IS LARGE, the Landing Attitude is ___

Watch out

If the WING INCIDENCE IS SMALL, the Landing Attitude is ___

No problem

Angle of the wing with respect to the horizontal when seen from the front

DIHEDRAL

Tends to roll an aircraft whenever it is banked

DIHEDRAL

_____of sweep provides about 1° of effective dihedral

10°

Produced by excessive dihedral effect

Dutch Roll

Repeated side-to-side motion involving yaw and roll

Dutch Roll

To counter the tendency of Dutch Roll, the vertical area must be _____

increased

If there is a POSITIVE DIHEDRAL, the Spiral Stability is ____

Increased

If there is a POSITIVE DIHEDRAL, the Dutch Roll Stability is ____

Decreased

If there is a POSITIVE DIHEDRAL, the Ground Clearance is ____

Increased

If there is a NEGATIVE DIHEDRAL, the Spiral Stability is ____

Decreased

If there is a NEGATIVE DIHEDRAL, the Dutch Roll Stability is ____

Increased

If there is a NEGATIVE DIHEDRAL, the Ground Clearance is ____

Decreased

Allows placing of the fuselage closer to the ground

High Wing

Provides sufficient ground clearance without excessive landing gear length

High Wing

Wingtips less likely to strike the ground

High Wing

usually presents less weight but struts adds to drag

strutted wing

For a ______ aircraft, a high wing provides ground clearance for the large flap necessary for high CL

STOL

Prevents floating which makes it hard to land on desired spot

High Wing

Intended to operate at unimproved fields

High Wing

External blisters and stiffening is needed which adds weight and drag

High Wing

Better visibility towards the ground

High Wing

Restricted visibility towards the rear

High Wing

Obscures pilot vision in a turn

High Wing

Blocks upward visibility in a climb

High Wing

Least interference drag

Mid Wing

to a degree, has the ground clearance advantage of the high wing

Mid Wing

Superior aerobatic maneuverability due to absence of actual or effective dihedral which will act in the wrong direction in inverted flight

Mid Wing

Needs fuselage stiffening; means more weight

Mid Wing

Carry-through structure will limit space for a passenger or cargo aircraft

Mid Wing

Landing gear can be attached to the wing

Mid Wing

Allows for a shorter landing gear strut which means less weight; however there still must be enough ground clearance

Mid Wing

Given enough ground clearance, aft fuselage upsweep can be reduced, reducing drag

Mid Wing

Ground clearance problems may be alleviated by a dihedral

Mid Wing

Placing the propeller above the wing increases interference effects and cruise fuel consumption

Low Wing

Affects take-off and landing field length, cruise performance, ride through turbulence and weight

WING SIZE AND WING LOADING

Wings can be kept small using ___

flaps

For flight at high altitudes and at low speeds, a ______ is required

larger wing

In High Wing aircraft the Interference Drag is _____

Poor

In High Wing aircraft the Dihedral Effect is _____

Negative

In High Wing aircraft the Passenger Visibility is _____

Good

In High Wing aircraft the Fuselage Mounted is _____

Long/Heavy

In High Wing aircraft the Wing Mounted is _____

Possibly Draggy

In High Wing aircraft the Loading & Unloading is _____

Easy

In Mid Wing aircraft the Interference Drag is _____

Good

In Mid Wing aircraft the Dihedral Effect is _____

Neutral

In Mid Wing aircraft the Passenger Visibility is _____

Good

In Mid Wing aircraft the Fuselage Mounted is _____

Long/Heavy

In Mid Wing aircraft the Wing Mounted is _____

Possibly Draggy

In Mid Wing aircraft the Loading & Unloading is _____

Easy

In Low Wing aircraft the Interference Drag is _____

Poor

In Low Wing aircraft the Dihedral Effect is _____

Positive

In Low Wing aircraft the Passenger Visibility is _____

Poor for some

In Low Wing aircraft the Fuselage Mounted is _____

Long/Heavy

In Low Wing aircraft the Wing Mounted is _____

Short/Light

In Low Wing aircraft the Loading & Unloading is _____

Need Stairs

If the Wing Loading is High, the Field Length is ____

Long

If the Wing Loading is High, the Stall Speed is ____

High

If the Wing Loading is High, the Max. Lift-to-Drag Ratio is ____

High

If the Wing Loading is Low, the Stall Speed is ____

Low

If the Wing Loading is High, the Ride quality in Turbulence is ____

Good

If the Wing Loading is High, the Weight is ____

Low

If the Wing Loading is Low, the Field Length is ____

Short

If the Wing Loading is Low, the Max. Lift-to-Drag Ratio is ____

Low

If the Wing Loading is Low, the Ride quality in Turbulence is ____

Bad

If the Wing Loading is Low, the Weight is ____

High

A ____ tip is more effective than a rounded tip in alleviating tip vortex effects

Sharp

The ____ tip is the most widely used low-drag wingtip

Hoerner

Tip curved upwards/downwards increase effective span without increasing actual span

WING TIPS

A ______ tip addresses the condition that vortices tend to be located at the trailing edge of the wing tip; increases torsional load

swept wing

It is used for supersonic aircraft; part with little lift is cut-off; reduced torsional load

Cut-off forward swept

Low structural Weight

BIPLANE WINGS

Relatively short wing span

BIPLANE WINGS

Half induced drag compared to monoplane producing same lift

BIPLANE WINGS

The vertical distance between the two wings

Gap

The ratio between the shorter to the longer wing

Span Ratio

The longitudinal offset of the two wings relative to each other

Stagger

When upper wing is closer to the nose

Positive Stagger

When lower wing is closer to the nose

Negative Stagger

Relative incidence between the two wings

Decalage

When upper wing has a larger incidence

Positive Decalage

Rear section of the airfoil is hinged so that it can be rotated downward

Plain Flap

With a _____ flap, CLmax can be almost doubled

simple plain flap

Creates more lift simply by mechanically increasing the effective camber of the airfoil

Plain Flap

Increases the drag and pitching moment

Plain Flap

Only the bottom surface of the airfoil is hinged

Split Flap

Causes a slightly higher CLmax than that for a plain flap

Split Flap

Performs the same function as a plain flap, mechanically increasing the effective camber

Split Flap

Produces more drag and less change in the pitching moment compared to a plain flap

Split Flap

A small, highly cambered airfoil located slightly forward of the leading edge of the main airfoil

Leading Edge Slat

Essentially a flap at the leading edge, but with a gap between the flap and the leading edge

Leading Edge Slat

CLmax is increased with no significant increase in drag

Leading Edge Slat

The slot allows the higher-pressure air on the bottom surface of the airfoil to flow through the gap, modifying and stabilizing the boundary layer over the top surface of the airfoil

Single-Slotted Flap

Higher CLmax compared to a single-slotted flap

Double-Slotted Flap

This benefit is achieved at the cost of increased mechanical complexity

Double-Slotted Flap

Mechanically sucks away a portion of the boundary layer through small holes or slots in the top surface of the airfoiI which delays flow separation

Boundary Layer Suction

Translates or tracks to the trailing edge of the airfoil to increase the exposed wing area and further increase lift

Fowler Flap

A leading-edge slat which is thinner, and which lies flush with the bottom surface of the airfoil when not deployed

Krueger Flap

The ______ exists mainly for trim, stability and control

empennage

Lightweight Horizontal tail is in the wake of the wing Does not allow for aft-mounted engine Low horizontal tails are best for stall recovery

Conventional

Heavier due to strengthening of the vertical tail to support the horizontal tail

T-Tail

Allows for a smaller vertical tail due to end plate effect

T-Tail

Horizontal tail is clear of wing wake and propwash

T-Tail

Allows for an aft-mounted engine

T-Tail

Most prone to Deep Stall, Where the wing blankets the Elevator causing a stall

T-Tail

Compromise between conventional and T-tail

Cruciform

Less weight penalty compared to T-tail Undisturbed flow in lower part of rudder at high angles of attack No endplate effect

Cruciform

Undisturbed flow in vertical tails at high angles of attack

H-Tail

May enhance engine out control in multiengine aircraft with the rudders positioned in the propwash

H-Tail

Endplate effect on the horizontal tail; reduced size possible

H-Tail

 Heavier than conventional  Hides hot exhaust from heat seeking missiles

H-Tail

Allows for smaller/shorter vertical tail

H-Tail

May allow for a reduced wetted area Reduced interference drag

V-Tail (Butterfly)

Control/Actuation complexity Adverse roll-yaw coupling Surfaces are out of the wing wake

V-Tail (Butterfly)

Proverse Roll-Yaw Coupling Reduced spiraling tendencies Ground clearance problems

Inverted V-Tail

Avoids complexity of ruddervators V surfaces provide pitch control only Rudder in third surface

Y-Tail

Avoids blanketing of the rudders due to wing and forward fuselage at high angles of attack

Twin Tails

Reduces height; area is distributed between the two vertical tails Usually heavier than a single centerline mounted vertical tail

Twin Tails

Allows for a pusher propeller configuration are typically heavier than a conventional fuselage construction May be connected or not; high-, mid-, or low-mounted horizontal tail, which can have a V configuration

Boom-Mounted Tails

 Doubles as a propeller shroud  Conceptually appealing, however proven inadequate in application

Ring Tail

Negligible contribution to lift Used to control angle of attack of wing Used to balance pitching moments due to flaps

Control Canard

 Contributes to lift; higher aspect ratio for reduced induced drag; greater camber for increased lift  Pushes wing aft; bigger pitching moments due to flaps  Canard is closer to CG; less effective pitch control; surface must be increased; resulting in more trim drag  Pitch up tendencies are avoided

Lifting Canard

 50% theoretical reduction in induced drag because lift is distributed between the two wings  Aft wing experiences downwash and turbulence caused by the forward wing  Wings must be separated as far as possible

Tandem Wing

Theoretically offers minimum trim drag Additional weight; more interference drag; complexity

Three Surface

 Incorporated into a faired extension of the wing or fuselage  Used to prevent pitch up but can also serve as a primary pitch control surface

Back Porch/Aft-Strake

Offers the lowest weight and drag Reduced wing efficiency Most difficult configuration to stabilize

Tailless

Drag of the proposed installation Accessibility and Maintainability The vertical and/or lateral location of the thrust line(s) are critically important in this respect Weight and balance consequences of the proposed installation Inlet requirements and resulting effect on 'installed‘ power and efficiency Acceptable FOD characteristics Geometric clearance when static on the ramp: o No nacelle or propeller tip may touch the ground with deflated landing gear struts and tires Geometric clearance during take-off rotation: o No scraping of nacelles or of propeller tips is allowed with deflated landing gear struts and tires Geometric clearance during a low speed approach with a 5 degrees bank angle No gun exhaust gases may enter the inlet a jet engine

ENGINE DISPOSITION CONSIDERATIONS

a) Wing-Mounted b) Fuselage-Mounted c) Empennage-Mounted d)Any Combination of the Above

WING MOUNTING

The vector sum of the rotational speed and the aircraft’s forward speed

Tip Speed

PROPELLER DIAMETER 𝑑 = 22 4^√𝐻p

Two Blade

PROPELLER DIAMETER 𝑑 = 18 4^√𝐻P

Three Blade

PROPELLER DIAMETER 𝑑 = 20 4^√𝐻P

Three Blade (Agricultural)

The propeller or inlet plane is forward of the CG There is a more effective flow of cooling air for the engine

Tractor

Tend to be destabilizing with respect to static longitudinal and directional stability

Tractor

The propeller is working in an undisturbed free stream

Tractor

The propeller slipstream disturbs the quality of the airflow over the fuselage and wing root

Tractor

The propeller or the inlet plane is located behind the CG Tend to be stabilizing May save empennage area

Pusher

Allows a shorter fuselage, hence smaller wetted surface area Higher-quality (clean) airflow prevails over the wing and fuselage Engine noise in the cabin area is reduced

Pusher

The pilot's front field of view is improved Propeller is more likely to be damaged by flying debris at landing Engine cooling problems are more severe

Pusher

PROPELLER CLEARANCES Tricycle

7 inches

PROPELLER CLEARANCES Conventional

9 inches

PROPELLER CLEARANCES Over Water

18 inches

Employed by many sailplanes for its simplicity

Single Main

 Flat attitude take-off and landing  Aircraft must have high lift at low AOA (high AR with large camber and/or flaps)

Bicycle

 Used by aircraft with narrow fuselage and wide wing span CG should be aft of the midpoint of the 2 wheels

Bicycle

 More propeller ground clearance  Less drag and weight  Easier lift production due to attitude, hence initial AOA

Conventional/Tail Dragger

 Inherently unstable (ground looping)  Limited ground visibility from cockpit  Inconvenient floor attitude

Conventional/Tail Dragger

Stable on the ground; can be landed with a large “crab angle” (nose not aligned with runway) Improved forward ground visibility

Tricycle

Flat cabin floor for passenger and cargo loading

Tricycle

Flat take-off and landing attitude Permits a very low cargo floor

Quadricycle

For extra heavy aircraft (200-400 kips) Redundancy for safety

Multi-Boogey

Maximum load anticipated in service

Limit or Applied Load

Maximum load, which a part of structure is capable of supporting

Design or Ultimate Load

𝐷𝑒𝑠𝑖𝑔𝑛 𝐿𝑜𝑎𝑑 = 𝐿𝑖𝑚𝑖𝑡 𝐿𝑜𝑎𝑑 × 𝐹. 𝑆.

Design or Ultimate Load

Factor which the limit load must be multiplied to establish the ultimate load Normally 1.5 unless otherwise specified

Factor of Safety

Load factor corresponding to limit loads

Limit Load Factor

Load Factor corresponding to ultimate load

Ultimate Load Factor

Ratio of the specified load to the total weight of the aircraft

Load Factor

Greatest air loads on an aircraft usually come from the generation of lift during high maneuvers Aircraft load factor expresses maneuvering of an aircraft as a multiple of the standard acceleration due to gravity g(32.174 ft/sec2)

Maneuver Loads

At lower speeds, the highest load factor an aircraft may experience is limited by the maximum lift available At Higher Speeds the maximum load factor is limited to some arbitrary value based upon the expected us of the aircraft

Maneuver Loads

-The loads experienced when the aircraft encounters a strong gust can exceed maneuver loads in some cases -When an aircraft experiences a gust, the effect is an increase (or decrease) in angle of attack

Gust Loads

Maneuvering Load Factors For Normal Category

2.5 < 𝑛 < 3.8

Maneuvering Load Factors For Utility Category

2.5 < 𝑛 < 4.4

Maneuvering Load Factors For Acrobatic Category

2.5 < 𝑛 < 6.0

Negative limit Maneuvering Load Factor Should not be less than -0.4n

Normal and Utility

Negative limit Maneuvering Load Factor Should not be less than -0.5n

Acrobatic

Obtained in a pullout at the highest possible angle of attack on the wing The lift and drag forces are perpendicular and parallel respectively to the relative wind

Positive High Angle of Attack

Occurs in intentional flight maneuver in which the air loads on the wing are down or when the airplane strike suddenly downwards while in level flight

Negative High angle of Attack

The wing has the smallest positive angle at which the lift corresponding to the limit-load factor may be developed

Positive Low Angle of Attack

Occurs at the diving-speed limit of the airplane Occurs in an intentional maneuver producing a negative load factor or in a negative gust condition

Negative Low Angle of Attack

AIRPLANE CATEGORIES Limited to airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff of 12,500 pounds or less Intended for non-acrobatic nonscheduled passenger, and non-scheduled cargo operation Limited to: o Any maneuver incident to normal flying o Stalls except whip stall o Lazy eights, chandelles, and steep turns, in which the angle of bank is less than 60°

Normal Category

AIRPLANE CATEGORIES  Limited to airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff weight of 12,500 pounds or less  Intended for Normal operations and limited acrobatic maneuvers  Not suited for snap or inverted maneuvers  Used in operations covered under the normal and limited acrobatic operations  Limited to: o Spins o Lazy eights, Chandelles, and steep turns, in which the angle of bank is more than 60° but less than 90°

Utility Category

AIRPLANE CATEGORIES Limited to airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum certificated take-off weight of 12,500 pounds or less Have no specific restrictions as to type of maneuvers permitted unless the necessity therefore is disclosed by the required flight test

Acrobatic Category

AIRPLANE CATEGORIES limited to propeller-driven, multiengine airplanes that have a seating configuration, excluding pilot seats, of 19 or less, and a maximum certificated takeoff weight of 19,000 pounds or less Cannot be type certificated with other categories on a single airplane Limited to: o Normal flying o Stalls (except whip stalls) o Steep turns, in which the angle of bank is not more than 60°

Commuter Category

LIMITED ACROBATIC MANEUVERS The degree of back varies from 45 to 75°

Steep Turn

LIMITED ACROBATIC MANEUVERS If done intentionally and a flight condition if it occurs, which is a result of a complete stall after which the airplane, still in stalled altitude, loses altitude rapidly and travels downward in a vertical helical or spiral path

Spin

LIMITED ACROBATIC MANEUVERS  Airplane is operating at an angle of attack of maximum lift  Loss of flying speed and in many cases temporary loss of lift and control

Stall

LIMITED ACROBATIC MANEUVERS The result of a complete stall in which the nose of the airplane whips violently and suddenly downward In some cases, The airplane slides backward a short distance before the nose of the plane drops Causes severe strains on the engine mounts and all surfaces

Whip Stall

LIMITED ACROBATIC MANEUVERS Combines the dive, turn and the climb The nose of the airplane describes a horizontal figure eight lying on its side upon the horizon

Lazy Eight Flight

LIMITED ACROBATIC MANEUVERS Maneuver of the composite type, combining climb and turn, approach to a stall and recovery back to normal flight

Chandelle

WING SPAR LOCATION 15-30% of the chord

Front Spar

WING SPAR LOCATION 65-75% of the chord

Rear Spar

WING RIBS SPACING Light Airplanes

36 inches

WING RIBS SPACING Transports

24 inches

WING RIBS SPACING Fighters and Trainers

Vary Widely

EMPENNAGE SPAR LOCATION Front Spar

15-25% of the chord

EMPENNAGE SPAR LOCATION Rear Spar

70-75% of the chord

EMPENNAGE RIBS SPACING Light Airplanes

15-30 inches

EMPENNAGE RIBS SPACING Transports

24 inches

EMPENNAGE RIBS SPACING Fighters and Trainers

Vary Widely

STRUCTURES MMTB Flashcards

(299 cards)