Configuration Design part 2HIGH WING: PROSC-17Cessna 152Slide 5Quiet Short Research AircraftShorts 330Boeing 314-AHIGH WING: CONSFokker F-27Hawker Siddeley HS.660 ArgosySlide 12Slide 13MID WING: PROSF-18 Hornet & T-37MID WING: CONSLOW WING: PROSSlide 18LOW WING: CONSConfiguration Design Configuration Design part 2part 2Wing Wing PlacementPlacementHIGH WING:HIGH WING:PROSPROS1. Quick loading and unloading.1. Quick loading and unloading.C-5, C-17C-5, C-17Loading and unloading through nose / tail doors: important Loading and unloading through nose / tail doors: important to have low floor level.to have low floor level.Low-wing ac: main deck floor is 16-17 ft (5 m) above the Low-wing ac: main deck floor is 16-17 ft (5 m) above the apron because the wing carry-through structure passes apron because the wing carry-through structure passes below the floor. Necessary to have special loading and below the floor. Necessary to have special loading and boarding equipment.boarding equipment.2. Best for braced-wing monoplanes.2. Best for braced-wing monoplanes.CessnaCessnaStruts cause little interference when attached to the lower Struts cause little interference when attached to the lower side of the wing.side of the wing.Lighter struts because they are stressed in tension.Lighter struts because they are stressed in tension.3. The wing is generally lighter.3. The wing is generally lighter.C-17C-17Cessna 152Cessna 152HIGH WING:HIGH WING:PROSPROS4. The nose-wheel gear is shorter and lighter.4. The nose-wheel gear is shorter and lighter.5. Best for STOL5. Best for STOLQSRAQSRAClose proximity of the wing to the ground during TO and Close proximity of the wing to the ground during TO and LNG may cause pronounced undesirable ground effects.LNG may cause pronounced undesirable ground effects.Required ground clearance for large, fully deflected TE flaps Required ground clearance for large, fully deflected TE flaps and large props would entail a very tall and heavy LG in a and large props would entail a very tall and heavy LG in a low wing configuration.low wing configuration.6. Safer.6. Safer.Damage and fire risk is limited during a forced LNG.Damage and fire risk is limited during a forced LNG.7. Less Ground Effect in CTOL7. Less Ground Effect in CTOL Shorts 330Shorts 330Smaller LNG distance.Smaller LNG distance.8. Best for amphibians8. Best for amphibians Boeing 314-ABoeing 314-AKeeps engines away from HKeeps engines away from H22O.O.Quiet Short Research AircraftQuiet Short Research AircraftShorts 330Shorts 330Boeing 314-ABoeing 314-AHIGH WING:HIGH WING:CONSCONS1. Problem w. the retraction of the main1. Problem w. the retraction of the main LG.LG.In small, high-wing propeller ac, main LG can be retracted In small, high-wing propeller ac, main LG can be retracted into engine nacelles (into engine nacelles (Fokker F-27Fokker F-27) or in tail booms () or in tail booms (Hawker Hawker Siddeley ArgosySiddeley Argosy). In large ac, however, this would make the ). In large ac, however, this would make the LG too tall and heavy.LG too tall and heavy.A solution for large ac: fuselage-mounted LG.A solution for large ac: fuselage-mounted LG.Problem 1:Problem 1: strengthening of the fuselage structure required strengthening of the fuselage structure required for the transmission of the LNG impact results in W for the transmission of the LNG impact results in W increase. increase. Problem 2:Problem 2: with a fuselage mounted main LG the track may with a fuselage mounted main LG the track may not be sufficiently wide.not be sufficiently wide.2. No ground effect in CTOL.2. No ground effect in CTOL.Increased TO distance.Increased TO distance.Fokker F-27Fokker F-27Hawker Siddeley HS.660 ArgosyHawker Siddeley HS.660 ArgosyHIGH WING:HIGH WING:CONSCONS3. No room for underfloor cargo.3. No room for underfloor cargo.Fuselage section below the floor is flattened to reduce LG Fuselage section below the floor is flattened to reduce LG height + keep the floor low (4-4.5 ft = 1.2-1.4 m).height + keep the floor low (4-4.5 ft = 1.2-1.4 m).Solution: longer cargo hold in cabin.Solution: longer cargo hold in cabin.Problem 1:Problem 1: longer fuselage. longer fuselage.Problem 2:Problem 2: large cg travel. large cg travel.4. Unsafe4. UnsafeFuselage will sink when ac is forced down on water. Provisions Fuselage will sink when ac is forced down on water. Provisions must be made for escape through the cabin roof.must be made for escape through the cabin roof.5. Not good for highly maneuverable ac.5. Not good for highly maneuverable ac.Too stable in roll.Too stable in roll.HIGH WING:HIGH WING:CONSCONS6. ~ 20% more S6. ~ 20% more SVV than a low-wing than a low-wing configuration.configuration.7. OEW is generally higher.7. OEW is generally higher.8. Structural design is generally more 8. Structural design is generally more complicated.complicated.MID WING:MID WING:PROSPROS1.1.Min D in high-speed flight.Min D in high-speed flight. (fighters, trainers) (fighters, trainers)Surfaces at wing / fuselage junction meet at 90Surfaces at wing / fuselage junction meet at 9000 angles; angles; interference between BLs at low interference between BLs at low  is minimized. is minimized. Fuselage section at the location where the wing is Fuselage section at the location where the wing is mounted is roughly cylindrical; divergence of airflow mounted is roughly cylindrical; divergence of airflow over wing root is minimized.over wing root is minimized.2.2.Best maneuverability.Best maneuverability.3.3.Wing can be continuous through the Wing can be continuous through the fuselagefuselagetransfer of loads from the wing can take place via transfer of loads from the wing can take place via almost solid “bulkheads”, to which each wing-half is almost solid “bulkheads”, to which each wing-half is attached.attached.F-18 Hornet & T-37F-18 Hornet & T-37MID WING:MID WING:CONSCONS1.1.Reduced internal useful fuselage volume.Reduced internal useful fuselage volume.That is the reason why mid-wing configurations are That is the reason why mid-wing configurations are not adopted for transports.not adopted for transports.LOW WING:LOW WING:PROSPROS1.1.Efficient use of fuselage under-floor space.Efficient use of fuselage under-floor space.2.2.Large tail angle allows for optimum rotation during Large tail angle allows for optimum rotation during