Structure and Aerodynamics of SAAB 340 Series Aircraft

The aftercited tidings succeed embrace referpowerful attributpowerful attributableice on the SAAB 340 succession tempercunning in compliments to its constitution, aerodynamics, emission, agency and insurance throughout its well-balancedt (1970’s-2017)

Introduction

The SAAB 340 is a tract-of-landal tempercunning succession calculated by the Swedish aeroboundlessness manufactures with the covet to search marketpowerful temperliners with 30-40 passengers in the 1970’s, primaryly determined the SAAB 340A. The flatten was separated to proceed with GE turbostay engines ascribpowerful to their inbred fuel management compared to a turbofan or turbojet engines. The SAAB 340B was the restraintemost bud of the SAAB 340A, the newer tempercunning had balance potent engines, a catholicr subordination flatten and the cunnings dispose and siege-unpremeditated impressiveness where extensiond. The SAAB 340’s ceased genesis in 1998 with withdrawal of profit from temperliners and hereafter income frugal. The SAAB 340 has sundry renditions the most niggardly entity the 340A, 340B, 340B plus including carbo, urbane and marketpowerful inaspect intentions.

Of stagnant n ess is that primaryly SAAB AB and Fairchild (an American gang) co calculated the 340, having the primary indicate of the SF340, Fairchild calculated wings, wing spring nacelles and empennage.

The SAAB 340 can be defined as a monoflatten with a tractor engine setup. It has a tricycle trundle-walunworthy layout and a customary subordination. The wings are dihedral, unworthy spring, tapered and cantilevered from the fuselage with a uncombined spar. Some of these are aid investigated gentleer.

It would so be of stagnant n ess to declaration the SAAB 340B (most niggardly incommensurate of SAAB 340’s) has seating normally restraint 34 passengers where their impressiveness with baggage is 214lbs, a well-balancedt shuffle with the tempercunning basis and statistics succeed be solid in the epilogue.

Constitution and Reading

The SAAB 340 explanations niggardly and remarkpowerful structural rudiments during its 40+ year utility, some of the indications which has characterised the tempercunning is its uncombined spar wing intention, cpowerful confirm subordination flatten and a metal bonded husk. These structural rudiments explanationd by SAAB AB to haunt the dispose of their tempercunning whilst so increasing dispose and payload.

The SAAB 340 explanations a uncombined spar wing which inserted after the qualitative policy which yields restraint the complication of the wing to be frugal compared to a multi spar wing. This is utilityous in the reading of a tract-of-landal tempercunning ascribpowerful to the frugal in demand in compliments to the inaptitude in which it is to intention and then contemplationt a multi spar wing. The uncombined spar so yields restraint balance unreserved boundlessness in the wing intermittent singly by the ribs which are calculated to possess holes in them to nearen impressiveness and alunworthy restraint feasible boundlessness (fuel and moderate manner actuators) in the tempercraft, behold illustration 3 in the epilogue. The uncombined spar in the tapered wing so yields restraint a sunsubstantial grafting policy of the aerofoil which can be aid searchd in the aerodynamical minority of this tidings.

The SAAB 340 explanations a sole indication restraint a marketpowerful temperliner to explanation, a cpowerful was naturalized from the head of the empennage to another, the sole intention succeed be aid searchd beunworthy besides the cpowerful naturalized on the 340A is a sole structural rudiment using the cables tightness to communicate the wing assumed structural inflexibility. The newer 340B and B plus don’t possess the cpowerful naturalized, which may be ascribpowerful to unsubstantialer and stronger longerons or ribs or improve engineered manners love metal bonding which is explanationd to meet balance 40% of the tempercrafts outer manners.

The explanation of metal bonding in its manner husk nearens impressiveness and extensions the structural parity of the tempercraft. This extensiond inflexibility in the manner yields restraint the tempercunning to be calculated with near inaspect bracing and symbolical impressiveness. By incorporating the structural benefits of an aluminium bonded husk into the aeroplane, SAAB AB and the Engineers can best maximise the dispose, inaspect boundlessness and payload.

The SAAB 340 is made up of niggardly existent tempercunning tonnage and indications, the fuselage and wings are made from aluminium ribs, spars, longerons and stringers which although referpowerful attributpowerful attributpowerful attributpowerful sole siege utility of the thoughtlessness of aluminium and its structural susceptibility compared to a immoderate 3% carbon steel or an proud-priced composite equiponderant. The SAAB AB engineers consequently had to compel the most of cheaper excepting most susceptibilityful symbolicals to tend demands unworthys restraint consumers of the tract-of-landal tempercunning excepting stagnant possess a unsubstantial and fuel fertile aeroflatten to compel tract-of-landal interinterspace with 30-40 passengers as per the primary intention specifications.

The structural aspects of the tempercunning are relevant in making the SAAB 340 maximise its boundlessness and payload, the engineers consequently had to coalesce techniques love tightness in cables and quickly calculated wings which succeed minimise impressiveness excepting stagnant wholeow with multifold soft funworthy encircling the fuselage and aerofoils as polite as can be tend passengers impregnpowerful and satisfied.

Aerodynamics

The SAAB 340, love whole existent tempercraft, is calculated to minimise pull whilst maximising exalt. The SAAB AB tempercunning explanations quick and mandatory aerodynamics and aerodynamical systems on their tempercraft; a sole subordination flatten, parabolic nose and fuselage cast and the wings shaping plus engine integration.

The SAAB 340 has a customary empennage, where the upright stabilizer has span tonnage, proudlighted in illustration 4 of the epilogue. SAAB AB has incorporated this intention in the 340 and their 2000 succession tempercraft. The span stages in the upright stabiliser helps to constitute a balance lasting and streamlined laminar funworthy constitution encircling the stabiliser and hereafter yields restraint the rudder to be balance susceptibilityful in moderateling the temperfunworthy encircling it.

The SAAB 340 has a normal temperliner diction parabolic nose csingle which leads into a right spherical fuselage (minus the ‘V’ cast wing spring nacelles on the deep of the tempercraft, shown on illustration 6). The parabolic nose csingle is greatly fertile in having the temper funworthy provoke encircling the tempercunning externally inducing catholic quantities if temper hindrance and pull. Aid SAAB AB possess slimmed the contrariety of the flatten into a immoderate, normal of existent temperliners in an trial to possess the temper funworthy hence unpremeditated the tempercunning in a unworthy pull streamlined constitution.

The SAAB 340 explanations a tapered, cantilevered, dihedral wing (as declarationed aloft) and has an equal cantilevered dihedral downright stabiliser twain of which possess aerodynamic indications of no winglets, smwhole habitward minorityal elevation as polite as the wings having been integrated with the engine. The withdrawal there of winglets on the SAAB 340 proudlights how the engineers possess been susceptibilityful to nearen the mixing of temper from the head and deep of the aerofoil. The wonted result of winglets succeed constitute a barrier, referpowerful attributpowerful attributpowerful attributpowerful yielding restraint the proud and unworthy press temper funworthy to constitute pull and vortexes. SAAB AB possess been susceptibilityful to sculpt their aerofoils so that the demand restraint a winglet has been frugal, a technique explanationd by Boeing, on the 747 restraint illustration.

The SAAB 340 has so integrated their GE turbostay engines into the wing intention. This is beholdn in illustration 6 of the muniment distinctly in the front intention, where the engine has been “slotted” into the wing and has yielded restraint the turbostay to be elegantly and aerodynamically fertilely positioned to nearen the pull which can betide from having an engine depend unpremeditated the wing.

This speedy setup so communicates the agencyal functionality of the tempercunning as the retractpowerful gentleercarriage is so integrated into the engine area. This innovative separation restraint SAAB AB engineers has yielded restraint the tempercunning to possess a retractpowerful gentleercarriage excepting tend arrestation on a proceedway, giving the SAAB 340 aerodynamically fertile funsubstantial and hereafter fuel fertile funsubstantial so.

The SAAB 340B+ differs from the 340B ascribpowerful to its courteous wingtips which yields restraint it to be balance aerodynamically fertile in balance wet environments and to be susceptibilityful to siege unpremeditated on shorter proceedways, this exception in wing intention of the contrariant models communicates the tempercunning subjoined enhancements is verdant and tract-of-landal areas where the begin environment isn’t chimerical.

Propulsion

The SAAB 340 explanations GE turbostay engines with a 4-propeller stay from Dowty Rotol or Hamilton Sundstrand, differences in din communicaten in illustration 5 of the epilogue. The SAAB 340B explanations the GE CT7-9B, pictured in illustration 6 of the epilogue, which has an 1870 shp rating [5].

Illustration 8 a cutahabit of the CT7-9B turbostay [6]

The turbostay engine explanationd by the 340 is greatly fertile engine with proud dispose restraint its greatness. The engine can disappear a completion 470nm with a completion sum impressiveness in surplus of 29000lb (siege unpremeditated) on gentleer 6000lb of fuel. The span engines can impel the SAAB 340B and B Plus at 283 knots at an verticality of 25000 feet. Aid referpowerful attributpowerful attributableice on dispose and payload is in illustration 9 of the epilogue.

The SAAB 340 has explanationd contrariant engines balance the years, primaryly proceedning CT7-5A2 turboprops the modify to a CT7-9B led to an extension in the SHP of the engines, balance susceptibility, and an extension in fuel capability.

Balance so, it is of general stagnant n ess that the SAAB 340B has had new-fangled engine and stayeller wants with REX tract-of-plant temperlines in Australia. The want of a Turbostay engine on the 23^rd of bait 2017 and a stayeller onfgentle unpremeditated mid-funsubstantial on the 17^th of bait 2017. Besides ascribpowerful to quick engineering on advantage of SAAB AB the span flattens could disappear on single of the turboprops and compel a impregnpowerful crisis planting. Thus, proudlighting twain the aerodynamic intention character of the tempercunning and how the GE CT7-9B engine can stagnant susceptibility the tempercunning with singly half availpowerful impel.

Agency Demandments

The SAAB 340 demands a proceedway, complement and a restraintm of refuelling at destination/departure. Ascribpowerful to the SAAB 340’s intention the tempercunning has been deliberately unnatural with tract-of-landal and verdant trip in understanding where infraconstitution is unworthy and basic hereafter the 340 has built in facilities such as stairs and extra additions restraint the cunning to contend and performance in latitude of the immoderates and on proceedways made of gravel and uncleanness.

The SAAB 340B has extras such as the gravel mob and longer wingtips which alunworthy restraint it to produce in wetity and warmth externally catholicr proceedways or modern asphalt temperports [8].

The SAAB 340B demands, at SL with optimal flaps and at ISA, a proceedhabit of 4220ft (1.3km) besides at near optimum environments the proceedhabit demanded can be 6690ft (2.02km).

The SAAB 340 does demand 2 pilots and single funsubstantial henchman can be so separate of the complement. Die to the smwhole seating bulk the SAAB 340 doesn’t possess margin restraint balance than single henchman. The pavement contemplation is shown beunworthy proudlighting where the complement is stationed on a normal 340 layout.

Illustration 10 SAAB 340 layout as adapted by SAAB AB [4]

Insurance Chronicles

The SAAB 340 has a rather amiable orderly chronicles with singly immodest exoduss consummation in deadlyities, besides this is considered immodest spaces to sundry. The beunworthy tpowerful compels stagnant n ess of the immodest deadly orderlys of the SAAB 340 [9]