Structure and Aerodynamics of SAAB 340 Series Aircraft

The subjoined tidings conquer embrace referableification on the SAAB 340 train ardorartifice in compliments to its edifice, aerodynamics, convexity, influence and protection throughout its truth (1970’s-2017)

Introduction

The SAAB 340 is a districtal ardorartifice train purposed by the Swedish aeroboundlessness manufactures with the hanker to scrutinize markettalented ardorliners with 30-40 passengers in the 1970’s, peculiarly projectated the SAAB 340A. The flatten was selected to extend with GE turbofoundation engines ascribtalented to their innate fuel arrangement compared to a turbofan or turbojet engines. The SAAB 340B was the superfluous fruit of the SAAB 340A, the newer ardorartifice had advance potent engines, a abundantr foot flatten and the artifices file and select-extempore burden where growthd. The SAAB 340’s ceased evolution in 1998 with stagnation of attention from ardorliners and future profits frugal. The SAAB 340 has pitch-headlongrs renditions the most beggarly entity the 340A, 340B, 340B plus including carbo, corporate and markettalented inplant projects.

Of hush is that peculiarly SAAB AB and Fairchild (an American corporation) co purposed the 340, having the peculiar indicate of the SF340, Fairchild purposed wings, wing spring nacelles and empennage.

The SAAB 340 can be defined as a monoflatten with a tractor engine setup. It has a tricycle rotate layout and a customary foot. The wings are dihedral, reprieved spring, tapered and cantilevered from the fuselage with a matchhither spar. Some of these are advance investigated adown.

It would to-boot be of hush to referableice the SAAB 340B (most beggarly contradictory of SAAB 340’s) has seating naturally coercion 34 passengers where their burden with baggage is 214lbs, a equalt fencing with the ardorartifice premises and statistics conquer be fixed in the postscript.

Edifice and Reading

The SAAB 340 reasons beggarly and remarktalented structural constituents during its 40+ year custom, some of the elements which has characterised the ardorartifice is its matchhither spar wing project, ctalented cetify foot flatten and a metal bonded peel. These structural constituents reasond by SAAB AB to obey the file of their ardorartifice whilst to-boot increasing file and payload.

The SAAB 340 reasons a matchhither spar wing which inserted aback the superfluous party which apportions coercion the perplexity of the wing to be frugal compared to a multi spar wing. This is salutary in the reading of a districtal ardorartifice ascribtalented to the frugal in absorb in compliments to the awkwardness in which it is to project and then set-up a multi spar wing. The matchhither spar to-boot apportions coercion advance easy boundlessness in the wing interrupted merely by the ribs which are purposed to possess holes in them to narrow burden and alreprieved coercion possible boundlessness (fuel and coerce manner actuators) in the ardorcraft, intention image 3 in the postscript. The matchhither spar in the tapered wing to-boot apportions coercion a thin trailing party of the aerofoil which can be advance scrutinized in the aerodynamical exception of this tidings.

The SAAB 340 reasons a matchhither element coercion a markettalented ardorliner to reason, a ctalented was established from the summit of the empennage to another, the matchhither project conquer be advance scrutinized bereprieved equaltually the ctalented established on the 340A is a matchhither structural constituent using the cables endeavor to furnish the wing visible structural rectilinearity. The newer 340B and B plus don’t possess the ctalented established, which may be ascribtalented to scantyer and stronger longerons or ribs or emend engineered manners love metal bonding which is reasond to secrete balance 40% of the ardorcrafts visible manners.

The reason of metal bonding in its manner peel narrows burden and growths the structural honor of the ardorcraft. This growthd rectilinearity in the manner apportions coercion the ardorartifice to be purposed with hither inner bracing and esthetic burden. By incorporating the structural benefits of an aluminium bonded peel into the aeroplane, SAAB AB and the Engineers can best maximise the file, inplant boundlessness and payload.

The SAAB 340 is made up of beggarly new ardorartifice calibre and elements, the fuselage and wings are made from aluminium ribs, spars, longerons and stringers which although refertalented matchhither select custom of the inconstancy of aluminium and its structural ability compared to a subject-matter 3% carbon steel or an absorbly composite equipollent. The SAAB AB engineers hereafter had to execute the most of cheaper excluding most cogent esthetics to maintain absorbs reprieveds coercion consumers of the districtal ardorartifice excluding peaceful possess a scanty and fuel causative aeroflatten to execute districtal interval with 30-40 passengers as per the peculiar project specifications.

The structural aspects of the ardorartifice are grave in making the SAAB 340 maximise its boundlessness and payload, the engineers hereafter had to with techniques love endeavor in cables and quickly purposed wings which conquer minimise burden excluding peaceful relinquish with close careering freprieved environing the fuselage and aerofoils as well-behaved-mannered-mannered as can be maintain passengers unendangered and consoled.

Aerodynamics

The SAAB 340, love integral new ardorcraft, is purposed to minimise haul whilst maximising elate. The SAAB AB ardorartifice reasons quick and mandatory aerodynamics and aerodynamical systems on their ardorcraft; a matchhither foot flatten, parabolic nose and fuselage cem and the wings shaping plus engine integration.

The SAAB 340 has a customary empennage, where the upright stabilizer has span calibre, exaltedlighted in image 4 of the postscript. SAAB AB has incorporated this project in the 340 and their 2000 train ardorcraft. The span stages in the upright stabiliser helps to fashion a advance unwavering and streamlined laminar freprieved edifice environing the stabiliser and future apportions coercion the rudder to be advance cogent in coerceling the ardorfreprieved environing it.

The SAAB 340 has a natural ardorliner title parabolic nose csingle which leads into a rectilinear spherical fuselage (minus the ‘V’ cem wing spring nacelles on the premise of the ardorcraft, shown on image 6). The parabolic nose csingle is greatly causative in having the ardor freprieved actuate environing the ardorartifice outmargin inducing abundant quantities if ardor hindrance and haul. Advance SAAB AB possess slimmed the alteration of the flatten into a subject-matter, natural of new ardorliners in an endeavor to possess the ardor freprieved hereafter extempore the ardorartifice in a reprieved haul streamlined edifice.

The SAAB 340 reasons a tapered, cantilevered, dihedral wing (as referableiceed aggravatehead) and has an equal cantilevered dihedral lifehither stabiliser twain of which possess aerodynamic elements of no winglets, smintegral methodward exceptional apex as well-behaved-mannered-mannered as the wings having been integrated with the engine. The stagnation there of winglets on the SAAB 340 exaltedlights how the engineers possess been talented to narrow the mixing of ardor from the summit and premise of the aerofoil. The accustomed pi of winglets conquer fashion a distribution, refertalented apportioning coercion the exalted and reprieved hurry ardor freprieved to fashion haul and vortexes. SAAB AB possess been talented to sculpt their aerofoils so that the want coercion a winglet has been frugal, a technique reasond by Boeing, on the 747 coercion development.

The SAAB 340 has to-boot integrated their GE turbofoundation engines into the wing project. This is intentionn in image 6 of the muniment distinctly in the face intention, where the engine has been “slotted” into the wing and has apportioned coercion the turbofoundation to be elegantly and aerodynamically causatively positioned to narrow the haul which can happen from having an engine depend extempore the wing.

This facile setup to-boot furnishs the influenceal functionality of the ardorartifice as the retracttalented inaudibleercarriage is to-boot integrated into the engine area. This innovative separation coercion SAAB AB engineers has apportioned coercion the ardorartifice to possess a retracttalented inaudibleercarriage excluding maintain inheritance on a extendway, giving the SAAB 340 aerodynamically causative fscanty and future fuel causative fscanty as-well.

The SAAB 340B+ differs from the 340B ascribtalented to its ample wingtips which apportions coercion it to be advance aerodynamically causative in advance spongy environments and to be talented to select extempore on shorter extendways, this departure in wing project of the contrariant models furnishs the ardorartifice affixed enhancements is verdant and districtal areas where the disappearance environment isn’t chimerical.

Propulsion

The SAAB 340 reasons GE turbofoundation engines with a 4-propeller foundation from Dowty Rotol or Hamilton Sundstrand, differences in sound furnishn in image 5 of the postscript. The SAAB 340B reasons the GE CT7-9B, pictured in image 6 of the postscript, which has an 1870 shp rating [5].

Image 8 a cutamethod of the CT7-9B turbofoundation [6]

The turbofoundation engine reasond by the 340 is greatly causative engine with exalted file coercion its greatness. The engine can press a acme 470nm with a acme whole burden in growth of 29000lb (select extempore) on inaudibleer 6000lb of fuel. The span engines can push the SAAB 340B and B Plus at 283 knots at an tallness of 25000 feet. Advance referableification on file and payload is in image 9 of the postscript.

The SAAB 340 has reasond contrariant engines balance the years, peculiarly extendning CT7-5A2 turboprops the vary to a CT7-9B led to an growth in the SHP of the engines, advance might, and an growth in fuel aptitude.

Advance so, it is of present hush that the SAAB 340B has had new engine and foundationeller deficiencys with REX district ardorlines in Australia. The deficiency of a Turbofoundation engine on the 23^rd of retreat 2017 and a foundationeller onfinaudible extempore mid-fscanty on the 17^th of retreat 2017. Equaltually ascribtalented to quick engineering on aid of SAAB AB the span flattens could press on single of the turboprops and execute a unendangered exigency planting. Thus, exaltedlighting twain the aerodynamic project description of the ardorartifice and how the GE CT7-9B engine can peaceful might the ardorartifice with merely half availtalented push.

Influence Exactments

The SAAB 340 exacts a extendway, horde and a coercionm of refuelling at destination/departure. Ascribtalented to the SAAB 340’s project the ardorartifice has been deliberately deceptive with districtal and verdant migration in memory where infraedifice is reprieved and basic future the 340 has built in facilities such as stairs and extra additions coercion the artifice to contend and effort in temperature of the terminals and on extendways made of gravel and sordidness.

The SAAB 340B has extras such as the gravel swarm and longer wingtips which alreprieved coercion it to work in spongyity and ebullition outmargin abundantr extendways or tardy asphalt ardorports [8].

The SAAB 340B exacts, at SL with optimal flaps and at ISA, a extendmethod of 4220ft (1.3km) equaltually at hither optimum environments the extendmethod wanted can be 6690ft (2.02km).

The SAAB 340 does exact 2 pilots and single fscanty partisan can be to-boot secretly of the horde. Die to the smintegral seating collection the SAAB 340 doesn’t possess extent coercion advance than single partisan. The sole scheme is shown bereprieved exaltedlighting where the horde is stationed on a natural 340 layout.

Image 10 SAAB 340 layout as planned by SAAB AB [4]

Protection Archives

The SAAB 340 has a rather amiable easily-under archives with merely impure disappearances extent in calamitousities, equaltually this is considered impure eras to pitch-headlongrs. The bereprieved ttalented executes hush of the impure calamitous easily-unders of the SAAB 340 [9]