In the plan view, [Fig. 125], the distances AB and AC must be equal, the same applying to CD and BD. With modern machines external drift wiring is obsolete, so that discrepancies in these measurements must be rectified by alterations in the wiring of the fuselage, as it is inaccuracy at some point in the latter component to which the trouble may be ascribed. It is at this point that one realizes the need for precision in the construction of the fuselage. In [Fig. 126] is shown a plan view in which the main plane is very obviously out of square with the centre line of the body, the amount is not likely to occur in actual practice, but it has been exaggerated in the drawing. The cause of this trouble can be traced to the short wing spars in the fuselage, to which the lower plane is attached, or in other cases to the fittings, to which the lower plane is anchored, being out of centre, possibly only an insignificant amount. The lengths of the fuselage wing spars are also possible causes of trouble. Assuming that the rear spar is the correct length, and the front spar is over the length, this would result, when the outer sections were attached, in the latter sloping backwards, which again emphasizes the need for accurate part production.
Fig. 126.
With regard to the tail plane, measurements taken from the extremities of the back spar to some fixed point forward on the fuselage, to the strut sockets on the planes, or to the rear wing spar anchorage, as in [Fig. 125], should be equal.
The primary consideration with regard to the rudder and fin is that, viewed from the rear, they should be perpendicular, which can be verified by a plumb-line dropped from the top of the rudder-post. In plan view the fixed fin should correspond with the centre line of the fuselage although there are exceptions to this rule, notably where the fin is set over, to neutralize propeller torque, and in this case the measurements given in the general drawings must be adhered to.
Tension of Wires.
The correct tensioning of wires is a matter upon which some variation of opinion occurs. Although wires should not be left slack, conversely they should not be over-tensioned, as this results in the spars, wires, and struts, being initially stressed before any load due to flight is applied. In this connection the importance of even or uniform tension in the wires may be emphasized. The wires in one bay being of greater tension than those in an adjacent bay, is the frequent cause of bent or deformed struts. The more extended use of a tautness meter for the interplane wiring would result in greater uniformity and the more equal distribution of stresses.
INDEX.
- Aileron and warp control, [101]
- Aluminium, [16]
- Anchorage of wires to eyebolts, [55]
- Ash, [10]
- Ash, weight of, [10]
- Axle fairings, [98]
- Biplane trussing, [62]
- Birch, [12]
- Birch, weight of, [12]
- Brazing and welding, [52]
- Bridge-type undercarriage suspension, [98]
- Control systems, [101]
- Control by inherent stability, [102]
- Control, vertical column, [103]
- Control, wheel type, [104]
- Control, the “Dep,” [106]
- Control, the “Wright,” [107]
- Control surfaces, balancing of, [102]
- Cypress, [13]
- Drift bracing, [65]
- Drilling of bolt-holes, [124]
- Duralumin, [17]
- Engine mountings, [116]
- Engine mountings, rotary, [118]
- Engine mountings, overhung, [119]
- Engine mountings, stationary, [121]
- Engine mounting materials, [117]
- Erection and alignment, [123]
- Fabric, attachment of, [47]
- Fabric, sagging of, [40]
- Fabric, tension of, [48]
- Fabric, friction blocks, [49]
- False ribs, [41]
- Fineness ratio, [26]
- Fuselage construction, [67]
- Fuselage covering, [71]
- Fuselage contours, [75]
- Fuselage erection, [127]
- Fuselage fittings, [77]
- Fuselage struts, [28]
- Fuselage types, [67]
- Glue, defects of, in wing spars, [33]
- Hickory, [11]
- Interplane struts, tapering of, [26]
- Interplane strut connections, [51]
- Leading and trailing edges, [43]
- Lift wires, anchorage of, [62]
- Locking of bolts, [125]
- Longerons, [68]
- Longeron sections, [69]
- Longeron, jointing of, [70]
- Longeron, shaping of, [69]
- Mahogany, Honduras, [11]
- Mahogany, Honduras, weight of, [11]
- Mahogany, Cuban, weight of, [12]
- Main planes, truing of, [126]
- Main spars, shaping of, [32]
- Materials, [6]
- Maurice Farman strut arrangement, [62]
- Metal construction, general, [4]
- Metal wing construction, [45]
- Methods of manufacture, general, [3]
- Moisture content of timber, [8]
- Monoplane bracing, [60]
- Monocoque fuselage construction, [72]
- Multi-ply wood, [13]
- Oleo-pneumatic gear, [95]
- Oregon pine, [12]
- Parang, [13]
- Piano wire bracing, [108]
- Piano wire connections, [109]
- Plane construction, [30]
- Plane construction, details of, [40]
- Planes, arrangement of, [33]
- Poplar, [12]
- Pratt truss, [59]
- Raked wing tip, efficiency of, [43]
- Ribs, spacing of, [40]
- Ribs, types in use, [34]
- Ribs under compression, [36]
- Shakes, [14]
- Shrinkage, [7]
- Silver spruce, [8]
- Silver spruce, weight of, [8]
- Single-strut truss, [63]
- Spar construction, hollow, [20–22]
- Spar, laminated, [19]
- Spar sections, [19]
- Spars and struts, [18]
- Spruce fir, [9]
- Standardization of details, general, [2]
- Steel, [15]
- Steel tube, [16]
- Steel-tube fuselage construction, [84]
- Stranded cable, [109]
- Stranded-cable connections, [111]
- Streamline wires, [113]
- Streamline wires, attachments, [113]
- Strut sections, [23]
- Strut sections, design of, [26]
- Strut materials, [25]
- Strut socket, “Wright,” [53]
- Strut socket, “Cody,” [53]
- Strut-socket fairings, [58]
- Suspension springs, steel, [95]
- Suspension springs, rubber, [97]
- Tabulated tests, unreliability of, [8]
- Three-ply fuselage construction, [71]
- Thunder shakes, [11]
- Timber, defects in, [14]
- Trailing edge, wire, [43]
- Twisted grain, [14]
- Undercarriage brakes, [99]
- Undercarriage details, [93]
- Undercarriage, principles of design, [86]
- Undercarriage skids, [93]
- Undercarriage types, [89]
- Walnut, [11]
- White deal, [9]
- Wing baffles, [44]
- Wing fittings, attachment to spars, [51]
- Wing-tip construction, [39]
- Wing-tip details, [38]
- Wing-trussing systems, [59]
- Wireless wing structures, [61]
- Wires and connections, [108]
- Wires, results of tests on, [109]
- Wires, relative strengths of, [112]
- Wires, tension of, [134]
- Wood, choice of a suitable, [6]
- Wood, variable qualities of, [6]