Part 17 (1/2)

”VETTING” BY EYE--This should be practised at every opportunity, and, if persevered in, it is possible to becoht efficiency, stability, and control

The aeroplane should be standing upon level ground, or, better than that, packed up into its ”flying position”

Now stand in front of it and line up the leading edge with the e Their shadows can usually be seen through the fabric Allowance must, of course, be made for wash-in and wash-out; otherwise, the parts I have specified should be parallel with each other

Now line up the centre part of the main-plane with the tail-plane The latter should be syht each interplane front strut with its rear strut They should be parallel

Then, standing on one side of the aeroplane, sight all the front struts

The one nearest to you should cover all the others This applies to the rear struts also

Look for distortion of leading edges, es, tail-plane, and controlling surfaces

This sort of thing, if practised constantly, will not only develop an expert eye for diagnosis of faults, but will also greatly assist in i upon the memory the characteristics and possible troubles of the various types of aeroplanes

MISHANDLING ON THE GROUND--This is the cause of a lot of unnecessary daolden rule to observe is, PRODUCE NO BENDING STRESSES

Nearly all the wood in an aeroplane is designed to take merely the stress of direct co an aeroplane up fro it about, be careful to stress it in such a way as to produce, as far as possible, only direct compression stresses For instance, if it is necessary to support the lifting surface, then the packing should be arranged to come directly under the struts so that they may take the stress in the forned Such supports should be covered with soft packing in order to prevent the fabric fro, if possible, pull froe struts If necessary to pull fro the interplane struts as lon as possible Never pull by means of wires

Never lay fabric-covered parts upon a concrete floor Any slight movement will cause the fabric to scrape over the floor with resultant dae

Struts, spars, etc, should never be left about the floor, as in such position they are likely to become scored I have already explained the i the outside fibres of the wood Remember also that wood becomes distorted easily This particularly applies to interplane struts If there are no proper racks to stand theainst the wall in as near a vertical position as possible

TIME--Learn to know the ti jobs This is really inorance of this will lead to bitter disappoint is concerned, it will, to say the least of it, earn unpopularity with senior officers, and fail to develop respect and good here men are concerned

THE AEROPLANE SHED--This should be kept as clean and orderly as possible A clean, sy, and pride of work A dirty, disorderly shed nearly always produces slackness and poor quality of work, lost tools, and mislaid material

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[Illustration]

GLOSSARY

_The nue indicate the parts nuraation

=Aerofoil=--A rigid structure, of large superficial area relative to its thickness, designed to obtain, when driven through the air at an angle inclined to the direction of les to its surface Always cambered when intended to secure a reaction in one direction only As the term ”aerofoil” is hardly ever used in practical aeronautics, I have, throughout this book, used the term SURFACE, which, while academically incorrect, since it does not indicate thickness, is the ter surfaces, _ie_, the ”planes”

or ”wings,” and the stabilizers and the controlling aerofoils

=Aerodroround used for the practice of aviation It reallymachine,” but is never used in that sense nowadays

=Aeroplane=--A power-driven aerofoil fitted with stabilizing and controlling surfaces