FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1967
1967 - 0095.PDF
ftlGHT Internationa/, 19 January 1967 93 LIGHT-AIRCRAFT ELECTRONICS Official requirements, and equipment to meet them : a^'Flight" review CHOOSING ELECTRONIC EQUIPMENT for a light aircraft is abewildering enough exercise, owing to the sheer quantity, of the offerings by manufacturers—and for the British purchaser the task is only partly simplified by the Air Regis- tration Board classification system. This method of grading according to the intended operating circumstances is by no means a complete guide to the quality of equipment—most of which is made in America, where certification standards suit the operating circumstances. The problem for the ARB is that American law does not specify any standards for radio equipment used in private air- craft (in practice, thanks to the competitiveness of the market, poor-quality equipment soon goes to the wall). So in Britain, where operations are on a comparatively small scale and there is not so much dissemination of experience among the piloting community, regulations are framed to specify standards according to intended usage. Not surprisingly, this leads to apparent anomalies; for instance, cheap equipment may seem as reliable as more expensive equipment in the same Class. Thus, although equipment may have ARB light aircraft radio Class 1 approval (for IFR controlled airspace operation by private or public transport aircraft under 12,5001b gross weight) all such equipment is not made to the same standards—witness the enormous discrepancy in Class 1 equipment prices. How much should one pay for electronic equipment? The question seems to boil down to a matter of how much utilisa- tion and degree of regularity one expects to get out of an aircraft. For the private owner with an instrument rating who flies just a few hundred hours per year and is prepared to accept delay in order to avoid flying in really bad weather, then the lower-priced units would be quite satisfactory. For best possible regularity in all weathers, one would, of course, choose "Fully Approved" equipment (for unrestricted use in aircraft of any weight) or—to almost the same standard—the better Class 1 equipment. For the non-instrument-rated pilot having experience and training in blind flying and procedures, the cheaper Class 1 equipment is of interest for "Special VFR" in those countless situations in which weather fluc- tuates between IMC and VMC. What amount of equipment is desirable? For IFR in con- trolled airspace the law broadly requires that an aircraft should carry the following: a VHF communications transceiver with the appropriate frequencies; dual VOR (one of which may be the receiver element of the com unit); an ADF; and a marker beacon receiver. A Decca hyperbolic navigation system receiver or Gee are optional alternatives to VOR/ADF for use in British controlled airspace. ILS is specified for landing at certain airfields. The full requirements are spelt out in the Air Pilot RAC Section Chap 7. Although there is no legal requirement to fit either an autopilot or weather radar, both are finding increasing adoption. An autopilot of some sort makes single-handed IFR a far safer and less tiring operation: even a simple wing-levelling device gives a pilot a better chance to pay proper attention to chart reading and calculations. Weather radar, again not specified for light aircraft operations at low level, can be invaluable for regular flying along a route where thunderstorm activity is frequently strong. Above all, the choice of equip- ment is a compromise between cost and weight, yet the right amount can make all the difference to safety and peace of mind. Below is an article on the fitting and maintenance of equip- ment, and it is followed by tables detailing new equipment available on the British market. FITTING AND MAINTENANCE BY K W. B. FOUWEATHER IN THE UNITED KINGDOM the Air Registration Board, by dele-gation from the Board of Trade, is the authority responsiblefor the approval of radio equipment, its installation in air- craft and the applicable maintenance requirements. Minimum performance requirements are issued by the Board of Trade in document CAP.208. The majority of equipment in use and being installed in light aircraft is of American manufacture. There is consider- able variation in performance and manufacturing standards; and, as the Air Navigation Order requires all radio equip- ment to be type-approved in relation to the purpose for which it is to be used, an approval procedure had to be instituted. To accommodate this type of equipment, which is not formally approved in the country of manufacture (but which complies with international requirements for frequency stability and spurious emissions), the Light Aircraft Categories Class 1, 2 and 3 were introduced for radio equipment installed in air- craft not exceeding 12,5001b gross weight. Class 1 equipment is without operational restrictions and may be used for VFR or IFR flight in any kind of airspace, provided that it has adequate frequency coverage and number of channels for the particular area in which the aircraft is to operate. It may also be used for any of the purposes specified for Classes 2 and 3. Class 2 equipment (at present only VHF communication is approved in this class) may be used outside controlled airspace under VFR or IFR for communicating with ATC units at airfields where it is a normal condition of use of the airfield, •xtremes of equipment installations in light aircraft: left, a single-engined two-seat Cessna 150 with a Cessna-Crafted (ARC) communications ransceiver with integral power-pack. Right, the eight-seat Beagle B.206-S with ARC equipment: dual VHF com and dual nav receivers md ADF, all with remote power packs; the Sperry SPL.4S autopilot controller is of an earlier type
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
