FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1957
1957 - 1425.PDF
:i September 1957 515 while the new Mk 10 receiver and power unit weighs 83 lb.The total weight of a Dectra installation is about 146 lb, but much of this is common to both systems, so that a combinedDecca-Dectra installation should not weigh much more. Now comes D.I.A.N., the joint product of the Decca Navigatorand Radar companies. Recognizing that as yet Decca and Dectra have not achieved universal coverage and that a certain amountof ionospheric effect exists which can, at its worst, be only minimized (unless special anti-static aerials are fitted), the D.I.A.N.system incorporates in one integrated installation both Decca- Dectra and Doppler radar. The significance of such an installa-tion can well be gathered when one considers that the Decca element consists of the non-ambiguous Mk 10 receiver, alliedwith a Dectra receiver, together with associated computers, con- trol boxes and power supplies, feeding a single Flight Log; andthat this same Flight Log is also fed by the Doppler element when in use. Thus a complete hyperbolic aid covering all stagesof a long flight from terminal to terminal is available, with com- plementary information from Doppler, which is independent ofground installations. Thus, on leaving Decca or Dectra coverage the Doppler element is used to maintain the presentation on theFlight Log. Doppler by itself is not accurate enough to be comparable withDecca or Dectra, since cumulative errors are present; but at the same time, the error factor is not large enough to cause anyserious objection. It is not, however, suitable for A.T.C. pur- poses because, being independent of ground installations, errorsare peculiar to each and every installation and are not constant in magnitude or nature. Other valuable facilities provided by theDoppler element of D.I.A.N. are the display of wind velocity (if T.A.S. information is used) together with groundspeed, track,drift and ground miles flown. Two meters display this informa- tion, together with position co-ordinates, independently of theFlight Log display. The accuracy of the Doppler element is given as being better than one per cent, assuming no compasserror. The weight of the basic Doppler element is only 69 1b. Tothis must be added the common pictorial display and its control box, which serve all three elements of D.I.A.N. The Deccaelement weighs, complete, 101 lb 3 oz, including control box and aerial amplifier. The Dectra section of the installation weighs33 lb lj oz, while to the combined Decca /Dectra elemental total must be added 3 lb 10^ oz for the three Decometers. Thus,the weight for the complete D.I.A.N. installation is 223 lb or less. This is a small penalty to pay for the services provided.D.I.A.N. probably constitutes the most completely acceptable universal navigation system available or projected in the worldtoday. D.I.A.N. with Decca and Doppler weighs only 190 lb. Comparatively recently developed, and of interest to com-mercial operators, is the Standard Telephones and Cables, Ltd., SR 32/33 installation, which combines I.L.S., V.O.R. and markerbeacon facilities. Such equipment is useful in view of the fact that V.O.R, is being increasingly installed throughout the worldas the present I.C.A.O. standard, while I.L.S. is the standard approach system. It is obviously desirable to integrate as far aspossible; and I.L.S. and V.O.R. lend themselves to this admir- ably. Whatever main navaid is carried on the aircraft, a sound"backer-up" is always necessary and V.O.R. may well be the obvious choice, especially since the number of medium wave non-directional beacons in operation is being steadily reduced. The installation consists of the SR 32, including a combinedlocalizer/V.O.R. receiver, a glide-path receiver and a power unit. Associated with this is the SR 33 marker beacon receiver. Thecontrol unit is interconnected with the various receivers in such a way that the appropriate receiver for each frequency is auto-matically selected. Thus, when a localizer frequency is set up on the control unit, the appropriate glide-path frequency will beselected at the glide-path receiver without any further action. A normal V.O.R. bearing indicator is used, together with anI.L.S. cross-pointer and marker lights. The SR 33 marker receiver is controlled independently, for receiving fan markers onairways or in I.L.S. systems. V.O.R. information can be supplied to a radio magnetic indicator. The total weight of the SR 32/33,including R.M.I, coupling, is just over 100 lb. A similar recent development is the Marconi AD.704/706/708developed jointly by the English company and its Australian asso- ciate, Amalgamated Wireless (Australasia), Ltd. This installation,at 83.1 lb, has an advantage in weight over the SR 32/33. It pro- vides the same services and, apart from slightly different powerconsumption and dimensions (again somewhat in favour of Marconi's), there is little to choose between the two. On the subject of approach and landing, mention must be madeof the Standard Telephones and Cables Precision Approach Radar Type SLA.3-B/2. This is the only G.C.A. equipment beingcommercially produced in the U.K.; and although earlier versions have been adopted by overseas governments, there still exists acurious reluctance on the part of the M.T.C.A. to adopt anything in this line that smacks of development. A new G.C.A. is being'"stalled at London Airport, where it is very much needed, but it The Marconi SR.1000 radar self-contained transmitter/receiver and power supply cabinet, shown fully opened for easy direct access. is believed to have been designed by the Ministry's own radiobranch, and little is known about it. The SLA.3—B/2 is a simply interpreted and operated P.A.R.system using conventional techniques, with P.P.I, azimuth and elevation presentation on two tubes. The operator is normallystationed in the control tower, and reads directly off both. Elevation information does not have to be passed to him second-hand by the tracker, as in the case of the earlier G.C.A. The two 17-inch cathode ray tubes are mounted one above the other inthe same console, the elevation one being uppermost. Alignment of the tubes is such as to bring the range markers into coincidencein the vertical plane. The scan-sectors are ±10 deg in azimuth and from —1 to +6 deg in elevation; and a clear return from aircraftof 15 square metres echo area or larger will be received within these scan sectors at a range of at least nine n.m. from the radaraerials. The performance of the SLA.3—B/2 is at least as good as that required for P.A.R. equipment given in the Third Edition(1.12.52) of International Standards and Recommended Practices for Aeronautical Telecommunications (Annexe 10 to the Conven-tion on International Civil Aviation). Ekco were among the companies showing new equipment atFamborough, in the shape of their E.160 airborne search radar. Such radar is now considered to be of considerable importance;and the new E.160, which operates in the X-band, has been specified for the latest types of transport aircraft, including theComet 4, Vanguard and Boeing 707 (Britannias are normally fitted with the earlier E.120). Both these systems incorporate the iso-echo contour facility, by which extreme-turbulence cores within cloud returns can be distinguished from non-critical precipitationreturns. Since the pros and cons of the old X- versus C-band argument still remain unresolved Ekco have designed a C-bandsystem for those who prefer it. A.D.F. equipment—used almost universally—has undergoneconsiderable development over the past year. The Marconi AD.7092 series of units is by now more than just well known,being in widespread airline and Service use. A recent Marconi innovation is the AD.712, which has been designed for direct,simple operation by the pilot. It is exceedingly compact and provides for both automatic and manual D/F, range and Consolreception. Tuning is accomplished by selecting the required frequency on a dial like the latest V.H.F. tuning units. Crystalcontrol of the AD.712 ensures accurate tuning with the minimum of manipulation; the loop aerial is non-moving and housed in anear-flush plastic fairing. Another new Marconi A.D.F. is the sub-miniature type AD.722. Again, simplicity of operation is thekeynote, and the whole weighs only 24.2 lb including the loop aerial. It is intended for single-seat fighters. Shown for the first time in public at the S.B.A.C. Show wasthe Marconi AD.2000 Doppler Navigator (described in Flight for July 12). The later AD.2100, intended for mounting in an extern-ally carried pod, was also given its first public view. Details of the civil AD.230O Doppler navigator were given in Flight for June 21and July 12. Many new surveillance radars for traffic control have beenintroduced and developed over the last few years, ranging from the comparatively short range A.C.R. (Airfield Control Radar) to
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
