SAA Orange Tail

September 1966

No. 33

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THE ROTATING EYE

A lady passenger once asked why the “noses” of S.A.A.’s aircraft were painted black. Like many other passengers, she was most interested to learn that behind this black nose there is housed the radar antenna and unit for studying advance weather conditions en route. This nose-cone, incidentally, is constructed of glass-fibre which is a non­conductive material and painted with a non-conductive black paint to eliminate adverse effects on the operating of the radar installation of the aircraft.

Scientists have proved that a bat, when in flight, squeaks out almost inaudible sounds of a very high pitch (frequency) which, when these soundwaves bounce back from an object in its path, warn the bat to swerve. This, they claim, is why the bat can manoeuvre in such a remarkable way.

Radar, the abbreviation for radio, direction and range, basically operates on the same principle and today performs an indispensable role in the world of aviation. It operates roughly on the principle of sending out radio pulses of an ultra high frequency in a beam. When some of these pulses bounce back from an object it is met by a receiving aerial and projected on a fluorescent screen in the form of a lighted “blip”.

The huge rotating antenna of the aircraft tracking radar installation at Jan Smuts Airport.

Various forms of radar exist, each developed for a very special purpose. The most common usages are for tracking moving objects and the study of weather conditions.

Present airborne weather radars as used on S.A.A.’s aircraft bounce centimeter-wave signals off precipitation particles to warn pilots of thunderstorm turbulence. A study made in the U.S.A. confirmed in quantitive terms that pene­tration by aircraft of Cumulo-nimbus clouds could be hazardous. The study produced examples of sudden altitude variations of as much as 5,000 feet by aircraft flying between 15,000 and 40,000 feet and demonstrated that if pilots were not prepared for turbulence of this magnitude, control of the aircraft may be lost.

At Jan Smuts Airport there is an excellent surveillance radar installation for tracking aircraft flying in the Johannes­burg Air Traffic Control area. This radar unit has an effective range of more than 100 statute miles and simplifies the task of Air Traffic Controllers in the identification and separation of aircraft. The airport at Cape Town can boast with G.C.A. (Ground Control Approach) radar, capable of assisting aircraft right down to the runway in poor weather conditions.

With the nose-cone removed the weather radar antenna of the Boeing 707 is clearly visible on this photo.

Scientists have now even gone so far as to develop radar for high-flying jetliners to spot clear air-turbulence. Severe clear air-turbulence, although rare, can cause passen­ger discomfort and there has been concerted effort in recent years to develop a practical in-flight warning system to meet this hazard.

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‘N BESONDERE BESENDING

Goedkeuring is onlangs vir die S.A.L. verkry om horingvliese (corneas) gratis vanaf Londen na Johannesburg te vervoer vir die St. John-ooghospitaal, waar dit by delikate oogoperasies gebruik word. Op die foto oorhandig reiswaardin Lenie Coetzee die eerste besending wat in bevrore vorm in ‘n vakuumfles vervoer is, aan die sekretaris van die hospitaal, mnr. Stuart Godfrey. (Foto Die Vaderland).

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A FRIEND INDEED!

In the April, 1965, edition of S.A.A. News was published an account of how Senior Captain Eddie J. Strick, while flying an S.A.A. Viscount from Cape Town to Johannesburg, guided a light aircraft back to Johannesburg from a lost position somewhere over Southern Transvaal and thereby probably saved the life of a fellow pilot.

Strange how history repeats itself!

On August 16, Captain Strick, flying a 727 at 35,000 feet from Johannesburg to Cape Town, listened in to a radio conversation between two S.A.A.F. training Harvards. It was then just after 9 o’clock in the evening. Captain Strick gath­ered from their frantic search for landmarks, that the two cadet pilots were lost and because of their low altitude and distance inland could not make radio contact with a control centre. Our obliging skipper immediately contacted the two cadets who informed him that one had only 8 gallons of fuel left whilst the other carried a hair-raising 5 gallons. Captain Strick kept circling high above the two Harvards and relayed messages for their pilots to Cape Town until the one per­formed a safe “belly-landing” at Calvinia and the other landed normally in the vicinity of Fraserburg. Shortly afterwards both cadets telephoned to confirm that they were safe and unhurt.

Once again Eddie-NICE WORK!

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RUGBYNUUS

Op die jaarlikse rugbydag wat op 11 Julie gehou is, hat sowel die Avionparkontspanningsklub se eerste- en tweederugbyspanne met lof uit die stryd getree.

Die eerstespan het vir die tweede agtereenvolgende jaar die Chris Wiid­trofee, wat toegeken word aan die beste span in die tweedeliga ingepalm. Die puntetelling van die wedstryd wat teen Groblersdal gespeel is, was 14-8.

Eerstespan

Op dieselfde dag het die lode van die S.A.L. se tweedespan geskiedenis gemaak toe hulle vir die eerste keer ‘n beker verower het. Hierdie spannetjie het afgereis na Villiers waar hulle teen die Eikenhofspan op die veld gedraf en die gesogte wisseltrofee ingepalm het.

Lugdiens se eerstespan is tans die voorlopers in die C-afdeling van die Transvaalse tweedeliga om die Bailey-beker, en het tot dusver 250 punte behaal teenoor 97. Terselfdertyd kan dear met trots verklaar word dat die tweedespan tans tweeds op die punteleer staan in die derdeliga van die Transvaal C-afdeling.

Tweedespan

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AIR SCOUT

It was at the tender age of 9 years that Mr. F. Mason, at present Instruc­tor Class 1, Technical Train­ing School, Jan Smuts Air­port, attended his first Wolf Cub Pack meeting, little realising that Scouting was to become his life-long hobby.

Mr. Mason, or Frank as he is known to his col­leagues, is today a Rover Scout Leader and what makes it the more interest­ing is that he is Leader of the only troop of Air Scouts in the Transvaal i.e. the 4th Benoni Air Scouts.

Lord Baden Powell, foun­der of Scouts, was relieved of his army duties to organise a means of training youth to become good citizens. How well he succeeded is evidenced by the number of Scouts through­out the world today. The theme adopted is revealed in the mottos of the three branches of the movement i.e. Wolf Cubs -”Do Your Best”, Boy Scouts-”Be Prepared” and Rovers­”Service”. In accordance with the “Boy Scout Handbook”, the training is concentrated on teaching “Team Spirit” and “Leadership”. After World War II a third branch of the Boy Scouts, namely Air Scouts was added to the then existing Land and Sea Scouts. To train the boys of the Air Scouts to fly would be too costly but they learn navigation, communications, aircraft recognition etc., and at the moment are busy building a workshop in order to learn how to overhaul aircraft engines. These boys have a distinctive uniform of blue berets, grey shirts and navy blue shorts.

Having concentrated for the past thirty years on the senior section of the movement, the Rover Scouts, whose ages range from 17 to 25 years, Frank tells us that this section is extremely interesting as one deals with youths who have just left school and find themselves in a new and strange environment.

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VLINDERTJIE

Mejuffrou Annette van der Merwe, een van die Suid-Afrikaanse Lugdiens se ontvangsdames te Port Elizabeth, het onlangs haar „vlerke” gekry toe sy vir haar privaatvlieëniers-lisensie gekwalifiseer het.

As lid van die Algoavliegklub, het sy na slegs 18 uur se afrigting alleenvlugte onderneem, wat as ‘n goeie gemid­delde vir ‘n damestudent in die winderige Port Elizabeth beskou word.

Agtienjarige Annette se familie is ware vliegentoesiaste. Haar vader, mnr. Schalk van der Merwe, is sekretaris van die Algoavliegklub en een van Port Elizabeth se geesdriftigste privaatvliegtuigeienaars. Wanneer Annette se vader met sy Ercoupe, ZS-BSJ sakereise onderneem, tree haar 11-jarige broertjie, Eric dikwels as navigator op.

Baie geluk met jou onderskeiding, Annette!

Mej. Annette van der Merwe afgeneem agter die stuur van die ligte vliegtuig waarmee sy vir haar „vlerke” gekwalifi­seer het.

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VEILIGHEIDSIN

Alle skepe wat op die oop see vaar dra reddingsbote, maar gelukkig word dit deesdae baie selde of ooit gebruik. Tog meet dit daar wees-net in geval! Dieselfde soort voor­sorgmaatreëls word ook getref vir vliegtuie wat daagliks reise oor die groot oseane onderneem en in die reël word meer as ‘n halfton reddingstoerusting aan boord gedra. Dit wissel van suurstofapparaat, rubberbote, vars water in verseëlde blikke, waterdigte vuurhoutjies en reddingsgordels tot klein radio-uitsenders, en vele meer.

Rubberbote of „dinghies”, sees hulle alombekend staan, word ook in die S.A.L. se vliegtuie wat reise oorsee onderneem, gedra. Hierdie bote, soos wat op die by­gaande foto verskyn, word in pakkies van 4′ x 18″ x 12″ verpak en weeg slegs 119 lb. Wanneer dit egter oorboord gegooi word, blaas dit outomaties deur middel van ‘n kool­stofdioksiedsilinder binne 20 sekondes op en kan dan 26 persone huisves. ‘n Ingeboude battery wat, sodra dit met see­water in aanraking kom, self oplaai, voorsien krag aan ‘n geel bakenlig be aan die dak van die boot. Hierdie lig kan oor ‘n afstand van ten minste 5 myl gesien word. Die boot het ook ‘n seildak, met twee openings, vir beskerming teen die elemente. Die twee openings kan toegetrek word deur middel van ‘n toutjie terwyl die seildak ook as opvanger vir reënwater dien.

So lyk een van die S.A.L. se 26-sitplek rubberbote wanneer dit opgeblaas is.

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TYRE TIT-BIT

Ever since the evolution of air transportation, bigger, stronger and better tyres have consistently been developed so that the work required of aircraft could be done safely and efficiently. As a point of interest, the largest aircraft tyre ever was manufactured in 1946 and measured 110 inches in diameter. Nowadays, however, aircraft tyres are relatively small in relation to the aircraft. The main landing wheel tyres of a Boeing Intercontinental, for example, have a diameter of only 44″, but exhaustive testing has proved them fully worthy of their task. Aircraft tyres have of necessity to be tough, having been specially designed to withstand the tremendous stresses and strains of many landings and take-offs. An average of 70 landings is done with each set of tyres on the Boeing 707, whilst the main landing wheels and nosewheel tyres of the Boeing 727 give about 100 and 130 landings respectively. There is a limit, however, to the load that any tyre can safely carry and as a result more wheels, some in pairs or set in bogies, are employed to obtain a wider load distribution. When a modern jet, such as the Boeing 707 touches down, its tyres undergo a marked change. It should be borne in mind that the airliner’s wheels are stationery before touch­down and that the aircraft’s gross weight is considerably increased as a result of the downward movement. At the moment of impact the tyres naturally will bulge, and puffs of blue smoke can be seen as rubber burns from the tyres. This explains the clear “footprints” on the runway. Apart from tremendous ! eat, tyres must also withstand extremely cold outside air temperatures, such as minus 56°C at altitudes of abolit 40,000 feet. It is the air within the tyre which helps cushion the shock of landing and facilitates smooth and spaedy take-offs. Tyre pressures vary from aircraft to aircraft and the load per tyre is normally calculated on the basis that the main landing wheels carry the total gross weight of the aircraft. Over-inflation can cause much faster tread wear, rough bumpy landings and extra strain on the landing gear. It further puts the tread and sidewalls of the tyre under tension and makes it more susceptible to cuts and wear. Under-infla­tion, on the other hand, has also harmful and potentially dan­gerous effects. Tyres are more likely to creep or slip on the rims on landing, or when the brakes are applied. It also causes rapid, uneven wear along the edges of the tread and there is more opportunity for the sidewalls to be crushed.

A nosewheel tyre of the Boeing 727 incorporating a special “chine” in the side­ walls for the purpose of deflecting water.

New techniques in aircraft tyre design are introduced from time to time. The nosewheel tyre of the Boeing 727, for example, has been manufactured to incorporate a special sidewall “chine” to deflect water away from the jet engine intakes.

With the staff of S.A.A.’s Tyre Section at Jan Smuts Airport rests the task to ensure that the “shoes” of S.A.A.’s aircraft are always in a sound condition. They undertake checks for cuts, bulges, skid burns, foreign objects embedded in tyres, wheel misalignment, uneven wear, correct pressures, rim cracks and scores of other examinations to obtain maxi­mum tyre life. Great care is exercised by the men of this section who see to it that tyres do not come in contact with oils, gasoline, hydraulic fluids, rubber solvents or any natural enemies of rubber, as a means to ensure optimum life for our aircraft tyres.

Safety and service are the primary considerations in aircraft tyre manufacture, regardless of the structural dimen­sions or physical features that are dictated by the speed, weight and purpose of the aircraft. It is a feather in the cap of the South African manufacturing industry that tyres which fully comply with these exacting standards are made locally.

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PERSONALIA

Mnr. W. Theron

Gelukwense aan mnre. R. G. Brett en W. Theron met hul onlangse bevordering as Bestuurder vir Italië (verhoogde gradering) en Stasiebestuurder (lugdiens), Kaapstad, onderskeidelik.

Ons wens albei here bale sukses an voorspoed toe in hul senior betrekkings in die Lugdiensdepartement.

Mnr. R. G. Brett

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