Air Safety

Written when the infant airline industry was literally feeling its way in instrument flying, it provides a rare insight into all weather operations before the advent of radio aids, ATC, meteorological services, formal /FR training, or even flight plans. It also presents a fascinating perspective from which to consider Shortridge’s last fatal flight as captain of ANA’s Southern Cloud, lost in severe weather less than a month after his paper was published. As such, it contains some ominous safety messages for would-be “unofficial” instrument pilots today!

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The problem of blind flying has occupied the minds of aviation experts all over the world. Its many difficulties must be overcome by the average pilot to make commercial flying really safe.

Modern instruments are of a very high standard, and most pilots can be trained to fly blind by them. It is not a difficult art to be mastered by a select few, but within reach of any pilot possessed of common sense, aptitude for serious methodical practice, moderate flying experience, and a humble opinion of his own skill.

The instruments necessary are practically those already familiar to the average pilot: airspeed indicator, altimeter, lateral inclinometer, rev counter and oil pressure gauge, compass and watch. To these may be added the turn and bank indicator, and the longitudinal inclinometer essential for blind flying.

The placement of the instruments on the dashboard is almost as important as the instruments themselves. They should be positioned to be read in a definite direction, and in order of importance- “airspeed and direction” being considered first. The instruments should be switch illuminated, particularly the compass, which should be fitted so as to be seen at a glance.

It is essential that a pilot have implicit faith in his instruments, patience and the ability to concentrate, commonsense, and a thorough understanding of aerial navigation and compass flying. Unless a pilot can keep a perfect compass course, he will have great difficulty in blind flying. Therefore:

• Practice flying compass courses in clear weather. Vary this by climbing and gliding, remembering that an absolutely accurate course must be kept.

• Practice changing to pre-arranged courses to become familiar with the compass action under all changes of direction.

• Extend this to elementaiy cloud practice in single clouds, cloud banks, then cloud layers, always by compass on definite courses.

• Spin into, through, and out of clouds.

Unless a pilot is able to spin unconcernedly out of a cloud, then whip into control with minimum loss of height the moment his eyes focus on anything, he will forfeit valuable height if he ever happens to lose control while flying blind. Use common sense to achieve safety by: • Ensuring there is plenty of ceiling between the bottom of the

cloud layer and the top of the highest ground.

• Sticking to a set procedure on losing control to ensure no loss of time in regaining it.

• Carefully checking all courses flown and time on each, in case you get lost.

• Noticing drift, and the difference in ground speed when flying upwind and downwind.

• Not being tempted into flying blind for extended periods until you are really good over short ones.

• Being guided by advice from old hands. Remember it is their experience talking-not lack of nerve. Avoid pig headed bravado. • Getting as much practice as possible in bumpy weather. Bumps make blind flying very hard.

It will probably be useful now to describe all that has to be done on a cross country flight involving bad weather, blind flying, ice, snow, vertical gusts – and all those other things sent to try a pilot! Among other things necessary is a knowledge of:

• Map reading and course setting.

• Topographical features of the course to be covered.

• How to plan well ahead so as to be prepared for every situation before it arises – a good pilot is never in doubt.

• Elementary meteorology.

Before the flight

• Mark off on the map the course to be flown: measure distance, and for convenience mark off stages in tens of miles.

• Work out compass courses for each stage, from the starting point to each stage separately, and back bearings for each of these. (This reduces the amount of calculating and thinking to be done in the air).

• Estimate the time each course will take in still air ( allowance for winds will have to be made in the air).

• Mark off outstanding features on the map for easy recognition – railways, bridges, churches, crossroads, etc. In flight these should be constantly checked to determine progress.

• Work out a table with columns showing: course and distance for each stage; estimated time of arrival at each, with a column to show actual time of arrival; speed and direction of wind by observation; ground speed made good over each stage; height above sea level of high ground; height of departure aerodrome above sea level; height of destination above sea level.

• Study the layout of the country and select alternate routes for use in bad weather, safe areas over which to risk descending through cloud, likely forced landing country, and location of landing grounds.

• Try to get reliable weather reports, particularly of your destination. ‘Frequently a knowledge of weather ,conditions at the other end of the trip helps one to decide, on meeting bad stuff en route, whether to try and get through below it, go above it and fly by compass, or turn back for home.

Before taking off

• Set the altimeter to the height of your aerodrome above sea level. Heights of aerodromes and en route high ground are most important in cross country flying.

• Set the compass to the course you are to fly, noting the direction and angle through which your machine must be turned to take up that course.

• Note the actual time of taking off. If you are taking off into bad weather with the intention _of climbing through it, know exactly how you are going to with the situation until you are out of the danger zone of the first 2,000 feet- or that height above ground necessary for safe control. Remember that once off the ground you must help yourself; all the prayers in the world won’t keep you straight and level if you have let your bravado, false pride, cussedness, or Just plain blithering idiocy tackle more than your experience can handle.

In flight

Let us presume the weather is dirty, but there . . . Is a ceiling of 1,000ft over the takeoff spot. Faced with deciding either to get through below the clouds, or to climb above them and go by compass, one realises the choice is affected by the ground ahead. Hills of more than 1,000ft automatically wash out staying below the clouds. To those persistent beings who always want to “give it a go”, I can only offer this golden rule: unless you can see

a definite gap between the bottom of the cloud layer and the top of the high ground ahead of you, you should not try to get through under the clouds.

Do not be trapped into going up valleys, or following roads or railway lines. valleys frequently have dead ends – and you may not have enough room to turn back: roads have eventually to cross the high ground that is in the way, and railways frequently run into tunnels – even folding wings won’t help you if you don’t spot that tunnel in time!

So it must be climb up through the clouds and go by compass. Briefly, this is what you must do:

• Know your best climbing speed.

• Gain as much height as you can over the aerodrome.

• Get to the far side of the aerodrome and steady up on your course before entering the clouds.

• Have all your instruments set and steady, and start flying by them before you actually go blind. This will help you get your natural balance quickly.

• Note the actual time, and once blind, try and maintain a steady flight and correct course, gaining height all the time.

• Patience and determination are required because, when leaving the ground the ‘bus is invariably fully laden, climbs slowly, and being low, is bumped about. Frequently clouds go up to

12 000 feet and whether to climb up there or not depends upon the nature ‘of the country ahead and the urgency of the job.

Having got over the initial bumps on entering the cloud, don’t get excited don’ t over control – and believe your instruments! When in doubt owing to very bad bumps, check the instruments on a pre-arranged system with due regard to the special requirements of an aeroplane in trouble – speed!

Have faith in your machine. Remember that modern aeroplanes are designed for stability, and that with the speed controlled they almost fly themselves. Avoid jerky control movements and remember your early flying training of rudder and bank used separately. ” Never hurry! If the machine should swing hard or drop a wing, put on the necessary opposite control and give her time to recover. If in doubt straighten out – ie, centralise all controls. If in addition you put the stick forward slightly to preserve speed, the machine must straighten out.

Get everything balanced, and let your eyes wander about the instruments. Avoid focussing on any one. When the ‘bus is stable and almost flying herself, keep an eye on the compass. It will immediately show the slightest swing, and one soon learns how to use rudder and bank quickly and correctly.

The airspeed and fore-and-aft bubble are a sturdy combination to ensure speed, and the feel on the stick is easy to acquire. All one needs to do when in trouble is to lean forward on the stick, watch the airspeed, listen to the wires howling, then lean back when the needle and the howl show a safe speed- and finally get your wings level again.

But if it is really bumpy and everything . . . . , Is on the Jump, life s song is not so sweet and it is then one appreciates the value of early practice on instruments. It is hard to check bumps and keep a steady course, as the instruments all begin t? jump, bubbles hurtle sideways, and everything has to be put right at once. It is then also that one appreciates the importance of the compass.

Provided the course can be kept absolutely steady, everything else can be put right. A wing advertises a bad drop, and a stall is felt coming long before it arrives. Speed and level can be assured, but it is much easier to control them when rudder Is not causing the ‘bus to skid, thus putting on bank as well.

With experience a pilot is able to decide on a safe height, say 2 000ft above the highest point to be crossed and, having got there to continue blind ad infinitum. In time one is able to alter height at will and forget that one ever di? anything else but fly blind- the feeling of certainty and safety Is a very pleasant one.

“Snags” – and how to cope with them

. . Naturally, winter is the worst season. In add1t1on to gales and rain one has to contend with snow, hail, ice, fog, low clouds, and layers thousands of feet this the joys of leaving the ground with the prospect of going blind In the first fee feet, not knowing how high the clouds extend, but with route thousands of feet high. Only then does one realise the

importance of the hints on “before leaving the ground”! .

Having got off, the first few minutes staring at compass, _airspeed and altimeter to get that first 1,000:t are an agony of min?. Bumps, rain, cloud, moisture, darkness In the cushion, trim either nose or tail heavy- everything Is wrong and even the engine seems to falter for spite. The compass starts to rotate when everything else seems right and an awful suspicion is awakened that it is dud. At 1,000ft at last, and one realises the moisture round one’s neck is not rain!

Have you an air safety story to tell? Particularly one with a

lesson that might save other pilots from making a similar

error of judgement? If you have, write to Macarthur Job, cl- Australian Aviation, PO Box 3105, Weston Creek, ACT

2611. Contributors to this series are assured their anonymity will be fully respected!

Height is no guarantee against bumps in stormy weather, and make life very hard. Speed always helps to reduce bumps, but the difficulty is to maintain height while getting that extra speed. This is of the utmost importance until one is clear of danger from surrounding high spots. It is wiser to fly 20 miles (32km) in the opposite direction to gain height over flat country, rather than to gain it on course over rising country. As the altimeter shows 2,000, 3,000, 4,000, and still increasing, one feels ever so much happier. Also, feel and balance have arrived, and life is not so hard after all.

The next snag is temperature. Moisture from the clouds and rain is caught in every nook and cranny of the machine, and as the temperature decreases with height, freezing starts. Having started, it continues fast – ice thickens rapidly, and the places where it forms are innumerable and extraordinary. One has seen pushrods and valve springs encased in cylinders of ice, prop bosses so thickly covered that the ice looks like a spinner; petrol pipes, undercarriage, wings, wheels – every possible place covered with rapidly increasing ice. Imagine the weight of ice half an inch thick covering an Avro Ten’s giant wing, with its span of 72ft (22m)!

Heavy snow is a decided danger because it lodges where water will not and its weight can soon become too much. It is very easy for a careless pilot to be caught low over hilly country, run into a snow storm, and quickly find he is losing height. Full throttle may keep what height he has got, but it makes engine trouble more likely. A wise pilot studies the weather ahead and has an alternative route worked out.

Descent

All pilots agree that the real snag in blind flying is coming down again. It is the good pilot who studies the end of his trip as well as the beginning. This is where the art of blind flying comes in, and where a feeling of either confidence or “the wind up” can be transmitted to passengers. Many pilots just throttle everything back, stuff the nose down, give passengers earache and heart failure, and send up a few short, sharp prayers. Then when they see the ground, they pat themselves on the back and tell the world it was a good show – never realising the lesson or taking warning from the experience.

Decide to what height you can descend in safety, allow a safe margin, particularly over undulating country, and remember to exercise the utmost care if you are down to 1,000ft and still blind. The ideal destination is in flat, low country, or on a coast. The hazard of coming down is then practically removed, except in very low, dirty weather or fog.

Having decided to go down, throttle slowly back to about a quarter throttle or perhaps a little less, making the glide as flat as possible to avoid giving passengers that diving feeling. Keep a sharp lookout downwards, keep dead on your course, watch the altimeter carefully, and be especially alert as you approach 1,000 ft. Leave enough revs to enable you to get your engine in a hurry and not risk choking it, and glide slowly just above stalling speed for two reasons:

• If you have made a mistake you won’t hit the ground quite so fast or hard.

• There is less “lag” on the altimeter in a slow descent, and you get a more correct height reading.

Don’t take chances, and remember that if your destination is a coastal one, you can climb up into safety and go out to sea if you are in doubt about your ceiling.

Don’t dive through the first hole you see – it may be on the edge of a hill which remains obscured. Also, the moment you turn you lose your course – and you may lose your sense of direction too. When the moment seems opportune and you do turn, fly round the hole and try to peep under the far edges. On going down, try and circle around inside the hole over the same spot. Pick a landmark as a guide, and watchfor any high ground. On coming down to the cloud base,don’t be in a hurry to straighten out. Continue to circle down until you have a clear view all round, straighten up on your landmark, check your course, and continue by low flying, providing always there is that gap “between the bottom of the clouds and the top of theground ahead of you”.

Let us now consider the problem of a descent through clouds over a coastal destination, with mountain ranges up to 3,000ft running parallel with the coast up to 50 miles inland – conditions typical of the Australian coastline.

The first likely error is the miscalculation of ground speed, particularly in strong winds. It is always wiser to underestimate ground speed in a headwind. For example, if the 3,000 foot ranges are 30 miles (48km) from the destination aerodrome, and the estimated time of arrival is 1200 hours, an error of five mph (4. 3kts) after a four hour flight will mean the pilot has cleared the hills by a margin of 10 miles (16km) and is 20 miles (32km) short of the aerodrome. But an error of 10mph (8. 6kts) would make a difference of 40miles (64km) and he would be 10 miles(16km) short of the 3,000 foot barrier. His best policy would be to reduce his estimated ground speed by five to 10mph (8. 6kts) to be on the safe side, and to make 3,500ft his minimum safe altitude for his first descent.

On descending to this height and finding himself still blind, he should climb up to 4,000ft again and maintain course for a reasonable time, according to the wind and estimated ground speed.

High ground will slope gradually towards the coast-there will probably be undulating ridges, hillocks up to 2,000ft, and many other traps for the unwary. These all have to be considered when risking a descent below a known height. Also, an off-sea wind at 3,000ft at gale or greater force will knock ground speed down to an alarming extent. For example, Seymour is approximately 50 miles (80km) from Essendon aerodrome, and 414 miles (666km) from Mascot. The writer has done Mascot-Seymour in three hours 40 minutes, or 113mph (98kts), and then taken a further one hour 15 minutes to do Seymour Essendon, a ground speed of 40mph (35kts)! It is therefore essential to err on the side of caution. No rule is infallible, but the following is suggested as a guide: • On reaching estimated time of descent to 3,500ft, and still being blind on descending to that height, climb back to 4,000 and keep the same course for a further 15 minutes.

• Make the second descent to 3,000. If still blind, go back on full throttle to 3,500 and keep course for a further 10 minutes.

• Make the third descent to 2,000ft, but exercise the greatest caution once below 3,000.

The all important factor is course. Imagine coming down to 2,000ft five miles (8km) on the safe side (ie the sea side of the 3,000 foot hills), then allowing your machine to get off course and turn inland and downwind. It won’t take long to cover five miles withyour sudden jump from say 65mph (56kts) to 125mph (108kts), allowing a cruising speed of 95mph (82kts) and a wind of 30mph (26kts)!That is why we cannot stress the importance of the compass enough. Bank and turn indicators will keep you in control, but you must use your compass for direction.

Having descended to 2,000ft and still being blind, I suggest a climb back to 2,500. The extra 500ft being an allowance for hillocks etc, and fly a further five minutes on the same course. Now the reader will remark that the time allowance is already 30 minutes more than the estimated time, and that the pilot is probably well out to sea. Maybe so-but only maybe.

Having done the extra five minutes, the time has now come for a final decision. All things being equal, and 2,000ft having proved safe once, it is permissible to assume that 1,000ft should be safe if very carefully prospected from 1,500ft. If still blind on getting down to 1,000ft, one is rather in a dilemma. Half an hour’s extra time should be enough, but the wind may be stronger: the estimate of time may have been wrong to start with; one may still be over low hills, and 1,000ft above sea level may not be much after all. Remember too, the likelihood of cliffs.

The chances are that one is already over the sea. But what matter if one comes out 50 miles (80kms) out to sea? The course for home is now downwind, with a ground speed of 125mph (108kts)-a little less than half an hour in absolute safety, barring most unlikely accidents. Isn’t that better than allowing one’s impetuosity to risk descending prematurely and piling up on a hillside? No pilot can be too careful under such circumstances.

A matter-of-fact point of view must be taken. That the danger exists we all agree, but the risks are greatly minimised if the pilot knows his job. It is being proved daily in Australia that, in the hands of experienced men-who are not too proud to admit they have at times come down over the sea to be safe-all-weather flying of big commercial machines is an everyday job. It is not bravery or any “he-man” stuff that gets them through, but the ability and patience to apply diligently all they know to enable them to reach their destinations punctually, comfor tably and safely. So combine all your commonsense, responsibility, experience and patience – and never take what you feel is a chance. Keep your head and when in doubt, “climb, brother, climb!”

Flying in Australia has made great advances in recent years, but the success or otherwise of the airways is in the hands of the people who do the work-the pilots. No man can be born a fully trained pilot, nor for that matter can a pilot ever be fully trained. All pilots should ever be learning, ever striving to increase their own efficiency. Efficiency begets confidence, and thus safety. So always aim at being safe.

Footnotes:

1 This item is especially interesting. Had Shortridge followed his own sound advice on the fateful morning of 21 March 1931, the history of Australia’s airways development could have been quite different. (See ‘Air Crash’ Vol 1, Chapter 3).