Aviation Articles

Jim's Wisdom

General tips & tricks from Jim
Taxying to the Holding Point - Wednesday, 19 June 2002
Brakes against Power - Don't do it! - Wednesday, 19 June 2002
Inbound calls at Camden - Wednesday, 19 June 2002

Ask the CFI

Your chance to ask questions and see the answers online
Ask the CFI - Welcome to the column! - Tuesday, 9 July 2002

Tailwheel Articles

Good advice for flying tailwheel aircraft!
On Flying Tailwheelers - Friday, 31 May 2002
Differences between Taildraggers & 'Nosedraggers' - Friday, 31 May 2002

Press

Curtis Aviation in the Press
FireSpotter 67 - Wednesday, 25 September 2002

Pilot Articles

Articles written by our pilots at Curtis Aviation
A trip to Temora - Monday, 11 November 2002

Rob's Safety Briefs

Safety First - these articles are a must.
Fuel or Water? - Monday, 11 November 2002
Seats that unlock..... - Wednesday, 18 September 2002
Do's and Don'ts of Airmanship - Wednesday, 19 June 2002
Carburettor Icing - Wednesday, 19 June 2002
Autumn Weather - Wednesday, 19 June 2002

Curtis Aviation Pilots

Stories of the pilots of Curtis Aviation
Alan Turner - 1st flight 1936
Thursday, 26 September 2002

Taxying to the Holding Point

Safety First

Whether at Camden or other aerodromes, the Holding Point is a rather important point on the aerodrome. There are quite a number of factors to consider approaching the holding point, as we saw in last month's "Power against brakes". There might be a down slope, or a poor view of the runway or the approach path.

If you consider the holding point at Runway 28, almost opposite Curtis Aviation, the angle affords a good view down the strip, but not back along the approach path. In fact, the angle is such that the view of any aircraft on finals will be entirely obscured in a high-wing aircraft. You will want a good view of the approach path before entering a runway, whether you are at a CTAF/MBZ or controlled aerodrome. Therefore, when holding at 28, hold about 1.5 aircraft lengths from the holding point, facing more towards the Camden hospital. In a Citabria (for example) this will mean the wings no longer obscure the approach path and good visibility will be obtained prior to entering the runway.

Planning to hold well short, rather than with the nose on the "yellow lines" will assist you in other ways as well. Firstly, it will provide more time and space for you to act should your brakes fail near the holding point. This is particularly important approaching runway 24 given the down slope. Secondly, should you experience a radio problem, it will leave you space to manoeuvre the aircraft without a potential runway incursion. If you do not have a clearance to enter the runway, you may not do so.

Finally, on non-sealed runways, holding points are well travelled and may have more stones or gravel in that area and it is better to be rolling over these stones rather than powering up to over come the inertia of the aircraft on top of the stones.

REMEMBER: Hold well short rather than with the spinner on the lines, and make sure you can view the approach path to the runway.

Brakes against Power - Don't do it!

Jim's Wisdom - Brakes against Power

DON'T DO IT!

For every force there must be an equal and opposite force! Whilst Newton's Laws have stood the test of time, they were not intended to be expressed through the use of brakes whilst the aircraft is under power. We use power when taxying an aircraft to overcome it's inertia. Once momentum is built, a reduction in power might be more useful than application of brakes.

Whilst brakes result in a fairly immediate retarding effect, reduction in power is not so immediate, and therefore requires some anticipation. This makes for excellent practice being in the air, where you are required to be "ahead of the aircraft", so why not start on the ground? If brakes are used constantly on the taxi out to the run-up bays and runway, they may, particularly in hotter weather, become so hot as to provide no braking effect when you might need it most. This can be approaching the holding point for Runway 24 (which has a considerable downslope) whilst an aircraft is on short finals for the runway, or during an aborted take-off when you require considerable braking force.

Tips for avoiding brakes against power.

1. Use enough power to overcome the inertia of the aircraft

2. Anticipate turns and downslopes and retard the power well in advance

REMEMBER: Keep the brakes in good condition for when you might need them most:
The runway & The holding point

Inbound calls at Camden

Why do we give inbound calls to the tower at Camden? The first most obvious reason is to obtain a clearance from the controller to enter the zone. However, it is also equally important for other pilots to hear where you are and how high you are, both on the inbound call and the next reporting call.

Pilot responsibilities include: 'A pilot must sight and maintain separation from other aircraft whilst operating in the GAAP CTR'. In other words, it is you, not the tower that provides primary traffic separation. ATC will only provide a separation service, or rather, a traffic information service, when:

a) pilot of one aircraft is required to give way to, follow, or otherwise adjust the aircraft's flight path relative to that flown by another aircraft. AND / OR

b) the relative positions of aircraft cannot be established, and a collision or near miss may be likely unless one or both aircraft adjust their respective flights paths.

The pilots must maintain a good lookout and good listening watch supplemented with useful position reporting.

It is therefore important to report position and height as you approach the reporting point requested by the tower.

Jim's suggested calls

PILOT: Camden Tower, Mike Whiskey Yankee, a Citabria, is Bringelly, one-thousand, eight-hundred, inbound (for circuits)* with Mike.

TOWER: Mike Whiskey Yankee, join downwind, report again at two miles.

PILOT: Join downwind, Mike Whiskey Yankee.

PILOT: Mike Whiskey Yankee, approaching two miles downwind, one-thousand eight-hundred

Making your reporting call whilst approaching the reporting point and providing details of your height will help other pilots in the circuit sight and maintain separation.

* If you require circuits upon return, make sure you request such on your inbound call, however, absolutely no later than the two-mile call.

REMEMBER: A circuit entry instruction does not constitute approval to descend. A sequencing instruction (MWY, you're #2) does constitute an approval to descend.

Ask the CFI - Welcome to the column!

Welcome to the new column 'Ask the CFI' (Chief Flying Instructor).

At all levels aviation is an ongoing learning experience, and to facilitate we welcome you to put questions to Craig via email. We'll post the questions and answers online. Email: craig@curtisaviation.com.au

On Flying Tailwheelers

The landing phase is the most challenging (and fun!) part of tailwheel flying. Managing the airspeed. Battling the wind. Judging the touchdown point. And above all, actively working the controls to keep the airplane straight during and after landing. That means learning to use the rudder continuously to keep the tail behind you, where it belongs.

Pilots must, of course, become proficient in all of these elements to fly any airplane safely, but they are especially important in tailwheel airplanes in order to maintain directional control and to avoid an ego-deflating groundloop.

What exactly is a groundloop, anyway?

Any unwanted curving of the airplane's path when you're operating on the ground is a groundloop. The tendency to groundloop, however, is greatest while rolling out after touchdown. Groundloops can be either controlled or out-of-control maneuvers. The out-of-control kind can be rather benign--the airplane drunkenly meandering off the runway, for instance. Or they can be severe--a tight pirouette, with the airplane veering hard off the runway, poised precariously on one main wheel, wingtip dragging across the ground as everyone on the airport watches. High-speed groundloops can collapse the landing gear, can bend metal and tear fabric, and might include carving up asphalt with the propeller before the dust settles.

Pilots can and do groundloop tricycle and conventional gear airplanes alike. But the legend of the taildragger is rooted in its willingness to groundloop with minimal provocation. The relationship between the airplane's center of gravity (c.g.) and the main landing gear makes this so:

For example, in properly loaded tricycle gear airplanes, the c.g. falls ahead of the main landing gear. This configuration is directionally stable on the ground. Consequently, tricycle gear airplanes inherently track nose-first. Properly loaded conventional gear airplanes, on the other hand, wind up with the c.g. located aft of the main landing gear. As a result, tailwheel airplanes will more readily swap ends on the ground unless the pilot continuously intervenes with corrective rudder inputs.

But this groundlooping tendency isn't necessarily a negative. The fact that the taildragger doesn't cut the pilot any slack during the landing phase is what makes the tailwheel transition so rewarding. Every good landing in a tailwheel airplane is due solely to piloting skill. Neither luck nor airplane stability can take any credit for it. The objective of tailwheel training, of course, is to learn to make more good landings than bad!

What do the terms 'three-pointer' and 'wheel landing' mean?

Takeoffs and landings directly into the wind in conventional gear airplanes come in two basic flavors: three-point and two-point. These terms refer not only to the airplane's attitude, but also to the number of wheels in contact with the ground as the airplane rotates on takeoff or as it touches down on landing.

The three-point attitude is identical to the attitude the airplane has when it's parked on the ramp. All other things being equal, the three-point attitude allows the pilot to operate at slower airspeeds: on takeoff, the airplane levitates into ground effect sooner; on landing, the airplane touches down slower, resulting in a shorter ground roll. Soft field operations usually call for a three-point or tail-low attitude during takeoff and landing. Three-pointers may be prescribed for short field landings, too. (Three-point landings are sometimes referred to as full stall landings, yet the airplane might not actually be stalled when the wheels contact the ground.)

The three-point attitude does have potential disadvantages, though. One is reduced forward visibility during takeoff and landing in some taildraggers. Another may be a false sense during takeoff that an under powered airplane (or one that is operating at high density altitude) is capable of climbing out of ground effect while still in the nose-high, low speed, high drag, three-point attitude. Some airplanes may only be able to wallow along in ground effect in this configuration.

The true two-point attitude, by comparison, corresponds to the attitude the airplane assumes in level cruise flight. Pilots transitioning to tailwheel airplanes might initially fear that the two-point attitude would bring the propeller precariously close to striking the ground. This apprehension can be alleviated, however, with a simple demonstration: With the prop of a parked taildragger positioned vertically (be extremely cautious when moving any propeller!), have your instructor pick up the tail of the airplane until it's in a level, two-point attitude. Check out the clearance between the ground and the prop.

All other things being equal, two-point takeoffs generally allow the airplane to accelerate quicker and offer improved forward visibility. They also permit the pilot to gain more speed--and hence, have better control authority--prior to becoming airborne in gusty wind conditions. A short field may command the use of a two-point attitude during takeoff.

Two-point landings are commonly referred to as wheel landings. In fact, any landing during which the tailwheel is held off the ground--even if it's only an inch or two--qualifies as a wheel landing. Wheel landings in certain airplanes may offer better forward visibility during the landing roll. Some pilots also argue that a wheel landing is preferable to a three-pointer when encountering gusty crosswinds. Others claim that quirks in a particular taildragger's design may necessitate the use of wheel landings for better controllability. Pilots of Stardusters and Swifts, for instance, swear by the wheel landing.

But the two-point attitude has its disadvantages, too. Forcibly raising the tail on takeoff, for example, adds a sometimes-significant gyroscopic component to the left-turning effects of torque, P-factor, and spiral slipstream. The pilot must anticipate the need for additional right rudder as the tail rises. On the other end of the pattern, the wheel landing occurs at a higher ground speed than a three-point landing. Consequently, wheel landings tend to use up more of the available runway. It's also easier to instigate a pilot-induced-oscillation (PIO) during a wheel landing. If not checked quickly, this can culminate in a prop strike, a groundloop, or a little bit of both. Eventually, the wheel landing is transitioned into a three-point attitude. The possibility of a brief lapse in control authority is greater during this transition.

Keep in mind we're not necessarily restricted to the two- and three-point attitudes described above, either. We can set intermediate attitudes during takeoff and landing, too. And during takeoff and landing in crosswind conditions, we might choose a three-point attitude modified with the downwind main wheel raised off the ground (i.e.: aileron into the wind) as part of our crosswind correction. Similarly, we might choose a two-point attitude, but again with the downwind wheel raised off the ground.

Are taildraggers trickier to handle in windy conditions?

Trickier, no. Less tolerant of pilot inattentiveness, yes. The pilot must be acutely aware of wind direction and strength. Make it a habit to look at the wind indicators on the airport before taxiing, just before takeoff, and on short final. If the windsock is straight out, it's blowing at least 15 knots.

Taxiing into the wind? Think 'climb into' the headwind: elevator control full aft, with left aileron into a left quartering headwind, right aileron into a right quartering headwind.

Taxiing downwind? Think 'dive away from' the tailwind: elevator control full forward if the wind speed is faster than your taxi speed, and right aileron with a left quartering tailwind, left aileron with a right quartering tailwind.

And don't forget about the wind generated by the propeller, either. Be sure to hold the elevator control fully aft before adding run-up power; otherwise, the prop blast may be sufficient to raise the tail, possibly driving the propeller into the ground.

Be sure to adhere to the crosswind limitations of your taildragger as well. If the Pilot's Operating Handbook (POH) fails to list a maximum demonstrated crosswind, use 20 percent of the airplane's calibrated stall speed in the landing configuration (Vso calibrated). Certification requirements specify that light airplanes shall have no uncontrollable groundlooping tendency in a 90 degree crosswind up to 0.2Vso in strength.

Can taildragger techniques be used in tricycle gear airplanes?

Not only can they be used, but they should be used. You should fly tricycle gear airplanes in the pattern as though they were taildraggers. You'll be pleasantly surprised how tailwheel techniques thus applied will improve your tricycle gear takeoffs and landings. Tailwheel techniques directly carry over to floatplane flying, too.

What are some of the common problems pilots have transitioning to taildraggers?

The biggest problem can be summed up in three words: rudder, rudder, rudder. Too many pilots have grown accustomed to being reactive with their rudder inputs--waiting for the airplane to do something, then responding--or worse, actually bracing their legs against the rudder pedals, especially during landing. The key in a taildragger is to be proactive with the rudder. To be light, loose, but active on the rudder pedals all the way through the takeoff and all the way through the landing.

The second problem concerns the elevator. Pilots flying tricycle gear airplanes tend to relax back elevator pressure instinctively during the landing roll out. In a taildragger landing in the three-point attitude, relaxing back elevator pressure reduces directional control, thus making it more difficult to keep the airplane straight during the roll out. The key in a three-point landing is to hold the elevator control fully aft during the entire landing roll while actively using the rudder to keep the airplane aligned with the runway.

The third problem appears during wheel landings. The key difference between the three-point landing and the wheel landing is sink rate. Successful wheel landings require minimum sink rate. If the airplane at all settles, falls, or sinks toward the runway in the last few feet, a wheel landing will be difficult or impossible. And if the pilot flinches and applies back elevator as the main wheels touch down, the airplane will rebound into the air. At this point, the pilot needs to react quickly and efficiently--either convert the landing to a three-pointer or add power and execute a go-around.

Can you recommend any books on the subject?

My favorite is 'The Complete Taildragger Pilot' by Harvey S. Plourde. But don't forget about the FAA's new 'Airplane Flying Handbook,' which devotes an entire chapter to tailwheel flying. Combining the information from these publications with structured ground and flight instruction will make for an enjoyable tailwheel transition experience.

Even if you don't plan on regularly flying a taildragger, a few hours of tailwheel training will markedly improve not only your rudder awareness, but also the quality of your landings in nosewheel airplanes. This alone should be incentive enough to add a tailwheel sign-off to your 'To Do' list. Find a school that has something fun like a Citabria, Champ, or J-3 Cub and give it a try!

Differences between Taildraggers & 'Nosedraggers'

DIFFERENCES ON THE TAILDRAGGER

There is only one significant difference between a 'taildragger' and a 'nosedragger' and that is where the center of gravity (CG) is located relative to the main gear.

In the tricycle gear 'nosedragger' airplane the center of gravity (CG) is forward of the mains which gives it two endearing qualities. Firstly, when you land any harder than greasing-it-in on the mains, the CG wants to continue going down and helps to bring the nose down so that the airplane stays on the ground. Secondly, if you brake or rudder a little bit off center during the rollout, the CG wants to pull the nose of the airplane in the direction the airplane is rolling, thus straightening out the nose and helping the pilot to correct the mistake.

In the conventional gear 'taildragger' these same qualities work against you. In a 'wheel landing' where you touch down the mains first, the CG, now being behind the mains, continues going down which causes the tail to come down instead of the nose. Instead of helping to keep the airplane on the ground, you'll find yourself airborne again. This is frequently called 'bouncing it back into the air', but that's not really true. In actuality the CG going down increases the angle of attack which causes you to become airborne again. The 'Texas Taildragger' has a very heavy tail, making it particularly difficult to do wheel landings, but you can use a lot of brake without putting it on its nose.

Secondly, if you brake or rudder a little bit off center during the rollout, the CG wants to pull the tail instead of the nose of the airplane in the direction the airplane is rolling, thus adding to the mistake and causes the airplane to speed up the turn which can easily result in a ground loop and breaking parts of the airplane.

Asa Dean

FireSpotter 67

Curtis Aviation participated significantly during the Christmas 2001 Bushfires.

Below you'll find an article reproduced from the NSW Rural Fire Services

Commemorative Edition Magazine of the Christmas 2001 Bushfires.

A trip to Temora

By Frank Gray

HI there fellow aviator,

This is just a little note to let anyone know who are interested in warbirds and aviation museums. To get up, up and away down to Temora next weekend the 9th & 10th of Nov. It's only 1 hr flying time from Camden or 3 hrs by car (which the wife and I did)

We both had a great time, the drive down was great and easy. We stopped at the Budget motel in Cootamundra, which looked after us really well the rooms are neat & clean. There are plenty of places to eat, and our pick was the Globe hotel.

The drive from Cootamundra to Temora is a 30min drive, driving through fields of yellow & green Canola, which look like a patchwork quilt.

The museum is very well set up, most of the aircraft being flown both days. Undercover seating is provided and the commentary is spoken by someone who knows what they are talking about. The local fire brigade, at competitive prices, provides food & drinks with a steak sandwich (which I can recommend) costing $3.50.

For more information visit their web site at www.aviationmuseum.com.au/temora if you decide to have a visit I am sure that you will have a great time as the wife and I did.

Cheers

Frank & Pat

Fuel or Water?

The following article on Fuel Tank water drain checks has been reproduced from the Aviation Safety Digest.

The pilot completed the daily inspection and preflight checks on his Cessna 182 and everything appeared normal. However, just as the aircraft became airborne the engine stopped. Fortunately for the pilot he was able to land the aircraft straight ahead on the remaining runway, without further mishap.

Initially, the pilot was adamant that there had been no sign of water in the fuel during his preflight drain check. He also confirmed that there had been fuel in both tanks and that the fuel selector had been turned on.

The pilot subsequently checked thoroughly the fuel remaining in his aircraft's tanks and found that in fact it was heavily contaminated with water. Indeed, the sample he had taken from the tank water drains during his daily inspection had been all water! Because the liquid he had drained seemed the same colour as the fuel the aircraft used and there were no signs of contamination, he had assumed that the liquid was uncontaminated fuel. About 135 litres of liquid were drained before all evidence of water was removed.

There are two important aspects of this incident, namely, how the water got into the fuel and why the pilot failed to identify the problem during the daily inspection. While the question of how the water got in the fuel is most serious, it is the latter issue with which this article is concerned.

The report from the Bureau of Air Safety Investigation confirmed that the original sample taken by the pilot was all water. The report continued: 'Pilots should become thoroughly familiar with the characteristics of aviation fuels and if a sample is of uniform consistency (as in this case), the fact that it is fuel can and must be verified.

One method of doing this is to drain the sample into a vessel that already contains a sample of known fuel. If the sample from the aircraft is all water, it will be readily visible. Another 'ad hoc' method is to pour a little of the sample into the palm of one hand: if it is fuel it should vaporize and leave the skin dry; it will also feel cool as it evaporates. Water will remain on the skin. The sense of smell should also be used to help with identification.

The size of the fuel sample taken is important, as it must be sufficient to be conclusive. It will vary depending on the fuel capacity of the particular aircraft.

Check on the amount you need to take from each drain on your aircraft, either in the aircraft operating manual or from an appropriately qualified engineer, to ensure a positive result.

Finally, the point need to be made that the fuel/water checks discussed above should be used only when more positive tests cannot be made. If a visual check is inconclusive, then the best and only certain way to ensure your fuel is free from the danger of water contamination is to test a sample with water sensitive paste or capsules.

Rob's Note: For the aircraft we operate at Curtis Aviation, a full single fuel drain per tank is acceptable. I always do a full drain on the first tank, and once positively confirmed that what I have drained is actually fuel, and not part water or all water, I then discard half, and then drain from the second tank.
Seats that unlock.....
Seats that unlock...

In recent times there has been an accident and a number if incidents relating to seats becoming unlocked either during ground maneuvering or during the take-off. In the recent Victorian accident the pilot lost control of his aircraft immediately after take-off resulting in a fatal accident.

Many of our pilots have learned to fly in the Citabria which only has a seat that can be moved into two different positions, however, aeroplanes such as the Warrior, Dakota and the Cessnas have seats that will move a considerable distance rearward should they unlock at a critical stage of flight. This will then result in the pilot usually hanging on to the control column as the seat moves rearward resulting in a steep pitch up of the aircraft. The pilot may also attempt to hang on to the throttle, closing the throttle, which with the high nose attitude will result in a stall, and the consequences of this happening close to the ground do not bear mentioning.

The pilots operating handbooks for some popular aircraft types include the pilot's check of the adjustment and locking of seats, belts and shoulder harnesses in the 'before starting engine' checklist but not in the take-off checklist. Others do not include a check of the seat itself, mentioning only seat belts and harnesses. As some pilots find it necessary to adjust their seats, 'belts, harnesses and seat locked' should be included in the 'before takeoff' and 'before landing' check. The security of the seat should be should be tested with firm back pressure after checking that the adjusting mechanism is in the lock position.

The seat is often stopped in the desired position by a locking device linked to a bar or handle for use by the pilot in releasing or locking the seat in place. Most seats are locked by pins which slip down into holes in the track, although a few use other devices such as clamps or 'shoes'. A security stop at the end of the rails prevents the rollers from overrunning the tracks.

The adjustment mechanism is usually spring loaded, so that when the handle is released the pins drop automatically into the locking slot. However, in some cases there is no spring and the pins must be manually positioned or the seat will slide under pressure.

A training aircraft, flown by pilots of varying size, will have its front seats shunted back and forth frequently, subjecting the movable mechanism to considerable wear and occasional abuse by the impatient pilot. This may lead to the end stops becoming weak and prone to overriding, or to the intermediate stops becoming enlarged and prone to slippage. For these reasons, a periodic check of the mechanism is included in the maintenance requirements. The following is a list of the checks carried out by LAME during periodic maintenance and it is considered vital that pilots carry out these checks during the daily inspection as wear and tear may have taken place since the last periodic inspection. This inspection should include the following:

· The metal framework of the seat, particularly the joints.

· The rollers and roller brackets - check for proper alignment and wear.

· The locking mechanism, including the actuating arm, linkage and locking pins - make sure the release spring, if there is one, is intact, and the action is positive.

· The floor mounted rails - make certain they are tight to the floor and tracking true; the rail stops should be clear and not distorted, and the end stops solid.

While you have your nose down on the floor, this is a good time to remove any foreign or loose objects hidden under the seat. Coins, combs, keys and other abandoned miscellany take malicious delight in jamming vital mechanisms at the worst possible time.

Do's and Don'ts of Airmanship

¨ Do shut down your engine before loading or unloading passengers.

¨ Do warn people to keep away from the propeller and not to touch it for any reason.

¨ Do taxi at a speed from which you can come to a stop at any time.

¨ Do have someone on each wing tip for guidance when taxiing in confined spaces.

¨ Do taxi at night only on lighted taxiways.

¨ Do leave the controls locked after parking the aircraft.

¨ Do set the brakes or chock the aircraft on the apron.

¨ Do tie down the aircraft when parking overnight.

¨ Do use the radio only for what it was intended - and keep the channels open for operational or emergency messages.
¨ Don't start your engine before being assured your propeller is clear.

¨ Don't start your engine with the aircraft's tail towards other aircraft or open hangars.

¨ Don't start your engine while people are standing in front or behind your aircraft.

¨ Don't use high power while taxiing in close proximity to other aircraft.

¨ Don't conduct a long pre-flight run-up in the vicinity of offices or occupied buildings.

¨ Don't ask for weather information right after take-off - you can check it by Internet, fax or telephone before departure.

¨ Don't taxi on to an apron at a fast rate. Your brakes could fail.

Carburettor Icing

This is the time of the year when carburettor icing is likely to catch some pilots unawares - that is, unless they are ready to take positive, correct action to counter the condition as soon as the very first symptoms of carburettor icing appear.

Uncertain, hesitant, "fiddling" with carburettor heat control can often do more harm than good (by raising the carburettor air temperature just enough to put it in the optimum icing range) and the stage can quickly be reached where the engine has lost too much power to be able to provide the heat necessary to clear the accumulated ice from the throat of the carburettor. Take this case for example:

On the northern tablelands of New South Wales, a pilot was making a private cross-country flight in a Cessna 150. Some 15 minutes after take-off, while cruising normally at about 4,000 feet, the engine began to run roughly. Believing the trouble was carburettor icing, the pilot operated the carburettor heat control several times but the rough running continued intermittently. The pilot then decided, that as carburettor heat did not seem to be rectifying the trouble, to return to his departure aerodrome. Soon after turning back the rough running worsened and even with full throttle applied, the engine continued to lose power.

Eventually the pilot realised he would have to make a forced landing. He selected a suitable paddock, transmitted a MAYDAY call and commenced an approach. By this time the engine was running extremely roughly and the maximum r,p,m. had dropped to 1,600. Turning on to final approach, the pilot closed the throttle and the engine stopped completely. The forced landing was nevertheless successful and the aircraft was not damaged.

Subsequent examination of the engine failed to find any fault and after a satisfactory ground check, the aircraft was flown back to its base without further trouble. It was established that the existing meteorological conditions were favourable to the formation of carburettor ice and it was learned that another pilot who was flying in the same area at the time had experienced a tendency for carburettor ice to form. In the circumstances, there was little doubt that carburettor ice was the cause of the engine trouble and that the pilot has not used the carburettor heat control correctly to counter its development.

The Australian Safety Digest published an article recommending the use of full carburettor heat at frequent intervals in suspected icing conditions to check for the presence of ice. The article also pointed out that carburettor heat must be applied for long enough - 30 seconds was suggested - to rid the induction sytem of the ice that had formed. It seems clear, however, that the pilot of the Cessna 150 did not appreciate this point. When his application of carburettor heat did not immediately cure the symptoms he was experiencing (and probably further caused a further, though very temporary, loss in power), he concluded that carburettor heat could not correct the trouble.

The pilot's reference to gradually increasing the throttle opening, eventually to full throttle, to try and compensate for the loss of power is also significant. The digest article pointed out that this set of circumstances can lead to a complete loss of power if sufficient carburettor heat is not applied long enough to overcome the rapidly increasing accumulation of ice in the induction system.

There may be some pilots who, on reading of this incident, feel that they too may be a little "rusty" on the theory of carburettor icing. There may be others who have not yet experienced symptoms of carburettor icing themselves and who may not be fully confident about using the carburettor heat control in flight. Pilots who believe they may be in these categories should obtain a thorough briefing on the subject from any of the Curtis instructors (experienced in the type of aircraft they intend to fly), before venturing off into conditions in which carburettor icing is possible.

It is important to remember too that these conditions are not confined only to cold weather. Carburettor icing can occur on quite warm days if the humidity is high enough. For example, with a relative humidity of 60%, and outside air temperature between 5OC (41O F) and 27OC (81O F) can be conducive to the formation of carburettor ice.

Autumn Weather

Autumn generally sees the progressive transition between the weather experienced in summer to that in winter, with features of the summer scene often persisting into early autumn and features of the winter scene often evident in late autumn.

Generally good flying conditions are experienced during the daytime in mid-autumn. However, pilots should be wary of:

·Carburettor icing, particularly if flying in low level moist onshore streams.

· Running out of daylight as the days are rapidly shortening

· Increased incidence of fog/low cloud.

Average number of fog days (per month) at various locations showing increased incidence from late summer through autumn, for example are:

FEB MAR APR MAY

YSCN    2        5        7       9


YSCB   1           3        4          8

Late autumn generally sees an increase in the frequency of cold frontal and stream weather along the southern coastal areas of Australia. With these fronts are wind changes, often low cloud, reduced visibility, precipitation, wind shear and turbulence.

While talking in very broad terms about 'average' autumn weather, large variations from the 'average' may be experienced, e.g., a late season tropical cyclone affecting northern coastal areas, an inland deep low pressure system or an upper air disturbance leading to very poor flying conditions. The principles of 'weatherwise' flying must always be observed even at this generally 'weather benign' time of the year. Anticipation and proper preparation are the key elements to obviate any potential problems that may arise.

Alan Turner - 1st flight 1936

Alan Turner took his first flight at Hargreave AirPark (near Warwick Farm) in 1936. 66 years later, in 2002, Alan still flies, however, the aircraft are a little newer these days.

That first flight in 1936 was in an Avro Cadet, 'orange in colour' Alan remembers, and it cost 5 shillings. Still at school, Alan took the ticket in to prove to his class mates that he has actually been flying. Flying at Hargreave AirPark predated Bankstown Airport, however, the AirPark was closed down after the war as it became the Naval gaol.

Most private flying stopped during the war, and shortly thereafter the Royal Aero Club, still flying out of Mascot, moved to Bankstown.

Alan completed most of his flying with the Royal Aero Club of NSW whilst based at Bankstown. Aircraft that Alan flew included Cessna 152, 172, 182, 206, and even a C185 Float Plane. Alan also flew all the Cherokees and Mooney Executive.

Alan's favourite plane? Grumman AA5-B

Most Interesting? GY80 Sud Horizon - had a narrow undercarriage and used to'waddle like a tram driver' whilst it taxiied.

Worst Aircraft? Fuji FA500-181 - CSU with fixed undercarriage - just terrible.

With 1200 hours of private flying now under his belt, Alan aims to fly at least once per month ('slip one entry in the log book every month'). Into his third log book, Alan flies VH-PBS at least every month and is still loving every minute of it!