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Agony Aunt.. By Jannie Matthysen Your favourite aunt in the helicopter business has been hard at work again. This month we discuss career prospects, helicopter IFR, turbine reliability, and we redesign the EC120  Q: I am finally in a financial position to fulfill my lifelong ambition of becoming a Commercial Helicopter Pilot. This means that I will be making a career change at the age of 30. How do I secure a job after completion of my training? Any advice? Charles. A: Well Charles, I wish that there was only good news, but this is sadly not the case. The reality is that the economic downturn has also affected the helicopter industry, although certain segments remain surprisingly robust. The world is still consuming oil at an alarming rate, and statistics show oil companies producing oil at an ever-increasing tempo. These oil companies simply cannot operate their offshore platforms without helicopter support. This means that the oil producers have a number of new aircraft on order for delivery over the next few years. Obviously, new pilots are required for these new machines. Other spheres in the industry have also not been adversely affected. Services such as Emergency Medical Support, Law Enforcement, and Government / Military operations are not influenced by the economy to the same extent as commercial operations. Employment opportunities in these sectors require pilots with extensive experience. The implication is that pilots are drawn from other sectors within the helicopter industry, thereby creating a void lower down the experience-chain. Another interesting factor is that the demand for pilots has reduced somewhat, but it has certainly not diminished. What has disappeared, however, is the funding for training. We are currently faced with a situation where there are willing and able candidates for helicopter training. The demand for pilots will always exist at fluctuating levels, but for now, there is no funding available to put these candidates into the pilot's seat. If you are able to fund your own training, it puts you in a very strong position to be one of very few qualified pilots available to fill a selection of posts in years to come. The most challenging phase of your career will be finding your first employment opportunity at low hours and relatively little experience in the industry. It is not an easy process but the rewards will make the effort worthwhile - good luck. Q: A friend of mine is a Commercial Aeroplane pilot with an Instrument Rating. He owns a Cessna 210 and regularly flies it IFR. I am a Commercial Helicopter Pilot with an Instrument Rating and cannot legally fly my Robinson R44 under IFR. Both aircraft are very similarly equipped. Why is this? Tom. A: The Cessna 210 is certified for IFR flight, as is the case with most other aircraft in its class. When certifying an aircraft type for IFR, one of the major considerations is that of stability. Most fixed-wing types such as the 210, are stable enough thereby requiring a relatively low pilot workload. An autopilot usually reduces the workload even further. Most helicopters, and certainly the R44, are very unstable under normal conditions. Add the pressure of IFR with the usual vibration, noise, and the myriad of forces working against each other and you are left with a very unsuitable IFR platform. Amongst other considerations such as instrumentation, power supply, fuel systems and hydraulic systems design, the stability issue requires a very complicated and expensive remedy. Obviously what we need is an autopilot. The problem is that due to the helicopter's inherent characteristics, a very complex autopilot and stabilizing system is required. These products are available, but the cost would comfortably exceed the total value of your R44. As a general rule, "entry level" IFR helicopters are designed from the onset with all the relevant equipment as standard. These are usually twin-engine with all the redundant safety systems as part of the package. Examples of these "entry level" IFR ships are the AW109 series, Bell 430, and Eurocopter 135. Q: I recently started flying a Eurocopter EC 120. There is not much to dislike about the helicopter, although I have heard many people complain that it's underpowered. I must admit that all helicopters I've flown appear to require more power than they are produced with. Why can't the manufacturers just solve this one little problem? Craig. A: You can never have enough power or enough money, right? The truth is that too much of a good thing is not always good. Let's take the EC 120 as example. In its current configuration the engine produces around 500 horsepower. The drivetrain, gearboxes, rotor system, hydraulic, and electrical systems are all designed to cope comfortably and reliably with the amount of power produced by the engine. The fuel system holds enough fuel for a useful 2,5 to 3 hour endurance. This is neatly packaged with some compromises within the 120's weight limitations. Now we convince Eurocopter to add another 100 horsepower. Nirvana? Not quite... A 600 horsepower engine will weigh more, consume more fuel, and put more strain on the dynamic components of the drive system. To carry more fuel, we need a bigger fuel tank. We need a more robust drive system and bigger gearboxes to cope with all that extra power. Oh, and the landing gear needs to be strengthened due to all the additional weight. While we're at it, why not add another seat or two? Surely we have enough power? Our high performance 120 is now much bigger and heavier. And yes, you guessed it; we still don't have enough power! In the process we've also created an "EC125" that requires the certification process to be started all over again. See, the design parameters are set very early on in the design process. When a manufacturer decides to build a five-seat single engine turbine helicopter, all aspects are relatively clearly defined from the start. They need to consider the all-important safety, reliability and cost implications when adding all the nice-to- have luxuries such as an abundance of power. All that we as pilots can do is to fly the aircraft to the best of our abilities within the limitations set by the manufacturer. Q: You always hear of experienced pilots refusing to fly piston engine helicopters because of their unreliability. Turbines are apparently much more reliable, but I've never heard of a piston engine failure in a helicopter while we've heard of many turbine failures. Where's the catch? Nic. A: There is a misconception that helicopter turbine engines are a lot more reliable than their reciprocating counterparts. Statistics published by the American NTSB (National Transportation Safety Board) show that for a given period, less than 2% of all piston-powered helicopter accidents were due to engine failure, while the accident rate reflected more than 10% for turbine engines in the same period. We all know that there are many ways to interpret statistics, but the NTSB is not the only source confirming this general trend. Let's look at the general design and differences between the two. The piston engine is very heavy for the amount of horsepower it produces. In aviation we're constantly trying to keep the weight as low as possible, meaning that the piston engine's power to weight ratio becomes very inefficient above 300 horsepower. The engine simply becomes too big. A turbine in contrast, is very light, and masses of horsepower can be produced for a relatively low weight. Piston engines have been around for over a century and these engines have benefited from continuous development for applications in cars, machinery, ships, and aircraft. A turbine engine features a much simpler design and is often compared to a gas stove where the size of the flame is simply varied in order to produce more power. Turbines are manufactured to very high quality standards with extremely small tolerances. This factor, and the types of materials used, contribute to the high cost of these engines. Modern turbines are becoming more complex and require software to manage and control countless parameters in producing the required output. This high level of complexity is the root cause of most of the turbine's woes. Even the smallest error in manufacture, assembly or maintenance could lead to a catastrophic failure in this high-tech power plant. The modern turbine does fortunately assist the pilot with its software capabilities, and the all-too-common pilot error is negated to a large extent. Piston engines are relatively cheap and simple to design and manufacture. Many helicopter engines are simply variants of identical engines found in many fixed wing aircraft. Specific requirements of helicopter performance often require these engines to produce more power than it has been initially designed to do. One of the more popular ways of increasing output is to raise the RPM. An engine being stretched to run at a higher RPM in order to produce more power is simply not going to last as long or be as reliable as the same engine running at a much lower RPM. This caused many failures during the early era of the piston helicopter. The good news is that manufacturers have learnt their lessons, and any piston engine found in a helicopter in the past 30-odd years is as reliable as any turbine - even more reliable when you believe the NTSB. |
