by Tony Abbey, NAFEMS Training Manager
Tony Abbey has over thirty years industry experience, working for BAE Systems, Rolls Royce, Airbus, Westland Helicopters, Boeing, MBDA, Goodrich and Alenia. Building on his extensive industry expertise, Tony has developed and taught a wealth of FEA based training over the last fifteen years including many of NAFEMS classroom and e-learning courses.
As you may have guessed from the title, this week’s blog has an aviation theme. Many years ago I used to be a flying instructor and I spent most weekends, when the weather was good, teaching people to fly. I was reminded of all this a few days ago when browsing through an aviation magazine. The instructing scene has changed dramatically since I flew, with many new regulations, aircraft types and navigational aids. There seems to be an iPad in every cockpit, but the fundamental principles of flying remain unchanged. The article I was reading commented on the need for old-fashioned airmanship to still be taught effectively.
The case in point was ‘demonstrating slow flight’. Picture the scenario, the little plane is struggling along with the engine at high power, flaps down and nose high. The objective here is to teach the student to fly the aircraft accurately just above minimum control speed. This is practiced by flying straight and level in this condition and then height and heading changes are added. You may ask what an earth this has to do with normal flying, and in fact this was the basis of the article. The answer is, not much. However what it teaches the student is the extraordinary sensitivity of the aircraft at low speed and high power settings. Any carelessness results in a potential stall and spin. Very gentle inputs are needed with careful energy management. Contrast this to a side slipping approach to land, where plenty of full-blooded control and throttle inputs are needed. There will be occasions in a pilot’s career where he or she will get very slow, with a high power setting – probably combined with a low altitude, busy workload and plenty of distractions. That’s when the mind and muscle memory of the slow flying exercises can be a lifesaver.
The author of the article had noticed quite a lot of reluctance over recent years to take these exercises seriously. With more emphasis on new technology there is perhaps a drift away from important traditional skills.
I was thinking about this in the context of FEA training; perhaps we are overemphasizing some of the pitfalls that an engineer may face when setting up an FEA model. There is an interesting parallel here; we probably won’t ever create a project model in such a clumsy way, which shows the same bad errors as the demo or teaching examples. The demo models are often simple and it is pretty obvious that they are going to give poor results.
To that extent the demo models are similar to our flying exercise; we don’t drag an aircraft around at maximum power and minimum speed for hours on end in every day flying, so it is all a bit artificial. However, every now and again when building a complex model we may see the same symptoms as our simple demo. That is exactly the point of the exercise; hopefully this will jog the memory as to why the error is occurring, and how to cure it.
I used to teach stall and spin awareness and recovery as well as the slow flight exercise. I would also add an extra demo or two into the training and set up a scenario where we were tired, sloppy and turning onto final approach with flaps down and high power. Many training aircraft are eager to stall and spin beautifully when thus provoked! Hence ‘full opposite rudder, stick forward’ to recover.
I am pondering now how we can sneak more realistic and dramatic examples into the NAFEMS training, those flying days were fun….
Until next time,