All photos me too, copyrighted
On the face of it, July was probably not the most enjoyable of times to have my Multi-Engine Class training. The summer’s record temperatures – once peaking at a toasty +55 Centigrade in the cockpit – really did us no favors at the best of times; and had certainly not done justice to our little, slightly underpowered Piper Seminole :). So keen to see what it – and I – could actually do given some favorable weather conditions, I was very much looking forward to my Multi-Engine Instrument training, slated to take place in the much more agreeable near-zero temperatures at the beginning of November…
Now, as mentioned in a previous post on the topic, flying a twin engine airplane is fairly easy – provided both engines are operating :D. When one decides to quit however, things can become interesting – still safe, but quite interesting nonetheless. The biggest and most immediate problem in this situation is the sudden lack of power – as my flight instructor had graphically put it, when you lose an engine, you don’t lose just 50% of the available power; in effect it’s as if you lose 75%, since you now also have the dead weight – and additional drag – of the inoperative engine. Specifically, it’s this drag that causes the biggest control problems: with one engine “dragging behind” and the other pulling forward, the airplane wants to yaw and bank around its center of gravity into the inoperative engine, a tendency that has to be neutralized by liberal application of opposite rudder (and possibly some aileron) :). With the rudder now deflected (at low speeds often fully), the drag increases yet again, forcing the airplane down to its speed for minimum drag (and hence minimum required power) – a flight regime that, especially during landing, requires considerable planning ahead…
When simulated for training purposes, this One Engine Inoperative situation also makes the aspiring student appreciative of the simplicity of the turboprop engine – especially if you’re flying a piston-engined Seminole, an aircraft seemingly designed to make your life then and there as complicated as possible :D. Given that many in-flight engine shutdowns are caused by small, easily-rectifiable problems rather than catastrophic failures, each aircraft has a specific set of “diagnostic” procedures the pilot needs to run through to verify whether one of the engines has indeed failed, identify the inoperative engine and – if all else fails (pun intended) – secure it. On the 100-cockpit-lever Seminole (though they’re broadly similar for other piston twins) these include:
- moving both mixture levers forward into the Full Rich position – the idea being that maybe you’d forgotten to move them forward during descent and the fuel/air mixture had become too weak for the engine to run
- moving both propeller levers forward. This may seem a bit odd given that one of the engines has failed or is in the process of doing so, but until you’re certain WHICH one it is, better have both props at their maximum
- moving the throttles all the way to the Maximum Continuous Power setting, for the same reason
- turning on the carburetor heaters (or opening the alternate air ports on fuel-injected engines) to see whether the problem is simply ice blocking the carburetor/air intake
- turning on both auxiliary fuel pumps, in case the main engine-driven pumps had failed and no fuel is being drawn from the tanks
- and then looking around to see whether you’d accidentally shut something off, like the fuel selectors or magnets
If once you’re done the inoperative engine still refuses to cooperate, you identify it and proceed with securing it – which is basically the reverse procedure to the above: close the throttle, feather the prop, cut the mixture and shut everything down related to the engine, such as magnetos, fuel pumps, alternators and the like… you may also have noticed that the above procedure is performed on both engines simultaneously; the rationale is that whatever plagues one engine can easily happen to the other – which is especially likely if the root cause is icing or incorrectly set mixtures.
Despite being a “screenfull”, out on the Seminole this procedure is pretty straightforward and comparatively simple – dare I say fun 😀 – in visual conditions: conditions where you always have a visible horizon and ground contact, and can afford to drift a bit off course while you get the hang of the airplane. In instrument conditions though that luxury is gone, with the only spatial reference you have provided by the instruments – which implies, in addition to everything stated above, continual scanning of the primary flight and navigation instruments and maintaining an image of your position and attitude in your head. Now factor in an ILS or VOR/DME approach and you have a party :D.
Given that during these flights I was want for a few more arms, I did not have the liberty to photograph at will as I usually do, so – after having drifted off course quite badly with this post 😀 – I thought I’d just throw together a small photo gallery of the ME/IR “tools of the trade”… 🙂
And finally, honorable mentions go to two photos I’ve snapped in flight with my mobile phone… due to a somewhat “expedited” departure from Pleso airport, I’d left my camera in the luggage compartment and couldn’t get at it in flight – so I had to use whatever I had at hand… 🙂