Ab Initio 54: “What Happens if the Engine Stops?””

In which I aim a glide at various bits of the Welsh countryside.

It seems to be a popular question, trotted out with depressingly regularity by friends or acquaintances that have just heard I’m taking flying lessons.

“What if the engine stops?”

The simple-sounding “land somewhere” never really seems to satisfy them, perhaps the media images of plunging machines accompanied by Stuka-style wailing is too firmly ingrained in the public imagination.

In contrast, Carl assured me during our briefing for today’s lesson than he knew plenty of people who’ve managed it and walked away.

Out came the whiteboard markers and we went through the plummeting-free version of events.

The two most common causes of engine failure in light aircraft tend to be lack of fuel, or carb ice. The first step then is to get the carb heat and fuel pump on and change tanks. This can be done quickly while slowing down to best glide speed (70 knots in the Tomahawk) and getting trimmed.

If that doesn’t help then the next step is to work out/remember/read from your bit of paper, the wind direction, and select a field to land in, using “the five Ss”…

Size: The bigger the better obviously!

Shape: Wide enough and long enough in the direction of the wind, something suitable on one day might be less suitable with the wind from another direction.

Surface: Grass or stubble is good, ploiughed fields not so good. We’ve got plenty of beaches around and as long as the sand is reasonably firm they’re okay too.

Slope: Flat, or slightly uphill. Downhill not so good as it’ll extend the roll out you’ll use.

Surroundings: No obstacles in the way, close to other suitable fields in case you mess up the approach to the first one!

There’s a couple of methods for arranging yourself in the sky in such a way as to reach your field, but the method we were using involved picking a spot 1000′ above the ground on what would be a close base leg if one visualised a normal circuit around the field.

Pick a landmark at that point to aim for and get to 1000 over it one way or another. Sounds simple enough but requires a bit of judgement and practice to get right.

From there it’s a relatively normal approach, except you start off aiming well down the field, and only when you’re certain of making that do you lower the flaps and aim closer to the near edge.

On the way down to the 1000′ point is time to check possible causes for the engine failure (assuming it hasn’t gone bang dramatically!) and attempt a restart if desired. Rather then remember mnemonics which I’m hopeless at anyway Carl suggested a logical working from right to left checking each item in turn.

First the temperature and pressure gauges, as if there was something obviously wrong like no oil then it would show up here and you could skip the restart attempts. If there was nothing obviously wrong then move on to check the primer–if it’s not locked it could be flooding the engine and causing the problem.

Next up, the throttle quadrant. Check the mixture (did we forget to put it back to rich after leaning?), fuel contents (are there some?) and give the throttle a waggle to see if it’s still actually connected to anything.

Carb heat and fuel pump, to the left of that, we switched on straight away, so onto check the magnetos individually and try the starter.

Assuming none of that helps then we start preparing for the actual landing. Mayday call and transponder to 7700 while we’re still high enough for anyone to hear us, then start securing things for the landing. Again rather then mnemonics it’s a logical work around the cockpit. Unlatch the roof catch to the doors, get the front seat passenger to push their seat all the way back and check their harness.

Then work through everything switching things off as required. The aim is to get rid of anything that could contribute to a fire if the landing is less than gentle. Throttle shut and mixture to idle cut off, fuel off, mags off, all electrics except the radio and transponder off. Those and the master switch go off last of all, on short final for our field, by which time talking to anyone becomes rather irrelevant!

As usual this all seems relatively simple on the ground, so out to try it in practice!

It was an extremely calm day, the windsock dangling lifeless on it’s pole. We took off on 22 turned towards Gower and climbed up to 2500′. A pair of Yaks were twizzling about and chasing each other through the sky over Swansea which was rather pretty, I’ve never watching aerobatics from the air before! They broke off as we got closer and headed off, leaving us free to practice.

I stared around, noticing not for the first time just how many fields there were out here in Wales, and more to the point how few of them were:

a) flat (or even flatish) and
b) not full of sheep (which sounds like every sort of cliché going but is sadly true!)

Our first ‘target’ therefore was an easy looking strip of beach near Whitford Point. Carl took control to demonstrate.

In his hands it all seemed surprisingly leisurely (I think we should start a campaign to demonstrate the manoeuvre to over enthusiastic journalists.)

It was rather less so in mine, and I arrived still halfway through my checks, though more or less on target. Shame about the walkers who turned up and made me go around higher than planned. I do hope I put on the power before any panicked phonecalls about crashing aeroplanes had been initiated…

We climbed back up to 2500′ and headed up the Loughor for a trickier try into a field. I picked one of a cluster of them along a road, overshot it completely but would probably have made the one beyond it without too much drama, though it did take a bit of a sideslip.

The reason for the “Surroundings” bit in the selection of a field was now extremely apparent!

Another beach, and two onto the airfield and we were out of time. The last one all the way to touchdown on the runway went reasonably well, the landing itself no worse than usual, prompting my sister, watching from the car, to comment “If that’s was an emergency landing I’d be quite happy!”

I suspect a bit more practice will be required at gaining the same sort of judgement when landing anywhere else however!

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