37- Secondary Safety Issues

  • Safety Articles

Hello Everybody,

In the light of recent events, can I gently ask you all to go and take a careful look at your aeroplane (or re-consider the one you are building).

Is there an easy means of opening its door or canopy from the outside? If not, please work on making one.

Is that handle or latch clearly placarded? By that I mean, so clearly placarded that it can be read in the dusk by eyes half-shut against smoke and flames? If not, I am sure Allen Buzza will be happy to help you with an appropriate sticker.

Are your seat cushions made from Temperfoam, Dynafoam, Conforfoam or another conformal-type foam? These foams are available from Aircraft Spruce, and probably WAM. They are heavier and much more costly than ordinary furniture or cushion foam, but they are far more comfortable in use, and much safer in an accident. If you can afford them, Oregon Aero make superb seats from this stuff for most production aeroplanes, and will satisfy custom orders.

Ordinary foams compress instantly under high G, allowing your spine to bash hard on to the underlying structure. Conformal foams compress only relatively slowly, giving good G absorption. If you don't believe me, again ask Allen Buzza, who used to be six feet tall. He reckons expanded polystyrene foam (styrofoam) is as good as conformal foams and much cheaper. I do not know whether he is right, but I have used a combination of both types of foam in my aeroplanes.

Finally, particularly if your seat is at all reclined, do you have a five-strap harness? That fifth strap (the 'negative G' or 'crutch' strap) is there, not to hold you in place while inverted, but to stop your body from sliding under the lap belts during harsh decelerations. If you don't have one, and your aeroplane comes to a sudden stop, however tight they are, you shoot under the lap straps and your spine is bent backwards over the front seat lip.

It is a universal requirement for all commercial and military aircraft that their pilots' harnesses have five straps. Even Boeings, with their upright seats, have them.

You might remember the British 'Kegworth disaster' of fifteen years or so ago? The two pilots of a nearly-new British Midland Airways Boeing 737 mis-identified a failed engine, and shut down the wrong one. On short final to Castle Donnington (East Midlands) airport, the running (but severely damaged) engine failed completely, leaving them in a big, heavy glider. They landed in a field a mile short of the threshold, just before the M1 motorway. The aeroplane went down the motorway embankment at high speed, across both carriageways, and impacted into the far embankment, coming to a stop suddenly.

Many passengers and crew survived, including both pilots, but the captain had not bothered to fasten his negative G strap, believing it unnecessary. He shot forward under his belts, his spinal cord was snapped, and he never walked again. I think five-point harnesses are a good idea, and urge you all to consider them.

It is great if your aeroplane has good 'primary' safety, like excellent controls, brilliant visibility and great performance, but just once in a lifetime, good 'secondary' safety items like this can become important.

Please take the time to inspect and if necessary modify your aeroplanes.

I am going to fit an external handle to my Fournier's canopy as soon as I get back to WA.

Yours,

Bob "Bob the Grim" Grimstead
SABC Safety