The Grob 109B - one of the two planes that Jim regrets selling. Photo by Ian Howat on AirHistory.net.
bloody undercarriage. You see, the air around us hasn’t changed much since the 1930s – so the flying bit of the aeroplane is fine. But the advent of runways – instead of nice open grass fields – has caused all sorts of problems for the bits of the aeroplane that interact with the ground. The wheels, the tyres, the brakes, the suspension – just kidding there isn’t any. The silly marie biscuit tyres were meant to absorb all the bumps. When the Junkers was designed you taxied a short distance in a straight line to your takeoff point and then turned into wind. Same when you had landed – a straight line taxy to your parking spot. With the advent of runways things became complicated. You have to taxy a hell of a long way on a hard unforgiving surface, and you have to keep turning on to different taxiways. Nothing about the structure below the wings was designed to cope with such things. There are no toe brakes - simply massive rudder pedals with leather straps over your feet. The straps serve two purposes, they help you keep your feet on the rudders in turbulence, and they enable you to shove with one foot and heave with the other. Almost everything on the aircraft
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requires massive physical strength. There’s no power steering or fly by wire – you physically push and pull things that are connected via railway fixings to other things. My mate “Squintin” – Mike St Quintin – says, “The JU bounced along during taxi, it had no oleos, springs etc. The bouncing came from the tires acting like a spring with no shock absorber. This, I believe, is what caused a loosely fitting tire to come off the rim.” Except it didn’t just happen once – it was a reasonably common event. Mike goes on to say, “I never had trouble with the air brakes other than they were unpredictable in how effectively they would work. They could be a bit grabby and equal pressure applied to both brakes was never guaranteed to cause equal braking. Actually it very seldom did. The brakes are powered by a compressed-air bottle under the co-pilot's feet. This air is fed through a mass of pipes, valves and pressuregauges, to… guess where… the throttle levers. Throttle back the left motor and you have left brake. The right throttle will do the same for that brake, while the centre throttle works both binders.
