After a good deal of thought and pencil sucking I came up with a carbon/glass fibre composite spring that looked far more satisfactory. Next stop Mr. G.Gratton Esq. Chief Technical Officer at the BMAA. He gave me his testing requirements which, armed with a load cell and a camera, I duly carried out.

For the technical among us the results were:

Spin Up test 1650kgs at 40 degrees off load path.

Spin Back 2032kgs at 32 degrees off load path

Max. Vertical Reaction 2260kgs at 17 degrees (both in drag and compression)

These tests were carried out without the tyres on which if added would add 1484kgs to all the results.

The u/c showed no damage or deterioration after the testing.

I also tested my CFM supplied u/c which failed (due to a sever compression/shear fracture on both pultrusion rods) at 1120kgs.

Fitting the new undercarriage is fairly simple. The main spring uses the four holes that are occupied by the U-bolts holding on the old undercarriage and the drag struts are replaced by two arms extending forward either side and bolted to two aluminium brackets bonded to the inside of the hull tub and reinforced by carbon fibre plates. The old wheel hubs and brake drums can be used again. Disregarding resin curing times, the whole thing can be fitted in a couple of hours

I have done about 60 landings with the new u/c and the difference is well worth the effort. Taxiing on roughish ground doesn't have the same rolling gait and when you put it down on the runway it doesn't have the tendency to throw you back in the air again ( or is it only me that suffers from that??). My strip is only 160 yards long so the technique has to be 'positive'(!) with this new u/c and now I don't have to hold my breath if my landings is less than feather-like.

My own undercarriage has full Section S approval. I am now wrestling with the BMAA over production so if any one is interested please get in touch, as more voices would make my life easier!

Mick Newman