The Installation of the Grove

Aluminium Undercarriage

On G-XPXP

The left original glass undercarriage gear failed after some 700hrs of flying from my grass strip. Some 150 hours earlier, the gear was in contact with a stray lamb on the runway and my belief is that it was this incident that caused the eventual delamination of the glass under the left hand mounting point. Repairs were considered impossible and so a new gear was ordered from Grove. G-XPXP is a relatively early Pulsar with wood spars and a gross weight of 960lbs. Grove made a 'special' Pulsar Lite gear for me for this gross weight. It is somewhat thinner than the standard 1200 lb gross Pulsar gear they supply and turned out to be only 2lb heavier than the original.

Installation was relatively easy although not without its problems. I decided to invert the fuselage so everything had to be taken out, engine, instruments etc. The major problem was that the Grove gear is narrower at the mounting point than the original glass gear. This meant building up the fuselage mounting points to accommodate the new dimensions. Pictures show it better:

The old and new gear legs together.

Note that the new gear is also a little taller which allows a deeper installation in the fuselage and better clearance for the rudder cables etc.

The mounting tabs now formed and bent for correct alignment with lots of Duralac and zinc chromate paint.

Drilling the mounting holes was less traumatic than expected. The gear was placed in the fuselage and clamped in yje correct position, using a pencil with a good sharp point and just the right size for the hole, I carefully inserted it to give one small pencil mark on the gear tab. The gear was removed and drilled. It worked! Everything lined up exactly.

I installed several extra layers of glass from the fuselage bottom and into the gear well fore and aft. I then made 'aluminium epoxy' pads to take up the space left by the thinner Grove gear.

Each 'pad' has a hard aluminium centre where the bolt goes through to take the clamping loads. Again these were made on the fore and aft sides of the gear well to take up the gaps. The gear was put in place with sellotape on the lugs and the aluminium epoxy pushed into place. A thin layer of glass finally covered them to give a little more durability.

The gear in place showing the need for the spacer pads.

Not shown is the bonding on to the trailing edge of the leg of a 5/16" ID HDPE tube to take my brake cables. This was bonded on with micro and glassed over with two layers of very thin glass cloth wrapped right around the legs. It has stayed in place so far. With gear finally bolted in place, the bottom close-out was replaced and the area resprayed. I made some removeable fairings to cover the holes where the legs enter the fuselage and I went flying again!

'XP back on her feet

I've been very impressed with the Grove gear. It took a few weeks to arrive but the workmanship was excellent and I can tell no difference in handling on the ground. The aircraft stands just a little higher than it did before, but again, there is no discernable difference in take off / landing characteristics. Thanks to the folks at Grove, my inspector Dave Silsbury and the Popular Flying Association for approving the mods.