ZZS Bead seating.

[ScottR400D]

James, yes that's basically a good idea but that cage will only really help with a split rim or a rim with a locking ring becoming loose during inflation. If the tyre fails there could be quite a bit of shrapnel flying!  

If there's any doubt about the tyre itself, you'd want a much more enclosed cage or a Kevlar bag type safety system. 

I've never felt the need to use one for car tyres but have occasionally inflated with a long airline and stood around the corner!

[Beagler]

When pressurising  the Eurofighter cockpit canopy in a jig there was a cargo type net over it and secured. I think that was kevlar.

[aerobod - near CYYC]

Hi Peter, I agree with aircraft tyres and the danger of the much higher operating pressures of 200PSI or so, you do need a full cage as the sidewalls will turn into shrapnel when they explode.The specialist tyre fitter I use says that with a steel belted car radial the full cage isn't really required, as the tread won't fail, the sidewall will burst, ejecting the tread as a whole or the wheel rim itself, so protection to retain the big pieces between the operator and wheel is needed, eye protection being needed for the small debris.

Lots of energy in aircraft tyres, both from an air pressure perspective and momentum at takeoff speed. One of the most dangerous and funniest incidents I had some involvement with when working at WestJet was a 767-300 that had a wheel bearing set fail and separate on a main gear bogie at Calgary airport a number of years ago. The wheel weighing about 250kg stayed on the ground when the aircraft rotated, continuing down the 14,000ft runway another 5,000ft or so before bouncing on the grass and finally losing much of its momentum before tearing out part of the perimeter fence and luckily stopping before running across the roads beyond the airport. The lackey in the Maintenance dept who had to retrieve it was the son of my IT project manager.

Hi Beagler, the most interesting aerospace pressure test I know of was when I was working at RAE Farnborough in the late '70s and early '80s. They had to test the pressurized 5m wind tunnel before commissioning to about 50% beyond it's 3 Bar maximum working pressure. They used anti-submarine netting over it and evacuated local residents and stopped traffic in a couple of mile radius during the test.

[Beagler]

Forgive me if this is off topic but I to have fond memories at Aerospace.

Three Tornadoes F3's seeing who can get closest to the control tower Sitting on the loo and suddenly a Tornado on reheat goes vertical over the hangar roof (Messy). Roland Beaumont test pilot flying between two hangars at 100ft in a lightning. (He was in Colditz diring the war). Just a couple of memories among many.

[Geoff Brown]

ScottR400D - Glad that you resolved the problem of seating.

Seems to be more of an Apollo wheel problem than any other type ? As to the poor balancing of the 420 wheels at only 700 miles should I suggest that once again CC have shown their real colours.........

Having worked in a 'big heavy' aircraft wheel & tyre bay I can say without hesitation that a cage is the only way to go. After a tyre change the wheel is locked in the cage with the N2 line already connected to the external supply & pressure regulator.

The regulator was at least 6' feet away so one could slowly raise the pressure to the max of about 250psi. I was always taken by surprise by the bangs when the beads seated. Even though one was expecting it. Tyre & wheel was then left to soak for at least 20 minutes before entering the cage & adjusting the pressure for transit.

The cage was quite substantial, about 5' square on side & about 3' wide enclosed in eighth inch diagonal wire spaced at half inch but had substantial dents in it when allegedly things had gone wrong in the past.

As with most aircraft wheels they are split rims so changing a tyre was an all day process as every component was cleaned, closely inspected, replaced if necessary, NDT carried out as required by the schedule. Also a repaint if the surface condition was beyond limits or was due in the life cycle which then meant a 2-3 day job. So then you moved on to the next one.