Decommissioning

[Flying Sorcerer]

A few years ago the RAAF retired their F-111s. They decided the F-111s were too expensive to scrap so they were cut into sections and buried. Is this a common problem? How difficult or expensive is it to cut up and recycle an old aircraft, armoured vehicle or warship? Will the widespread use of composites make decommissioning more problematic? The older generation of aircraft were built of light alloys that (I thought) might find a salvagers market.

 

[Zoo Tycoon]

I believe the original contract demanded that no bits of F111 could be sold to anyone and could only be returned to OEM for disposal. But when GD declined to take any back what do you do with em? ..... dig a big hole. Military aircraft frequently have these type of clauses;- nearly all former USAF donated to organisations are prohibited from being scrapped even though this is straight forward and quite necessary if neglected.

Older aircraft are simple to recycle....Nothing to do with the cost of gas axe or cutting disc’s or toxic materials.

Currently CFRP is a pain because you need to cut it up in a hazmat suit, bag it up and landfill it;- Similar to asbestos but hopefully in a few years we might be able to do better.

 

[jeffb]

Same in Australia, remaining aircraft buried.

"Separately, Australian media reported that 23 F-111s were buried in a landfill near the Australian town of Ipswich."
- Flight Global

 

[lordroel]

Same in Australia, remaining aircraft buried.

"Separately, Australian media reported that 23 F-111s were buried in a landfill near the Australian town of Ipswich."
- Flight Global

View attachment 648139

Reminds me of Iraq burying their aircraft during the 2003 war.

 

[Foo Fighter]

Did they not fly their more important types into Iran?

 

[jeffb]

Same in Australia, remaining aircraft buried.

"Separately, Australian media reported that 23 F-111s were buried in a landfill near the Australian town of Ipswich."
- Flight Global

View attachment 648139

Reminds me of Iraq burying their aircraft during the 2003 war.

I get the feeling, hearing that GD didn't want them back, the Brits burying theirs as well and the horror stories about (iirc) resealing fuel tanks on the RAAF ones, that they were too toxic to do anything else with. To be clear though, that's just speculation.

That said, they have kept (I think) 6 for static displays and museums.

 

[Zoo Tycoon]

No F111 were owned by the Brits, so none were buried by the Brits. We only O/H’ed Uncle Sam’s here;- I remember when the F111 were retired from the USAF, freshly overhauled F111 being flown straight out of our facility directly to Davis Monthan (DM) for scrapping. Indeed one aircraft with a cracked centre wing box had to have a replacement centre wing box fitted, which itself came from a scrapped F111 at DM, only so it could be flown to DM for scrapping ( the centre section came from an earlier model so needed a far more onerous mod process)..... you couldn’t make this stuff up. Everything unserviceable coming off the F111 during OH had to be returned to US, even down to the hanger floor sweeping.

It’s quite routine for maintenance engineers to work inside fuel tanks.The guys in the US had no problem with gas axing F111 fuel tanks. Likewise all other aircraft from the same period with the typical tank sealants are being scrapped.. Hence I’m pretty sure there’s nothing you could put in a fuel tank that would make it too toxic to scrap.

 

[Foo Fighter]

Can these materials not be recycled in some way?

 

[Zoo Tycoon]

Aluminium and steel are easypesy to recycle. Titanium and Nickel cannot be separated from other alloying elements;- each part needs to manually scanned and batched with others of the same alloy = expensive hence low scrap metal price.

GRP and CFRP are landfill but there’s studies ongoing to investigate if carbon fibre can be extracted from a cured matrix.

Tyres are used for all sorts,- rubber crumb for soft exercise surfaces, retreaded for agriculture vehicles and ship bumpers..to name a few.

Most other materials just go to land fill.

 

[shedofdread]

Recycling CFRP is getting quite a thing now. The matrix (resin) is burnt out and the resulting fibres chopped up. This can then be used to make moulding compounds (as distinct from the usual, long fibre type laminates). If memory serves correctly, Bentley make their bonnets using this material. Obviously, not economically viable for GRP.