Dump and gone

On Saturday night, I ended up at a Highgate Hill park with hundreds of other people watching the Brisbane Riverfire fireworks display, most noteworthy this year because it apparently really is the last time the city (or anyone in Australia?) will see an F111 dump and burn.

An explanation as to why this is a unique trick of this particular aircraft is given here:

Wing Commander Gray, who will be piloting one of the F-111s on Riverfire night, says the dump and burn is simply down to a quirk of design.

"Every big aircraft that carries a lot of fuel - even big airlines have that ability to be able to dump fuel in case they need to come back to lighten the load," he said.

"With the F-111 the dump port where the fuel comes out is actually between the engines and because we are an after-burner aircraft, which is gives us more power, we basically inject fuel into the exhaust. That's what most fighter-type aircraft do.

"If we're dumping fuel at the same time when we're in afterburner the fuel ignites, whereas in other aircrafts it would just be seen as a vapour stream."

Given that they have always been based at Amberbley, I suspect Brisbane is pretty unique in having this as a regular feature of our fireworks and other displays.

I think, but haven't been able to confirm through Google yet, that the first time it was done here for entertainment purposes was for the Commonwealth Games in 1982. There were four of them that peeled apart while alight, causing some surprised residents to think the Four Horsemen of the Apocalypse were paying a visit.

Anyhow, the people in the park on Saturday night seemed particularly pumped to see the F111, which did put on 3 particularly long burns this year. Low cloud makes it look brighter too. I've looked at various movies taken of it on Youtube, and I think this is one of the best: