Low flying military aircraft

[classic33]

[QUOTE 3038429, member: 9609"]Since there are a few aero engineers on this thread - an off topic question. On radial engines (where the cylinders don't rotate) how does the engine scavenge oil when running? I understand the need to turn them before starting to clear oil build up in the lower cylinders that could cause hydraulicking, but when the engine is running, how do they stop the lower cylinders being swamped?[/QUOTE]
From http://en.wikipedia.org/wiki/Aircraft_engine#Rotary_engine
"However, the gyroscopic effects of the heavy rotating engine produced handling problems in aircraft and the engines also consumed large amounts of oil since they used total loss lubrication, the oil being mixed with the fuel and ejected with the exhaust gases."

 

[Cow Pie]

[QUOTE 3038429, member: 9609"]Since there are a few aero engineers on this thread - an off topic question. On radial engines (where the cylinders don't rotate) how does the engine scavenge oil when running? I understand the need to turn them before starting to clear oil build up in the lower cylinders that could cause hydraulicking, but when the engine is running, how do they stop the lower cylinders being swamped?[/QUOTE]

Scratching my head and trying to remember the last time I worked or even saw one of those. Doing my basic engineering cert I think.
Radial engines use a dry sump system with the lower cylinders having a separate sump from the others. The earlier ones simply allowed the oil to drain into this tank and the oil via a scavenge pump was then fed back into the main wet tank. The later ones used bypass or bleed air to pressurise the oil flow and return it to the wet sump via a scavenge pump. Radial engines have a high compression ratio but lose a lot due to their design so tapping air off isn't a problem.
Each engine would carry several gallons of oil due to oil usage but the majority was reclaimed. The scavenge system returning at a higher rate than the feed system so ensuring a positive recirc flow.
The very early radial engines, better known as rotary engines, had no such systems and the oil was burnt through the combustion chamber and any that was not was simply vented to atmosphere via the exhaust. Castor oil was used a lot during this time hence the pilots requesting toilets on the runway. OK I made the toilet bit up but the pilots were known the be very regular
I have now taxed my brain to the point of now needing a lie down and a cup of sweet tea.
Hope it answers your question to some degree. I have simplified it somewhat but you get the gist

 

[Cow Pie]

[QUOTE 3038429, member: 9609"]Since there are a few aero engineers on this thread - an off topic question. On radial engines (where the cylinders don't rotate) how does the engine scavenge oil when running? I understand the need to turn them before starting to clear oil build up in the lower cylinders that could cause hydraulicking, but when the engine is running, how do they stop the lower cylinders being swamped?[/QUOTE]

Good pic showing the dry sump/scavenge sump (seen between the bottom 2 piston/cylinders)
http://farm3.staticflickr.com/2271/2476338864_3fa3452c5e_z.jpg?zz=1

 

[Spinney]

Came across this via facebook - that is insanely close - far more nuts than the flying-so-low-along-a-runway-that-you'd-crash-if-you-lowered-the-undercarriage. At least runways don't normally move!

 

[Doseone]

Just had a low fly over the house by one of these.

Had to Google it, it's a V22 Osprey. I'd never heard of it or seen one before, sounded a bit like a Chinook approaching but flew over much quicker.

 

[Mad Doug Biker]

Just had a low fly over the house by one of these.

Had to Google it, it's a V22 Osprey. I'd never heard of it or seen one before, sounded a bit like a Chinook approaching but flew over much quicker.

Apparently they have an awful safety record!

 

[Doseone]

Apparently they have an awful safety record!

It doesn't look as thought it should be able to fly!! Funny looking thing.

 

[Yellow Fang]

I still blame Harold Wilson and Dennis Healey for scrapping this beauty:

The BAC TSR2. It would have been so cool. They scrapped it saying the American F111 would be a lot cheaper, which it turned out not to be, so they weren't bought neither. Someone I worked with said the Wilson government ordered all the design documents to be scrapped so that the project could not be resurrected. I saw a bit of one of these in the Brooklands Museum.

 

[classic33]

From the front.

 

[welsh dragon]

From the front.
View attachment 44430

Blimey. That does look weird.

 

[Spinney]

I still blame Harold Wilson and Dennis Healey for scrapping this beauty: ...

The BAC TSR2. It would have been so cool. They scrapped it saying the American F111 would be a lot cheaper, which it turned out not to be, so they weren't bought neither. Someone I worked with said the Wilson government ordered all the design documents to be scrapped so that the project could not be resurrected. I saw a bit of one of these in the Brooklands Museum.

I used to work with a bloke who'd worked on TSR2 - he used to reminisce about it nostalgically ...

 

[classic33]

Blimey. That does look weird.

Saw one when Bell were behind the project. Flying into Shannon Airport.

 

[The Jogger]

We just got buzzed by two F15's screaming over. They are proper loud! One was doing a hard banked turn. On a sunny evening like this seeing these appear over the hill and disappear down the valley there are few more impressive sights. I could watch them all day. Those guys must have one of the best jobs in the world.

We witnessed something similar when we stayed in a cottage in Libanus , Brecon. It made me jump they first time they appeared over the hill but what an amazing sight.

 

[Nigel-YZ1]

I was a regular at the Finningley air shows. Not seen the like for years.
Vulcan, Blackbird etc. Those were the days!

 

[classic33]

[QUOTE 3066817, member: 9609"]I wonder if it can make them spin in opposite directions[/QUOTE]
They are spinning in opposite directions. A bit like a twin rotor helicopter to keep it stable.