1 engined Lancs(2004 Zombie)

sorry it won’t let me upload it – file is too big apparently

Just found this old thread. Sharkie if you wish to PM me I will assist in getting your picture to a postable size.

It just needed one very tiny ‘cough’ from the donk that was running for the entire crew to discover that adrenaline was brown!!
Resmoroh

Is this the picture you were looking for?

Galdri, my gut feeling and (limited in regard to aircraft engines) mechanical knowledge tells me you’re right although I have no personal experience to refer to.

Referring to Bomberboy’s extremely unpleasant post, I sincerely hope it can be proved you ARE right.

Thanks for that dhfan.

I think I know, more or less, how a piston engine with full feathering prop works. I have, however, no desire to enter in a flame war with someone who knows it all so much better, and has even seen an engine running with the prop in feather. 🙁

Quite the opposite, I believe. Unfeather a serviceable engine at 200mph and it should start, assuming fuel, ignition, etc.
Like bump-starting a car using a highish gear, it would be best to start in coarse pitch if possible. Too fine presumably would generate excessive drag as well as making it difficult to turn the engine over.

Would it have something to do with whether the aircraft was at standstill (on the ground) or flying?

Point being that if at standstill, there’s no airpressure on the blades to speak of, therefore relatively easy to rotate them at low revs.

But if you’re doing say 200mph wouldn’t there be a lot of air pressure on the blades to keep them from rotating?

Galdri, my gut feeling and (limited in regard to aircraft engines) mechanical knowledge tells me you’re right although I have no personal experience to refer to.

Referring to Bomberboy’s extremely unpleasant post, I sincerely hope it can be proved you ARE right.

Bomberboy,

I bow to your superior knowledge!

I do not know the first thing about engines :confused:

What we need is somebody current on big piston engines or with access to some manuals.

FLUFFY!

Would be nice seeing a Lancaster with three engines out doing an upward barrel roll. 😮

Cees 😀

Galdri,
“Hummm, not quite sure where you are comming from here.” – Obviously, I thought I spelled it out very simply!

Paragraphs 1 & 2; – Totally irrelevant here, any reference for parrafin props was never made!

Paragraph 3; – All piston engines are direct drive engines, you can not turn the engine without turning the prop…….. very good we ppear to be getting somewhere!
With regards to the rest of the paragraph I’ll give you an old saying – Proof in the pudding is in the eating, and I’ve seen a few puddings in my time. (no I’m not a F*t biffa)
The following scenario could happen if you start by unfeathering the prop first….The engine does not start and now your left with a windmilling prop that you will have to feather again…..darn it.
Even when you’re flying along with a feathered prop it still can turn a bit, provided of course nothing has seized, so to start an engine with the prop feathered is no big deal.
I’ve seen many an engine run with the prop in full feather and have not seen the engine quit through detonation.

“So how do we start piston engines from feather? On a big thing like a Merlin, I think (without knowing for sure)”
Now call me stupid, but didn’t you just tell us exactly how we should all start or big piston engines. If there’s one thing that niggles me and that’s………………………….

Bomberboy

Sycamore,

You can start an engine and keep it in the feathered position until you are up and running, where you can then unfeather the prop and put it on load immediately.
If it decides not to unfeather then at least it’s in the right position.

Your ‘inference (there’s that word again) suggests that in restarting a feathered engine will immediately cause major drag problems, particularly where asymetrics are concerned.
But as I detailed above, engines can be re-started with no ‘significant’ problems and regardless of which position on a multi engined aircraft.

Bomberboy

Hummm, not quite sure where you are comming from here.

What you are actually talking about would be the airstart and unfeathering process of a free wheeling turbine, like the PT6, PW120 or something similar. They are, in the course of normal operation and during attempted airstarts, started with the prop in the feathered position. This is possible due to the fact that the prop is not connected to the gas generator turbine. On these engines, there are, say, three turbine discs at the rear. The two of them, that are nearest to the cans, are fixed together and are called, collectively, the gas generator turbine. The gas generator turbine runs the engine’s compressors located at the front end via a shaft. The rear most turbine would be called the Power Turbine, and that one would run the prop via a shaft running INSIDE the shaft powering the gas generator. As the prop and the compressor do not share the same turbine, it is possible to start the engine with the prop feathered.

Now lets look at a direct drive turbine like the Garret TPE 331. On that engine the Gas Generator Turbine and the Power turbine are one and the same. Two (IIRC) turbine discs at the rear driving one shaft, onto which are put the compressor and the prop (via a gearbox). Now, what would happen if you tried to start an engine like that in feather? The drag of the propeller rotating in feather, would either burn (set fire) to your starter motor, OR you would cook the engine itself when trying to spool it up to idle speed. All aircaft with direct drive turbine engines have UNFEATHERING buttons to be used before airstart is attemped from the feathered position.

All piston engines are direct drive engines, you can not turn the engine without turning the prop. If you try to start a piston engine in feather, one of two things will happen. Your starter will go up in smoke, due to the drag of the prop in full feather OR your engine will be ruined due dentonation (spelling). Dentonation is what happens if you put a lot of stress on your engine. A lot of heat will build up inside the cylenders and hot soot will begin to collect there. When the next portion of fuel/air mixture is put into the cylender the soot will set it alight and there will be an istantanious uncontrolled explosion as opposed to the controlled burn of normal operation. Very, very bad for your engine. So how do we start piston engines from feather? On a big thing like a Merlin, I think (without knowing for sure) that there would be an UNFEATHERING pump that would put the prop into fine pitch, and from there the engine (maybe with starter assist) would windmill till it was running.

Sycamore,

You can start an engine and keep it in the feathered position until you are up and running, where you can then unfeather the prop and put it on load immediately.
If it decides not to unfeather then at least it’s in the right position.

Your ‘inference (there’s that word again) suggests that in restarting a feathered engine will immediately cause major drag problems, particularly where asymetrics are concerned.
But as I detailed above, engines can be re-started with no ‘significant’ problems and regardless of which position on a multi engined aircraft.

Bomberboy

There was a piece on this in flypast in the last 18 months or so. they have flown on one engine over raf watton and raf shepherds grove the aircraft was from the same unit. I was speaking to someone recently who remembered this happening.

sorry it won’t let me upload it – file is too big apparently

i hope this works!

attached is the photo of the Lanc

It’s a sad day when an Antipodean such as myself is caught correcting native speakers of the Queen’s English!

No need to worry about the empire FlyingKiwi since I’ve never been a native English speaker! Which is why I was concerned about my grammar! :rolleyes:

Sharkie: If the image is on your computer you can just attach it to a post with the button ‘manage attachments’.

1 engined Lanc

Thanks DHfan – I took my photo at Booker in 69/70 ? No autofocus or auto wind on in those days and metering was semi auto – the result is a sharp but under exposed shot.

Not too many cameras around in wartime, or long lenses, but Geoffrey de Havilland Jr.’s party trick was upward rolls on one engine in a Mossie.
Impressed the powers-that-be no end.

Regarding the photo it’s actually an image I downloaded from a website and it’s now my wallpaper – and before you ask I don’t remember which one although it was probably a site devoted to Lancs as I just love them!

Sharkie – if it’s on your PC get cracking and post it! re. copyright, just say what you’ve said above (that you don’t know where it came from).