Picture of the day

Gibbs505 said:
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That's that's a beautiful pic!!!
 
AP said:
Certainly dont know much about aircraft ... but I thought aircraft piston engines used magnetos that were completely independent of the other electrics and had multiple (two) magnetos for redundancy.. with each piston being served by both magnetos...??
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You are 100% correct about magnetos for ignition.

It has been awhile since I played with feathered engines, but if I get this wrong I am sure someone here will set the record straight.

Propeller pitch is controlled by hydraulic action, using, I think, engine oil and the pressure of the engine oil pump. Once the engine is shut down and the prop feathered, there is no oil pressure to un-feather. Un-feathering oil pressure comes form an electric pressure pump. It draws a lot of current.

A smart pilot, familiar with his airplane electrics, would shut down extra electrics, like radar and some radios, so as to not over tax the generator. If the circuit breaker pops, the battery may not (usually not) have the juice to run the pump and un feather the engine.

As the prop unfeathers it starts to spin and the engine then re-starts, if the gas is turned on.

Are you familiar with Murphy? It is a standard training procedure to practice an engine shut down and feather. Murphy would intervene on the re-start and instead of hitting the un-feather switch, he would hit the feather switch of the running engine. In a twin engine plane, this induces a condition known as gliding.

It is from Murphy we learned that with no engines running, the battery alone was insufficient to un feather a prop.

BTW, this is a good example of a lesson I have learned from the experience of others.

Note: I just ckecked a handbook on a twin. It appears my description above is correct.

DC starter / generators, HP fuel pump and the oil pumps are located on the accessory gear box. The AC Wild generators, PCU, feather pump (HP), aux. feather pump and overspeed governor are on the reduction gear box at the front of the engine.

The aux. feather pump is electrically driven. Prop is moved by oil from the HP feathering pump on the RGB. No springs or counterweights in the prop hub all moved by oil. (Of course, there are springs and counterweights in the PCU that control the prop speed by changing blade angle commands but those are not in the prop hub.) Metered pressure moves the prop blades toward flat pitch (decreased pitch) (and supply pressure) moves the props toward feather (increased pitch). When feathering the prop with the CL, you're moving a rod that opens a valve to dump metered pressure, allowing supply pressure to feather the prop. When the fire handle or ATPCS feathers a prop, a valve is electrically opened (feather solenoid valve) to dump metered pressure.
 
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Any of you guys playing Warthunder? I can't stop flying these WW2 beast! Plus all the tanks! Amazing free game for those into ww2 aircraft and vehicles.
 
purple said:
Another solution to the old airborne/airmobile dilemma of getting in fast, but going in light on anti-armor, mobility and direct fire support capabilities. The US tried to solve this problem with the aluminum alloy Sheridan tank which had the Shillegh ATGM/155mm low velocity gun combination. The missile was never that successful and the tank bucked like a mule when you fired the 155mm gun.

Nowadays people look to organic attack helicopters and close air support to compensate for these shortcomings, but their availability can't always be counted on. A bitter lesson of the airborne side of Market-Garden at Arnhem when people jumped into an armored enemy, along with using DZs too far from the objective and having your troops trickle in over a period of several days. Poor intelligence, hasty planning and spending too much time on the air plan, instead of the ground game, was bad too.
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The US military is still acutely aware of the problem. It's even worse now, given that any illiterate peasant with a few minutes of training and a modern shoulder fired guided missile can easily take out a helicopter or low/slow flying aircraft dropping off paratroopers. It means that now, more than ever, troops have to get dropped a significant standoff distance away from the target, and hoof it the rest of the way in. Often that means leaving a lot of heavy gear (including fire support capabilities) off the equipment list.

WarIsBoring discusses it in their write up of the Wiesel - which is still in use with the Bundeswehr, and saw use in Afghanistan.

https://warisboring.com/the-german-wiesel-is-a-cute-mini-tank-54da99f08cae#.cjc9stu0o

And ever fond of bad graphics and video, the US military has a 9&1/2 minute CG animation on how they want to solve it:

 
There's a fairly well known photo of a USMC Sherman on one of the Pacific islands with a KO'd Japanese tankette on its back deck, kind of like how you'd haul a deer home from the hunt.

There's another photo of a Sherman in the Goodwood battle in Normandy that rammed a German King Tiger. That's getting a kill the hard way.
 
Inside the Chieftain's Hatch is my absolutely favorite YT channel.I learned so much from those videos i wouldn't know where to even start.
I'm hoping they will do T-34/76,Stuart and Pzr 2,3,4 some day.
I could read 1000 books on the subject but seeing one video beats them all.
Forgotten Weapons is number 2 on my list for exactly the same reason.
 
Ganderite said:
You are 100% correct about magnetos for ignition.

It has been awhile since I played with feathered engines, but if I get this wrong I am sure someone here will set the record straight.

Propeller pitch is controlled by hydraulic action, using, I think, engine oil and the pressure of the engine oil pump. Once the engine is shut down and the prop feathered, there is no oil pressure to un-feather. Un-feathering oil pressure comes form an electric pressure pump. It draws a lot of current.

A smart pilot, familiar with his airplane electrics, would shut down extra electrics, like radar and some radios, so as to not over tax the generator. If the circuit breaker pops, the battery may not (usually not) have the juice to run the pump and un feather the engine.

As the prop unfeathers it starts to spin and the engine then re-starts, if the gas is turned on.

Are you familiar with Murphy? It is a standard training procedure to practice an engine shut down and feather. Murphy would intervene on the re-start and instead of hitting the un-feather switch, he would hit the feather switch of the running engine. In a twin engine plane, this induces a condition known as gliding.

It is from Murphy we learned that with no engines running, the battery alone was insufficient to un feather a prop.

BTW, this is a good example of a lesson I have learned from the experience of others.

Note: I just ckecked a handbook on a twin. It appears my description above is correct.

DC starter / generators, HP fuel pump and the oil pumps are located on the accessory gear box. The AC Wild generators, PCU, feather pump (HP), aux. feather pump and overspeed governor are on the reduction gear box at the front of the engine.

The aux. feather pump is electrically driven. Prop is moved by oil from the HP feathering pump on the RGB. No springs or counterweights in the prop hub all moved by oil. (Of course, there are springs and counterweights in the PCU that control the prop speed by changing blade angle commands but those are not in the prop hub.) Metered pressure moves the prop blades toward flat pitch (decreased pitch) (and supply pressure) moves the props toward feather (increased pitch). When feathering the prop with the CL, you're moving a rod that opens a valve to dump metered pressure, allowing supply pressure to feather the prop. When the fire handle or ATPCS feathers a prop, a valve is electrically opened (feather solenoid valve) to dump metered pressure.
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I follow ('most of') that --- thanks!!

(I presume the phrase: In a twin engine plane, this induces a condition known as gliding" is a euphemism for falling like a stone?)
 
AP said:
I follow ('most of') that --- thanks!!

(I presume the phrase: In a twin engine plane, this induces a condition known as gliding" is a euphemism for falling like a stone?)
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No, not really. Gliding means you are only going one way - down, but you still get to choose the place of landing/impact. You will recall that Air Canada (Gimli Glider) and Air Transat both treated a plane full of passengers to a gliding session.

Both incidents showed good airmanship to cure a problem caused by the pilots themselves.

I had a gliding session in my Mooney when it ran out of gas. The fuel sampling valve was stuck open. Pilot error....
 
donor said:
Inside the Chieftain's Hatch is my absolutely favorite YT channel.I learned so much from those videos i wouldn't know where to even start. I'm hoping they will do T-34/76,Stuart and Pzr 2,3,4 some day. I could read 1000 books on the subject but seeing one video beats them all. Forgotten Weapons is number 2 on my list for exactly the same reason.
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The host Nick Moran is a friend of mine. He does have a knack for this work. (And the way he fell into the job is a great tale.) :)
 
ARCHIVE.ORG

Please - if you are not aware of this site ... it is wonderful for various reasons that you can find for yourself by exploring it.... BUT for an excellent insight into the First World War period - and a months worth of reading (with great photos!) ... go here to see online copies of the 'Times' History of the War ( I have hard copies that were my fathers -- and then found these online!)
https://archive.org/details/timeshistoryofwa03lond



 
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Different shot of the same machine-Royal Aircraft Factory B.E.2

Unfortunately those machines were usual fodder of Fokker Eindecker when it arrived to the front in 1915.

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CV32-IMHO what Nick Moran does is a piece of fantastic work- I hope he sticks around for a long while.
 
Kaga
kaga01.jpg


Always was intrigued by it since a youngster.
Kaga is a Portuguese slang verb for something done while sitting down on the porcelain throne.
it's verb conjugation in six tenses is quite interesting.
 
Ganderite said:
No, not really. Gliding means you are only going one way - down, but you still get to choose the place of landing/impact. You will recall that Air Canada (Gimli Glider) and Air Transat both treated a plane full of passengers to a gliding session.

Both incidents showed good airmanship to cure a problem caused by the pilots themselves.

I had a gliding session in my Mooney when it ran out of gas. The fuel sampling valve was stuck open. Pilot error....
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I don't think Gimli was really the pilot's fault. This happened just when we were switcing to the metric system. The fuel was measured in kilos instead of pounds, so only 1/2 the correct amount was filled.
 
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