Eyeglasses

"Savageduck" wrote in message
news:2009050220185823810-savageduck1REMOVESPAM@mecom...
On 2009-05-02 20:04:28 -0700, "Bill Graham" said:


"Savageduck" wrote in message
news:2009050219354029267-savageduck1REMOVESPAM@mecom...
On 2009-05-02 19:24:42 -0700, Savageduck
said:

On 2009-05-02 17:58:05 -0700, "Bill Graham" said:


"Neil Harrington" wrote in message
news
"Savageduck" wrote in message
news:2009050112220531729-savageduck1REMOVESPAM@mecom...
On 2009-05-01 11:39:50 -0700, "Neil Harrington"
said:


"Savageduck" wrote in message
news:2009043014370550073-savageduck1REMOVESPAM@mecom...
On 2009-04-30 14:02:10 -0700, "Neil Harrington"

said:

His unofficial kill was on a long range P-38 patrol around Buna in
New Guinea.
My father recalls the P-47 incident. It was what made believers of
all the fighter pilots. That took place at Dobodura NG.
They had been trained to not change cruise settings from the manual.
Lindbergh had them run with low RPM, high manifold pressure (which
is counter manual & counter intuitive) and dialed back prop pitch.
After his tour they were able to conduct long distance patrols far
exceding specs, and return with fuel in reserve.

--
Regards,
Savageduck

That's very interesting. I stand corrected on the kill. I think it
was in his "Wartime Journals" that I read about the P-47 business,
but I don't recall whether he went into much detail on the exact
technique. I *thought* it involved going to a leaner mixture than
pilots liked to use (for fear of burning the exhaust valves) but I
don't remember now where I got that, and may be entirely mistaken.

It is common practice to adjust your mixture to the leanest point
after taking off and reaching your required altitude and heading, and
then enriching it to the point where your cylinder head temperature
steadies out and no longer rises......

As noted above, Lindbergh had these pilots cruise with lean fuel
settings and high manifold pressure, which was counter intuitive for
all of these pilots (and their manuals & training.) They and their crew
chiefs all believed the engines would be damaged. It was only after
Lindbergh demonstrated otherwise that they took his advice and had
massive gains in range. These pilots conducted the longest raids of the
war in any Theater.

The strange thing was, they never used his techniques in the European
Theater, given the ranges for many of the raids in the SW Pacific
exceded those on the 8th AF daylight raids on Germany. This developed
the myth of the P-51 to the cost of the European reputation of the P-47
& P38. This was certainly a political decision.

There was one element I failed to reitterate, that was low RPM, along
with the leaned fuel and high manifold pressure settings at altitude.

--
Regards,
Savageduck


Too bad they didn't have variable pitch props.......They might have been
able to improve their mileage even better........

If you had read the complete thread on this subject you might have seen
the following "Lindbergh had them run with low RPM, high manifold
pressure (which is counter manual & counter intuitive) and dialed back
prop pitch."
They certainly had variable pitch props, and these were also factored into
the equation.
--
Regards,
Savageduck

I am surprised.....I didn't know that the fighter pilots had that
ability.....I thought that in WW-II, only the helicopters could do that in
flight.....

On 2009-05-03 00:13:38 -0700, "Bill Graham" said:


"Savageduck" wrote in message
news:2009050220185823810-savageduck1REMOVESPAM@mecom...
On 2009-05-02 20:04:28 -0700, "Bill Graham" said:

Too bad they didn't have variable pitch props.......They might have
been able to improve their mileage even better........

If you had read the complete thread on this subject you might have seen
the following "Lindbergh had them run with low RPM, high manifold
pressure (which is counter manual & counter intuitive) and dialed back
prop pitch."
They certainly had variable pitch props, and these were also factored
into the equation.
--
Regards,
Savageduck

I am surprised.....I didn't know that the fighter pilots had that
ability.....I thought that in WW-II, only the helicopters could do that
in flight.....

Hamilton Standard developed variable pitch props in the 1920's.
Lindbergh used a Hamilton Standard variable pitch prop on the Spirit of
St. Louis in 1927.
After the first two position pilot selected pitch adjustment, some of
the newer designs were automatic variable pitch, which adjusted pitch
via centripetal counter balancing so as to maintain optimal RPM.
During WWII electrically controlled props were developed.
Fighters and multi-engined aircraft benefited with auto-feathering
props in the event of engine failure to reduce drag and improve gliding
properties. They also had the benefit of full manual pitch adjustment.

....and as far as WWII helicopters go, I believe a little research on
your part will show these were in minimal use and barely out of
functional development, with a few exceptions such as the German Focke
Fa224, Fa223 & Fa336. The USA had mostly experimental helicopters, but
several such as the Sikorsky YR-4B, & R-4B "Hoverfly" and Sikorsky R-5A
were used in limited operations. The British had the Wier W.5/6 and the
Bristol RI/II, but mostly used the Sikorsky YR-4B/R-4B.


--
Regards,
Savageduck

Savageduck wrote:


There was one element I failed to reitterate, that was low RPM, along
with the leaned fuel and high manifold pressure settings at altitude.

Too bad they didn't have variable pitch props.......They might have
been able to improve their mileage even better........

If you had read the complete thread on this subject you might have seen
the following "Lindbergh had them run with low RPM, high manifold
pressure (which is counter manual & counter intuitive) and dialed back
prop pitch."
They certainly had variable pitch props, and these were also factored
into the equation.

Drag is proportional to velocity squared and so is lift. Drag is also
proportional to angle of attack. Normal cruise speed is faster than
maximum range speed. Slowing an airplane down 10-15 miles an
hour from the normal cruise speed will significantly increase range.
We routinely flew in the high arctic at speeds designed to optimize
range to conserve fuel. Some of these flights lasted as long as
13 hours. We could move fuel from the cockpit between tanks
and by playing with the residual fuel in the tip tanks and extreme
fuselage tanks we moved the CofG so the trim was slightly nose
down. This would extend range by reducing drag and increasing
cruise speed.

Running an engine at a lower RPM may or may not help with range.
Lower RPM would mean lower friction losses that might be offset
by lower engine efficiencies. Most large WW II era engines tended
to have a relatively narrow efficient working range.

To achieve the same power the manifold pressures and combustion
pressures are higher and may impact engine life and reliability.

Variable pitch props have been around since before WW II
to match the engine torque curves to airspeed. Full pitch range and
feathering were available on many WW II aircraft.

w..

"Savageduck" wrote in message
news:2009050301414811967-savageduck1REMOVESPAM@mecom...
On 2009-05-03 00:13:38 -0700, "Bill Graham" said:


"Savageduck" wrote in message
news:2009050220185823810-savageduck1REMOVESPAM@mecom...
On 2009-05-02 20:04:28 -0700, "Bill Graham" said:

Too bad they didn't have variable pitch props.......They might have
been able to improve their mileage even better........

If you had read the complete thread on this subject you might have seen
the following "Lindbergh had them run with low RPM, high manifold
pressure (which is counter manual & counter intuitive) and dialed back
prop pitch."
They certainly had variable pitch props, and these were also factored
into the equation.
--
Regards,
Savageduck

I am surprised.....I didn't know that the fighter pilots had that
ability.....I thought that in WW-II, only the helicopters could do that
in flight.....

Hamilton Standard developed variable pitch props in the 1920's.
Lindbergh used a Hamilton Standard variable pitch prop on the Spirit of
St. Louis in 1927.
After the first two position pilot selected pitch adjustment, some of the
newer designs were automatic variable pitch, which adjusted pitch via
centripetal counter balancing so as to maintain optimal RPM.
During WWII electrically controlled props were developed.
Fighters and multi-engined aircraft benefited with auto-feathering props
in the event of engine failure to reduce drag and improve gliding
properties. They also had the benefit of full manual pitch adjustment.

...and as far as WWII helicopters go, I believe a little research on your
part will show these were in minimal use and barely out of functional
development, with a few exceptions such as the German Focke Fa224, Fa223 &
Fa336. The USA had mostly experimental helicopters, but several such as
the Sikorsky YR-4B, & R-4B "Hoverfly" and Sikorsky R-5A were used in
limited operations. The British had the Wier W.5/6 and the Bristol RI/II,
but mostly used the Sikorsky YR-4B/R-4B.



IMO, helicopters are, " barely out of functional development " today....
During my lifetime, an enormous number of people I have either known
personally, or who were public figures have died screwing around with those
machines.....