Off Topic - Spruce Goose

[Steve Beaver]

We have all seen the film of the Spruce Goose lifting off the water for a
few seconds only to be retired to its hangar never to fly again but I
wonder, what would its performance have been? Did Hughes determine in that
brief hop that the aircraft was no good or did ecconomic concerns ground it?

There are all kinds of aircraft performance analysis programs available now.
Has anyone ever plugged in the Goose specifications and determined how it
would fly?

[VideoFlyer]

Good question! I've often wondered about that myself.

[Richard Isakson]

"Steve Beaver" wrote ...
> We have all seen the film of the Spruce Goose lifting off the water for a
> few seconds only to be retired to its hangar never to fly again but I
> wonder, what would its performance have been? Did Hughes determine in that
> brief hop that the aircraft was no good or did ecconomic concerns ground
it?

I believe he discovered the airplane didn't have enough power to fly out of
ground effect even at empty weight. Others say that he had to fly one time
to collect the money from the contract. In either case, it's been shown
that it wouldn't have flown with a full load.

Rich

[Bill Daniels]

"Richard Isakson" > wrote in message
...
> "Steve Beaver" wrote ...
> > We have all seen the film of the Spruce Goose lifting off the water for
a
> > few seconds only to be retired to its hangar never to fly again but I
> > wonder, what would its performance have been? Did Hughes determine in
that
> > brief hop that the aircraft was no good or did ecconomic concerns ground
> it?
>
> I believe he discovered the airplane didn't have enough power to fly out
of
> ground effect even at empty weight. Others say that he had to fly one
time
> to collect the money from the contract. In either case, it's been shown
> that it wouldn't have flown with a full load.
>
> Rich
>
The prototype Hercules used 8 Pratt and Whitney R-4360 of 3500 HP each - the
wrong engines. The 5000 - 7000 HP Lycoming XR7755, then under development,
was the intended engine. The Convair B-36 and the Northrop B-35 were also
supposed to use the R7755. See:
http://www.aviation-history.com/engines/xr-7755.html

With a total of 56,000 HP instead of "just" 28,000 the "Spruce Goose" would
have been a outstanding success - don't blame the failure on the airframe.

It's interesting to speculate how these huge aircraft would have performed
with the enormous Liquid cooled Lycoming.

Bill Daniels

[Rich S.]

"Bill Daniels" > wrote in message
link.net...
>
> The prototype Hercules used 8 Pratt and Whitney R-4360 of 3500 HP each -
the
> wrong engines. The 5000 - 7000 HP Lycoming XR7755, then under
development,
> was the intended engine. The Convair B-36 and the Northrop B-35 were also
> supposed to use the R7755. See:
> http://www.aviation-history.com/engines/xr-7755.html
>
> With a total of 56,000 HP instead of "just" 28,000 the "Spruce Goose"
would
> have been a outstanding success - don't blame the failure on the airframe.
>
> It's interesting to speculate how these huge aircraft would have performed
> with the enormous Liquid cooled Lycoming.

Are plans available?

Rich "Sharpening my chisel" S.

[Frank Stutzman]

Bill Daniels > wrote:

> The prototype Hercules used 8 Pratt and Whitney R-4360 of 3500 HP each - the
> wrong engines. The 5000 - 7000 HP Lycoming XR7755, then under development,
> was the intended engine. The Convair B-36 and the Northrop B-35 were also
> supposed to use the R7755. See:
> http://www.aviation-history.com/engines/xr-7755.html

> With a total of 56,000 HP instead of "just" 28,000 the "Spruce Goose" would
> have been a outstanding success - don't blame the failure on the airframe.

Well, maybe.

According to the website you referanced the R7755 burned 580 gallons per
hour at 5,000 HP. For the Goose that would mean 8*580= 4,640 gallons an
hour or 27,840 pounds an hour. Nothing like burning 13 TONS of fuel an
hour!

However, according to http://www.sprucegoose.org/Specification.htm, the
Goose had a payload of 65 tons (130,000 pounds). It also says that the
cruise speed was supposed to be 175 mph. Lets we were going to fly it
from San Francisco to Honolulu (which seems to me to be a reasonable
mission). We've got a fair tail wind and we are going to get 200 mph
groundspeed. We are going to throttle back to 6 tons an hour. Thats a
2400 mile flight that will take 12 hours and burn 72 tons of fuel. Looks
to me like we were going to need fuel about a hour before we got to
Hawaii.

Now maybe the "payload" number on the sprucegoose website is after full
fuel. Maybe the R7755 were lighter than the R4360. It certainly seems to
me that it was doubtful that the goose could have had met its intended
use.

> It's interesting to speculate how these huge aircraft would have performed
> with the enormous Liquid cooled Lycoming.

Indeed.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

[L.D.]

Frank Stutzman wrote:

>Bill Daniels > wrote:
>
>
>
>>The prototype Hercules used 8 Pratt and Whitney R-4360 of 3500 HP each - the
>>wrong engines. The 5000 - 7000 HP Lycoming XR7755, then under development,
>>was the intended engine. The Convair B-36 and the Northrop B-35 were also
>>supposed to use the R7755. See:
>>http://www.aviation-history.com/engines/xr-7755.html
>>
>>
>
>
>
>>With a total of 56,000 HP instead of "just" 28,000 the "Spruce Goose" would
>>have been a outstanding success - don't blame the failure on the airframe.
>>
>>
>
>Well, maybe.
>
>According to the website you referanced the R7755 burned 580 gallons per
>hour at 5,000 HP. For the Goose that would mean 8*580= 4,640 gallons an
>hour or 27,840 pounds an hour. Nothing like burning 13 TONS of fuel an
>hour!
>
>However, according to http://www.sprucegoose.org/Specification.htm, the
>Goose had a payload of 65 tons (130,000 pounds). It also says that the
>cruise speed was supposed to be 175 mph. Lets we were going to fly it
>from San Francisco to Honolulu (which seems to me to be a reasonable
>mission). We've got a fair tail wind and we are going to get 200 mph
>groundspeed. We are going to throttle back to 6 tons an hour. Thats a
>2400 mile flight that will take 12 hours and burn 72 tons of fuel. Looks
>to me like we were going to need fuel about a hour before we got to
>Hawaii.
>
>Now maybe the "payload" number on the sprucegoose website is after full
>fuel. Maybe the R7755 were lighter than the R4360. It certainly seems to
>me that it was doubtful that the goose could have had met its intended
>use.
>
>
>
>>It's interesting to speculate how these huge aircraft would have performed
>>with the enormous Liquid cooled Lycoming.
>>
>>
>
>Indeed.
>
>
>
I don't know if it is true or just hanger talk but I've always heard
that aeronautical engineers say it is impossible for a bumble bee to
fly. However we all know they do it well. I would like for someone to
plug in aircraft performance analysis programs a bubble bees
specifications and see if it is possible for him to fly. OH well it
probably won't work because a bumble bee isn't an aircraft, or is he?

[BlakeleyTB]

The Hughes Flying Boat was intended to fly in ground effect.

[Ed Wischmeyer]

> The Hughes Flying Boat was intended to fly in ground effect.

Wow, never heard that before!! What's the reference?

thanks

Ed Wischmeyer

[Bill Daniels]

"Frank Stutzman" > wrote in message
...
> Bill Daniels > wrote:
>
> > The prototype Hercules used 8 Pratt and Whitney R-4360 of 3500 HP each -
the
> > wrong engines. The 5000 - 7000 HP Lycoming XR7755, then under
development,
> > was the intended engine. The Convair B-36 and the Northrop B-35 were
also
> > supposed to use the R7755. See:
> > http://www.aviation-history.com/engines/xr-7755.html
>
> > With a total of 56,000 HP instead of "just" 28,000 the "Spruce Goose"
would
> > have been a outstanding success - don't blame the failure on the
airframe.
>
> Well, maybe.
>
> According to the website you referanced the R7755 burned 580 gallons per
> hour at 5,000 HP. For the Goose that would mean 8*580= 4,640 gallons an
> hour or 27,840 pounds an hour. Nothing like burning 13 TONS of fuel an
> hour!
>
> However, according to http://www.sprucegoose.org/Specification.htm, the
> Goose had a payload of 65 tons (130,000 pounds). It also says that the
> cruise speed was supposed to be 175 mph. Lets we were going to fly it
> from San Francisco to Honolulu (which seems to me to be a reasonable
> mission). We've got a fair tail wind and we are going to get 200 mph
> groundspeed. We are going to throttle back to 6 tons an hour. Thats a
> 2400 mile flight that will take 12 hours and burn 72 tons of fuel. Looks
> to me like we were going to need fuel about a hour before we got to
> Hawaii.
>
> Now maybe the "payload" number on the sprucegoose website is after full
> fuel. Maybe the R7755 were lighter than the R4360. It certainly seems to
> me that it was doubtful that the goose could have had met its intended
> use.
>
> > It's interesting to speculate how these huge aircraft would have
performed
> > with the enormous Liquid cooled Lycoming.
>
> Indeed.
>
> --
> Frank Stutzman
> Bonanza N494B "Hula Girl"
> Hood River, OR

I suspect the 580 GPH is a gross error. Assuming a Specific Fuel
Consumption of 0.42 Lbs./HP/Hr., The R7755 would have "only" used 2100
pounds per hour at 5000 HP output. Assuming 70% power at cruise the fuel
consumption drops to 1470 PPH.

If the engine had been developed to put out 7000 HP and the SFC came in at
0.40, the 70% cruise fuel burn would have been 1,960 PPH. All eight
engines would burn 15,680 PPH or "only" 7.84 Tons per hour.

Given the liquid cooling, variable cam timing and gear box the SFC might
have been even lower.

Bill Daniels

[BPattonsoa]

>We have all seen the film of the Spruce Goose lifting off the water for a

My father was the lead structural engineer for the Goose fues. analysis. He
and two others designed all the frames and other parts you see in the big hull.
He was employed at Hughes 1939-44, employee number 60 (I think) an Structural
Aero Engineer from Carnigie Tech.

His opinion was simple. The aircraft would not have been controllable in
"normal" flight. The control surfaces were direct driven with some sort of air
assist. Hughes insisted on direct connection to the surfaces, and it would
have not been possible to fly. With some of the boost systems developed in the
later 50's, it would have worked, but just ask those who flew the big bombers
in WW2 what it was like.

Bruce Patton
(more later, got to go now)

[Bill Daniels]

"BPattonsoa" > wrote in message
...
> >We have all seen the film of the Spruce Goose lifting off the water for a
>
> My father was the lead structural engineer for the Goose fues. analysis.
He
> and two others designed all the frames and other parts you see in the big
hull.
> He was employed at Hughes 1939-44, employee number 60 (I think) an
Structural
> Aero Engineer from Carnigie Tech.
>
> His opinion was simple. The aircraft would not have been controllable in
> "normal" flight. The control surfaces were direct driven with some sort
of air
> assist. Hughes insisted on direct connection to the surfaces, and it
would
> have not been possible to fly. With some of the boost systems developed
in the
> later 50's, it would have worked, but just ask those who flew the big
bombers
> in WW2 what it was like.
>
> Bruce Patton
> (more later, got to go now)

There are many ways to get control boost that were known during the
development. It could be as simple as a servo tabs that offset the air
loads. The B-35 had a bellows device that used pitot pressure to provide
control boost that was proportional to airspeed. Even hydraulic control
boost was well known.

Remember, this was only a prototype and many enhancements could be expected
had it moved through normal flight test. Imagine if the first flight had
been in 1940 with the Atlantic full of German submarines. We might have
seen a fleet of huge flying boats.

The real reason that the project was cancelled was that the aircraft just
wasn't needed anymore at the time of the first flight.

Bill Daniels

[Ed Wischmeyer]

> >We have all seen the film of the Spruce Goose lifting off the water for a
>
> My father was the lead structural engineer for the Goose fues. analysis. He
> and two others designed all the frames and other parts you see in the big hull.
> He was employed at Hughes 1939-44, employee number 60 (I think) an Structural
> Aero Engineer from Carnigie Tech.
>
> His opinion was simple. The aircraft would not have been controllable in
> "normal" flight. The control surfaces were direct driven with some sort of air
> assist. Hughes insisted on direct connection to the surfaces, and it would
> have not been possible to fly. With some of the boost systems developed in the
> later 50's, it would have worked, but just ask those who flew the big bombers
> in WW2 what it was like.

When I saw the Spruce Goose a few years ago, the Docent said that it
initially had one kind of control system boost (perhaps pneumatic), but
when that didn't work, it was changed to hydraulic. Don't recall if that
was before or after the flight.

This doesn't seem consistent with the opinion proffered.

The Docent also said that Hughes refused to fly with any other pilot.
The right seater on the one hop was something like a terrified engineer
-- not to mention the folks downstairs who probably didn't know that the
boss was planning to lift off..

Ed Wischmeyer

[Morgans]

"BlakeleyTB" > wrote in message
...
> The Hughes Flying Boat was intended to fly in ground effect.

Your source is ????
--
Jim in NC

[Corky Scott]

On Mon, 05 Jan 2004 14:58:46 -0600, "L.D." >
wrote:

>I don't know if it is true or just hanger talk but I've always heard
>that aeronautical engineers say it is impossible for a bumble bee to
>fly. However we all know they do it well. I would like for someone to
>plug in aircraft performance analysis programs a bubble bees
>specifications and see if it is possible for him to fly. OH well it
>probably won't work because a bumble bee isn't an aircraft, or is he?

Your information is mistaken. This is a very old story and was
corrected almost immediately.

Here's what constitutes the usual explanation: "It apparently first
surfaced in Germany in the 1930s, and the story was about a prominent
Swiss aerodynamicist. One evening, the researcher happened to be
talking to a biologist at dinner, who asked about the flight of bees.
To answer the biologist's query, the Swiss engineer did a quick
"back-of-the-napkin" calculation.

To keep things simple, he assumed a rigid, smooth wing, estimated the
bee's weight and wing area, and calculated the lift generated by the
wing. Not surprisingly, there was insufficient lift. But that was
about all he could do at a dinner party. The detailed calculations had
to wait.

To the biologist, however, the aerodynamicist's initial failure was
sufficient evidence of the superiority of nature to mere engineering.
The story spread, told from the biologist's point of view, and it
wasn't long before it started to appear in magazine and newspaper
articles."

The further explanation is that once the aerodynamicist got back to
his lab he researched further and examined a bumblebee under a
microscope and realised his initial calculations were way off. He
corrected his error but of course the correction did not get the print
that the original statement got, and folks have been scoffing at
scientists ever since.

Corky Scott

[C.D.Damron]

"Corky Scott" > wrote in message
...
> The further explanation is that once the aerodynamicist got back to
> his lab he researched further and examined a bumblebee under a
> microscope and realised his initial calculations were way off. He
> corrected his error but of course the correction did not get the print
> that the original statement got, and folks have been scoffing at
> scientists ever since.


I think the missing links were the figure-8 flapping motion and wing-warping
that the bee used.

[Ron Natalie]

"C.D.Damron" > wrote in message news:0fzKb.299691$_M.1710730@attbi_s54...

> I think the missing links were the figure-8 flapping motion and wing-warping
> that the bee used.

Yes, the biggest factor is that they moving wing generates more lift than the
fixed wing theory would predict. In addition, the low reynolds numbers
involved also screws up attempts to extrapolate to larger flying craft.

[Eric Miller]

"C.D.Damron" > wrote in message
news:0fzKb.299691$_M.1710730@attbi_s54...
>
> I think the missing links were the figure-8 flapping motion and
wing-warping
> that the bee used.
>

All of this was after the Wright Brothers' patent for wing-warping and what
the aerodynamicist really said was that there was no way a bumblebee could
fly... without infringing on that patent =D

Eric

[Corky Scott]

On Tue, 06 Jan 2004 14:03:40 GMT, "C.D.Damron"
> wrote:

>
>"Corky Scott" > wrote in message
...
>> The further explanation is that once the aerodynamicist got back to
>> his lab he researched further and examined a bumblebee under a
>> microscope and realised his initial calculations were way off. He
>> corrected his error but of course the correction did not get the print
>> that the original statement got, and folks have been scoffing at
>> scientists ever since.
>
>
>I think the missing links were the figure-8 flapping motion and wing-warping
>that the bee used.

Right. But the point is, the original premise: that scientists proved
erroneously that the bumblebee couldn't fly, is false. "Scientists"
did not prove this, it was a cocktail estimation by one person made
with what he knew was inadaquate information. It only proved:
"garbage in, garbage out". It was just passing conversation blown out
of proportion and the media and critics of science have run with this
ever since.

Corky Scott

[Wright1902Glider]

There seems to be an important part of the story missing in this thread. The
aircraft's original designation was HK-1, which stood for Hughes-Kaiser. But
when the aircraft finally flew, it was only designated H-1. So what happened
to our 'ol buddy Henry Kaiser? He saw the light. Without a war, a
monster-airplane is just that. And without payloads, that means a monster
hangar-queen. Which is what the H-1 eventually became. Kaiser quit the
project before it was finished. Hughes, on the other hand, kept at it. And as
systems problems delayed to completion of the plane, questions arose. He
didn't have much of a choice when it came to finishing and flying the plane...
he was being investigated by a Congressional committee who believed the entire
project was nothing more than a boondoggle.

Still, it would be intresting to see what the performance numbers would be. My
guess is that it would be very slow and very sluggish... not unlike a certain
other famous airplane built by two brothers from Ohio. Its longest flight
lasted about as long.

Harry

[Bill Daniels]

"Wright1902Glider" > wrote in message
...
> There seems to be an important part of the story missing in this thread.
The
> aircraft's original designation was HK-1, which stood for Hughes-Kaiser.
But
> when the aircraft finally flew, it was only designated H-1. So what
happened
> to our 'ol buddy Henry Kaiser? He saw the light. Without a war, a
> monster-airplane is just that. And without payloads, that means a monster
> hangar-queen. Which is what the H-1 eventually became. Kaiser quit the
> project before it was finished. Hughes, on the other hand, kept at it.
And as
> systems problems delayed to completion of the plane, questions arose. He
> didn't have much of a choice when it came to finishing and flying the
plane...
> he was being investigated by a Congressional committee who believed the
entire
> project was nothing more than a boondoggle.
>
> Still, it would be intresting to see what the performance numbers would
be. My
> guess is that it would be very slow and very sluggish... not unlike a
certain
> other famous airplane built by two brothers from Ohio. Its longest flight
> lasted about as long.
>
> Harry

Henry Kaiser talked Howard Hughes into the project in the first place. In
1942, Kaiser was building Liberty Ships which were being sunk by Hitler's
submarines at an alarming rate. Henry wanted to deliver high priority cargo
by air and avoid the subs.

175 MPH is slow for a big airplane, but it is very fast compared to a 12
knot Liberty Ship. Had the HK-1 been available in '42 it would have been
seen as a war winner.

Is it fair to say that the HK-1 was late or that the war was won sooner than
many planners thought? Had critical battles in Europe gone Hitler's way,
WW2 might have lasted until 1950, and the HK-1's fate might have been very
different.

Bill Daniels

[CecilWilliams]

Interesting anectdote on the one flight of the Spruce Goose. I took a
second tour through the inside of it recently at the Evergreen
Aviation Museum in McMinnville (first time was in Long Beach around
'81) and the old timer who was giving the talk said that when the HK-1
(H-4) Spruce Goose was airborne, the fuselage flexed more than it was
designed to and that there were a lot of cracking wood sounds...

Here are a couple of photos I took fore and aft of the innards of the
Goose, since I haven't seen any others around:

http://www.photo.net/photodb/photo?photo_id=1946559

http://www.photo.net/photodb/photo?photo_id=1946571



- Cecil


"Steve Beaver" > wrote in message >...
> We have all seen the film of the Spruce Goose lifting off the water for a
> few seconds only to be retired to its hangar never to fly again but I
> wonder, what would its performance have been? Did Hughes determine in that
> brief hop that the aircraft was no good or did ecconomic concerns ground it?
>
> There are all kinds of aircraft performance analysis programs available now.
> Has anyone ever plugged in the Goose specifications and determined how it
> would fly?

[Rich S.]

"CecilWilliams" > wrote in message
om...
>
> Here are a couple of photos I took fore and aft of the innards of the
> Goose, since I haven't seen any others around:
>
> http://www.photo.net/photodb/photo?photo_id=1946559
>
> http://www.photo.net/photodb/photo?photo_id=1946571

Remarkable shots, Cecil. Thank you for sharing them with us.

Rich S.

[Blueskies]

Yes, Thanks. What are all the red bottles on the floor?

--
Dan D.



..
"Rich S." > wrote in message ...
> "CecilWilliams" > wrote in message
> om...
> >
> > Here are a couple of photos I took fore and aft of the innards of the
> > Goose, since I haven't seen any others around:
> >
> > http://www.photo.net/photodb/photo?photo_id=1946559
> >
> > http://www.photo.net/photodb/photo?photo_id=1946571
>
> Remarkable shots, Cecil. Thank you for sharing them with us.
>
> Rich S.
>
>

[Corrie]

First I've heard that the B-36 was originally designed to use the Lyc.
AFAIK it was always intended to use the Pratt 4360. The B-36 could
carry 84,000 lbs of weapons, on top of fuel and crew.
"Featherweighted" versions could exceed 48,000 ft (and outfly fighters
with heavier wing-loading), come close to 400 MPH over the target, and
flew missions of over 24 hrs (no inflight refueling). Not all at the
same time, of course. Range or payload, pick one.



"Bill Daniels" > wrote in message . net>...
> "Richard Isakson" > wrote in message
> ...
> > "Steve Beaver" wrote ...
> > > We have all seen the film of the Spruce Goose lifting off the water for
> a
> > > few seconds only to be retired to its hangar never to fly again but I
> > > wonder, what would its performance have been? Did Hughes determine in
> that
> > > brief hop that the aircraft was no good or did ecconomic concerns ground
> > it?
> >
> > I believe he discovered the airplane didn't have enough power to fly out
> of
> > ground effect even at empty weight. Others say that he had to fly one
> time
> > to collect the money from the contract. In either case, it's been shown
> > that it wouldn't have flown with a full load.
> >
> > Rich
> >
> The prototype Hercules used 8 Pratt and Whitney R-4360 of 3500 HP each - the
> wrong engines. The 5000 - 7000 HP Lycoming XR7755, then under development,
> was the intended engine. The Convair B-36 and the Northrop B-35 were also
> supposed to use the R7755. See:
> http://www.aviation-history.com/engines/xr-7755.html
>
> With a total of 56,000 HP instead of "just" 28,000 the "Spruce Goose" would
> have been a outstanding success - don't blame the failure on the airframe.
>
> It's interesting to speculate how these huge aircraft would have performed
> with the enormous Liquid cooled Lycoming.
>
> Bill Daniels

[Bill Daniels]

"Corrie" > wrote in message
om...
> First I've heard that the B-36 was originally designed to use the Lyc.
> AFAIK it was always intended to use the Pratt 4360. The B-36 could
> carry 84,000 lbs of weapons, on top of fuel and crew.
> "Featherweighted" versions could exceed 48,000 ft (and outfly fighters
> with heavier wing-loading), come close to 400 MPH over the target, and
> flew missions of over 24 hrs (no inflight refueling). Not all at the
> same time, of course. Range or payload, pick one.
>

The Lycoming R7755 (http://www.aviation-history.com/engines/xr-7755.html)
likely would have been very efficient at cruise power due to the liquid
cooling, two speed gearbox and variable cam timing. The extra power would
have eliminated the need for the B-36's four jet engines that were required
with Pratt 4360's. This would have expanded the range, speed and/or payload
options. Additionally, the liquid cooling would have allowed vastly smaller
cooling inlets on the wing leading edge (think better wing performance)
while eliminating the notorious cooling problems with the Pratts. The same
things could have been true of the Spruce Goose and the Northrop B-35.

The XR-7755 was just one of the incredible piston engines under development
in the late 1940's. Probably the pinnacle of piston engine development was
the Napier Nomad 2-stroke diesel in Britain. This compact and powerful 12
Cylinder boxer had a sfc of 0.345 lb/ehp/hr.
http://www.home.aone.net.au/shack_one/nomad.htm

It's interesting to speculate what an alternate aviation history would have
looked like had these engines emerged from their development stage and gone
into production. Turbines would have had a harder time displacing pistons.

Bill Daniels

[ChuckSlusarczyk]

In article m>, Blueskies
says...
>
>Yes, Thanks. What are all the red bottles on the floor?

CO2 for the fire suppresent system ,if I remember right. I was there, I saw it
and it was neat and so was the Queen Mary.

See ya

Chuck (I like wood planes too) S

[Wright1902Glider]

Another interesting factoid that I ran across about the Lycoming... its water
pump was rated at 750 GPM... more that an average fire truck.

Even if these monsters had made it into production, it would not have been long
before the turbines caught up to and eclipsed them. I've read that Wright
intended its 3350-compound turbo engine (Super Connie) to be the market leader
for the next 50 years. Shortly thereafter, the big piston market dried up and
so did Wright.

Its not just the weight savings or increased operating efficiency that make
turbines better than big pistons. Its the incredible savings in maintenance
through increased TBO's and fewer AOG's. Of course, they'll never sound as
cool.

[Rich S.]

"Wright1902Glider" > wrote in message
...
>
> Its not just the weight savings or increased operating efficiency that
make
> turbines better than big pistons. Its the incredible savings in
maintenance
> through increased TBO's and fewer AOG's. Of course, they'll never sound
as
> cool.

Harry.............

Believe it or not - spark plug cost was a big factor.

Say, $5/plug in those days. B-36, six engines, 72 plugs/engine = 432 spark
plugs, every 100 hrs = $2160/100 hrs = $21.60/hr.

Rich S.

[Bill Daniels]

"Wright1902Glider" > wrote in message
...
> Another interesting factoid that I ran across about the Lycoming... its
water
> pump was rated at 750 GPM... more that an average fire truck.
>
> Even if these monsters had made it into production, it would not have been
long
> before the turbines caught up to and eclipsed them. I've read that Wright
> intended its 3350-compound turbo engine (Super Connie) to be the market
leader
> for the next 50 years. Shortly thereafter, the big piston market dried up
and
> so did Wright.
>
> Its not just the weight savings or increased operating efficiency that
make
> turbines better than big pistons. Its the incredible savings in
maintenance
> through increased TBO's and fewer AOG's. Of course, they'll never sound
as
> cool.

All true. However, it was a long time after turbines became common in
fighter aircraft that the unrefueled long range capabilities of piston
engines were eclipsed - and then only by airborne refueling of turbine
aircraft. The Lockheed Neptune "Truculent Turtle" and, of course, the Rutan
Voyager were piston long-range aircraft that prove the point.

One could wonder what would have happened if jet fuel costs in 1957 at the
dawn of commercial jet travel had been $2 a gallon instead of $0.10. Those
old piston airliners might have had much longer careers.

For unrefueled range, pistons still rule.

Bill Daniels

[Wright1902Glider]

All true, but again, you have to factor in the cost of maint. and AOG's.

By the way, I'm having a little trouble following the math on the spark plug
equation. An R-4360 has 28 cylinders x 2 plugs per cyl. = 56, not 72. So a
B-36 would need 336 plugs @ $5 = $1680. Not terrible considering what turbine
blades on a JT-8D probably cost. But here's the rub: how long does it take to
change a spark plug in a tightly cowled and baffled radial? Lets see, at a
bare min, you'll have to pull the wire, the "cigarette", and the old plug, gap
the new plug, and then put it all back together. That's IF you don't have to
pull any baffles or pannels to get at it... which you probably will.

I know a few old KC-97 pilots who told me they would be AOG for days while the
plugs were changed.

Harry "engine? what's an engine?" Frey