Bear question

Just yesterday a friend asked me if there were stability issues during the
design of the Tu-20. This was on account of its extremely long and slender
fuselage which obviously presents a huge mmt arm. I though maybe cruise/drag
considerations or structure limitations may have been the rationale behind
it. The engines are quite close inboard, so I guess the large arm is not
based on yaw requirements for an engine-out/wind case.

I've not been able to find anything on this, does anyone know what the deal
is?

Jim Doyle wrote:

Just yesterday a friend asked me if there were stability issues during the
design of the Tu-20. This was on account of its extremely long and slender
fuselage which obviously presents a huge mmt arm. I though maybe cruise/drag
considerations or structure limitations may have been the rationale behind
it. The engines are quite close inboard, so I guess the large arm is not
based on yaw requirements for an engine-out/wind case.

I've not been able to find anything on this, does anyone know what the deal
is?

I can't answer your question about the length of the Tu-95 - but the slender
fuselage is because it is a direct lineal descendant of the Boeing B-29 !!

The B-29 was reverse-engineered into the Tu-4 Bull.

The Bull spawned the Tu-80 & Tu-85.

The Tu-95 evolved from them.

They all have the same diameter fuselage.

A good starting point on the Tu-95 is the Aerofax book on the 'Tupolev
Tu-95/-142 Bear' by Yefim Gordon & Vladimir Rigmant.

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++
Ken Duffey - Flanker Freak & Russian Aviation Enthusiast
Flankers Website - http://www.flankers.co.uk/
++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++

"Ken Duffey" wrote in message
...
Jim Doyle wrote:

Just yesterday a friend asked me if there were stability issues during
the
design of the Tu-20. This was on account of its extremely long and
slender
fuselage which obviously presents a huge mmt arm. I though maybe
cruise/drag
considerations or structure limitations may have been the rationale
behind
it. The engines are quite close inboard, so I guess the large arm is not
based on yaw requirements for an engine-out/wind case.

I've not been able to find anything on this, does anyone know what the
deal
is?

I can't answer your question about the length of the Tu-95 - but the
slender
fuselage is because it is a direct lineal descendant of the Boeing B-29 !!

The B-29 was reverse-engineered into the Tu-4 Bull.

The Bull spawned the Tu-80 & Tu-85.

The Tu-95 evolved from them.

They all have the same diameter fuselage.

A good starting point on the Tu-95 is the Aerofax book on the 'Tupolev
Tu-95/-142 Bear' by Yefim Gordon & Vladimir Rigmant.


Thank you Ken for the info! - The book sounds a great source and a good
read, I'll look it up and see if I can get my hands on it.

Cheers,

Jim D


++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++
Ken Duffey - Flanker Freak & Russian Aviation Enthusiast
Flankers Website - http://www.flankers.co.uk/
++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++

"Ken Duffey" wrote in message

descendant of the Boeing B-29 !!

it is my understanding all modern passenger airframes are based on the
design of the B29

"Ozman Trad" wrote
"Ken Duffey" wrote

descendant of the Boeing B-29 !!

it is my understanding all modern passenger airframes are based on the
design of the B29

That would be a bit far fetched.

All modern passenger airframes are swept wing? Which large aircraft had
that first? (I'm thinking B-47, but I'm probably wrong).

All modern passenger airframes have the fuselage on top of the wings, and
not in the middle (ala B-29).

The Bear bomber is a utilitarian delivery machine, designed for high-speed
over tonnage. It was/is probably one of the best bombers ever designed by
any aircraft company. We should have bought them in 1991 and phased-out
the B-52! :-) A Bear-H is probably about the best cruise-missile platform
there is. We could fly cruise-missile missions from the east coast to Iraq
and back, with no air refueling in a Bear-H (24 hour endurance unrefueled).

"S. Sampson" wrote in message
news:ToqVb.16319$Q_4.12353@okepread03...
"Ozman Trad" wrote
"Ken Duffey" wrote


All modern passenger airframes have the fuselage on top of the wings, and
not in the middle (ala B-29).


Nope some are high wing like the BAE-146

Keith

"S. Sampson" wrote:

The Bear bomber is a utilitarian delivery machine, designed for high-speed
over tonnage. It was/is probably one of the best bombers ever designed by
any aircraft company. We should have bought them in 1991 and phased-out
the B-52! :-)

Absurd. The Bear was approx. 200 mph SLOWER than the Stratofortress.

The Bear bomber is a utilitarian delivery machine, designed for high-speed
over tonnage. It was/is probably one of the best bombers ever designed by
any aircraft company. We should have bought them in 1991 and phased-out
the B-52! :-)

Absurd. The Bear was approx. 200 mph SLOWER than the Stratofortress.


A B-36 was capable of 40+ hour missions, but that doesnt mean it could have
made it to Iraq and back either.

A P-3 has a very long endurance too, when 2 engines are shut down, when it
needs endurance.

I do not quite think a Bear could have made it from US to Iraq and back,
unrefueled, just because it can stay in the air 24 hours. It would probably
have to slow down considerable to be able to achieve that.

You can have speed and you can have endurance, but it is hard to have both.




Ron
Pilot/Wildland Firefighter

.. Absurd. The Bear was approx. 200 mph SLOWER than the Stratofortress.

Not at cruise altitude it wasn't. The bears I intercepted were clocking .8
IMN, about 480 KTAS. At altitude, the Buff isn't that much faster,
certainly not "200 mph" faster.

R / John

In article ,
"Ozman Trad" writes:
"Ken Duffey" wrote in message

descendant of the Boeing B-29 !!

it is my understanding all modern passenger airframes are based on the
design of the B29

The B-29 pioneered a lot of the construction techniques and materials
used in modern aircraft (Well, a950-1960s modern, anyway, B-29s didn't
make any use of composites, for example.) Thick-skin construction,
the first large pressurized aircraft, the first large airplane built
with the armamant and sensor systems integrated into teh airframe from
the beginning, that sort of stuff.

It was also pretty much the first "Systems-Oriented" airplane, where,
in order to fly it effectively, it _required_ an integrated crew.
Before the B-29, Flight Engineers were, for the most part, Airborne
Crew Chiefs, as much there for Damage Control as anything else. In
the B-29, the FE was an integral part of the crew, acting as the
Systems Manager for the powerplants, fuel, and environmental systems.

That being said, there was a big departure in structural techniques
when the first U.S. jetliners wre designed (Boeing 707 & DC-8).
Instead of using the stuctural techniques that had been common
practice up to that point, ("Safe Life", which menat that you could
pretty much guarantee that an airframe would hang together for a
certain amount of time) both Boeing and Douglas developed "Fail Safe"
structures, which meant that, as much as possible, ther were no single
load paths which would allow, say, something like a fatigue failure to
cause catastrophic damage. I suppose a good practical example of that
would he the Hawaiian 737 that lost most of the upper portion of the
forward cabin in-flight.




--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster