Quiet Airliners of the Future?

On 12 Sep 2005 15:55:39 -0700, "Ben Hallert"
wrote in .com::

There's been a lot of work over the years at Boeing on the Blended Wing
Body, I wonder if this is the same airplane, just retasked as a quiet
plane as well as a fuel efficient/large one.

http://en.wikipedia.org/wiki/Blended_Wing_Body
http://funimg.pchome.com.tw/img_uplo....tw_230558.jpg


Jack Northrop knew in the early days of aviation, before 1927, that
the path of aircraft evolution was necessarily going to eliminate the
empennage. After successfully designing a tailless bomber*, he
conceived of flying wing passenger airliners:
http://www.warbirdforum.com/paxwing.htm

* http://www.wpafb.af.mil/museum/fta/fta198.htm

If empennage elimination is such an "obvious" improvement, how come
it's taking so long?

I'm guessing that controllability is the major problem, and developers
are trying to fix that with electronic control systems?

On 14 Sep 2005 10:22:51 -0700, "Paul kgyy" wrote
in . com::

If empennage elimination is such an "obvious" improvement, how come
it's taking so long?

You have to look at it from a 1927 perspective. First, the empennage
was moved from the front (Wright) to the rear (Curtiss), then the
bi-wing was reduced to a monoplane, and then the wing was fully
cantilevered. What possible further revolutionary design changes
remain?

To Jack Northrop, the answer to that fundamental question was obvious:

http://www.wpafb.af.mil/museum/fta/fta198.htm
The year 1946 brought the Northrop Flying Wing B-35 bomber, a
bomber which dwarfed all previously built versions of all-wing
aircraft. It measured 172 feet in span, and was built for an
overload gross weight of 209,000 pounds, more than 104 tons. Four
Pratt & Whitney Wasp Major engines, developing a combined 12,000
horsepower, drove counter rotating propellers which pushed the sky
giant through the air. Elimination of the fuselage and tail
surfaces increased its efficiency by cutting down drag and
reducing the airplane to a nearly pure supporting surface in which
every part contributed to weight-lifting ability. The B-35 had a
range of more than 5,000 miles with a 10,000 pound payload.

The XB-49 was a jet-powered version of the B-35, containing eight
TG-180 (J33) Allison turbojet engines within the wings. Its gross
weight was approximately 206,000 pounds, and was capable of a
4,000 mile range with a 10,000 pound payload at 450 miles per
hour, (over 500 miles per hour maximum cruise speed), an
outstanding achievement in the era of that airplane, 1946. The
airplane had full power irreversible controls, the first aircraft
to incorporate this feature. It was also the first aircraft to
incorporate artificial stability augmentation. The airplane had
accommodations for a crew of 10, with four bunks, a gallery, and
head. An interesting feature of the XB-49 was the main control
arrangement... the pilot, co-pilot, navigator bombardier, flight
engineer, and the forward gunner, all were located together, being
able to see and speak to each other at all times. The maximum
length of the airplane, including sweepback, was 53 feet, and had
a wing thickness at maximum cockpit section, of seven feet. It had
a fantastic rate of climb and was extremely maneuverable.

The XB-49 was followed by the YB-49 Flying Wing bomber in 1947,
also powered by eight turbojet engines. It, like the B-35 and
XB-49, was an all-metal, tailless bombardment type airplane built
on the true Flying Wing design principle, with no tail surfaces,
using "elevon" controls as both elevators and ailerons, as did the
B-35 and XB-49. Its maximum weight, loaded, was 213,000 pounds. It
had a wing span of 172 feet, and had speeds in the 500-mph class.
The YB-49 was powered by eight General electric designed
Allison-built TG-190 (J35) turbojets, developing 4000 pounds of
thrust each.

The YRB-49A Flying Wing (1950) was an all-wing six engined
photo-reconnaissance type turbojet aircraft built to the Flying
Wing configuration. It had a span of 172 feet, the same as its
predecessors, the B-35 and YB-49. Six Allison TG-190 J35 turbojet
engines provided the power. Four of the engines were wholly
enclosed within the wing; two were suspended on pods.

I'm guessing that controllability is the major problem, and developers
are trying to fix that with electronic control systems?

Northrop's visionary aircraft were relegated to the scrap heap by
politics.

The story printed in the December 8, 1980 issue of the Los Angeles
Times newspaper states:

...
Then, in 1949, Flying Wing [B-36] production was abruptly canceled
and all test planes were ordered destroyed.

For three decades, Northrop has refused to discuss why his
promising airplane -- the culmination of his lifelong dream --
was scrapped so suddenly.

But in a dramatic taped interview broadcast last week, the
85-year-old Northrop Corp, founder finally told his secret. The
Flying Wing was canceled, he said, because he refused to obey an
Air Force order that he merge his then-fledgling company with a
more established competitive firm. When he balked, Northrop said,
the Air Force summarily awarded the bomber contract to the
competing firm.

Northrop said he kept quiet for all these years because he feared
the Pentagon would blackball his company if he disclosed the
story. He said he even committed perjury before Congress to hide
the facts.

Northrop's allegation shed new light on a generation-old
controversy that has become one of the biggest mysteries in
American aviation. ...

Northrop's story was corroborated by Richard W. Millar, 81, who
witnessed the drama as chairman of the Hawthorne-based aerospace
company at the time and who still serves as Northrop vice
chairman. ...

The Air Force secretary accused of issuing the merger order,
former Sen. Stuart Symington (D-Mo), 79, refused to be interviewed
...

To select a bomber to succeed World War II's B-29s, the Air Force
pitted Northrop's Flying Wing, designated the B-36 in 1948 and
later the B-49, against a traditionally configured bomber built by
Consolidated Vaultee Aircraft Corp. (Convair), which later became
a division of General Dynamics Corp. The Flying Wing won a
competition against Convair's B-36 in 1948 and the Air Force
awarded Northrop a contract to build 35-bombers, with the
possibility of ultimately producing 200 to 300 planes.

But Northrop's elation turned into disbelief when he and company
chairman Millar were summoned to meet Symington shortly after
winning the contract in June 1948, according to their taped
statements.

Noting that his was "a vary strange story and perhaps difficult to
believe," Northrop told KCET reporter Roberts that Symington
launched into a "lengthy diatribe" about how the Air Force did not
want to sponsor any new aircraft companies because the Pentagon
could not afford to support them with continuing business on
declining post-war budgets. Then, Northrop said, Symington
demanded that Northrop corp. merge with Convair.

At that point, Northrop recalled, Brig. Gen. Joseph T. McMarney,
commander of the Air Materiel Command and subsequently president
of Convair said, "Oh Mr. Secretary, you don't mean that the way it
sounds."

"You're ... right I do," Symington answered, according to Northrip
and Millar.

Northrip and Millar told KCET's Roberts that they then visited
Floyd Odlum, head of Atlas Corp., which controlled Convair, to
discuss a possible merger. But talks soon ended, Northrop said,
because Odlum's demands were "grossly unfair to Northrop."

A few days later, Northrop recalled, Symington telephoned him and
said, "I am canceling all your Flying Wing Aircraft."

"I said, 'Oh, Mr. Secretary, why?"

"He said, 'I've had an adverse report,' and hung up," Northrop
recounted. "and that was the last time I talked to him and the
last time we could reach him by phone or any other way."

As part of the cancellation, Millar added, the Air Force ordered
the destruction of seven Flying Wings then under construction.
"Those airplanes were destroyed in front of the employees and
everybody who had their heart and soul in it," said Millar, his
voice cracking.

After the Air Force canceled the Flying Wing and awarded the
contract to the competing Convair B-36, a House Armed Services
subcommittee held hearings in 1949 to investigate allegations that
the Pentagon used coercion in its aircraft procurement practices.

According to the press accounts at the time, the investigation was
prompted by "ugly rumors" about Symington and other Pentagon
officials. One rumor investigated - and denied by whiteness at
the hearing - was that Symington had been considered to head the
firm that would result from the proposed merger between
Consolidated Vaultee and Northrop.

Among the witnesses who denied seeing any evidence of Pentagon
coercion was John K. Northrop.

Northrop testified that he did not "feel there was any
unjustifiable or unreasonable pressure in the cancellation of the
B-49 contract. I would call the move reasonable and logical."
When asked under oath if he was in fear of Pentagon reprisal,
Northrip laughed and said, "have no fear of reprisal."

Thirty-one years later, when asked about his testimony by reporter
Roberts, Northrop responded, " My reaction is that under pressure
of the life or death of Northrip Corp., I committed one of the
finest jobs of perjury that I've ever heard."

Northrop said in the taped interview that he did not tell the full
story until now because he feared that Symington would cause the
"complete obliteration" of his company. Millar said that the
meeting with Symington was so "brutal and bare-faced" that "you
almost had to assume that he would be prepared to take further
steps if we didn't do as good boys and go along."

After serving as Air Force Secretary, Symington was elected to the
U. S. Senate, where he remained for 24 years. He was an
influential member of both the Armed Services and Foreign
Relations committees, and unsuccessfully ran for the Democratic
presidential nomination in 1960. ...

[In early 1979] NASA already decided, however, to put the Flying
Wing design "on a back burner" because it was best suited for much
larger cargo planes than will be needed by the military or
commercial users for the next two decades, Kayten told The Times.

None the less, in a letter sent to Northrop after the meeting,
NASA Administrator Robert A. Frosch acknowledged Northrop's
pioneering work and said "our analyses confirmed your much
earlier conviction as to the load-carrying and efficiency
advantages of the design approach."

In 1988 the Secretary of the Air Force announced on April 20 that the
first flight of the Advanced Technology Bomber, or B-2, is currently
scheduled for this fall. Northrop Corporation is the prime contractor
on the B-2 program.

Paul kgyy wrote:

If empennage elimination is such an "obvious" improvement, how come
it's taking so long?

In the case of passenger aircraft, the problem with a Jack Northrop
style flying wing (as opposed to a Sonic Cruiser style blended thing)
has much more to do with passenger comfort than technical issues.

The long aluminum tube places all of the passengers close to the
longitudinal axis, so that relative displacement of the passenger
compartment in roll is small. The opposite is true of a flying wing
design, so you end up with crap sliding off seat back trays, drinks
spilling and other passenger-unfriendly annoyances. Then there's the
distinct lack of windows, which also turns out to be an issue.

Flying wings are great for freight (including the explosive sort), but
not so hot for people.

I'm guessing that controllability is the major problem, and developers
are trying to fix that with electronic control systems?

Nah. Jack figured this out a long time ago, although computers have
allowed control systems to become even more clever.

On Wed, 14 Sep 2005 22:15:12 GMT, Chris Kennedy
wrote in ::

The long aluminum tube places all of the passengers close to the
longitudinal axis, so that relative displacement of the passenger
compartment in roll is small.

Agreed.

The opposite is true of a flying wing
design, so you end up with crap sliding off seat back trays, drinks
spilling and other passenger-unfriendly annoyances.

In a _coordinated_ turn, which necessitates a bank, or roll, on
longitudinal axis, there will be no such lateral displacement as you
predict, however, turbulence may produce some if that. If the roll
rate is brisk, there may be some increase in G felt by passengers in
the rising wind, and decrease in G felt by those in the descending
wing, but with today's computerized fly-by-wire control systems, all
these concerns could be largely eliminated in nearly all cases.

"Paul kgyy" wrote in message
ups.com...
If empennage elimination is such an "obvious" improvement, how come
it's taking so long?

It didn't take long at all. Read up on Jack Northrop

I'm guessing that controllability is the major problem, and developers
are trying to fix that with electronic control systems?

Jack Northrop had it figured out and working extremely well back in the
'40s.