The Swearingen-TEB incident: control issues with twins

An engine loss in a Garrett powered aircraft such as the Swearingen or
MU-2 would be quite noticeable at any power setting.

The Negative Torque Sensor (NTS) on the Garrett TPE331's will dump oil
pressure from the prop dome when the engine flames out. The spring load
on the prop will drive the prop to a high pitch, lower drag
configuration, but does not feather the prop. The pilot must manually
perform this task.

I have been told that in a MU-2 with a four bladed prop, should an
engine quit and the NTS fail, a minimun turn of 90 degress will occur
before the pilot gets the prop feathered. The NTS should be checked
every engine start and is a no go item should it not test properly.

The Searingen Metro, like th MU-2, is a handful of airplane with 2
pilots and 2 engines. One pilot and one engine? ew.......


G. Lee

wrote:

I have been told that in a MU-2 with a four bladed prop, should an
engine quit and the NTS fail, a minimun turn of 90 degress will occur
before the pilot gets the prop feathered. The NTS should be checked
every engine start and is a no go item should it not test properly.

The Searingen Metro, like th MU-2, is a handful of airplane with 2
pilots and 2 engines. One pilot and one engine? ew.......


G. Lee


Yes, same on Turbocommandes, engine faillure and NTS malfunction can be
a killer on 331's

wrote in message
oups.com...
An engine loss in a Garrett powered aircraft such as the Swearingen or
MU-2 would be quite noticeable at any power setting.

The Negative Torque Sensor (NTS) on the Garrett TPE331's will dump oil
pressure from the prop dome when the engine flames out. The spring load
on the prop will drive the prop to a high pitch, lower drag
configuration, but does not feather the prop. The pilot must manually
perform this task.

I have been told that in a MU-2 with a four bladed prop, should an
engine quit and the NTS fail, a minimun turn of 90 degress will occur
before the pilot gets the prop feathered. The NTS should be checked
every engine start and is a no go item should it not test properly.

The Searingen Metro, like th MU-2, is a handful of airplane with 2
pilots and 2 engines. One pilot and one engine? ew.......


G. Lee


It is not quite as bad as all that. NTS failures on takeoff are saveable at
least in the simulator but immediate feathering is required. The airplane
will not yaw or roll 90 deg.

Mike
MU-2

On Wed, 01 Jun 2005 15:03:52 GMT, "Mike Rapoport"
wrote:

It is not quite as bad as all that. NTS failures on takeoff are saveable at
least in the simulator but immediate feathering is required. The airplane
will not yaw or roll 90 deg.

Mike
MU-2
Speaking of difficult to handle twins.

In 1939, the Martin Co. responded to a request for a high speed medium
twin engined bomber with a submission that was named the "Marauder"
and designated the 26th such commissioned design, or B-26.

Martin assigned a young aerodynamics engineer to the task of designing
the airplane. The specifications called for a top speed of 300 mph or
better, but DID NOT specify a landing speed. The designer responded
by installing the two biggest engines in production at the time, the
Pratt and Whitney R-2800, coupled with an enormous four bladed Curtiss
electric prop, and giving the B-26 very short wings which gave it the
top speed he wanted, at the expense of a landing speed that topped 130
mph.

There was never a prototype, the Army needed the bomber and flight
testing was conducted with the first production models.

A series of circumstances and misfortunes dogged the Marauder crews
during it's workup and training, causing so many accidents (almost
exclusively on takeoff and landing) that it was investigated 4 times
by Congress.

The initial problems were the result of assigning pilots to train in
the B-26, most of whom had not flown twins. Those who had trained for
twins, flew the "Bamboo Bomber" a small Cessna twin with a cruise
speed slower than the B-26 stalled.

To say that they were intimidated is an understatement. The
inexperienced pilots had many difficulties landing the Marauder.

Then there were the operational problems: The training command
switched fuels and the new 100 octane aeromatic fuel disintegrated the
diaphrams in the carburators. The ground crews were unfamiliar with
the engine and the prop and maintenance was minimal or improperly
conducted. The result was a near total disaster as the training crews
suffered numerous engine failures during takeoff, or the prop went
into flat pitch, also during takeoff.

Many of the training flights involved takeoff at max gross. At that
weight during takeoff, the loss of an engine or having the prop slip
to flat pitch was disasterous. The bomber rolled into the dead engine
virtually instantaneously and pitched into Tampa Bay, or impacted the
ground upside down. "One a day in Tampa Bay" became the bitter
refrain.

Experienced combat crews did not have the problem the green training
crews had though, they liked the airplane.

The Army decided it needed the airplane for the war effort and sent it
to Europe (as well as to the South Pacific Theater). By the time it
was headed for England, the training accidents had been reduced
greatly due to better understanding of the airplane and better
training.

I have a video at home about the B-26. In it a veteran instructor was
interviewed and he spoke of being sent to Tampa to investigate the
very high accident rate. He arrived, spoke with the commanding
officer and requested their very best B-26 pilot trainee. They took
off and climbed to 8,000 feet (I think, could have been 12,000) where
the instructor told the pilot to configure the bomber as if he were
taking off. So the pilot slowed down, dropped flaps and gear, pitched
up and advanced power to takeoff settings. At that point the
instructor told the pilot he was going to chop power to one of the
engines, and told him which engine it would be. Then he cut the
power.

The bomber flipped over inverted and immediately went into a spin.
The instructor waited a bit while the pilot struggled to get out of
the spin, then announced that they were in a standard inverted spin
and proceeded to recover. By the time they pulled out they had lost
many thousands of feet of altitude.

Martin eventually relented it's stance in regards the wing and made
the follow up models with much larger wings and tail surfaces.

In the event, the Marauder had an almost charmed combat career,
suffering one of, if not the, lowest rates of combat lost of any
bomber.

The reason for this was due less to the robust construction of the
bomber or it's flight characteristics than to the Luftwaffe's orders
to concentrate on the heavy bombers at the expense of all other
operations. When the heavies were up, it was usually because the
weather favored visual bombing. That being the case, all other
bombers were usually also flying missions. The Luftwaffe did not have
the numbers to respond to each and every type of enemy incursion, so
they concentrated on the heavies.

So the Marauders kind of drew a bye when they flew on bombing
missions. They even got lucky with the AA artillery because most of
it was removed from the fronts to surround the cities in defense
against the heavy bomber attacks. But the missions were not a piece
of cake as any B-26 combat veteran can tell you, there was plenty
enough AAA still around to make missions harrowing.

Corky Scott

"Corky Scott" wrote in message
...
On Wed, 01 Jun 2005 15:03:52 GMT, "Mike Rapoport"
wrote:


Snip Great History Lesson

I have a video at home about the B-26. In it a veteran instructor was
interviewed and he spoke of being sent to Tampa to investigate the
very high accident rate. He arrived, spoke with the commanding
officer and requested their very best B-26 pilot trainee. They took
off and climbed to 8,000 feet (I think, could have been 12,000) where
the instructor told the pilot to configure the bomber as if he were
taking off. So the pilot slowed down, dropped flaps and gear, pitched
up and advanced power to takeoff settings. At that point the
instructor told the pilot he was going to chop power to one of the
engines, and told him which engine it would be. Then he cut the
power.


Snip More Great History Lesson

Corky,

IIRC, the "instructor" they sent down was Jimmie Doolittle, was it not?

Jay B

On Wed, 1 Jun 2005 11:59:45 -0700, "Jay Beckman"
wrote:

IIRC, the "instructor" they sent down was Jimmie Doolittle, was it not?

Doolittle was put in charge of demonstrating the airplane to prove
that it could be flown safely, but he wasn't the guy who did most of
the flying. According to my information:" General Doolittle sent his
technical adviser, Captain Vincent W. "Squeak" Burnett" to do the
demo flying.

I watched in the video as he (I assume it was he) brought in a B-26 on
one engine. The final approach was incredibly steep, and the pilot
pulled the nose up at the last second and greased it on. From what I
could see, this was a do or die type of landing (given the approach
speed): pull up too late and the landing gear is history (given the
rate of descent I saw), pull up too early and the airplane would
instantly stall to the runway wiping out the gear again.

Corky Scott

There is no doubt that many military aircraft have narrow envelopes and
require extreme precision to fly. The same is not true of certified
civilian airplanes and thankfully so.

Mike
MU-2

"Corky Scott" wrote in message
...
On Wed, 01 Jun 2005 15:03:52 GMT, "Mike Rapoport"
wrote:

It is not quite as bad as all that. NTS failures on takeoff are saveable
at
least in the simulator but immediate feathering is required. The airplane
will not yaw or roll 90 deg.

Mike
MU-2
Speaking of difficult to handle twins.

In 1939, the Martin Co. responded to a request for a high speed medium
twin engined bomber with a submission that was named the "Marauder"
and designated the 26th such commissioned design, or B-26.

Martin assigned a young aerodynamics engineer to the task of designing
the airplane. The specifications called for a top speed of 300 mph or
better, but DID NOT specify a landing speed. The designer responded
by installing the two biggest engines in production at the time, the
Pratt and Whitney R-2800, coupled with an enormous four bladed Curtiss
electric prop, and giving the B-26 very short wings which gave it the
top speed he wanted, at the expense of a landing speed that topped 130
mph.

There was never a prototype, the Army needed the bomber and flight
testing was conducted with the first production models.

A series of circumstances and misfortunes dogged the Marauder crews
during it's workup and training, causing so many accidents (almost
exclusively on takeoff and landing) that it was investigated 4 times
by Congress.

The initial problems were the result of assigning pilots to train in
the B-26, most of whom had not flown twins. Those who had trained for
twins, flew the "Bamboo Bomber" a small Cessna twin with a cruise
speed slower than the B-26 stalled.

To say that they were intimidated is an understatement. The
inexperienced pilots had many difficulties landing the Marauder.

Then there were the operational problems: The training command
switched fuels and the new 100 octane aeromatic fuel disintegrated the
diaphrams in the carburators. The ground crews were unfamiliar with
the engine and the prop and maintenance was minimal or improperly
conducted. The result was a near total disaster as the training crews
suffered numerous engine failures during takeoff, or the prop went
into flat pitch, also during takeoff.

Many of the training flights involved takeoff at max gross. At that
weight during takeoff, the loss of an engine or having the prop slip
to flat pitch was disasterous. The bomber rolled into the dead engine
virtually instantaneously and pitched into Tampa Bay, or impacted the
ground upside down. "One a day in Tampa Bay" became the bitter
refrain.

Experienced combat crews did not have the problem the green training
crews had though, they liked the airplane.

The Army decided it needed the airplane for the war effort and sent it
to Europe (as well as to the South Pacific Theater). By the time it
was headed for England, the training accidents had been reduced
greatly due to better understanding of the airplane and better
training.

I have a video at home about the B-26. In it a veteran instructor was
interviewed and he spoke of being sent to Tampa to investigate the
very high accident rate. He arrived, spoke with the commanding
officer and requested their very best B-26 pilot trainee. They took
off and climbed to 8,000 feet (I think, could have been 12,000) where
the instructor told the pilot to configure the bomber as if he were
taking off. So the pilot slowed down, dropped flaps and gear, pitched
up and advanced power to takeoff settings. At that point the
instructor told the pilot he was going to chop power to one of the
engines, and told him which engine it would be. Then he cut the
power.

The bomber flipped over inverted and immediately went into a spin.
The instructor waited a bit while the pilot struggled to get out of
the spin, then announced that they were in a standard inverted spin
and proceeded to recover. By the time they pulled out they had lost
many thousands of feet of altitude.

Martin eventually relented it's stance in regards the wing and made
the follow up models with much larger wings and tail surfaces.

In the event, the Marauder had an almost charmed combat career,
suffering one of, if not the, lowest rates of combat lost of any
bomber.

The reason for this was due less to the robust construction of the
bomber or it's flight characteristics than to the Luftwaffe's orders
to concentrate on the heavy bombers at the expense of all other
operations. When the heavies were up, it was usually because the
weather favored visual bombing. That being the case, all other
bombers were usually also flying missions. The Luftwaffe did not have
the numbers to respond to each and every type of enemy incursion, so
they concentrated on the heavies.

So the Marauders kind of drew a bye when they flew on bombing
missions. They even got lucky with the AA artillery because most of
it was removed from the fronts to surround the cities in defense
against the heavy bomber attacks. But the missions were not a piece
of cake as any B-26 combat veteran can tell you, there was plenty
enough AAA still around to make missions harrowing.

Corky Scott

"Corky Scott" wrote in message
...
Speaking of difficult to handle twins.

In 1939, the Martin Co. responded to a request for a high speed medium
twin engined bomber with a submission that was named the "Marauder"
and designated the 26th such commissioned design, or B-26.

Martin assigned a young aerodynamics engineer to the task of designing
the airplane.

The same guy (Ted Smith ?) who designed the Rockwell/AeroCommander series,
now called the Twin Commander.

On Wed, 1 Jun 2005 18:26:50 -0700, "Matt Barrow"
wrote:

The same guy (Ted Smith ?) who designed the Rockwell/AeroCommander series,
now called the Twin Commander.

Don't know about Ted Smith, the information I have, which was compiled
by Joseph Baugher and posted to the internet years ago is as follows:

Requests for proposals were widely circulated throughout the industry.
Proposals were received from Martin, Douglas, Stearman, and North
American. The proposal of the Glenn L. Martin company of Middle
River, Maryland (near Baltimore) was assigned the company designation
of Model 179. Martin assigned 26-year old aeronautical engineer
Peyton M. Magruder as Project Engineer for the Model 179. Magruder
and his team chose a low-drag profile fuselage with a circular cross
section. Since the Army wanted a high maximum speed but hadn't
specified any limitation on landing speed, the team selected a
high-mounted wing with a wingspan of only 65 feet. Its small area
gave a wing loading of more than 50 pounds per square foot. The wing
was shoulder-mounted to leave the central fuselage free for bomb
stowage. The wings were unusual in possessing no fillets. The
engines were to be a pair of 1850 hp Pratt & Whitney R-2800-5 Double
Wasp air-cooled radials, which were the most powerful engines
available at the time. Two-speed mechanical superchargers were
installed in order to maintain engine power up to medium altitudes,
and ejector exhausts vented on each side of the closely-cowled
nacelles. The engines drove four-bladed 13 foot 6 inch Curtiss
Electric propellers. Large spinners were fitted to the propellers,
and root cuffs were added to aid in engine cooling.

I archived a number of his aircraft development histories, they are
comprehensive and dry, tending to the technical side with long lists
of serial numbers for respective models and where each was deployed.

Corky Scott

"Corky Scott" wrote in message
...
On Wed, 1 Jun 2005 18:26:50 -0700, "Matt Barrow"
wrote:

The same guy (Ted Smith ?) who designed the Rockwell/AeroCommander
series,
now called the Twin Commander.

Don't know about Ted Smith, the information I have, which was compiled
by Joseph Baugher and posted to the internet years ago is as follows:


http://www.twincommander.com/aero_design.htm

The story of the man begins with Ted Smith, and the dream starts when, as
project engineer at the Douglas Aircraft Company during the Second World
War, Smith envisioned the day when peace would come and the airplane would
fill its promise of usefulness to man as a transportation vehicle. The
airlines had already developed a growing network of schedules and yet the
air transport system, as it was and as it showed signs of developing, did
not provide for the many needs of business and individual travelers whose
requirements placed a premium on going between origin and destination
(frequently not on the airline map) and doing so with all the convenience,
flexibility and time saving that only a privately owned aircraft could
accomplish. At the same time, comfort, dependability, and safety must be the
ultimate that the aviation industry could achieve.