Old Airline Ads, pt 2 - Braniff.jpg (1/1)

"Mitchell Holman" wrote in message
...

The aircraft depicted in the ad was lost on its acceptance flight:
http://aviation-safety.net/database/...1019-0&lang=en.
--
Andrew Chaplin
SIT MIHI GLADIUS SICUT SANCTO MARTINO
(If you're going to e-mail me, you'll have to get "yourfinger." out.)

"Andrew Chaplin" wrote in news:u-
:

"Mitchell Holman" wrote in message
...

The aircraft depicted in the ad was lost on its acceptance flight:
http://aviation-safety.net/database/...1019-0&lang=en.



Rolling a 707 so violently that the engines are torn off
is not recommened.

Mitchell Holman wrote:
"Andrew Chaplin" wrote in news:u-
:


"Mitchell Holman" wrote in message
...

The aircraft depicted in the ad was lost on its acceptance flight:
http://aviation-safety.net/database/...1019-0&lang=en.




Rolling a 707 so violently that the engines are torn off
is not recommened.



A Dutch roll is a rhythmic maneuver that most instructors agree is about
as useful as patting your head while rubbing your tummy. In contrast,
the Slow Dutch Roll proved to be a very powerful tool.

When executing an ordinary Dutch roll, you keep the nose of the airplane
pointed at a speck on the horizon while rapidly wagging your wings with
your ailerons and holding the nose steady with your rudder pedals.

When you move the stick to the left, the nose wants to swing to the
right forcing you to step on the left rudder pedal, but not quite as
much as you would in a turn. Then, as the bank increases, you have to
step on the other pedal to keep the nose steady. And so the exercise
continues. But to what purpose?

anyone got any court line ads the airline that copied braniff for coloured
jets

Mike

"Mitchell Holman" wrote in message
...

Maple1 wrote i
A Dutch roll is a rhythmic maneuver that most instructors agree is
about
as useful as patting your head while rubbing your tummy. In contrast,
the Slow Dutch Roll proved to be a very powerful tool.

When executing an ordinary Dutch roll, you keep the nose of the
airplane
pointed at a speck on the horizon while rapidly wagging your wings
with
your ailerons and holding the nose steady with your rudder pedals.

Copy and Paste from a web site

WARBIRD NOTES #41 14 Jun 2000 (31)

“DUTCH” ROLLS vs “COORDINATION” ROLLS
Here's another example of terminology being used in error. I’d never
thought this would need any discussion, however several computer forum
exchanges within the past few months have delved into this subject and –
in the words of one student of my acquaintance – “Wow, those guys must
really be misinformed, huh?”
Before we get into a discussion of the “rolls” we’re talking about here,
I should mention a couple “tongue-in-cheek” definitions of “rolls” and
aerobatics from the CAF dictionary of the past (circa 1967); they just
somehow seemed apropos to this subject. The “sweet roll” (as well as
the “Puerto Rican sixteen”) found their way into that dictionary as
maneuvers.
Anyhow, now back to the serious stuff. Over the years, I’ve seen this
maneuver taught in two or three ways. And I’ve taught different ways of
doing it – depending upon the objective. So I guess we have a consensus
among flight instructors of the maneuver’s validity – but not of the
terminology.
(1) One method would be while in straight and level flight to pick a
point on the horizon and enter a turn away from it for some amount of
turn and then, without stopping, reverse the turn to pass through the
original point in the opposite direction, then again reverse the turn
and so on, while all the time coordinating the flight controls
(especially the rudder and ailerons). (2) Another variation or method
used is to pick a straight road or a point on the horizon. Then
precisely hold that point while initiating a bank (takes opposite
rudder), then reverse the bank to an equal amount in the opposite
direction. This is repeated over and over while using the flight
controls to precisely maintain that point (especially the rudder and
ailerons). This variation especially lends itself to getting the
student ready for the aggressive use of the rudder in acrobatic flight.

Evidently – to a certain number of instructors – the above
aileron/rudder coordination exercises (especially #2, the one that holds
the reference point) that we all give our new students are called “dutch
rolls”.

Well, we’ve got some news for you, chum! Those aren’t “dutch rolls”,
they’re simply plain old garden variety “coordination exercises” or
“coordination rolls”. And – undeniably – they’re extremely useful for
teaching coordination or for quickly evaluating an aircraft’s handling
qualities! I’ve used them from the very first time I took my first
lesson in an Aeronca Champ right up until the present. When we were
aviation cadets in “Bevo” Howard’s USAF T-6 school, we were taught them
from the very first day of our flight training. BUT THOSE ARE NOT DUTCH
ROLLS! You copy that? “Sorry Charlie” but no cigar, those are NOT
dutch rolls! No big deal, you say? Well, OK, but you need to realize
that when you use an incorrect term it’s teaching your student
something completely wrong. It’s sort of like the media using the term
“Piper Cub” for every airplane less than a medium sized jet. And –
besides perpetrating a falsehood – it can later kill him/her! And if
you don’t think or realize that a dutch roll can easily become lethal,
look up the Braniff/Boeing 707 (N-7071) flight training accident
involving the tossing of a couple of pylon mounted engines off the wings
in the fall of 1959.



So you say, “well then, just what IS a dutch roll”? In test pilot
school we were provided with a detailed description. While that
description seems to be far more technical than required for this
discussion you can look it up in your copy of “Aerodynamics for Naval
Aviators“ or any other reliable reference book available. I’ve never
been able to induce a satisfactory “dutch roll” in any straight-wing
training type airplane. This roll/yaw coupling phenomenon is usually
found only in swept-wing types. One might ask where the term “dutch
roll” originated, most seem to think that it probably found its genesis
in the rolling motion of a ice speed-skater on the frozen canals of
Holland. At any rate, I can attest that the recovery from this
potentially violent and lethal maneuver is completely non-intuitive! In
fact, I’d describe it as the antithesis of coordination. It is a good
portion of the reason for the development of yaw dampers (upon their
first development they were referred to as dampeners and later, as
dampners) on modern day jet transports. It is also the reason why – if
one experiences a yaw damper becoming inoperative on the Boeing 727 –
that the overriding priority is to extend the spoilers and descend NOW
to a cruise altitude in the twenties.



Stuff yet to write:



Research into some possibilities for erroneous use reveals that it might
have had it’s origin in a FAR 141 student pilot training syllabus
(approved by Cessna), in which it appears that the term was used –
incorrectly. Also, an FAA source tells me that his instructor also used
the term incorrectly years ago in a Piper Warrior while teaching him to
fly. So – no wonder, huh? It’s sorta like that line in that old song by
Johnny Cash, “bad news travels like wildfire!”



One person also mentioned that “since swept wings are a relatively new
aviation development”. Allow me to exhibit a sly grin here – like the
Germans weren’t conducting aeronautical research on this configuration
about six or seven decades ago!



Any instructor hopes that his student will later proudly recall him as a
font of knowledge regarding the things he taught. Imagine that same
student’s disillusionment and disappointment years later if he learns
that his instructor was just plain wrong. One instructor says he feels
it’s shorter to say “dutch roll” than “coordination exercise”. Well,
that might very well be, however it’s also shorter to call an aileron a
flap – but no one that I know does! Also, he said “aerobatic pilots
in particular have a long tradition of giving their maneuvers colorful
names”. That’s certainly true and some of them certainly are
descriptive, the “torque roll”, “top hat”, “humpty-bump” and others
immediately come to mind here. One instructor who’s always used the
correct term told me that it more likely was because a school that
included “dutch rolls” in their school’s literature or syllabus could
ask for higher fees from its students. Oh – if it were only that
simple!


Mentioned in ”Fly The Wing” by Webb. Mentioned in “Basic Aerobatics” by
Kershner. Mentioned in USAF 51-1 “Primary Flying”. Mentioned in xxxxxx



YOU MIGHT CONSIDER TELLING THOSE WHO DO NOT UNDERSTAND THAT THE "DUTCH
ROLL" IS SOMETHING SWEPT WING PILOTS LEARN THE RECOVERY FROM!





Verne Jobst – “Civil Pilot Training Manual”. It (1941 edition) refers to
them under “coordination exercises”.


Dutch Roll - bill howell

Many swept wing aircraft suffer a dynamic instability problem known as
Dutch Roll.

Dutch roll happens when the aircraft has relatively strong static
lateral stability (usually due to the swept wings) and somewhat weak
directional stability (relatively.) In a Dutch roll the aircraft begins
to yaw due to a gust or other input. The yaw is slow damping out so the
aircraft begins to roll before the yaw is stopped (due to the increased
speed of the advancing wing and the increased lift due to the swept wing
effect.)

By the time the yaw stops and begins to swing back toward zero slip the
aircraft has developed a considerable roll rate and due to momentum plus
the slip angle the aircraft continues to roll even once the nose has
begun returning to the original slip angle.

Eventually the yaw overshoots the zero slip angle causing the wings to
begin rolling back in the opposite direction.

The whole procedure repeats, sometimes with large motions, sometimes
witch just a small churning motion. Like all dynamic stability problems,
Dutch roll is much worse at high altitudes where the air is less dense.

Dutch roll is almost certain to happen in a jet aircraft is the Yaw
dampener is turned off at high altitude. Therefore, the first thing to
check if an aircraft begins to exhibit Dutch roll is that the Yaw
Dampener is on. The pilot should then try to minimize the yawing
oscillations by blocking the rudder pedals (i.e. hold the rudder pedals
in the neutral position.) Next apply aileron (spoiler) control opposite
to the roll. The best technique to use is short jabs of ailerons applied
opposite to the roll. Try to give one quick jab on each cycle (i.e. turn
the wheel toward the rising wing, then return it to neutral.) Finally
accelerate to a higher speed, where directional stability will be
better, or descend into more dense air, for the same reason.

Bob Moore
ATP CFI B-707 B-727
Taught many Dutch Rolls in B-707s
PanAm (retired)