barrel roll in 172

Utility category allows some limited acro maneuvers, and a
list of approved maneuvers is on the placard on the side
wall of the cabin and in the POH. If you want to do rolls,
snap rolls, etc, rent or buy an airplane designed and tested
and certified as such. Can the 172 do acro, sure, with Bob
Hoover doing the flying. Can some ham handed 100 private
pilot do it with out falling out of the roll, and pulling 9
Gs in the recovery? Probably not.

Parachutes are required when you exceed certain attitudes,
the mental attitude being the most important.


§ 91.303 Aerobatic flight.
No person may operate an aircraft in aerobatic flight-

(a) Over any congested area of a city, town, or settlement;

(b) Over an open air assembly of persons;

(c) Within the lateral boundaries of the surface areas of
Class B, Class C, Class D, or Class E airspace designated
for an airport;

(d) Within 4 nautical miles of the center line of any
Federal airway;

(e) Below an altitude of 1,500 feet above the surface; or

(f) When flight visibility is less than 3 statute miles.

For the purposes of this section, aerobatic flight means an
intentional maneuver involving an abrupt change in an
aircraft's attitude, an abnormal attitude, or abnormal
acceleration, not necessary for normal flight.

[Doc. No. 18834, 54 FR 34308, Aug. 18, 1989, as amended by
Amdt. 91-227, 56 FR 65661, Dec. 17, 1991]

§ 91.307 Parachutes and parachuting.
(a) No pilot of a civil aircraft may allow a parachute that
is available for emergency use to be carried in that
aircraft unless it is an approved type and-

(1) If a chair type (canopy in back), it has been packed by
a certificated and appropriately rated parachute rigger
within the preceding 120 days; or

(2) If any other type, it has been packed by a certificated
and appropriately rated parachute rigger-

(i) Within the preceding 120 days, if its canopy, shrouds,
and harness are composed exclusively of nylon, rayon, or
other similar synthetic fiber or materials that are
substantially resistant to damage from mold, mildew, or
other fungi and other rotting agents propagated in a moist
environment; or

(ii) Within the preceding 60 days, if any part of the
parachute is composed of silk, pongee, or other natural
fiber, or materials not specified in paragraph (a)(2)(i) of
this section.

(b) Except in an emergency, no pilot in command may allow,
and no person may conduct, a parachute operation from an
aircraft within the United States except in accordance with
part 105 of this chapter.

(c) Unless each occupant of the aircraft is wearing an
approved parachute, no pilot of a civil aircraft carrying
any person (other than a crewmember) may execute any
intentional maneuver that exceeds-

(1) A bank of 60 degrees relative to the horizon; or

(2) A nose-up or nose-down attitude of 30 degrees relative
to the horizon.

(d) Paragraph (c) of this section does not apply to-

(1) Flight tests for pilot certification or rating; or

(2) Spins and other flight maneuvers required by the
regulations for any certificate or rating when given by-

(i) A certificated flight instructor; or

(ii) An airline transport pilot instructing in accordance
with §61.67 of this chapter.

(e) For the purposes of this section, approved parachute
means-

(1) A parachute manufactured under a type certificate or a
technical standard order (C-23 series); or

(2) A personnel-carrying military parachute identified by an
NAF, AAF, or AN drawing number, an AAF order number, or any
other military designation or specification number.

[Doc. No. 18334, 54 FR 34308, Aug. 18, 1989, as amended by
Amdt. 91-255, 62 FR 68137, Dec. 30, 1997; Amdt. 91-268, 66
FR 23553, May 9, 2001]


--
James H. Macklin
ATP,CFI,A&P

"Bob Moore" wrote in message
. 122...
| Morgans wrote
| I'll bet he is not going to wear a parachute, either,
which is
| required.
|
| Where does it say that?
|
| The answer to rolling a normal category plane should be
no, always.
|
| The C-172 that I fly is a Utility Category airplane, if I
want it to be.
|
| Bob Moore
| ATP CFI

"john smith" wrote

Certified? No.
Possible? Yes, but you will finish much lower than where you started.

Don't encourage that type of behavior with a yes. If he had to ask, he is
probably not a competent aerobatic pilot, and a blown barrel roll could
stall the plane, or overstress it, so it fails then, or later.

I'll bet he is not going to wear a parachute, either, which is required.

The answer to rolling a normal category plane should be no, always.

We don't want his, or someone else's blood on our hands.
--
Jim in NC

Don't encourage that type of behavior with a yes. If he had to ask, he is

I'm slightly disappointed by how quickly you've assumed my complete
brainlessness. Yes I know what FARs say, and what POH says, and no, I'm
not going to read this newsgroup and go break my neck the next morning.
What I was hoping to hear was an opinion of someone who's familiar with
what is involved in test-flying for normal/utility category and how much
it covers the type of stress imposed on the airframe and systems in a barrel
roll.


Andrey

Possible? Yes, but you will finish much lower than where you started.

So, basically it's just because of a low-hp engine that the maneuver
can't be properly executed?



Andrey

Andrey Serbinenko schrieb:

I'm slightly disappointed by how quickly you've assumed my complete
brainlessness.

If this surprizes you, then you don't read this group often.

Stefan

A properly done mild acro maneuver is well within the limits
of even a normal category airplane [3.8G], but it is easy to
botch a maneuver and then the recovery can require much
higher forces. They only test using qualified and competent
pilots and they only test for maneuvers they intend to
certify the aircraft to do.
Some airplanes may be certified for "flick" maneuvers or
accelerated maneuvers entered at higher speeds, such as
snap rolls. Some aircraft are approved for unlimited
maneuvers and they sometimes break.

see http://www.faa.gov/regulations_polic...a_regulations/
§ 23.151 Acrobatic maneuvers.
Each acrobatic and utility category airplane must be able to
perform safely the acrobatic maneuvers for which
certification is requested. Safe entry speeds for these
maneuvers must be determined.


Browse Previous | Browse Next


§ 23.221 Spinning.
(a) Normal category airplanes. A single-engine, normal
category airplane must be able to recover from a one-turn
spin or a three-second spin, whichever takes longer, in not
more than one additional turn after initiation of the first
control action for recovery, or demonstrate compliance with
the optional spin resistant requirements of this section.

(1) The following apply to one turn or three second spins:

(i) For both the flaps-retracted and flaps-extended
conditions, the applicable airspeed limit and positive limit
maneuvering load factor must not be exceeded;

(ii) No control forces or characteristic encountered during
the spin or recovery may adversely affect prompt recovery;

(iii) It must be impossible to obtain unrecoverable spins
with any use of the flight or engine power controls either
at the entry into or during the spin; and

(iv) For the flaps-extended condition, the flaps may be
retracted during the recovery but not before rotation has
ceased.

(2) At the applicant's option, the airplane may be
demonstrated to be spin resistant by the following:

(i) During the stall maneuver contained in §23.201, the
pitch control must be pulled back and held against the stop.
Then, using ailerons and rudders in the proper direction, it
must be possible to maintain wings-level flight within 15
degrees of bank and to roll the airplane from a 30 degree
bank in one direction to a 30 degree bank in the other
direction;

(ii) Reduce the airplane speed using pitch control at a rate
of approximately one knot per second until the pitch control
reaches the stop; then, with the pitch control pulled back
and held against the stop, apply full rudder control in a
manner to promote spin entry for a period of seven seconds
or through a 360 degree heading change, whichever occurs
first. If the 360 degree heading change is reached first, it
must have taken no fewer than four seconds. This maneuver
must be performed first with the ailerons in the neutral
position, and then with the ailerons deflected opposite the
direction of turn in the most adverse manner. Power and
airplane configuration must be set in accordance with
§23.201(e) without change during the maneuver. At the end of
seven seconds or a 360 degree heading change, the airplane
must respond immediately and normally to primary flight
controls applied to regain coordinated, unstalled flight
without reversal of control effect and without exceeding the
temporary control forces specified by §23.143(c); and

(iii) Compliance with §§23.201 and 23.203 must be
demonstrated with the airplane in uncoordinated flight,
corresponding to one ball width displacement on a slip-skid
indicator, unless one ball width displacement cannot be
obtained with full rudder, in which case the demonstration
must be with full rudder applied.

(b) Utility category airplanes. A utility category airplane
must meet the requirements of paragraph (a) of this section.
In addition, the requirements of paragraph (c) of this
section and §23.807(b)(7) must be met if approval for
spinning is requested.

(c) Acrobatic category airplanes. An acrobatic category
airplane must meet the spin requirements of paragraph (a) of
this section and §23.807(b)(6). In addition, the following
requirements must be met in each configuration for which
approval for spinning is requested:

(1) The airplane must recover from any point in a spin up to
and including six turns, or any greater number of turns for
which certification is requested, in not more than one and
one-half additional turns after initiation of the first
control action for recovery. However, beyond three turns,
the spin may be discontinued if spiral characteristics
appear.

(2) The applicable airspeed limits and limit maneuvering
load factors must not be exceeded. For flaps-extended
configurations for which approval is requested, the flaps
must not be retracted during the recovery.

(3) It must be impossible to obtain unrecoverable spins with
any use of the flight or engine power controls either at the
entry into or during the spin.

(4) There must be no characteristics during the spin (such
as excessive rates of rotation or extreme oscillatory
motion) that might prevent a successful recovery due to
disorientation or incapacitation of the pilot.

[Doc. No. 27807, 61 FR 5191, Feb. 9, 1996]

"Andrey Serbinenko" wrote in
message ...
| Don't encourage that type of behavior with a yes. If he
had to ask, he is
|
| I'm slightly disappointed by how quickly you've assumed my
complete
| brainlessness. Yes I know what FARs say, and what POH
says, and no, I'm
| not going to read this newsgroup and go break my neck the
next morning.
| What I was hoping to hear was an opinion of someone who's
familiar with
| what is involved in test-flying for normal/utility
category and how much
| it covers the type of stress imposed on the airframe and
systems in a barrel
| roll.
|
|
| Andrey
|

No, poor pilot skill.


--
James H. Macklin
ATP,CFI,A&P

"Andrey Serbinenko" wrote in
message ...
| Possible? Yes, but you will finish much lower than where
you started.
|
| So, basically it's just because of a low-hp engine that
the maneuver
| can't be properly executed?
|
|
|
| Andrey

In article kMMvg.78923$ZW3.78738@dukeread04,
"Jim Macklin" wrote:


Parachutes are required when you exceed certain attitudes,
the mental attitude being the most important.

Read it again. Parachutes are not required if you're solo.

Andrey Serbinenko wrote

I'm slightly disappointed by how quickly you've assumed my complete
brainlessness. Yes I know what FARs say, and what POH says, and no,
I'm not going to read this newsgroup and go break my neck the next
morning. What I was hoping to hear was an opinion of someone who's
familiar with what is involved in test-flying for normal/utility
category and how much it covers the type of stress imposed on the
airframe and systems in a barrel roll.

First Andrey, you will probably find much disagreement on this group
as to what actually constitues a "barrell roll". If conducted as
normally accepted in the aerobatic community, it consists of a
combination loop and roll which at most, places about 3g's on the
airframe. The g loading is not the problem in the utility category C-
172, its lack of power to complete the loop portion is what makes it
particularly difficult.
Below, I have copied a description of a "barrell roll". This may or may
not be the maneuver that you have in mind. It would obviously be much
easier in one of the higher powered 172s than in the O-300, 145hp
powered version that I fly. :-)

After reading the following, you might find that you really didn't mean
to say "barrell roll". :-) BTW the two following descriptions are how
I was taught to perform the "barrell roll" in Navy flight training. :-)

From:
http://acro.harvard.edu

The Barrel Roll is a not competition maneuver. The barrel roll is a
combination between a loop and a roll. You complete one loop while
completing one roll at the same time.
The flight path during a barrel roll has the shape of a horizontal cork
screw. Imagine a big barrel, with the airplanes wheels rolling along the
inside of the barrel in a cork screw path.
During a barrel roll, the pilot experiences always positive G's. The
maximum is about 2.5 to 3 G, the minimum about 0.5 G.

And another description from Kershner's Flight Instructor's Manual:

THE BARREL ROLL
• Preparation. It's almost impossible to draw a barrel roll
on the chalkboard, but a model will give the desired results.
Have the trainee study the references.

•Explanation. The barrel roll is a precise maneuver in which
the airplane is rolled around an imaginary point 45° to
the original flight path. A positive-g level is maintained
throughout the maneuver, and the ball in the turn indicator
should stay in the middle.

You may wonder why the barrel roll is taught this late,
since it appears to be so simple. Well, it is a precise maneuver
requiring particular airplane attitudes at particular reference
points, which is difficult for the average trainee to do properly
at first.

This maneuver might be considered an exaggeration of the
wingover, but instead of starting to shallow the bank at the 90°
position, the pilot must steepen it continually until the airplane
has rolled 360° and is back on the original heading. The rate of
roll must be much greater than that used for the wingover
because the airplane must be in a vertical bank at 45° of turn,
and it must be inverted at 90° of turn. The roll and turn is
continued until the airplane is headed in the original direction with
the wings level. Compare the barrel roll in Fig. 23-12 with the
same view of the wingover in Fig. 20-7.

From behind the maneuver looks as though the airplane is being
flown around the outside of a barrel. This is a very good maneuver
for gaining confidence and keeping oriented while flying inverted in
balanced flight.
Good coordination is required to do the barrel roll properly and
the trainee will show an improvement in that area after a session of
barrel rolls.

The barrel roll is generally more difficult and precise than the
aileron roll, and he may have to work on this one awhile.

Why-
The barrel roll is one of the best maneuvers for improving orientation.

Unlike the other acrobatic maneuvers covered thus far, the barrel
roll requires a constantly changing bank and pitch (with attendant
changing airspeed) and a radical change in heading (90°) while the
airplane is rolling. The average trainee probably will be looking at the
wing tip at a time when he should be checking the nose, or vice versa.
When he is able to stay well oriented in the barrel roll, he is ready to
move on to the reverse Cuban eight or reverse cloverleaf.

How-
You might use the following explanation, or develop your own:
(1) Make sure the area is clear, then pick a reference on the horizon
off the wing tip as in the wingover and lazy eight.
(2) Set the throttle to low cruise rpm and ease the nose over to pick-
up about 10 K more than used for the wingover or set up the
airspeed used for a loop, whichever is higher. Power adjustment
should not be necessary during the maneuver. You might have
some of your sharper trainees apply full power as the airplane
approaches inverted and then remind them to throttle back as the
airspeed picks up in the last part of the maneuver.
(3) Smoothly pull the nose up and start a coordinated climbing turn
(note that it will have to be at a much faster rate than was used
for the wingover) toward the reference point. (Assume that at first
the roll will be to the left.)
(4) When the nose is 45° from the original heading, it should be at its
highest pitch attitude and the left bank should be vertical.
(5) When the nose is at 90° from the original heading, you should be
looking directly at the reference point that was originally off
the
wing tipfrom a completely inverted position (momentarily).
(6) When the airplane heading is again 45° from the original, the bank
is vertical but you will be in a right bank as far as the ground
is
concerned; that is, the right wing is pointing straight down at
this
instant of roll. The nose will be at its lowest pitch attitude at
this
point.
(7) The roll is continued to wings-level flight as the nose is raised
back
to the cruise attitude.

The maneuver must be symmetrical; the nose must go as far above the
horizon as below. The barrel roll requires definite checkpoints to
ensure
that the airplane is at the correct attitude throughout. It is
interesting
to note that if the barrel roll is to the left, all of the airplane's
path is to
the left of the original line of flight and the airplane's nose is
always
pointed to the left of the original flight line (until it merges again
at the
completion of the maneuver). The opposite occurs, naturally, for the
barrel roll to the right.

Another method of doing a barrel roll is to pick a reference on the
horizon, turn the airplane 45° to the reference point, and proceed to
make a wide roll around this real point. One disadvantage of this
method for the newcomer is that it depends on the pilot's own
judgment of how large the orbit around the point should be. For an
introduction to the maneuver, the first method is usually better, but
you
may prefer the second and work out your own techniques of instructing
it.

Demonstration.
Try not to lose the reference point yourself while demonstrating
this one. You may find your explanation is not keeping up with the
airplane, which usually results in sputtering and stuttering while the
maneuver proceeds to its foregone conclusion -and then you have
to do a new demonstration. Don't worry, this will happen plenty of
times during your career of instructing aerobatics -when your mouth
can't keep up with your brain or the maneuver-and it can ease tension
if you react to it with humor.

Usually the trainee is surprised to see the same wing tip back on the
reference point and may confess that, like the first snap roll, the
earth
and sky were blurred and he had no idea where the reference was
during the maneuver.

Practice.
You may rest assured the trainee will "lose" the reference point during
the first couple of barrel rolls. He'll usually stare over the nose,
seeing
nothing but blue sky or ground and not really seeing the point at all.

Common errors during barrel rolls include these:
1. Not pulling the nose high enough in the first 45° of the maneuver,
which means that the highest and lowest nose positions are not
symmetrical to the horizon.
2. Not maintaining a constant rate of roll. Usually things are fine at
the
45° position; the nose is at its highest pitch and the bank is
vertical.
As you approach the position of 90° of turn you will probably find
that he is not going to be completely inverted at that point and
will
have to rush things a bit to make it. The usual reason is that he
did
not maintain a constant rate of roll. Remember that the nose is up
and the airspeed is slower in this segment of the maneuver, so the
controls must be deflected more to get the same rate. This is where
coordination comes in. Watch for it in particular.
3. Letting the nose drop after passing the 90° point; losing too much
altitude and gaining excess airspeed.
4. Failure to roll out on the original heading; having the wing tip well
ahead, or well behind, the reference when the maneuver is completed.

Evaluation and Review.
Review each barrel roll briefly in the air, and have the trainee use
the model on the ground. This one can be hard to "see," so go over it
again as necessary after getting on the ground.

By the time a half-dozen barrel rolls have been practiced, the
average
trainee should be oriented throughout the maneuver even though he may
still have minor problems of heading and symmetry. After a dozen rolls
he should be starting to work on a constant roll rate and starting to
ease
his heading problems. After several hundred, he may begin to be
satisfied
with his barrel rolls but will realize that constant practice is
required.

Possible? Yes, but you will finish much lower than where you started.

So, basically it's just because of a low-hp engine that the maneuver
can't be properly executed?

The answer is not that simple. Low horsepower engine is one, design and
strength of the airframe is another, skill of the pilot is a third,
design of the airfoils selected, design of the the control system,
design of the engine systems, etc. Many factors contribute to "how" a
maneuver can be flown.