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.


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§ 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
|