Dudley Henriques wrote:

On Wednesday, December 16, 2015 at 10:55:13 PM UTC-5,
wrote:
Well I guess bob Hoover was also a moron. He looped amd rolled everything
he flew and also said any airplane could be rolled or looped as long as
the g limits of the plane wasn't exlxceeded. And the positive g for the
150/152 is 4 g's im sure he didn't exceeded them. I have a 150h and I
haven't looped or rolled it but I have done rolls,loops, and hammer heads
in an RV6 and entered the loop at around 200 and pulled pretty hard going
into the loop and never even hit the 2g mark and on rolling the rv never
got above 1.5 g's and the most of that was pulled coming out of the roll.
It isn't legal to roll a 150 or 152 that isn't an aero bat but it's
perfectly safe as long as you don't mess up. If you do then your in
trouble because you don't have that 2g cushion that an aerobat has and
yes you will probably die

Hoover was right. Done correctly a loop or a roll can be performed within
the g limits of a normal category airplane. The problem occurs when a
maneuver is done incorrectly. That coupled with the asymmetrical g loading
associated with rolling pullouts can easily exceed normal g limits.
Regulation wise of course, what is illegal remains illegal. I would add
that I do not recommend at any time attempting aerobatics in any airplane
not certificated for aerobatics, nor do I recommend performing them in
certified airplanes without proper instruction from an instructor
qualified to instruct in aerobatics and that isn't your everyday CFI.

Hi Dudley, good to see you.
Rolliing pullouts are special - and not in a good way.
They stress an airframe in unexpected ways -
Back in the late '40s/Early '50s, the Northrop F-89 jet interceptor suddenly
started coming apart in very public and very fatal crashes.
(At low altitudes, and often at airshows) Some if these were test birds
with V-G recorders on board - the data showed that the wings were failing
well within the tested G limits, and fatigue wasn't a factor.
These airplanes were grounded several times, and strict limitations placed
on them as they tried to suss out the problem,
It turns out that pulling Gs while rolling - especially with the tip tanks
on mounted - was imparting a twisting force on the wings that exceeded the
wing's torsional strength, snapping off the wing.

So - be careful, all, and remember that unless otherwise stated, the G
limits in the handbook are for symmetrical flight. If you start getting
complicated, you're becoming a test pilot.

--
Pete Stickney
Always remember to close all parentheses.
We're not paying to air-condition the entire paragraph.