Marcus Paine

[Colonel]

Yes - that pilot received 100 hours of dual
for his Mooney training.  And, then landed
gear up.

Ok.  Found the video of Marcus Paine's
last loop.

Loops can go wrong in several common
ways.  Still looking for footage of the T-28
that crashed at the Cold Lake airshow
recently.

Anyways, it sure looks to me like Marcus
did not make his top gate when inverted
at the top of the loop.

No one taught me this, but I figured out
on my own that before I subtend an angle
of 90 degrees to the horizon, I have to
obtain specific altitude and airspeed
parameters, for the aircraft and conditions.

Every time, if you want to live.

Note that Madras is at 1600 feet elevation
and it's over 90F there today, so the density
altitude is 3700 feet.

As density altitude increases, so must the
altitude parameter of your top gate, because
the radius of your loop is a function of true
(not indicated) airspeed.

It's as if you're flying a different aircraft.  I
hope it would be obvious that you need
more room to loop a P-51 as opposed to a
cub.

Over the top of a loop, things are actually
moving quite slowly.  The altimeter catches
up, and you have a moment to glance at
it.

If you do not make your top gate altitude,
you simply drop the nose, 1/2 roll, and
exit in a 1/2 cuban-8, subtending only 45
degrees to the horizon, the recovery pull
from which takes far less height.  You
can do that kind of free-styling when you
are a solo. 

Look at 1:28 of this video:

[url= of surface loop[/url]

The cockpit footage shows me glancing at
the altimeter just before inverted over the
top of the loop.  I made my top gate, so
I continue the loop.  If I don't make the
top gate, I drop the nose and 1/2 roll
upright and pull.

Similarly, look at 1:54 of the same video,
when I am about pull from a vertical upline
to a vertical downline (with a 1/2 roll).

Again, I am checking for top gate.

[url= of humpty[/url]

If I don't make the top gate, I just let
the nose fall to the 45 inverted downline
and 1/2 roll.

People ridicule me for flying low altitude
formation aerobatics, but that activity
teaches you in addition to learn about the
entry gate, which tells you if you're going
to make your top gate.

If you don't make your entry gate, the formation
does a wingover instead of continuing with
the (eg) loop, because converting a formation
to a 1/2 cu-8 over the top of a loop is a
receipe for disaster.

But I'm just a moron compared to most pilots,
so what would I know?

TC has stated that I will never, ever be an ICAS
ACE, to diminish my influence so that I don't teach
this material to other new airshow pilots and keep
them alive.

One has to wonder if Arlo has incurred any legal
liability as a result of his malfeasance.

[Gravel Digger]

Sounds pretty straight forward, me sitting in my chair reading it. It has a military precision to it with no variances, if x<y you're out.

Obviously, there's a discipline required to make that decision at the top of the gate that seems to be missing. I don't know how many of these loop accidents I have seen in the last 5 years, but the answer is far too many.  I don't understand if it's ego saying "it'll be a little tight, but should be good, I've got this, I've done this" or the incorrect type of exposures in training. I've heard that voice a few times, but I wasn't low on energy less than 100 feet above the ground with gravity reaching up to claim its overdue payment. 


There's a discipline required to admitting when an approach gets unstable to push the power up and try it again that gets ignored far too often as well, so no surprise the same issue would poke its head into the world of aerobatics.

[Colonel]

How often has TC (or some other moron)
told you:

[b]Plan the flight, Fly the Plan[/b]

That's in fact what TC insists you do -
submit a detailed sequence for your
low-altitude aerobatics, and hope that
TC doesn't take your licence away if
you have to vary from the plan.

See, if some TC Inspector asshole comes
up to me after a flight and tries to
give me shit for varying from my submitted
sequence, I will tell him to fuck off because
he's too stupid to understand, and besides
he can't stop my mortgage payments if he
pulls my licence.  Again.

This gives me a certain freedom to stay
alive, and do what I need to do, even if
it enrages TC.  Fuck them.

[cgzro]

In addition to density altitude non linearly affecting the turn radius, there is another insidious gotcha and that's any kind of wind correction during the loop.


Lets say there is a strong wind blowing you toward the show line. To be safe and avoid crossing it you have two choices. You can roll into the wind a bit so that your lift vector is both looping you and moving you, or you can add rudder a bit and yaw your way into it as you go around. Both of these will cause your loop to be of larger radius.


So high density altitude you need a few hundred more feet (or more), strong cross wind you may need a few hundred more feet also.
Add them together ..

[Colonel]

I've never really found spiraling a loop to make
that huge a difference to the energy required.

Density altitude is what kills you.  You need
a higher altitude for the top gate because of
the true airspeed increase with the same
indicated airspeed, but with the thinner air,
you are unable to even make your top gate
at sea level because of the decreased performance
of the engine, prop and wing with the thinner
air.

I've often thought a squirt of dry NO2 to restore
the engine's power to sea level would be a
nice idea at high density altitudes, but the
TC twit brigade would go bananas, and off
to court we would go again.

[cgzro]

NO2 has been done. The guy that restored the Lysander at Vintage wings put Nitrous on his Pitts ;) don't think he ever told TC.
Apparently it was pretty hard on the engine ;)

[Colonel]

If rated sea level power just isn't enough:

[David MacRay]

Can you adjust the timing electronically with magnetos?

Another great video, something was wired with the sound though.

[pdw]

Cgzro, good you mention the "insidious gotcha" ... "any kind of wind correction".


Density is #1 and also the simplest to calculate.


Not so obvious however to prove cutting into the different air during the loop in addition to that .. re 'low airspeed' maybe sudden at topgate ?. Cold Lake accident is potentially one .. where two local wx station's have different wind data.


I checked a lot of wx history after-the-fact (many accidents) ... you know just to see if 'wrong place at wrong time' for the topgate etc. Just saying here it might be more the chance of something along the lines of what Cgzro says there ...  had contributed additionally to DA in claiming the lives of some of these good flyers.


Who knows for sure .. hey, everyone of these flyer's margin for safe execution of their required 'loop radius' may have had safeguards in place except when adding together the smaller subtractions in performance (the bigger difference).


Ya ok sure .. i see where some N02 assist would be useful to have there (ie when all else fails)