8/31/2008
I thought maybe some of you would be interested in a
beginner’s perspective on competing at an IAC aerobatics contest in an
RV8.
The event was this last weekend at Brenham, TX. hosted by the IAC
chapter 25. There were about 20 aerobatic aircraft and about 25 pilots.
There were several Pitts but there were also Sukhois, Extras, Yaks,
Giles and others. There was competition in all five categories: Basic,
Sportsman, Intermediate, Advanced and Unlimited. I flew in the Basic
category.
Friday was registration, technical inspections and practice. My RV8
which I built as per the plans (no modifications) passed without any
problems. I have fuel injection, a fixed pitch prop, no inverted fuel
and no inverted oil systems.
The practice slots on Friday were 15 minutes long. I went up and did the
Basic routine 3 times with a very experienced aerobatic pilot critiquing
me on the radio. The Basic routine consisted of a 45 deg pitch up, a 1
turn spin, a ½ Cuban eight, a loop, a 180 deg turn and a roll. A
sampling of my critiques are, my 45 pitch up was shallow, my spin did
not end up pointed straight down, the 45 deg down on the ½ Cuban was
shallow, my loop was not constant radius, I lost altitude in the turn
and my roll looked bobbled. On the positive side, I improved each time
around.
On Saturday, the competition started with a safety briefing very early
in the morning. The briefing consisted of the order of flight,
designation of judges, assistants, scribes and safety. Part of the
safety briefing was the designated propeller hot zone, where to hold
before entering the aerobatics box, minimum altitudes, frequencies in
use and more.
When it was my turn, I pushed my RV8 across the engine start line and
hopped in. The starter verified I was buckled up, wearing a parachute,
had my altimeter set to 0 AGL, had fuel, oil and that I appeared to be
coherent (which I was). The rest of it was pretty much like practice. I
took off and climbed to the holding area. When the previous competitor
was finished I was cleared into the box. I started level at 2500 feet
and 140 knots. Other dragier planes have to dive but RVs have enough
speed at low cruise to start just about any maneuver. A wing wag starts
the judging.
The range of altitudes for Basic is from 1500-3500 AGL and the box is 1
kilometer by 1 kilometer. It seems kind of tight for an RV8 but I think
as I gain more experience I shouldn’t have any problems. In Basic, there
is very little penalty for leaving the box on the sides and top so I
didn’t worry about it too much.
I finished my routine, descended down to pattern altitude, landed,
parked the plane and walked to the diner for a thirst quenching
milkshake. OK, it is really more fattening than thirst quenching but
those of you who have been to the Brenham airport diner know their
milkshakes are a Texas landmark. Back on topic - my score was 77%. I
believe this is pretty good for Basic and about average for Sportsman.
I flew again on Saturday afternoon and Sunday morning. My scores were a
little better each time with an 81% on Sunday. My biggest problem was
with the roll. It has to be completely flat with no noticeable change in
pitch or heading. This means during the roll you have to use “up” rudder
and “up” stick to keep the nose pointed at a fixed point in the sky. The
problem for me is that this isn’t second nature so my control inputs
were jerky. I end up noticeably off heading and not level throughout.
On Saturday late afternoon, I was volunteered to be a judge’s scribe for
the Intermediate and Advanced competition. There were three judges and
each one had a helper (who called out the maneuvers) and a scribe (to
record the scores and critiques). It happened to be that my judge was
Debby Rhin-Harvey.
On Sunday after I flew I was assigned to be one of the line judges (I am
sure I am getting the terminology wrong here). At this position I was in
the middle of a cow pasture and my job was to radio the chief judge
whenever someone went out of the box to the north or to the west. I was
out there with an ice chest full of water bottles, a chair, two radios
and a pickup. I was apprehensive at first because I didn’t want to mess
up anyone’s score but it soon became apparent that it was an easy job.
On Sunday afternoon, the diner opened for just us at 4pm. We had a great
meal, speeches were made, pictures were taken and awards were given out.
Then I flew home.
I am not an engine expert so I have to claim ignorance on the importance
of an inverted oil system is for Basic and Sportsman. I had my Dynon EMS
set up to alarm for low oil and fuel pressure and it never went off for
either. I did end up with oil on the belly and lost about ½ a quart over
the three days. The most continuous inverted was about 1.5 seconds
during the ½ Cuban and about 1 second during the roll. I have the Dynon
set up to alarm for excessive RPMs and it did go off once at the bottom
of a ½ Cuban at 2750 RPM and 160 knots indicated. I botched this one
because I can usually keep it below 150 knots at this point. The most Gs
I pulled were 4.5 positive (in a loop) and -1.1 negative. Again, I think
I overdid it on the loop because usually 3.5G is enough for decent
results. My maximum altitude was 3200 feet and minimum was 2100 AGL.
The folks who put on this event and the pilots who competed and judged
were the friendliest I have ever met. I never felt like an outsider.
This much is a fact - we RV pilots are invited and very much encouraged
to participate in these events.
I can’t wait until next time. Now I need to work on rolls and those
Sportsman maneuvers.