http://www.nhgc.asn.au/node/1747

Cameron Tunbridge <<cameron.tunbridge>>
writes:

Gulgong 2012 task 2, storm chasing or just taking a shower.

The Gulgong Classic provided a great opportunity for many pilots to fly on four
task able days, one of which was task two a 130km triangle from Cudgegong
gliding airfield to Wellington airfield then to a road intersection direction
north and return, a flight that I will certainly recall more specifically than
others due to a narrow escape from the jaws of a massive convergence storm.

Our morning weather briefing was delivered and the mention of afternoon storms
accompanied the usual cautionary remarks from weather man Alan.

Start gate opened 13:45 conditions where strong climbs and associated cumulus,
sun and blue sky as we raced towards the first turn point. However a cu-nimb
cell centered some where south west of Wellington already made effects on the
task area. It cast a dark shadow, overburden and a band of high cirrus across
the second leg of the course as pilots progressed towards the second turnpoint.

I, having already climbed to 3000m above the first turnpoint took a long
perusing glide, whilst remaining pilots recovered altitude from long glides with
almost zero thermal activity. It was giving the impression that thermal
conditions had become somewhat inactive and the third leg became a test of
attrition to staying airborne as I slowly picked my way to goal. Having flown
the exact same task on a previous year, resulting in landing out, I was
determined to exercise enough patience to make it this time.

I was co-flying with fellow pilot Dave May in light lift for over an hour until
a radio transition came over the air from Jonny to Glen who had just announced
he was on final about 5km ahead, informing us that an LD of 10-1 from 20km was
enough to make it in. A while later it was time to make my decision and as a
line of sight to goal came into view I made the observation that conditions to
the north east of goal indicated storm activity.

Dave went on final at 12 to 1 from slightly above, whilst I estimated enough
time to make 10 to 1 and still have time for a conservative glide into Cudgegong
airfield hangars before a possible stopped task. Afterwards I learned we were
not the only pilots faced with a similar decision. Conrad landed before goal and
Trent reached goal and retreated 15km away to land. Some had landed at goal and
thought OMG.

As I started final glide and saw gradually overshooting data on my Compeo,
indicated a tailwind factor assisting progress, so I sped up the descent for a
relatively smooth approach angle and reduced arrival height as further
observations gave renewed perspective that the sky was starting to turn ugly
above. With nasty turbulence about 10km out, I held true to goal, focused on
getting into a safe landing ASAP.

I radioed the pilots on the ground who informed me that conditions were marginal
but seemed okay for an arrival just get here quickly. Things were noisy and hard
to hear the transition maybe even some jokes about the stratosphere or was this
subconscious voices. 5km out I could clearly see Dave about to land and I was
totally committed with straight arms, arse clenched and toes pointed, but it was
already too late.

At that point the area of the sky that I had just previously flown through had
just gone crazy and I was in an area of massive convergence and things were
deteriorating rapidly turning black and green, actually faster than I could
process. Passing over goal cylinder at 1400 m going up 2-3 mps, my aim was to
head east towards some light grey area thinking that I had passed through the
worst and find some air to wind down.

After spending some minutes searching for any signs of sink or even less strong
lift, attempts at spinning down and spiral diving proved futile and with more
lift came the realization that I had grossly miss judged the conditions and I
was about 10km inside the jaws of a storm of fast rising air and the potential
for serious circumstance had become more evident.

Cloud base was 3000m and I had already risen to 2200m in a matter of minutes
beneath a convergence cell of unknown proportions, not a time to panic, but I
was getting concerned and needed to make a decision about how to recover the
situation and escape ASAP.  I made radio contact with the ground and
announced, okay guys I'm in serious trouble, effective pan pan, strong lift,
heavy turbulence, options are disappearing fast, conditions are deteriorating
even faster and rain approaching quickly.

To the east was forest and rain, north, lightning, south, black and green clouds
and west was the track I had already come from, not an option. North west was
maybe the only chance. Further communication with the ground confirmed that was
the best option and from my perspective this meant getting very wet.

Within a matter of seconds the entire area started to down pour the heaviest
rain imaginable. Getting drenched apparently the radio PTT was shorted and
locked on talk continuously giving transmit. Not a time to panic, but this was
stretching my ability to cope and I  had decided to glide towards the north
west. Just repeating on the radio my decision and current situation gave me some
reassurance that I was not totally alone in the storm: "heading north west
direction of Dunedoo, straight arms, full rope going up 3mps in heavy rain and
server turbulence, viability almost zero." Occasional slight view straight down
and a few known ground features, a creek bed and road intersection and GPS
pointing towards the goal co-ordinate to navigate.

Many minutes passed and the sky became brighter in the direction I was heading.
The rain started easing, but still surging strong lift for 20km gliding away
from the cell towards Dunedoo. Another cell was forming like an atomic bomb
blast and a lower ring of black tendrils in the direction north of Dubbo was
sucking surface winds 50-60 kmh.

After gliding away from Gulgong and the local air mass developing into cu
cloud's, then a gust from sheer just to make things interesting before a
vertical descent in a large field next to the Golden highway 40 km from goal I
unclipped my nose wires and after 15 minutes laying on top of my glider I got a
phone call in my harness from Jonny and Glen. Shane was on the way. Thanks guys,
yes, down safely now and my retrieve crew is on the way.

Lyn, Adam and Grant arrived and I was please to see them. Yes, I know the
situation could have been avoided and it appears there was a motive to
compromise personal safety to make goal, but the main thing I learned from this
incident is, given best assessments of the soaring conditions, things can be
different and can changing faster than anything previously experienced Given the
same circumstances leave more margin, nature is all mighty. Weather quote: "when
it looks ugly it's ugly."

Later that week during the competition, task four yielded another rain storm and
gust front on the course line in Cappatree valley, delivering another drenching
and struggle with violent surface winds after landing out. Later pilots managed
to navigate around and almost made goal. The area was void of cell phone service
so there was not an effective mechanism for communication with head quarters,
raising the question of stop tasks. Ultimately it's pilots own responsibility to
land for safety.