World Record set in Jabiru UL in the UK still
holds
It all started when I had just flown back from
Popham in my Xair microlight , an epic journey which took over 3 hours, due
to a head wind of up to 30kt. Considering the cruise of the Xair was 52kt,
this represented 58% of my forward progress. A few more knots could be
coaxed out of it, but at the expense of a massive increase in fuel
consumption. I eventually ended up back at Farthing Corner with 4 litres
left in the tank, and near airsickness.
I realised that what I got out of flying was the travelling. The speed the
Xair went was fine, providing no headwind, so I decided I needed something
which would cruise at 52kt ground speed in say a 25 kt headwind. Hence I put
a deposit on an Ikarus C42. A bit of an ugly duckling, and not that far
removed from the Xair, but the vendor promised it had such a turn of speed
that it held a world speed record for microlights. After several missed
promises for approval and the non-resolution of technical issues however, I
cancelled my order after 3 months wait. The cancellation didn’t go down too
well at all, but at the end of the day, I didn’t get what was promised and
hence I pulled the plug.
Casting around for an alternative got me looking at a Jabiru. It was faster,
sexier and more importantly - a fair bit cheaper! The downside was that I’d
have to build it but after looking at the manual and finding someone to do
the pinholing & painting I decided to go for it. Two days later the kit was
on the high seas from oz on its way to me, and 3 months after I received the
kit, the test flight was carried out at Rochester by Jim Stevens. Jim
identified early on that the (fixed pitch Kremen) prop was far too fine for
the engine as you couldn’t get any speed on without over revving the engine.
A new prop was ordered, which didn’t come for 3 months, but in the meantime
I decided to go for the world record since it was within the capabilities of
my machine.
Being a Project Manager helped and I worked towards getting all the
prerequisites for such an attempt. Keith Reynolds was persuaded to be the
independent observer and I applied for my FAI (International Aeronautical
Federation) licence. I got hold of and read the FAI rules and found out that
in fact the weight limit is a few kilos less than the that in the UK. Being
that many ‘hot ship’ microlights are very close to the limit, many wouldn’t
fall into the FAI category and as such wouldn’t qualify for records under
this category. This, I believe, is largely due to the cantilever wings which
require heavy beams to provide the necessary strength.
The other factor in the definition of a microlight is to prove the stall
speed. This, unbelievably, involves flying at stall speed close to the
ground and timing the aircraft between 2 points. I managed to persuade the
FAI to accept a letter from the PFA confirming the stall speed of the
aircraft, a much safer approach I think!
There are in fact several records to be had for microlights, and in the end
I plumped for the two held by the Ikarus; for 2 seat three axis microlights
over a distance of 50 and 100km. In essence, each record involves flying a
triangle covering the competition distance and finishing up higher than you
started.
The final and most important device is a logging GPS which I rented. This
device logs your progress and stores the data in a secure format so that the
data can’t be altered and therefore you can’t cheat! Of course, you could
put the logger in Concorde and claim an exceptional record and that is where
Keith came in to ensure the log is done in my aircraft and additionally to
witness the check weighing of the aircraft to ensure it comes within the
defined limits.
Finally, a passenger was required and so long term Rochester microlighter
Bob Sharp, otherwise known as ‘skinny Bob’ was enlisted, his svelte form
likely to help in my quest for more speed. Of course this has now changed
somewhat with the superb feeding he now gets from the Horizon Café!
The trip was planned, entering the turning points in my GPS and the logger
and a few practice flights were carried out to minimise travelled distance
in turn at high speed, as well as to practice turning round a ‘virtual’
point. We also tried to pick out various landmarks, such as Shivering Sand
Tower, famous for once being a Pirate Radio Station.
We also decided as a side line to go for the UK altitude record, although
that was easy because the records for the UK had then only recently been set
up and we could have got this by taking off from Rochester, doing a circuit
and landing again! In the end, we got up to FL104 which is the highest we
could get to in Kent, just off the coast at Margate. We were talking to
Manston who were perplexed at what we were doing and repeatedly told us to
keep out of controlled airspace, which we did.
The records were fun in themselves. Bob kept the lookout, and I had to
concentrate hard not to lose time by deviating from track, or from varying
my height. I kept the revs down from max in order to preserve the engine
being that we could have broken the then current record without doing so. On
the 100k record, lifejackets were donned since we were out over the sea in
part. After much paperwork (and a few beers) the submission was sent off to
the FAI and in due course the certificates came through showing records
confirmed at 187 and 186 km/hr (about 100kt) for the 100 and 50km records
respectively.
Subsequent fitment of a GT prop has made further improvements to the Jab’s
performance, with it now able to hit VNE in S&L flight at 116kts. I thought
about another pop at the record, and may well do this one day but I think
I’ve proven my point and have been slightly disappointed at the lack of
appreciation from Jabiru or the UK media in the event.
Julian Harris