Thanks, Justin, for sharing with us your unfortunate experience and your new
rules are avoid recurrence.
I should like to add one very important rule that we publicised about five
years ago, which is "NEVER apply the brakes while turning". The reason for
this is that the outriggers are behind the centre of gravity, and therefore
it is much easier to tip a monowheel Europa over when the tipping axis is
mainwheel/outrigger rather than the mainwheel only (as when static or moving
straight ahead). This rule applies just as much to taxying (except when
moving very slowly, for the experienced) as it does to the landing roll.
A further point, which follows from your Rule 2, is "ALWAYS throttle back
before applying the brake". This is particularly important if the aircraft
starts to move forward during a power run-up: the natural tendency to grab
the brake and apply it harder to stop the movement must be resisted until
the engine has been throttled back.
Fly (and taxi) safely
Mike
Europa Club Safety Officer
safety@europaclub.org.uk
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Justin Kennedy
Subject: Europa-List: Europa G-ZTED Prop Strike
<Justin@systemwise.co.uk>
Prop Strike!
Our aircraft G-ZTED is a Europa Classic Monowheel Rotax 912S with an
Airmaster A332 Propeller.
Our lovely Europa, our pride and joy, was only 17 hours old when we went to
our first fly-in. I was taxiing on rough grass and slightly out of wind, the
tail lifted and, o woe and thrice woe, the propeller dug into the soft turf
breaking three blades off and damaging the variable pitch mechanism of the
prop.
Lots of thought and soul searching not to mention upset later we have come
up with a set of rules for taxiing our Classic Monowheel which will
hopefully avoid this happening again. The Rules are on the back door of our
trailer stuck to the broken blades to remind us. I would like to have seen
these and thought about them before it happened to me. I offer the story
here in spite of the embarrassment, knowing that if it saves just one
propeller that it is worthwhile.
The elevator of the Europa is powerful, it's brakes are good and the Centre
of Gravity is not that far behind the mainwheel. Coupled with this we have
the Rotax 912S with an Airmaster A332 constant speed prop which, when set
to fine, can produce a thrust of over 500 lbs on the ground. Each one of
these things can lead to the tail becoming light and in a number of
circumstances they can add together to cause a certain propeller strike. All
these forces act in the same way conspiring to wreck your propeller, your
day, your self esteem and your bank balance.
So, to counter this, we have devised a set of Rules which I am going to
adhere to.
It should be food for thought for new Monowheel owners.
Rule 1: DO NOT Use more than 3000 rpm to taxi.
This puts a limit on the amount of thrust which tends to tip the nose
forward. If the ground is so rough that more than 3000 rpm is required then
you should not be there. Shut Down and pull her out. It is a lot cheaper
than a propeller.
Rule 2: DO NOT Taxi with Power against the Brakes
This is much the same as number one. Taxiing against the brakes produces a
tendency to tip the nose forward. I can think of no occasion when it is a
sensible thing to do so it is now off limits.
Rule 3: ALWAYS Do the run up check directly into wind
This may seem obvious but given the situation where you were say 40 degrees
out of wind in a blustery 25kt wind. The power goes on for the run up
against the brakes. This makes the tail lighter but you pull the stick right
back. Due to the strong side wind the prop wash is not operating on the
upwind side of the elevator and the aircraft is very tail light. The
blustery wind gusts under the windward elevator and the equation is suddenly
not in your favour. Obey rule three and this won't happen.
Rule 4: ALWAYS Centralise Control Stick when taxiing out of wind
Again this is obvious. The all flying elevator is so powerful that if pulled
back it is enough to lift the tail all on it's own without any of the other
factors helping it. Due to the taxiing attitude of the monowheel the
ailerons are best centralised out of wind.
Centralised controls make the Europa Monowheel quite stable when taxiing
downwind.
Rule 5: NEVER Taxi on Rough Grass
This is a bit extreme but after our experience we are going to stick to
this. The Europa Monwheel's big wheel makes landing on rough fields possible
but taxiing on rough grass is risky. If 3000 rpm won't take you then Shut
Down and get out and pull it out. Believe me it is cheaper to do that.
Rule 6: NEVER Use Power to overcome obstacles. When you get stuck. SHUT
ENGINE DOWN and get out and pull it out.
OK this is Rule five again but it is the most dodgy thing to do. Directly
into wind it may be possible to get away with more thrust but our Airmaster
Propeller is a wonderful piece of kit and makes our aeroplane very good
cruising machine. It can pull the nose over with very little help. Why risk
it.
The above instructions are now incorporated into our Pilot Notes.
We are just getting to know what a fantastic aeroplane we have made.
See you around.
Justin Kennedy
G-ZTED
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