Flight Test | Bücker Jungmeister

Flight Test | Bücker Jungmeister
B
arrel-rolling a Bücker
Jungmeister through a
superb September sky with
the pulse of the engine
throbbing through the
throttle and the warm wind playfully
tugging at my silk scarf is just too much
fun. My one regret? I wish I didn’t have
to give it back!
It’s widely accepted amongst vintage
aircraft aficionados that Carl Bücker
produced two of the best-handling
biplanes ever made−the famous
Jungmann and the fabulous
Jungmeister. The prototype Bü 133 first
flew in 1935 and soon generated
considerable interest. Not only was it the
Pitts Special of its day, but it remained
competitive as an aerobatic mount until
the 1960s. It’s an iconic machine. Most
recent addition to the Old Warden-based
stable of well-known vintage aircraft
collector and renowned Storch pilot
Peter Holloway, the Jungmeister comes
with an excellent reputation.
Having had a full briefing from
experienced warbird pilot Stu
Goldspink, and a further chat about the
type with the Shuttleworth Collection’s
Chief Pilot, Dodge Bailey, it was time to
examine the machine in detail. From
a distance this stubby little aircraft
has a pugnacious, almost wilful look
about it−but, as we’ll see, looks can
be deceptive...
70 | Pilot January 2015
The heart of any powered aircraft is its
engine−and the Jungmeister has a big
heart. Tightly encased beneath the big
‘bumped’ cowling is a Siemens-Bramo
SH14A-A4 seven-cylinder air-cooled
radial, which produces up to 160hp at
2,400rpm. It turns a laminated ash
Hoffmann two-blade, fixed pitch propeller
and is fed by a single 92 litre fuselagemounted tank, just aft of the firewall. The
fuel supply is actually a ‘tank within a
tank’, fuel being drawn via a flop tube
inside the smaller one. Quantity
remaining is shown by an indicator
needle attached to a float and viewed
through a Perspex pipe projecting
vertically up from the fuselage.
The cowling can be quickly removed
for easy access to the engine and
accessories, while to just check the oil
there’s a small hatch on top of the
cowling. The original carburettors have
been replaced by Ellisons, as the stock
carbs tended to flood in sustained
knife-edge flight (aerobatic ace Manx
Kelly also noted ‘a motor cough as she
switches to the inverted carb’ when
slow-rolling James Gilbert’s standard
Jungmeister for Pilot’s original 1972
flight test). Peter’s aircraft also has a
Christen inverted oil system.
The fuselage is constructed from
welded chrome-molybdenum steel-tube
and covered by a combination of
aluminium panels forward of the
cockpit and fabric aft, while the wings
are made almost entirely from wood and
fabric. There are ailerons on both
wings, which feature eleven degrees of
sweep-back. N-type interplane struts
support the centre-section, while the
outer wing panels are carried by
parallel struts braced with diagonal
streamlined wires. The ailerons and
elevator are actuated by pushrods with
cables for the rudder.
The main undercarriage consists
of spring-loaded Vees, with shock
absorption provided by a
combination of oil damping and
steel springs, and it is interesting
to note that the legs are
compressed considerably when on
the ground (in flight they extend by
about twenty centimetres). The brakes
are cable-actuated drums.
An unusual facet of the tail unit is that
the elevators use a fairly thick aerofoil
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The old masterJungmeister
A true thoroughbred, this 1930s aerobatic
biplane still has the power to amaze
Words Dave Unwin Photos Darren Harbar
section and their
hinges are set back
from the tailplane’s
centreline. This
creates a pronounced
slot, which must
increase pitch
authority. The solid
tailwheel steers through
the rudder pedals, and can be unlocked
from the cockpit for tight turns. It is so
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small that the
bottom of the
rudder is very
close to the
ground.
There are
cable-actuated
trim tabs in
both elevators
and a groundadjustable one in
the rudder. The
baggage bay just aft of
the cockpit is curiously
capacious, bearing in mind this
machine was specifically designed
for aerobatics.
Starting from cold, you must pull the
engine through at least eight blades to
ensure that there’s no hydraulic lock
while listening to the
metallic ‘clack’ of the
impulse coupler, then
it’s time to saddle up,
sensibly attired in
leather helmet, gloves and
that silk scarf. (Hey, if you’re going
flying in an open cockpit, single seat
biplane a silk scarf is practically
mandatory!) For a biplane, access to the
cockpit is good. Sweeping back the
wings obviously helps by moving the
centre-section forward; the wingroot
walkways are sensibly sized, the small
doors swing down on either side, and
there are well-located grab handles
immediately above the cockpit.
Strapping in is a bit of a faff, as you
need to fasten the seat-type parachute,
the four-point harness and a ratchet-type
secondary lap strap. The seat adjusting
mechanism is very neat−there’s a lever
on the starboard side and you just twist
the top to unlock it and then raise or
lower it to adjust the seat. This is a great
Pilot January 2015 | 71
Flight Test | Bücker Jungmeister
Above, from top: the name that for thirty years spelled
‘world’s best aerobatic biplane’; superb detailing
includes these leather gaiters for strut and bracingwire fittings; offset hinges give the elevator an
effective aerodynamic slot; adjustable for reach — the
rather wonderful stick grip; and those hyper-extending
oil-damped sprung undercarriage legs
Main image: bare essentials — the lightweight and
beautifully triangulated fuselage frame is there to see
72 | Pilot January 2015
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feature as you can sit up high when taking
off and landing, and lower yourself in the
cockpit in the cruise, out of the wind; I
really like this. Another neat facet of the
cockpit is that the stick-top can be
adjusted, although the rudder pedals are
fixed. Ergonomically, the Jungmeister is
pretty sound as the elevator trimmer,
wobble pump, oil shut-off valve, tailwheel
lock and fuel selector are all on the port
side. The fuel selector has three
positions−Off, Normal and Aerobatic.
When set to Aerobatic it picks up fuel via
the flop tube, but Stu had emphasised that
all takeoffs and landings must be made
with the fuel selector set to Normal in case
the flop tube gets kinked. The instrument
panel is fairly minimalist. I’d be minded to
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transpose the ASI and altimeter, and made
a note to ignore the original but U/S oil
pressure gauge.
Starting just about any aero-engine of
this vintage is something of a ritual, and
the big ‘Bramo’ is no exception. With the
fuel valve set to Normal the wobble pump
is… er wobbled to raise the fuel pressure,
then the throttle set to ‘half open’ and a
vigorous squirt of primer applied as each
blade is pulled through. As the ignition is
retarded at low throttle settings, it is
important not to open the throttle too
much on start in order to avoid a backfire
and an engine running backwards. Set the
rotary mag switch to both, Peter gives the
prop a healthy flip and the motor coughs,
fires and lazily chuffs into life. Puffs of
white smoke, accompanied by pops and
bangs emanate from the exhaust until all
cylinders are drawing fuel (the primer
doesn’t appear to charge each cylinder
evenly), but gently easing the throttle
forward makes the engine run smoothly
and the black blades dissolve into a
shimmering disc.
Check that the oil pressure is rising
nicely and then just sit back and listen
while the engine grumbles away to itself
with the wonderful, liquid rumble that
only a well-tuned radial can produce.
Once the oil is warm−after five minutes
or so−I ensure that the tailwheel is locked
and set off towards the active runway with
the exhaust emitting a smooth growl.
There is only one way to taxi a machine
Pilot January 2015 | 73
Flight Test | Bücker Jungmeister
Bückers have always had a reputation
for beautifully balanced controls
like this−and that’s
very carefully. My
stately progress
towards the
runway is
in a series of
slow, sinusoidal S-turns, as otherwise it is
simply impossible to see what’s directly in
front. With my feet in the rudder pedal
stirrups, I discover that while the toeoperated, cable-actuated drum brakes are
adequate, the geometry of the rudder
pedals is such that you really have to point
your toes to make the brakes work. I don’t
use them much.
The first item on the flying programme
was to shoot the air-to-airs, but as the
weather is NBG I elect simply to stay in
the circuit. With the uncomplicated
pre-takeoff checks complete (having
remembered that there’s no carb heat and
the mixture control is automatic), I line up
on Runway 03 and ease open the throttle.
Acceleration is good, and there’s no
difficulty in keeping straight. All the
controls come alive immediately and I
gently pick up the tail, significantly
improving the view forward. I anticipate a
slight swing as the tail comes up, then just
ease back on the stick at about fifty knots
and the Jungmeister leaps off the ground
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in around 150 metres.
Roaring skyward at 70kt produces
a reasonable view forward and a fair
vertical velocity (there isn’t a VSI, but it
seems to climb at around 1,000-1,200fpm)
but the aspect I’m immediately aware of is
the controls.
There’s just so much authority in all
three axes, and within seconds I know I’m
at the controls of a real thoroughbred.
Bückers have always had an enviable
reputation for beautifully balanced
controls, and the Jungmeister does not
disappoint. The four ailerons are light and
powerful and the elevator just about ideal
in weight, the pushrod actuation no doubt
playing its part in this. That said, harmony
of control isn’t perfect: at first I thought
that the directional stability was somewhat
‘soft’, but soon realised that I was simply
over-controlling. The rudder is both light
and powerful and as the Jungmeister is
quite short-coupled, heavy feet can get the
slip ball swinging. Apart from this−and I
soon get the hang of it−it’s an incredibly
impressive machine. The cockpit is warm
and snug and (for a biplane) the field of
view pretty good. The trimmer is powerful
and precise.
I like to ascertain how an aircraft
handles on the slow end of the speed scale
before
landing
it, so at a safe altitude (which
coincides with cloudbase) I
try a couple of stalls. These
are incredibly benign, as the
Jungmeister really doesn’t want
to stop flying. If you insist, it reluctantly
drops its nose and a wing, but simply
release the back-pressure and it starts
flying again immediately.
Time to try a few circuits, and I can see
from the limp windsock that what wind
there is still favours R03. A bit more
headwind would’ve been nice as 03’s
slight downslope will exacerbate any
tendency to float, but landings are very
straightforward; gently close the throttle
abeam the numbers and then simply fly a
classic curved approach. Sixty knots
‘around the corner’ tapering back to a ‘last
look’ of 55 feels about right, but the
elevator seems to lose a little authority in
the flare, so on the next landing I try
keeping just a dribble of power and this
seems to help. After half-a-dozen touchand-goes the landings are getting quite
smooth, but nevertheless it really seems to
pitch, buck and rock ’n’ roll on the ground
run. When afterwards I ask Peter how the
landings looked, he replies “fine” and
explains that the springy, short-coupled
Pilot January 2015 | 75
The ailerons and
elevators are light,
smooth and very
powerful...
Main image: owned by Peter Holloway, our subject
aircraft wears the markings of the Spanish air force,
which operated Jungmeisters long after WWII
Left: a thorough check of the external control wires
and bracing is an essential part of the Jungmeister —
and any other biplane — preflight
Flight Test | Bücker Jungmeister
undercarriage really exaggerates the
bumps in the runway. It feels much worse
than it looks.
A second bite
...while the
breakout forces
are almost
non-existent
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The following week I’m in close formation
with Peter’s immaculate Miles Magister
flown by Bob Morcom and carrying
photographer Darren Harbar. The shoot
goes well, and while the Magister heads
back to Old Warden I find myself a quiet
piece of sky to try a few aerobatics. The
spins, loops, rolls and flicks are as easy as
I’d thought they’d be, and are followed by
a smooth landing and bouncy roll-out.
Driving away from Old Warden I can’t
help but feel the Jungmeister and I have
unfinished business. I’ve got more than
enough to write a pretty comprehensive
report, but really want to dig a little deeper
into the envelope and−I can’t deny
it−the Jungmeister has really put a hook
in me. It is undoubtedly one of the finest
handling aircraft I’ve ever flown.
Diamond geezer Peter laughingly agrees
to my rather cheeky request for yet
another flight, and on a truly stunning
1 November I taxi eagerly out. Unlike my
two previous flights, there’s a fresh
south-south westerly blowing right down
the runway, and the Jungmeister is
airborne almost before the throttle hits the
stop. Climbing up into a flawless sky with
the radial roaring out its wonderful song I
just can’t believe my luck. It’s a perfect
day for flying, and I’m flying the perfect
machine.
Heading away to the east I briefly
re-examine the primary controls and
confirm my previous conclusions: for a
biplane designed in the mid-1930s the
handling is nothing short of amazing. The
ailerons and elevators are light, smooth
and very powerful, while the breakout
forces are almost non-existent. Even
harmony of control now seems ideal
(on the first two flights I wore boots,
but this time my lightweight trainers
give more finesse and I don’t overcontrol the rudder).
At a sensible altitude I run through
the ‘Hasell’ checks, select Aerobatic
on the fuel valve, give the wobble pump a
quick wobble, and the harness an extra
tug, then start off with a couple of spins.
The Jungmeister spins delightfully,
although as Manx Kelly noted, in just two
or three turns the rate of rotation will build
up to the point you end up ‘spinning like a
top’ at 300˚ per second. However, when
you apply opposite rudder and ease the
stick forward it recovers instantly. (In
Manx’s day, flying an aeroplane that was
forty years younger, inverted spins were
on the card, our aerobatics specialist
reporting that ‘inverted spins in both
directions show the same characteristics
[of instantaneous recovery with a
tendency to overshoot one’s line due to
the high rate of rotation], with a slight
flattening of the spin as she winds up.
Very exciting.’−Ed.)
Stall turns, chandelles, loops and rolls
are all a joy−indeed as the stick’s throw is
quite short and the control pressures so
light you almost need to just think about a
manoeuvre and it happens. Care does
have to be taken on both the up and down
lines, but for two very different reasons.
As the prop is fixed-pitch it’s quite easy to
over-speed the engine in a dive (the
factory red-line was 2,400rpm, but Peter
has built in a safety margin by red-lining
his at 2,200) while on the up-line it bleeds
energy very rapidly, although this is
clearly because its got more drag than a
Gay Pride parade! A great confidence
builder is that whatever you do, you never
get anywhere near the 182kt Vne.
Pulling up into a graceful chandelle and
watching the sunlight and shadows slide
swiftly across the taut fabric simply
confirms what I’d known within seconds
of leaving the ground on my first flight in
it. This thing really is way too much fun,
and my grin feels wider than the six-metre
wingspan. Time now to explore the
Jungmeister’s main claim to fame; the flick
roll. And here everything you’ve read is
true−‘she breaks smartly as you snap the
stick back, and completes one revolution
in 1½ to 2 seconds’ said Kelly: this thing
flicks like a demon, but as he observed−
with just a bit of artistic licence−‘those
marvellous controls enable the flick to be
stopped in a microsecond’. Add some
aileron at an appropriate moment and it
flicks even quicker. Manx didn’t say it, but
the swept-back wings must contribute to
these characteristics.
A couple of stall turns followed by a
delightfully slooooow roll and a glance at
the fuel indicator suggests that it’s nearly
time to be heading home. Suddenly a
thought occurs−could I put on a
respectable show in the Jungmeister? A
quick ‘Hell’ check, choose a prominent
line feature for my notional crowd-line and
here we go! Enter centre stage with a
three-turn spin, recover parallel with the
virtual crowd line, gain some speed
(watch the rpm!) and straight up into a
loop, then a chandelle to the left and one
to the right, more speed and a barrel roll.
Start slowing down, check speed, height
and rpm, then flick, recover and ease the
nose down. More speed, up into a loop
with a roll off the top, another flick and
Pilot January 2015 | 77
Flight Test | Bücker Jungmeister
SPECIFICATION
BÜCKER BU 133C JUNGMEISTER
■ DIMENSIONS
Wingspan
Length
Height
Wing area
6.60m
5.90m
2.25m
11.9sq m
■ WEIGHTS AND LOADINGS
Empty weight
Max takeoff weight
Useful load
Fuel capacity
Load factor
420kg
610kg
190kg
92 litres
+4/-2g
■ PERFORMANCE
Vne
182kt
Cruise
100kt
Stall clean
45kt
Take off distance (over 50ft) 280m
Landing distance (over 50ft) 300m
Climb
1,200fpm
Range
250nm
■ ENGINE AND PROPELLER
Siemens-Bramo Sh14A air-cooled
seven-cylinder radial, producing
160hp (119kW) at 2,400rpm, and
driving a Hoffmann two-blade fixed
pitch propeller
■ MANUFACTURER
Bücker Flugzeugbau & Dornier,
Germany/CASA, Spain
then exit stage left to tumultuous
applause… or not. You see, the snag is
that the only things I do near the ground
are take off and land. Consequently,
although my little routine might’ve been
quite good (and it certainly felt pretty
respectable) as I never went below 2,000ft
78 | Pilot January 2015
any airshow punters would be demanding
a refund! A further glance at the float
confirms that it’s definitely time to be
heading home, so it’s select Normal on the
fuel valve, a quick wobble of the wobble
pump and start searching for Old Warden.
On the way back power is briefly set to the
‘max continuous’
of 1,900rpm for a
look at the cruise.
This gives 90kt
while burning
about 36 litres per
hour, for a range
of about 250nm.
Cruising back
towards Old Warden with that lovely
round motor rumbling away (it’s one of
the smoothest radials I’ve ever flown
behind) and a waterfall of warm air
flowing around the cockpit is just
wonderful.
Back in the circuit, I’m determined to
get it right for my last landing. Ignoring
the displaced threshold (which does
produce a rather odd picture) I
concentrate on the numbers, and the
second I’m abeam them slowly close the
throttle, ease the elevator trim back and
immediately commence turning in,
intending to go from the downwind leg
onto short final in one great sweeping
curve, the way aeroplanes like this should
be flown. Due to the blustery wind I use
65/60kt, and with the wind sighing in the
wires the Jungmeister comes rumbling
over the fence. All the speeds and angles
are bang on, and as we cross the
threshold with just a hint of power on I
begin easing the stick back. It all feels
just right… and, you know, it very nearly
is. The bulbous nose slowly rears up,
completely obscuring the forward field of
view, but my confidence is up and my
peripheral vision firmly focused. With
barely a bump the
wheels kiss the
grass, just past
the numbers and
right on the
centreline. But it’s
been six weeks
since my previous
flight, and I’ve
forgotten how much the oleos extend in
flight. Instead of a perfect three-pointer
the mains touch first and there’s a slight
skip before the Jungmeister settles gently
onto the ground−bugger!
Back at the pumps I switch off the mags,
the glorious rumble dies away and the
prop lazily huffs over the last couple of
compressions and stops. In case you
haven’t guessed by now, I really like the
Jungmeister: it’s a fascinating
contradiction of a flying machine, in that
despite the (for its age) sparkling
performance and crisp handling, the low
wing loading means that it doesn’t have
any vices or vicious traits, and is actually
really quite easy to fly. It’s fantastic in the
air, while the steerable tailwheel, toeoperated brakes, large rudder and four
ailerons make it pretty tractable on the
ground too. It also just oozes charisma.
What a truly magnificent machine!
The Jungmeister’s
low wing loading
means that it doesn’t
have any vices
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