FlyPast 12.2018

102 FLYPAST December 2018

FROM THE WORKSHOP MESSERSCHMITT BF 109G

Another important factor is that
it has the Bf 109G-12 rear cockpit
and flight controls installed.
These modifications were made
by Meier Motors at Bremgarten
and were based on a handful
of original factory drawings,
with considerable help from the
Kbely Museum in Prague, Czech
Republic, which has an Avia
CS-199 (post-war, Czech-built Bf
109 two-seat trainer) on display.

Flight test
The Hangar 10 team commissioned
Michael Stock, of Stock Flight
Systems, to design and install
sophisticated data-recording gear
for a series of comprehensive test
sorties for all three Bf 109s. The
flights were completed in August
2018 with the G-14, and more than
30 hours flying across all three
aircraft have been carried
out at Heringsdorf
this year.
With the desire
to have the G-12
available for future passenger
trips, flight certification has been
designed to comprehensively
compare the differences in
performance and handling with an
unmodified Bf 109G. To achieve
this, a digital CAN Aerospace
Flight Data Acquisition and
Recording System (CDARS) was
created and installed by Stock
Flight Systems. At the beginning
of FlyPast’s visit in August 2018,
flight test engineer Stock and
his team were in the process of
fitting this equipment in the G-14.
It had already been employed
successfully in both the G-12 and
G-6. It is based on a networked
group of small computers,
installed in both cockpits and

in the right wing of the Bf

109. An Advanced Flight Log
     System probe was also installed
     temporarily on the underside of
     the right wing. Several sensors
     and cameras were set up in the
     cockpits to record all control
     inputs and engine performance,
     with the main pilot control
     elements of pitch, roll, yaw and
     engine power all being recorded
     on a Racelogic Vbox video
     system. The wing-mounted probe

comprises a

swivelling nose boom

head, incorporating a

pitot/static tube and

high precision air data

computer, which measures static/

total pressure, air temperature to

compute true airspeed, air density

and vertical speed. The wing

probe also ascertains precise

angle of attack and sideslip.

The system does not transmit

real-time data to the ground,

but instead collects all the

information and transmits it via

a CANaerospace data bus to the

cockpit. Finally, an integrated

flight state and navigation

system was temporarily installed

in the cockpit, to record GPS

track, height, heading and speed.

All flight data is recorded at 100

times per second so that flight

dynamics are captured in the

necessary detail.

After each test flight, data is

downloaded onto a laptop and

then analysed – CDARS includes

sophisticated online and data

processing tools for post-flight

analysis and reporting. These

quickly generate a collection of

reports, so the pilot and engineer

can determine the success of

the test flight and make any

amendments

and changes

for subsequent

sorties. A good

example of this, is

that the system can

immediately generate a

distance graph to show the effect

on take-

off performance

of varying temperatures,

also accounting for speed, fuel

loads and the impact of having

two people in the cockpits.

Exploring the

envelope

Test pilot Klaus Plasa came to

Heringsdorf to carry out most of

the trial flights, the first being

in the G-14 (with the flight data

recording system installed) on

August 16, 2018. Klaus kept the

aircraft in sight of the airfield,

in a wide, high orbit to execute

basic manoeuvres and assess

the data recording system.

This all went according to plan

before further comprehensive

test flights followed with more

advanced manoeuvres, gear up

and gear down stalls, landings,

approaches and basic aerobatics.

Earlier in the year, the Hangar

10 team had prepared the Bf

109G-6 for test flying and after

several tethered high-power

ground runs, Klaus flew it for the

first time since its restoration

was completed on April 26. As

he did during the G-12’s maiden

flight, Klaus kept the G-6 near

Heringsdorf airfield and then

completed a further two

sorties on April 27. Minor

adjustments were made to the

trim and the gear up micro-

switches, and cockpit

indicators

needed some

attention, but apart from

these the G-6 performed

very well.

The G-6 and G-14 both

have DB605 engines and

their smooth running

is a great tribute

to Michael

Rinner

and his

“That this unique Bf 109 can be fl own with a Merlin engine provides a more

practical and sustainable operating basis”

Above right
As part of its test-fl ight regime, AFA’s Bf 109G-
6 is put through its paces by Klaus Plasa.