page 45 - American Bonanza Society

Gear transmission lube
Greg Miller, Ankeny, Iowa
Q:
What types of gear lube are
approved for the landing gear
gearbox?
A:
Two types of oil are approved
for the landing gear gearbox,
Mobil 636 & Mobil Delvac 75W-90.
Both are available at Performance
Aero (www.performanceaero.com)
for a very reasonable price of $7.50.
—DH
A36TC power settings
Noah Bunker, Austin, Texas
Q:
I fly an A36TC and have previously
corresponding with you
about operating techniques. I attended
BPPP in San Antonio two years
ago. I am having some difficulty with
slowing down to approach speeds.
My instructor wants me to use 17" MP
and I think this makes me too slow.
But I wonder what your thoughts are
for approach speeds and settings/
configurations in an A36TC?
It’s a common misconception,
even among Bonanza-
A:
experienced instructors, that the
power settings that work for the normally
aspirated and turbonormalized
airplanes work the same way
in the A36TC/B36TC. Twenty inches
of mani fold pressure and 2500 rpm
with approach flaps results in about
110 KIAS in your airplane. Extend the
gear from this configuration and the
airplane will descend at 500-600 fpm
with no power change (perfect for a
precision approach). Reduce MP by
two inches (to 18") and extend the
gear to descend at 800-1000 fpm for
a non-precision descent, and increase
to 24" MP to level off at MDA (with
gear down and approach flaps set).
This is all documented in the ABS/
BPPP Guide to Initial Pilot Checkout
for your airplane, found under PILOT
TRAINING/BPPP on the ABS website.
—TT
Q:
www.bonanza.org
Auxiliary
fuel pump
output
Allan Safieh
Doral, Florida
I own a Bonanza F33A with an
IO-520BB. The shop changed
the auxiliary fuel pump to a new
one (because the old one reached
500 hours). But the new pump gives
me 14 gph, while the old one gave
me 16 gph. What is the normal flow
I should get?
A:
With the mixture and throttle
pushed all the way in, the pump
should indicate 16 PSI at 14-16 gph.
With the mixture and throttle pulled
all the way out, the pump should indicate
23 PSI and no indicated flow.
Completely unrestricted, the pump
will run at 42 gph. —BR
Q:
Recharging the
air conditioner
Tomas Ortega
Mexico City, Mexico
I had to reseal the original
factory installed A/C compressor.
I understand that the original
coolant was R12, and now all the A/C
people are charging with R-134A. Is it
a 100 percent direct replacement of
the R12? Can I just vacuum the system
and recharge with R134A?
A:
No, sir, I am sorry that is not
possible. R12 and R134 are two
totally different type refrigerants. The
oil in the 134 system may eat the seals
on the R12 system, and the systems
run at different pressures. You will
have to purchase the STC to convert
the system to R134. The cost of the STC
is $4000 from RAM Aircraft. —BR
Volume 13 • Number 5 AMERICAN BONANZA SOCIETY 63