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1 11th September 09:03
External User
Posts: 1
Default Bonanza F33A CG envelope question

I have been whittling down my pipe-dream list of planes, and a
late-model F33A is on the short list. One of the things I like is
that on paper it appears to have a decent full-fuel payload (~800 lbs.
left over with 74 gallons in the tanks), but have seen frequent vague
references to aft CG loading problems. What is the practical effect
of this issue? babies and puppies only in the back seat? My last
plane was a C-182, which hauled a lot and was pretty insensitive to
loading distribution.

Anyone have an F33A W&B spreadsheet they'd let me play with?

Also, what modifications (if any) are involved in the B. D'Shannon
100-lb. GW increase STC? And are tip-tanks available on the F33A?


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2 11th September 09:03
stu gotts
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Posts: 1
Default Bonanza F33A CG envelope question

The CG problems are a scourge for Bonanza owners. The funny thing
about putting tip tanks on is that you gat a paper 100 lb gw increase.
Big deal, it does nothing to strengthen the airframe. Why not just go
ahead and load it 100 lbs over without buying tips? What about when
you have fuel in those tips, how much do you gain? And with the paper
increase in gw, it takes the aircraft from the utility category to the
normal category.

post pictures to this newsgroup and ask the participants to do the
prebuy while discussing hotel rooms, gps's and autogas.

After OSH get with the ABS and see what their advisors can tell you
about any question you have about the Bonanza.
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3 11th September 09:04
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Posts: 1
Default Bonanza F33A CG envelope question

Check out

The weights are in kg and the fuel is in liters, but the site includes a
handy conversion calculator.

I have no F33A experience, but in playing with this W&B calculator it seems
to me that the envelope isn't all that bad. You should note, however, that
CG moves aft quite a bit with fuel burn, so you have to calculate the
envelope with takeoff fuel and with minimal fuel to make sure you will not
run past the aft limit during flight.

Another thing I note is that useful load isn't all that great (at least
according to this site). With four 170 lb (77 kg) adults aboard, no
luggage, there is only enough available load left for about 3.3 hrs
endurance with 45 min reserve. My Arrow will do MUCH better than that.

Anybody with real F33A experience, or at least data from the POH, that can
dispute this site's calculations, please have at it.

-Elliott Drucker
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4 11th September 09:04
david megginson
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Posts: 1
Default Bonanza F33A CG envelope question

You'd have to ask your insurance company that one.

All the best,

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5 11th September 09:04
dave butler
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Posts: 1
Default Bonanza F33A CG envelope question

I have no experience with either F33s or this STC, so that qualifies me to talk
about them on usenet :-)

In general, adding weight at the wingtips is an entirely different stress on the
airframe than if you added weight in the fuselage. Think of the bending moment
on the wing spars at the wing root. Adding weight at the wingtips actually
reduces that bending moment when in flight.

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6 11th September 09:04
g.r. patterson iii
External User
Posts: 1
Default Bonanza F33A CG envelope question

I've got an old flight planner that has the data for an A36 with club seating. It
totals 21 files, the largest of which is 3.6 meg, but I can zip it up and try to send
it to you if you can't find anything else.

George Patterson
In Idaho, tossing a rattlesnake into a crowded room is felony assault.
In Tennessee, it's evangelism.
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7 11th September 09:04
tom sixkiller
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Posts: 1
Default Bonanza F33A CG envelope question

Get an older model (1985 or so) right near TBO then stick a turbo normalizer
on it (TA Turbo). It kicks the GW up 379 lbs if you also get the IO-550 conversion (entioned below)

IO-550 conversion. (I'd rahte rhave the Millenium engine) (Middle of the page)
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8 11th September 09:04
peter duniho
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Posts: 1
Default Bonanza F33A CG envelope question

Because the 100 lb increase is only for fuel in the wingtips.

If you mean "why not just go ahead and load another 100 lbs in the
wingtips", then you have a point. If you mean "why not just go ahead and
load it 100 lbs over inside the fuselage without buying tips", well that
just doesn't make any sense.

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9 11th September 09:04
roger halstead
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Posts: 1
Default Bonanza F33A CG envelope question

Because the tips do not give you an over all increase. The only place
it can be is gas in the tip tanks and with Osborns it's 240#, Flight Extenders

You gain 30 to 40 gallons of gas. Surprisingly on mine it lowered the
stall speed. Not on paper, but in real life. OTOH power on stalls

Unless you have the bladder for the longer legs it would be a waste.

And I should care because?

A good prebuy is a given for any airplane. Finding a Bonanza
specialist is something else. I was lucky and have had my maintenance
done by a very good one, but unfortunately he passed away recently. I
lost a good friend as well as a mechanic.

Physically there isn't much. Engines are engines and it's a
relatively simple airframe, but there are quite a few ADs and those
can take quite a while to sort through on an old airplane.
Particularly important are the carry through and the rudder spar. I
had the rudder hinge mod done and no longer have to worry about that
one. The Magnesium elevator skins are important too.

On my first annual it took a good day to sort through the paperwork to
get everything in order.

I have the oldest straight tail in existence, yet my maintenance and
operating costs (I count everything) are less than some single owner
172s on the field.

After 12 years and a thousand or so hours I do need to replace the
flight extenders and I've been given a very attractive quote.

Why wait? Go to the Oshkosh fly-in and ask them.

They do have a relatively narrow CG range. The only problem I have
heard is, as fuel burns off the CG changes. That means watching your
loading, but it's one of the things you get used to. As mine only has
1000# useful load that is not a problem. The longest leg I've flown
was 5 1/2 hours and I had 36 gallons left out of 100. At 14 gph (260
HO IO-470N) that's about 2 hours plus reserve.

The F33 is not a "heavy hauler" and it is a lot slipperier than the
182. Its stall characteristics are not nearly so benign. OTOH with
practice you can put it into a departure stall and hold it there
although it takes judicious use of the rudder. It is one airplane
that enforces the "rudder only" when doing stalls. When doing full
stalls you keep the ailerons centered if you want to keep the greasy
side down. It's not a good idea to practice full stalls with the tip
tanks full, or even half full. That is a lot of momentum way out

Get a good knowledgeable Bonanza instructor to check you out and be
sure to take the ABS Pilot Proficiency training program. It is well
worth the money.

They are a joy to fly. Quick, responsive, and with good control
harmony. I think you will find them lighter on the controls than a
182. Another difference is the ailerons and rudder are
interconnected. You can easily roll it into a 2G turn with your feet
on the floor. Not a good practice, but it is easily done. It handles
turbulence very well (for the front seat occupants) However,
virtually any Bo used for IFR will have a good autopilot and not just
a wing leveler.

Once you learn the plane, it is very predictable and easy to handle.
I loved that part of proficiency training. Most of the pilots did not
want to do stalls with out having use of the ailerons and the
instructors were going to be holding the yoke so it couldn't be
turned. <:-)) They also made us calculate the proper speed for each
take off and landing and fly them within a couple knots. There was a
lot of complaining about that, as most Bo pilots land them way faster than book figures.

You will find the F33 is has a bit narrower CG than the 182. Nice
thing about the tip tanks is the weight is on the centerline.

Near as I can remember the useful weight went up from 1000# to 1400#
in 74. There may have been some minor changes after that.
They are also an outstanding short field aircraft for their size and I
believe you will find they can land shorter than a 172. Once you get
used to them they are also one of the easiest planes to land and land well.

There are the Osborn tanks which are 20 gallon aluminum and the
Deshannon "Flight Extenders" which are 15 gallon fiberglass (you can
actually get 17 gallons in them.) Last I knew the tip tanks gave you
all that weight as an increase and it all had to be in the tanks. I
think the 100# increase is a separate STC and I don't know what was
involved with that.

Although I love the old Deb, I'd really like to have a well equipped
late model 33. (with flight extenders)

I should add there is one characteristic I really don't like about the
F-33. The price. <:-))

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
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10 11th September 09:04
orval fairbairn
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Posts: 1
Default Bonanza F33A CG envelope question

Yes, it reduces the inflight bending moment, but it can drastically
INCREASE the loads on the outboard spar during an "indelicate" landing
with fuel in the tips. This problem affects a lot of old Cessna 310s,
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