Skymaster Question

[Shay]

What are the differences between a O-2 and a T337G?

Thanks

Shay
_____________
Semper Fortis

[krlang]

The biggest difference is the Turbo!

Another big difference should be the instrumant panel.
The Military airplanes had round military style engine gauges.
The C-337s had a set of square, automotive style analog gauges.

[skymstr02]

The following things are different:
a) Wings are different (structure)hard points
b) Wing attach fittings are different
c) Electrical system is different, alternator charging system
d) Fuselage is different (structure)additional windows
e) O-2's have a main cabin door jettison, 337's don't
f) Tachometer indicating system is different
g) Fuel quantity indicating system is different
h) Elevator control system is different, ie, deflection, spring missing, etc
i) Lower switch panel is different
j) Fuel system is different, ie, tanks, selector valves, plumbing
k) O-2's have an engine fire detection system, 337's don't
l) Cabin door is different from the 337G's(airstair door) to front hinged
m) O-2's have a gear warn horn silence system, 337's don't
n) Engine cooling baffling is different
o) Prop spinners are required items for flight on a 337, O-2's don't have
p) Rear engine cowling is different on O-2's
q) O-2's have a gun sight and armament control panel in front of pilot
r) Pitot tube is mounted further out on left wing to accomodate pylons
s) O-2's don't have cabin assist step mounted on belly
t) All sheet metal pieces on O-2's are zinc chromate finished, 337's aren't
u) Wing tips, vertical stab tips and caps are different on O-2's
v) Circuit breaker panel is different on O-2's
w) All instrument panels are different on the O-2's
x) O-2's only have seat rails to accomodate up to 3 seats in cabin
y) Rear muffler on O-2's have provisions for smoke generator system
z) Pilot seats on O-2's have armor plate bolted on seat pan (30 lbs each)

I havent't even gone into the avionics systems, lack of speakers, A.C. inverters and minor things.

[T J Johansen]

I seem to recall seeing a photo seen years ago of an O-2/337 in a mid- eastern country used for COIN operations. The a/c were to have armament in the nose instead of an engine, and quite possibly a larger engine in the back. Anyone remember this conversion? Think the photo appeared in Flight International.

T J

[skymstr02]

It was the "Sandcrab", built for the Irainain government.

[oscardeuce]

The O2-A had the longer chord 336 elevator to give a heavier feel to the military pilots.

O2-B standard 337 rotary mag/starter switches.O2-A military style toggle switches.

O2-B front engine was the IO-360C

BTW these differences are mostly between the O2-A and the 337. The O2-B was structurally a 337 taken off the line and modified with the leaflet drop chute, and the speaker amp system. Especiallty the first 37 B models with were off the shelf assembled but unsold 337s.

O2-A max gross weight 4850 lbs
O2-B max gross 4200 lbs

Some O2-A's have 2 skids under the fuselage to decrease damage in the case of a gear up landing due to combat damage.


Walt Shiel's "Cessna Warbirds" is an invaluable source for info on the O2 series.

[bilwor]

These 3 color photos were taken by me at Air Space America 88, Brown Field, San Diego, May 15, 1988. The aircraft was a Spectrum SA-550 "Spectrum One", c/n 006117, N15SA. (Modified Cessna-Reims Aviation FTB 337G Skymaster) This is NOT the "Sandcrab".

From the "Cessna Skymaster Web Site":
"Many thanks to Hendrik van der Veen for the information below

According to a Jane's 1985-86, the Spectrum SA-550 Spectrum One was an extensive modified Reims FTB-337G by Spectrum Aircraft Corporation of Van Nuys airport, CA.

Flight International magazine dated 04-10 August 1993 reported the following:
Thailand to build Cessna 337 single. A single engine conversion of the "push-pull" Cessna 337 Skymaster will be produced by Thailand in a venture with Basler Flight Services of Oshkosh, Wisconsin. Agreement is close on forming a company to convert the Thai military fleet of 40 Cessna O-2s to Basler Turbo 34 configuration, says Basler. The prototype was unveiled at the Experimental Aircraft Association convention in Oshkosh at the end of July. The company will explore US certification of the Turbo 34 as the Thai project proceeds. Conversions for the civil market would also be carried out in Thailand, Basler says. Conversions involves replacing the Cessna 337s fore- and aft mounted 156 kW (210 shp) piston engines with a 560 kW Pratt & Whitney Canada PT6A-34 turboprop in the rear fuselage driving a single propeller between the tailbooms. The aircraft is stretched 2.1 m and the wing centre-section is strengthend to allow a cross weight increase of 50%. "




According to the Quosent Air Musuem web site their O-2 is the Skymaster/Sandcrab coverted for use in Saudi Arabia.
http://users.ids.net/~qam/AircraftPages ... aster.html

There is also several paragraphs, artist's concept drawing and a photo of the Sandcrab in "Cessna Warbirds" by Walt Shiel.

bill word

[LadyO2Pilot]

I can't add much of anything that hasn't been said except, the O-2A model for USAF was built during years 1967 to 1970 and I believe there were about 480 built give or take a few.

The T337G was a civilian turbo model and I believe it was first built in 1972. It may also have had a pressurized model too but don't quote me on that.

[skymstr02]

You'r very close. Total production run on the O-2A's was 510 airplanes. There were 31 "B"'s aquired. No "B" models were built as B's.

The 337G's were the 1973 thru 1977 models. The pressurized units were all "G"'s. There were also G's built in France by Reims as normal aspirated, turbo charged and pressurized versions for the European market.

[TimAPNY]

Here is a shot of the Quonset O-2. I was told the plan is to restore it to a SandCrab when time and $ allow. Unless I heard wrong or plans have changed.



Tim

[LadyO2Pilot]

You'r very close.

DZ....not bad memory for a blonde girl.....eh??????

[Shay]

Thanks guys/gal.

I didn't realize that the differences would be so many, it good to know.

There is a T337G right down the road from me at a local airstrip. It's looking very long in the tooth (decrepid bordering on derelict). I was thinking the next owner would have to tear her down to "parade rest". And while they were at it I was wondering if it could be rebuilt in O-2 configuration.

But from the sound of it. It sounds like too many major things are dissimilar. But still a neat idea

Shay
____________
Semper Fortis

[skymstr02]

Twenty years, or so, ago, there were quite a few civillian Skymasters painted in O-2 colors. Sheep in wolf's clothing, so to speak. In 1986 or 87, there was a pressurized 337 in O-2 markings at Oshkosh.

[RickH]

DZ, Michael Speck still has his in Rhodesian AF Lynx colors.

[King]

It was the "Sandcrab", built for the Irainain government.

In 1984 we purchased Robertson Aircraft Corporation (R/STOL) and with that purchase came data on the "Sandcrab" Desert Utility Aircraft.

Very neat aircraft and at one time we had the tooling to manufacture the composite nose section and other parts.

I have some photos somewhere of the prototype and will post them if I find them.