What is the Take Off Weight of the O2?

[ConwayB]

Hello all,

I have purchased an O-2A and am getting it registered in Australia. Now, here's the problem...

When the new weight and balance was done, the maximum take off weight issued by the WB inspector is 4190 lbs!

The O-2A, according to the USAF O-2 manual, had a maximum take off weight of 4850lbs and a maximum landing weight of 4400 lbs. (The extra weight was in weapons which were jettisonable in an emergency).

The O-2A is equivalent to the 337B and later... and the civilian 337B flight manual (which I have to use as the official flight manual) says the following:

" Gross weight 4000 lbs and 4400 lbs" (but with no explanation of the two numbers) as shown in Performance specifications

"The cargo loading envelope allows loading up to 4400lbs."

So can someone please tell me where I can find the definitive answer on this issue so I can ensure my WB is correct? Is there an official Cessna document available?

Thanks in advance.

Conway

[Frank Benvin]

Gross weight

337A - 4200
337B - 4300
337C- 4400
337E - 4440
337F - 4630 take off 4400 landing

Frank

[WebMaster]

337D take off 4500 landing 4400

[hharney]

http://www.risingup.com/planespecs/i...plane192.shtml

The POH gives two scenarios for performance. The second column is for performance at a "less than gross weight" configuration, ie: 4000 pounds. The first column is at "gross weight" configuration, ie:4400 pounds. My POH for the 1968 C model is gross 4400 pounds, and the link above indicates that the 1967 B model is 4300 pounds. (landing category)

See attachment, second post on this thread page.
http://www.337skymaster.com/messages...+weight&page=2

[Ernie Martin]

The 337E (at least mine) is the same as the 337F, namely 4630 take off and 4400 landing.

Ernie

[skymstr02]

It doesn't matter what the limits are in the USAF flight manual, if you are civil licenced. You are required to follow the type certificate data sheet. Data sheet A6CE has this:

C.G. Range (Landing (+137.5) to (+143.3) at 4300 lb.
Gear Extended) (+136.0) to (+143.3) at 3600 lb. or less
Straight line variation between points given
Landing gear retraction moment is +3318 in.-lb.
Empty Wt. C.G. Range None
*Maximum Weight 4300 lb.
No. of Seats 4 standard (2 at +102, 2 at +141), 5-6 optional (1-2 at +170)

Maximum Baggage 365 lb. (Reference weight and balance for additional information)

Your maximum weight is 4300 lbs.

The USAF flight manual lists all weight in excess of 4400lbs must be jettisonable, which means loaded on the wing pylons, and each pylon is limited to 350 lbs.

I don't know if the civil aviation authorities in Australia follow the USA FAA TCDS's.

[ConwayB]

Hello all,

Thanks for all your replies.

I actually located the Type Data Sheet and obtained that information, Skymstr O2, just today... so thank you none-the-less.

For some unknown reason, the weight and balance guys gave the aircraft a MTOW of 1950 kilograms which is 4290 lbs! They robbed me of 10 lbs!

Herb, thanks for the post on the performance. I have that POH. Don Nieser got it for my O-2 purchase because our regulator won't accept the O-2 USAF flight manual, so I have to use the civilian manual. That's one of the reasons why I had the question; because it refers to 4400 lbs!

Oh well, even though the O-2 was flown at 4850 lbs... I guess I'll have to stick to 4290 lbs.

Once again, thanks to all.

PS. I'll post some pics of the glass cockpit I've had put into the machine. 1968 O-2 on the outside, 21st Century on the inside. Can't wait to get it in the air!

Cheers
Conway

[AussieO2]

Care to tell what the VH rego will be ? VH-OZA was registered to an O-2A, but cancelled some time ago without the a/c being flown.

[ConwayB]

G'day Mate,

Sorry I haven't replied earlier.

As for your query, I have reserved the rego VH-OTU (OH-Two) and am awaiting notification from CASA that I can use the smaller rego stickers instead of the 150mm letters.

The machine is currently at Archerfield and should be given its CofA and CofR next week whereupon it'll grace the airways and be based in YBAF and Townsville.

Where are you based in Brisbane? Are you a 337 owner?

Feel free to email me. My contact details are on my website at www.ipas.com.au

Cheers
Conway

[Mayhemxpc]

As others have said, your weight limit is 4300 pounds. Before you think that it should really be 4400, 4600, or 4850 (and therefore inclined to overload it) I offer some considerations: 1: USAF limits said everything over 4400 had to be on the wings. This was so you could jettison the weight if you had an engine failure. If you can't drop the weight, don't lose an engine. 2. Check to see what that extra weight does to your performance, even if both engines are running. A takeoff at 4500# requires more airspeed, 150 feet more ground run and almost 300 more feet to get over a 50' obstacle on a standard day. Other performance is similarly affected. 3. The O-2A is a 337B, which has a MGW of 4300#. Every year or so, Cessna increased the 337 MGW without doing anything else to the airplane based on demonstrated performance. But each time they did that, max ceiling, SE ceiling, time to climb and more all dropped. In short, don't lightly consider overloading that plane just because the U.S. Air Force flew at higher weights.

Its a heck of a fun plane to fly, and I can get my wife and three boys in the plane, with some baggage, and still stay within the envelope.

[ConwayB]

Thanks for your post.