O2A vs 337 Cruise Speed

[andy meyer]

I am considering buying a 337G or an O2A. The O2A is restored to near original on the exterior and has four wing pylons for armament mounting, authentic antenna placements, and bubble windows. It does NOT have the armaments hung on the pylons. In speaking with the owner it sounds like he flight plans for 125 to 130kts. While speaking with owners of 337's it sounds like many flight plan for 150kts. I certainly expected the O2 to be a bit slower, and even slower with armaments mounted, but not sure I was aware they were 20kts slower. Does anyone else have firsthand experience with O2A vs. 337 cruise speeds?

Thanks,
Andy

[edasmus]

My 1973 C337G is a solid 155kts TAS at various altitudes in the 5 to 9 thousand foot range on 17-18 GPH (8.5 to 9 GPH/engine) with 2 standard people on board. My airplane is as stock as they come with no belly pod and all gear doors still installed. YMMV

[mshac]

From the Air Force Museum website:

TECHNICAL NOTES:
Armament: Rockets, flares, 7.62mm mini-gun pods or other light ordnance hung on four wing pylons
Engines: Two 210-hp Continental 10-360s
Maximum speed: 199 mph
Cruising speed: 144 mph
Range: 1,060 miles
Ceiling: 19,300 ft.
Span: 38 ft.
Length: 29 ft. 2 in.
Height: 9 ft. 5 in.
Weight: 4,900 lbs. loaded

They note the cruising speed as 144 mph, or 125 knots. Interesting they claim the top speed to be 199 mph, or 173 knots. That's a big difference between those speeds.

I'd confirm with the O2A owner what RPM and manifold pressure he uses for cruise? Could be he just operates the airplane in leisurely, fuel efficient mode most of the time.

[andy meyer]

Would it be fair to assume, that if pylons and antennas were removed that an O2 should then cruise at similar speeds as a 337? The O2 I am looking at has a lower empty weight then the 337G by almost 100lbs, and I believe it was weighed after complete major restoration. Is there other components of the O2A that would create substantial drag? Maybe no spinners... which a guy could always add if it makes that much difference. Others?

[mshac]

Originally Posted by andy meyer

Would it be fair to assume, that if pylons and antennas were removed that an O2 should then cruise at similar speeds as a 337? The O2 I am looking at has a lower empty weight then the 337G by almost 100lbs, and I believe it was weighed after complete major restoration. Is there other components of the O2A that would create substantial drag? Maybe no spinners... which a guy could always add if it makes that much difference. Others?

I've heard the front spinner adds a couple of knots.

[edasmus]

Clearly it would be "fair to say" that any weight and/or drag reduction with all other things being equal would make the O2 go faster. Would the O2 equal the 337G? Only one way to find out, buy both. ;o)

In all seriousness, the question in my mind would be, do I want an O2-A or a 337G? If the type is truly important to you, then get the one you want. If the only concern between the two is the speed differential, then I suppose putting some type of value on the speed vs which is the better plane maintenance wise would be in order. Or buy neither until you find exactly what you want.

That last statement might be unrealistic considering the age of our airplanes. I personally would put an extremely high value on a well cared for 337/O2 over getting exactly what I want unless you are open to a complete restoration. Maintaining any airplane is where the real money is spent in my opinion. The easiest check to write is the one to buy the airplane. After that, it's "game on." How important is that 20 knots? How important is the type? How important is buying a well cared for O2/337? I would chase the airplane that in your judgement and that of your mechanic appears to have been well cared for. Buying an airplane that you want to fly but cannot because it is always broken goes exactly zero knots.

Good luck to you!!

[general]

In Real world conditions:

With ordinance on the 4 pylons, plan on about 130 knots on the O2

But I'm sure those are dummies and they don't weigh 350 lb per pylon