I had the opportunity one day to follow a Gurmman Ag-Cat on his take off run. For those that don't know, an Ag-cat is a radial engined Bi-winged spray plane. This particular day there was very little wind and this cropduster was using the oil road north of my place as a runway. He was pulled off of the road and was being refilled with spray when I got there. After filling he pulled out onto the hiway so I pulled out behind him in my SUV. I left him about a hundred feet of space when he poured the coal to it. It was interesting to watch the rudder action as he gained speed and worked to stay on the narrow road that had ditches on either side.
Does anybody care to guess at what speed he lifted off the ground fully loaded[sm=confused.gif]

I'll be back with the answer.
Chris

P.S.
The climb rate was very low.

85 - 95 mph

50 mph? Some of the most amazing, hair raising flying is done by cropdusters, and Alaskan bush pilots. What a treat to watch!

i'd say around 50 or 55 as well.....

With the pitch thrown into the prop I'll guess 40 ????

If I remember correctly it was powered by a Wright Whirlwind (sp?) radial. What really caught my eye wasn't the name of the engine but the amount of oil that was dripping out of it. No kidding! I would bet that the plane hadn't been setting there more than 15 minutes and there was already a good puddle of oil on the ground. From what I'm told they haven't made that engine for many years but you can still order a plane with a reconditioned Wright installed. It would be interesting to see some of the planes that engine had been in during it's long life. OOhhh if it could only talk.
Keep those answers coming. I will say that it was over 50 mph. but less than 100. There is nothing sweeter than the sound of radial except maybe a 2 cylinder John Deere.
Chris in South Dakota

AS they say any wright radial engine that is not dripping oil can mean only one thing........
It has no oil left.....

I'd say it lifted off at about 65 seen on take off at the Grumman plant across the runway looked better than the A-6 or F-14.....

about 47mph

69 MPH

Don't ever ride in a full scale plane that is not leaking oil. "Because there is no oil in it." Rucker Tibbs W90.

68.6570375830 mph?

I see they moved me. I guess I was living in the wrong Neighborhood. Anyway if My speedometer was correct it was right at 60 mph. So quite a few of you were very close. Thanks for taking a shot at the question. I know that I would not have come close to the actual speed.
Chris

I have over 2000 hours flying ag cats on rowcrop here in North Dakota. There was ever only one model of ag cat that came with a wright whirlwind and that was the C model. It never made it to mass production and there aren't any working right now. Ag Cat's haven't been produced since 1990 and was produced mostly with Pratt & Whitney R-985's or R-1340's. When they began production back in the 50's they had 300 H.P. Jacobson radials and were nicknamed "shakey Jakes". They're still a good workhorse in the ag industry and are known for they're good turning ability and short field operation. They also do a good job of keeping the pilot alive when you ball one up. I usually pull it off around 60-65 loaded and got it up to 80 before I try any kind of maneuvering. At that speed....loading the wing up makes for some shakey turns. Loaded light...you can see below 50 at the top of a turn. Working speed down the field is between 105-110mph in the raidal versions. There's a few companies out there now refurbishing Ag Cat frames and converting them to Garret and Walter Turbines. They raise the top wing...extend both wings...drip in a 450 gallon hopper...and put taller gear on it. It's an incredible machine. Check out Skytractor.com And the oil...yeah, they leak. But hopefully not when they're running. When they're sitting...depending on how the valved on the bottom cylinder came to rest...oil can flow out and into the exhaust and make a nasty puddle on the ground. They really are incredible workhorse airplanes!

an old saying...radials don't leak, they just mark their territory.

Its when they stop leaking you have to worry!

cropdusterdave,

Would you mind PM'ing me?

Thanks!

Lightly loaded AgCats get off quick. But early one summer morning I watched one use all the asphalt runway and most of the grass over run on the end before his wheels lifted off. From the sound of that PW radial up front it was wound up!
We watched him run off down onto the dew laden grass where he looked more like an Offshore racing boat than a plane with the rooster tail his wheels were kicking up! He was overloaded and the combination of heat, humidity, gross weight and little wind kept him rolling longer than usual. Once he got airborne and headed out to his job location he never got higher than 30 or 40 feet while flying past some old oak trees. They're not the prettiest planes on the ramp, but they're ballerinas in the air. Its my all time favorite airplane. And to hear two of those old PW powered AgCats in close formation going over sends chills up my spine.
I've drawn up plans for an RC model AgCat and one day it will fly.

I'm an Agcat mechanic out here in CA, and our outfit has a dozen Cats of various types. We have two KingCats, C models that use the 1200hp Wright 1820. The rest are A, B and C models with P&W 1340s or PT6-20 or -34 turbines. We only break out the Kings for Rice planting season, when its massive capacity gets fully used. It's an oily sumbich. I imagine that when DC3s used Wright engines, airline passengers must have just got used to stepping in oil puddles.

Hag

Cropdusterdave,

Nice to see a fellow Cat driver. I've got a little over 1,000 hours in B models. Started in a 450 and got the bulk of my time in the 600. I've been around 1 C model with the 1820 a few years ago in Arkansas. That is a load haulin machine! I've got a friend who has an old 50 something Cat that up until last season still had a 300 Jake on the nose. He finally gave in and replaced it with a 985 though, and now it's for sale. Do you still fly ag up there? I had a chance to go to work last year for a guy in Stanley, ND, but passed it up. Wishin now I'd gone ahead and took it. I've been out of cropdusting for several years flyig pipeline patrol here in OK and North TX, and am really missing it.