proparc

What is the average speed of a typical F3A pattern ship DURING a contest? Also, what is the average thrust generated by a typical YS 140 or equivalent etc., with a contest grade prop?

jetmech43

My Feedback: (9)

probably around 80mph, its not about speed these days,

Hans Meij

http://www.rc-network.de/forum/showt...skussion/page4

(Look at page four. Somehow the link is not complete)

Magne

So assuming this was a F3A flight that took about 7 minutes, the average speed would be 9342/(7x60)=22.2 m/s=80 km/h or 50 mph.
(And the max speed was 204 km/h)

Magne

MTK

As the previous poster noted, 50 mph is the typical AVERAGE speed for many F3A models today. What we are after is lots of thrust at low speed. An electric set-up can be set-up to produce that kind of output as can the YS170 burning 30% nitro.

The YS 140 turning the typical prop (around a 15x12 or 16x10) and 30% nitro will produce possibly around 13-14 lbs of static thrust. An 11 pound plane will need more thrust than that to fly an F3A schedule well. But this is adequate thrust to fly Sportsman with the same 11 pound plane.

In terms of HP, the 140 is working its guts out trying to reach 3 HP (around 2250 watts, in electric terms). A YS 170 puts more than 4HP (3000 watts) at full power and a great deal of mid range grunt, and spends much of the flight in mid range. A well tuned electric set up puts out 3500 W, or almost 5 HP with a lot of mid range grunt too, (if the esc is set-up correctly).

A properly tuned gasoline engine in the 50cc to 60 cc range can put out around 5 HP which is great for F3A flying. But if it isn't properly set-up from the factory, (longer stroked, proper intake and exhaust timing, and proper carburetion) the 5 horses won't do much good in an F3A flight. Noise and weight are a problem too

adamd11pl

Hmm,
when the model flies vertically, its GPS speed and distance is zero! Check the GPS speed in Figure M (if you have data).
So the average 80km/h is too low... I think so...

From my own measurements:
horizontally - about 1000W, 33m / s (120km / h) at 5400 rpm (or sometimes more like 850W and 110km/h )
vertically - 2500W, 22-25m / s (80-95km / h), 6300 rpm

Vivat form Wistmodel, motor Hacker C50XL , propeller 21x13w, Rhino 4900, EagleTree + GPS + barometric altimeter (I don't have barometric speedometer..... I have not yet )

And yes, I was surprised when I saw data. If anyone has any other measurements, please share.

Adam

MTK

Adam,

In horizontal flight, model weight is lifted by the wing. Powerplant only needs to overcome model drag. Vertical flight, weight and drag must be overcome by the powerplant. Totally appropriate and expected to see the data you show Adam, for the motor/prop/bat indicated.

adamd11pl

Matt,
I am not surprised by the speed difference between horizontal and vertical flight. I was surprised that in a quiet horizontal flight in perfect weather, the speed exceeds 100km/h. I thought it is rather a 85-100km/h range. But this is only an illusion.
If plane fly at 170m, 120km/h is too slow to finish the flight within the prescribed time. Then the power goes to 1400W, speed exceeds 130km/h and 4000-4200mAh per flight is needed.
At 150m, width less speed, 3300-3600mAh is OK. But still it is rather pretty fast.

regards,
Adam

ps. Maximum speed 204 km/h is rather a GPS glitch. I've seen more of these.