F2A World Record - Control-line model aircraft speed.

As promised some time ago - a re-edit in higher quality from my original tape.
On Saturday 13 October 2001 at Fairmile Common near Cobham in Surrey, UK, Paul Eisner made an attempt on his existing World Record for Control Line Speed (1.0 to 2.5cc) which he had held at just over 194 mph since 1987. In unseasonably warm conditions (24C) the best run of the afternoon registered a provisional speed of 208.28 mph. This beats his existing record by the considerable margin of around 14 mph. The model is powered by an Irvine 15 "special" and uses a single-blade carbon fibre prop - as is usual with models of this type. More details and photos on my website at http://www.flyrc.org.uk/record/control_line.htm

Category:

Autos & Vehicles

Tags:

• F2A
• control-line
• c/l
• world
• record
• model
• aircraft
• airplane
• Paul
• Eisner
• control
• line
• speed
• Irvine

[TestECull]

Sorry bro but that is not an airplane. That is more like an arrow with an engine strapped to the front.

[johnpflyrc]

@TestECull OK, that's your opinion, to which you are of course entitled. The FAI disagree with you though...

[xXspartan125Xx]

why the would you use a one bladed prop? unless its weighted so its not off balance

[johnpflyrc]

@xXspartan125Xx Naturally the hub is weighted to balance the prop! Can you imagine the vibrations produced by an out-of-balance prop at 38,000 rpm?

One-bladed props are more efficient - the one blade is not operating in the disturbed air from the other blade. Additionally small changes in pitch can easily be made with a thin spacer behind part of the prop hub. This is not possible with two-bladed props.

[PLANAutomation]

@boulderdsvo Bingo. I worked out once that the aircraft has to do about 115-120 mph for centrifugal force to make it break ground. This lifts off way slower than that, they do fly on the wing. They use one wing because (a) you can with a tethered aircraft, (b) by moving all the wing surface inboard you reduce it's forward speed and thus drag, (c) the longer that wing is the more of the VERY draggy lines it can cover, and (d) the wing effectively has only one wingtip, which reduces induced drag.

[PLANAutomation]

@kyussfan6 No - though the prop is balanced centifugally you still have imbalanced dynamic forces. Single blade is the only way to have enough prop blade to be effective while loading these engines appropriately. Otherwise the prop would be much smaller in diameter and efficiency would suffer greatly.

[TheJascal]

LOL at testECull.

[TheJascal]

@kyussfan6 A single bladed prop is striving for the last bit of efficiency in a specific RPM range, which is not the case for for a typical RC plane. I have seen single bladed applications in FF and CL, but none come to mind with RC.

[TheJascal]

Geez someone needs to learn what an 'airplane' is. It doesn't matter if it is CL, RC or FF, or human carrying - not one single type of airplane can or will do everything well. Aircraft are a matter of compromises chosen to achieve one aspect very well. In the case of control line speed, the compromises will look odd. Single wing, one bladed props, minimal elevator surface, maybe even asymmetric, all work well and if you feel you can do better with a traditional planform, then build and compete.

[sopues]

That doppler effect is amazing :)

[kyussfan6]

should remote-control airplanes go single bladed if the hub was balanced?

[PlebScrubber]

if you wear shorts with a belt AND tuck your shirt in...

your a serious nerd

[PlebScrubber]

@johnpflyrc then why do we not see single blade props on real aircraft?

infact all modern aircraft have many many blanes in a turbine

[boulderdsvo]

@TestECull You lie, you lie. You didn't spin a weight around, all the way around the circle higher than the holding point. It's not physically possible without lift.

If the airplane is flying at the height of the control handle, or higher, it is in the air ONLY through aerodynamic lift. As for reading, you said "arrow".

Okay, so your definition of airplane is that it's stable when not connected to the line?  That lets out ALL C/L craft. You're definitely in the minority on that opinion.