Airdrome Aeroplanes Nieuport 17

[bookmaker]

Ron, I just noticed you are in Seattle. My son moved there last year and works for Oculus. We visited last Christmas. Nice place.

Dale

[bookmaker]

Playing with the connectors



Maybe just build a Penguin ???



Dale

[bookmaker]

Moved the project to my hangar where I can start attaching wing structure. I built several stands to support the fuselage and wings. Unfortunately, I mismeasured the spread to include both top and bottom wing cores and had to spilt them and add 4". Delayed progress today considerably.

Fuselage blocked up and level



Stab and rudder mounted to check level. Looked good



Lower wing spars leveled



First wing attached (temporarily for photo)



Dale

[Frank Giger]

At first I thought this was the long way around doing the task with some over-building of rigs, but is in fact the same way I did mine (the Airdrome 7/8th scale Nieuport 11 uses the same plans as the full scale Nieuport 17 with different measurements).

Washout on the lower wings is done through rigging, so check the level on the outer compression strut later when you put on the top wing and measure for the interwing struts.

[bookmaker]

I will not build washout in the lower wing, only the upper. It is my understanding that in a biplane, you want the lower wing to stall first.

Dale

[Frank Giger]

Not for nothing, check the plans. Mine say no washout in upper wing, small washout in lower.

[rwanttaja]

I will not build washout in the lower wing, only the upper. It is my understanding that in a biplane, you want the lower wing to stall first.

Doesn't seem right, to me. If you've got a biplane with staggered wings, letting the lower (aft) wing stall first moves the center of pressure FORWARD, causing a pitch-up. If the upper (forward) wing stalls first, the plane naturally pitches down towards recovery.

Ron Wanttaja

[Frank Giger]

Ron, not if they're spaced properly from each other.

The idea is that the wing with the least lift stalls first.

[rwanttaja]

Ron, not if they're spaced properly from each other.

The idea is that the wing with the least lift stalls first.

Well... as a Space Systems Engineer I ain't much of an aerodynamicist, but: I think it still really depends on what direction the Cp shifts after the stall. The combined CP of a biplane is between the individual CPs of the wings. Having this combined CP shift Aft when the forward wing stalls first is good; plane naturally pitches down. Forward is bad; plane pitches up. Magnitude of the lost lift doesn't really matter; what matters is there the combined Cp heads to.

On the other hand, if the two wings' angles of incidences are properly selected, you can ensure the top wing will stall first even with the washout. In this case, the washout keeps the ailerons effective closer to the stall.

Ron Wanttaja

[Frank Giger]

I'm relying on all of the stuff being pre-designed in - and by all accounts they pretty much mush and then stall cleanly. Maybe the lower wing needs the washout to stall with the upper one, or to prevent spins?

The last time I asked Robert Baslee (Designer, builder, holder of many relevant degrees) about aeronautical stuff and design he forgot who he was talking to and had me glassy-eyed in about twenty seconds.

Of course with these high-drag, low speed aircraft one could chop throttle, push the stick forward, and put an arm out against the spin to correct it.