We all know the Flying Flea as a airplane with two main wings. But in Argentina there was a designer, Juan de la Farge, who felt the need to add a extra surface at the rear and ... it flew good.
Surely needs some extra attention. I hope to gather some info to make you all understand why he did it that way. What were the advantages and disadvantages? What will this concept bring in the future?
The following pictures were a long time all you could find about the Pulga. Things you might see quickly are:
- the very long landing gear
- the T-tail which is very high
- the rotating rear main wing (in other words ... wing 2 of 3)
- something funny about the prop
In the beginning i heard about the Pulga, i was talk that the prop was the reason for the high landing gear. Maybe you did not notice it yet, but ... it was a single pal prop and one huge one. Juan de la Farge really wanted to be sure there was a good air flow over the front wing towards the T-tail. I heard that the rear main wing could rotate and that the third wing (don't call it a elevator as it has not that function) rotates upwards when the second wing is rotated. In my head i saw a complex system to do it all with levers and so. But ... i was really surprized when i saw how easy the control over these wing-deflections was.
Steering system
I got this scan from Juan Galvan. When i saw it, it became all clear. This system is steerd by A SINGLE LEVER! That stick is the steering stick. Talking about very easy control!
The two levers connected to the steering stick are at a specific angle. The one, that goes towards the front wing, is at 90° angle with the pushrod. A small movement results in wing deflection at once. The second lever, that goes towards the second main wing, is at a angle of 180° with the pushrod. Small movements on the steering stick will lead to no deflection of the second wing. But at larger movements of the steering stick, the second wing will start to rotate. At the same time the third wing will rotate the other way due to the linking pushrods.
Part of a scan about a project he never build. But it explains the steering system.
At last it makes sense to me.
Why a second wing rotating
Seems that Juan de la Farge was inspired by birds that land. If they land they rotate their wings downwards to slow down as much as possible. Slow speeds at landing are a real safety factor. So, lowering the second wing for landings seems like a very easy thought. But you need to keep it all out of the reach of a stall. And the balance must be under control. If the second wing of a normal flying flea would rotate, it would gain a lot of lift. The moment of that force around the center of gravity (CG) would be large. Too large for the front wing to compensate to keep it in balance. So ... something had to keep the rear of the airplane down or the front up. Juan de la Farge choose to install a T-tail and to have that third wing rotate downwards to generate a large moment to keep the airplane in balance.
A non-finished project by Juan de la Farge
This proposal looks different than the one you see above. Here the front wing is not above the cockpit. The pilot can even look over the front wing.
The first revival of the Pulga by Oscar Alfano
A first reconstruction of the Pulga ended sadly a sad history as it was destroyed by fire while they welded something on the airplane.
The constructor stands near the middle in a red jacket. He is Oscar Alfano de la ciudad de Firmat from Santa Fe, Argentina.
The second revival of the Pulga by Juan Galvan
Another Pulga is made by Juan Galvan. At first glance it looks very similar to the original Pulga, but technical it has differences. The second wing is fixed at 6° and the third wing fixed at 0°. Power is 85 HP.
I had talks/chats with Juan Galvan and his son Martin, who flies the new Pulga. Martin mentions me that it can take off in 60 meters (65 yards). it is very stable.
Parts of the plan. Not in same scale in display. Click one of the drawings to get the PDF.
At this moment he is not willing to lend the airplane to other pilots as they will not react properly to the typical flight behavior of the Pulga. Therefor his father, Juan, is busy with a next construction. See below.
Juan Galvan constructs a two-seater side-by-side Pulga
Not much is known yet about this project. But i like already the curved lines in its design. The purpose of this airplane is getting other pilots familiar with the Pulga-concept.