Wing profile of Ho 229

[spicmart]

What can be said of the wing profile of the Ho 229?

 

[ThomasP]

Conventional (non-laminar flow) 14% T/C at about 1/3 the distance from the centerline, to 8% at the tip. Between the 14% sections the airfoil of the wing and fuselage T/C gradually increased to 16%. There was a built-in twist/wash-out. The wing outboard of the engines was of wooden construction, the wingtips were metal. The center lifting body was a steel tube frame with metal and wood formers, with wood skinning for the most part.

I ran across a report on the Ho 229 a number of years ago - I think it was a NACA report but am not sure, and am also not sure what designator they used for the airframe. It described the wing in detail (including the theoretical drag characteristics) and gave the approximate NACA equivalent - I think they compared it to the NACA 2414 series but again I do not remember for sure.

 

[spicmart]

Can you estimate what benefits or drawbacks a laminar profile would have contributed to the design?
Or why the eventual profile had been chosen?

 

[ThomasP]

I have read, in a book about the Ho 229, that the airfoil choice was made because of the wooden wings and the difficulty of keeping laminar flow in service. I do not know if this is accurate or not, but I suspect not, as from an engineering & manufacturing viewpoint I do not see why they would have thought it was more difficult with wooden wings than metal (if that is what was meant, but maybe they were referring to maintenance issues?). From my viewpoint I suspect that they actually just kept it simple since the 34°-35° swept wing would allow the aircraft to reach its critical Mach number of ~M.85 without getting fancy.

The NACA 2414 airfoil has a critical Mach number of M.8-M.85 when combined with the sweep angle, so it should have done the job just fine.