Alternate Design to the Douglas DC-1

[Dynoman]

Nicknick, very interesting design. I like the concept of creating efficiency by using a parasol wing design that uses no external bracing (i.e. unlike the Catalina that used drag producing struts). The second parasol pylon and the bridged horizontal stabilizer will increase the integrity of the airframe.

Blending the fuselage into the pylon will help to reduce interference drag. Inside of the pylon on the Catalina was the engineers station. This might offer some additional baggage area for your airliner, especially if the overall design were scaled up. The twin fuselage also offers the ability to unload passengers at twice the rate of a conventional aircraft such as the DC-1.

 

[Nicknick]

Thanks.

I believe the boarding time wasn't a big issue those days and with only 12 passengers there might have been enough time to smoke a cigarette before entering the plane...

I'm not sure about the bracing. External bracing almost died out, but currently there are a lot of new concepts for high efficient airplanes with external bracing and an extremly long wingspan. I read a paper for a hydrogen concept plane with such a configuration. The struts caused 15 % of the total drag (which is quite a lot), but the higher wingspan, thinner wings and lighter constrution overcompensated it. The drag of the struts is mainly produced at the connection point to the wing, and it rises with narower angle between the strut and wing. A very high wing like in the concept showen would allow a quite large angle between the wing and the struts (e.g. 45°) which would be really helpful. I should have drawen the plane with long thin wings, this would fit much better to the approach.

 

[jcf]

If I remember correctly, the Douglas proposal in response to Frye's letter included at least a couple references to "...as on the Northrop Alpha...". Not surprising since that version of the Northrop Company was partially owned by Douglas and, when Jack Northrop wanted to go do other things, it became Douglas-Elsegundo. Amusingly enough, this building is once again owned by Northrop-Grumman Corp. and has been since at least the early F-18 days if not before.

Exactly because the DC-1/2/3 all made use of the multi-cellular wing construction design that Jack Northrop pioneered on his original flying wing and used on the Alpha-Beta-Gamma etc. series.

 

[riggerrob]

Thanks.

I believe the boarding time wasn't a big issue those days and with only 12 passengers there might have been enough time to smoke a cigarette before entering the plane...

I'm not sure about the bracing. External bracing almost died out, but currently there are a lot of new concepts for high efficient airplanes with external bracing and an extremly long wingspan. I read a paper for a hydrogen concept plane with such a configuration. The struts caused 15 % of the total drag (which is quite a lot), but the higher wingspan, thinner wings and lighter constrution overcompensated it. The drag of the struts is mainly produced at the connection point to the wing, and it rises with narrower angle between the strut and wing. A very high wing like in the concept shown would allow a quite large angle between the wing and the struts (e.g. 45°) which would be really helpful. I should have drawn the plane with long thin wings, this would fit much better to the approach.

I suspect that external struts feel out of fashion because they collect too much ice.
See how Transport Canada reduced Cessna 208 Caravan's certification for flight into know icing after a couple of Caravan's crashed in icy weather.

 

[Nicknick]

That’s a good point, but I think the DC-1 didn’t have anti icing boots and they were just been invented during the development phase of the DC-1. I guess, this was very likely not a criterion at that time.

With a double hull, the bending loads on the wings are already reduced very much, so struts wouldn’t have been as beneficial as on conventional designs, but on the other hand, they would have had a lower negative impact due to the more favorable angle to the wing. Its just an option in the end,

There are other aspects as well, using two hulls would mean, that two toilets and two stewardesses would be necessary on longer distances. On the other hand, the front mounted engines would have reduced cabin noise compared to the side mounted engines.

I wouldn’t be too surprised if the DC-1 would have turned out to be better plane than my approach....

BTW: here a video about new braced wing concepts by NASA:

View: https://www.youtube.com/watch?v=zkrdIw8LWrM&ab_channel=MentourNow%21