Pfalz Alarm oz7770

 

Pfalz Alarm - plan thumbnail image

Pfalz Alarm - completed model photo

This plan was found online 14/05/2016 at: http://www.rcgroups.com/forums/showpost.php?p=32967386&postcount=110
Outerzone planID: oz7770 | Filesize: 529KB | Format: • PDFbitmap | Credit*: Circlip, RFJ

   

About this Plan

Pfalz Alarm. Two channel RC glider model. Pfalz Alarm by W. Headley, from March 1975 AAM.

This design also featured in Aeromodeller Annual 1978, see https://rclibrary.co.uk/title_details.asp?ID=1224

Quote: "This model was built to have something different on my local slope. At the time the sky was full of Cirruses (or Cirri) and the like, all aspect ratio and slinkiness, so the challenge was to make something equally good at flying and equally opposite in appearance, Pfalz Alarm was the answer. The main design for a slope soarer in my neck of the woods is a low wing loading. The local wind is a mild sea breeze, that appears in the early afternoon and disappears around sunset. Conditions are best in the spring, which is when I do most of my gliding. From experience, wing loadings in the 8oz/sq ft seem to be ideal. The PA was designed for this sort of weight, and proved to be definitely a good flier, and definitely an ugly model. One problem I had with the original was a built-in warp in the right wing, which had to be steamed out for every flying session. A sheeted leading edge should cure this, and the added weight should be no problem in windier climes. My prototype was finished in transparent red (what else?). I did consider once a powered version of the PA, with twin pusher .049's behind the wing, but other projects got in the way, and it was never completed..."

Quote: "This little fable serves to introduce our non-scale WWI glider - a remarkable subject, as there weren't any gliders in World War I. However, it may not come as any surprise to confess that the Pfalz Alarm is based on the Ugly Stick (oz5175). But, like most of my designs, I sometimes go off base. In fact, I could probably start, with all good intentions, to produce a model of the Bede 5, and end up with something looking like a Junkers JU-87. But, back to the model of the moment.

It's a refreshing change from all the slick, high aspect ratio devices I see flying around my local hill; it's easy to build, and flies just as well as the aforementioned models; so why not have a go? For all of you who've been waiting patiently with balsa knife in hand, here are the building instructions.

CONSTRUCTION. Fuselage: Begin the fuselage by con-structing the basic box from good quality, 1/4 in sq balsa strips. The fuselage sides are first, and here two points should be noted: first, the upper longeron is stepped down at the rear to make a platform for the tailplane, and second, the lower longeron is spliced at the rear, not bent, for the correct rear fuselage taper.

When two identical sides have been made, join them together with the vari-ous frames and, also, 1/4 in sq spacers. After sanding off the gluey bits, pin this box down onto the plan (bottom up) and install the plywood servo mount, which sits on a framework of 1/8 x 1/4 strips. Note: If you are using small servos, then the framework can be omitted..."

Update 05/03/2019: Added article, thanks to RFJ.

Supplementary files

Article.

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oz7770 datafile

Pfalz Alarm  
by Jack Headley
from American Aircraft Modeler
March 1975 
76in span
Tags: Glider R/C
all formers complete :)
got article :)

 

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Notes

* Credit field

The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.

Scaling

This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.

 

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