Hell Razor


Hell Razor - plan thumbnail image

Hell Razor - completed model photo

Hell Razor  
by Walt Musciano
from Model Airplane News
August 1983 
50in span
Tags: IC F/F
all formers complete :)
got article :)

Submitted to Outerzone: 01/07/2017
Outerzone planID: oz8907 | Filesize: 948KB | Format: • PDFbitmap | Credit*: Circlip, RFJ


About this Plan

Hell Razor - Free flight power model. Originally designed in 1939 as a FF model, this here is a modern re-drawing of the plan (still by Walt Musciano) from 1983, that also shows optional radio control installation. This article is part 2 of 2, see The Answer (oz625) pages for the first part.

Quote: - "MURRAY/RITZ single-contour wings were discussed in Part 1 which appeared in last month's issue. Also presented was a construction drawing of Gordon 'Scotty' Murray's The Answer model design of 1938 which used his single-contour wing. Models fitted with Murray/Ritz wings had such a slow gliding speed with a low rate of sink that it seemed they would never return to earth! Yet, because of the exceptional drag created by the single-contour wing, the climb was not spectacular... as one who worked wilh Gordon Murray, such as helping with the drafting of single-contour wing designs, I began experimenting in early 1939 with variations of Murray/Ritz wing-fitted designs in an effort to improve the climb.
Design considerations consisted of lowering the thrust line so the nose would tend to rise under power, using a lifting airfoil in the stabilizer not only to increase the effective lilting area but to provide a force to counteract and keep the effect of the lower thrust line under control, and increased incidence angle to reduce the undercamber turbulence. The lifting tail shifted the center of lift aft and resulted in relocating the wing forward, which increased the distance between the wing and the stabilizer. The basic Murray-Ritz single-contour wing was used as well as the basic plan-form of Scotty Murray's The Answer design tail surfaces. To match the simplicity of the wing, a crutch-type modified diamond-section fuselage was selected: possibly one of ihe first examples of crutch construction. To top it all off, we also took advantage of the flexible Murray/Ritz wing and incorporated elliptical dihedral into our model. The stabilizer was located below the thrust line to keep clear of the wing-created turbulence...
As engines increased in power and more interest focused on the climbing ability, models assumed a sleeper climbing angle with very sharp banks. This revised the CLA thinking because now the models tended to slip into the center of the climbing circle and the CLA began to climb higher and higher. A high CLA was selected for our Hell Razor for stability during high angle of attack spiral climbing. The performance of our model exhibited a more spectacular climb. Instead of smooth, flat climb, the model 'corkscrewed' upward in a sharp bank and seemed to gain more altitude during the engine run...
In the late summer of 1939 the prototype model was lost overhead in a gliding session which lasted over eight minutes. Like most modelers, I had a multitude of projects underway and never did get around to building a replacement. World War II slowed modeling activities to a virtual halt and the project was all but forgotten.
'Hell Razor' is a name that sort of evolved at the flying field. A new design always attracted attention, whether it be Schoenbrun's Rocketeer (oz1083) or Schulman's Skyrocket (oz7435) and when my model made its its debut on the field, someone remarked on its 'lean and hungry' appearance and that it was like a razor. The name stuck and we added 'Hell' to make it a pun to sound like 'Hell Raiser'.
Our model is the epitome of simplicity with light yet rugged construction. The fuselage construction begins with the crutch which is the primary strength member, supporting and aligning the engine, wing, and tail..."

Mary, As promised in answer to inquiry, this is "part 2" of Answer (OZ 625) article. Hell Razor, MAN, August 1983.

Note: If this plan seems sketchy on detail for the wing parts, that is because the wing (and horizontal tail parts) used in this design are copies of and taken directly from The Answer (oz625) plan, as mentioned in the article text.

Direct submission to Outerzone.

Supplementary files

Article pages, thanks to RFJ.


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