Amazoom 400 (oz2368)

 

Amazoom 400 - plan thumbnail image

About this Plan

Amazoom 400 - Free flight power model. MAN Nov 1955.

Quote: "The Amazoom, by Stan Hill. Fourteenth in a series, this surprising free Right goes on from where the designer's well known Amazon left off. It is tops for .15's!

The Amazoom is the fourteenth in a series of aerodynamically similar ships begun in 1942 out of a desire for more stability under power than models of the day could offer. The more significant developments are described as they affected the characterstics and performance of the basic design. It should be kept in mind that these data are presented as they affected one design and shouldn't be applied indiscriminately to all free flight types.

The first model was not unlike a thinner and longer. Powerhouse but, between a dirty engine on every landing and Charlie Grant's influence, the thrustline and CG were raised as much as possible. With center of thrust, CG and center of drag nearly on the same line, the previously tight (and, therefore, power-wasting) spiral climb opened up to a loose one-turn-per-five-seconds while the rate of climb almost doubled. Except for the inevitable effect of careless adjustment, which no ship can entirely overcome, spiral dives under power disappeared.

A tour of duty flying P-47's during the war interfered somewhat with my modeling activities but did not stop them, and five ships from '44 to '48 showed minor refinements, such as buried belly wheel, higher aspect ratio (8:1), a thinner, more penetrating airfoil and general clean-up resulting in further stability and about 15 percent increased performance. Playing around with stabilizer dihedral demonstrated clearly that stab dihedral increased spiral instability, while anhedral created resistance to spiral dives.

In 1948, my wife, basing her work on the latest developed model, designed the Amazon (oz2688) to take advantage of the then-new glow engines. Aspect ratio went to 9:1 (about the limit for a hot ship) and loading went down, giving a beautiful glide. Its construction was a little complex but was exceptionally rigid to stop in-flight flexing and warping in the sun between flights. The second version of the Amazon was modified in structure only and was flown to victory at the 1952 Nats.

While we were testing two new ships to use in England at the '53 FAI finals, it became evident that the balance of thrust offset against twin rudder offset was a balance at one speed only, with thrust being more effective at a low speed and rudder at high speeds. What was needed was a set-up permitting a good balance of forces at all speeds under power whik still maintaining a good glide turn without trick gadgets such as auto rudders or drag stabs..."

Update 22/12/2013: Replaced with a clearer version, thanks to JJ.

Supplementary file notes

Article pages, text and pics, thanks to SimonBlake.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction

Amazoom 400 - completed model photo

Datafile:

003.jpg
003.jpg
004.jpg
004.jpg

Do you have a photo you'd like to submit for this page? Then email admin@outerzone.co.uk

User comments

No comments yet for this plan. Got something to say about this one?
Add a comment

 

 
 

Download File(s):
 

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.

 

Terms of Use

© Outerzone, 2011-2019.

All content is free to download for personal use.

For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.

Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.