"Mini Boomer" Design, What if the Cri-Cri and a Boomerang h

A place to discuss general aircraft design and ideas

How do you feel about this design idea as a chapter 40 project

Let's do it
1
50%
Undecided
0
No votes
No
0
No votes
I am not a designer or engineer, but am interested
1
50%
I have a better idea
0
No votes
 
Total votes : 2

Re: "Mini Boomer" Design, What if the Cri-Cri and a Boomeran

Postby erikfranks » Sun Sep 18, 2011 12:29 pm

I like the twin engine idea especially if it's near centerline because you can possibly attach a very experimental engine and still have reasonable reliability. I hope Sonex is able to sell an electric motor kit soon.
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Re: "Mini Boomer" Design, What if the Cri-Cri and a Boomeran

Postby Christian » Sun Oct 02, 2011 11:25 pm

I got some input from a reader (Aircar) at Homebuildairplanes.com and wanted to post it here for everyone. I hope he will join the forum to contribute:

Newimaging et al --your 'Miniboomer' link doesn't work for me --maybe it has expired but from the context I gather it might be a twinned CRI CRI as in two fuselages (four engines) and a new centre section joining the two hulls -- seems that twin bodies are back in the Zeitgeist what with Burt Rutan's BiPod the pipistrel G4 Brown CarPlane etc .

This would seem to be a feasible concept to me -- doubling the fin area is especially good since the moment of inertia of the two bodies in yaw goes up markedly but you can use the self same components pretty much and in fact add extra wing area in the centre section plus you lower the span loading greatly --you probably would want to use only one mainwheel on each hull rather than duplicate the spring gear or maybenot .

The bonded aluminum skin construction is as for the schreder sailplanes that I worked on and later also built an ultralight with 0.016 2024 bonded skins on hot wired in place styrofoam ribs --worked well .

I knew Morry Hummel quite well (lived around the block from him in Bryan Ohio )and admired the Hummel bird (converted from Windwagon using new fuselage skins and HP glider canopy etc plus Morry's 1/2 VW ) -- doing a Siamese twin version as a two seater would be a bit more difficult as losing one motor out of two is worse than one out of four in assymetrics and total thrust but as Morry used to say "friends don't let friends fly two strokes"

A second thought --can anyone photoshop a twinned CRI CRI perhaps ? --how about using one horizontal tail to join the fins (OV 10 Bronco style ) . Would it now be a CRI CRI CRI CRI ?

I will post a few of my mad twinned concepts on this thread and see what the reaction is -- the previous comments 'debunking' the idea of shoehorning a second pilot into something as tightly constrained as either a CRI CRI or hummel bird are quite true but the thought of "Twin Mustang" treatment is worth some consideration perhaps -- the Fouga Gemenaux is another duplicated design that comes to mind --the use of pre existing detail components and starting from existing hardware needs consideration. (even re mounting engines on the centreline eliminates the engine out case --push pull is possible also ......….

Excellent link Newimaging --and 'open source' concept (the Ligeti Stratos was similarly offered as open source but it has inherent problems --it went in inverted killing the designer . I was involved inadvertently from the very start after showing Charles the Lippisch design with the configuration and discussing the 'bullroarer' descent of the easy Riser biplane shown on a video at a meeting of the ultralight group ....... alas )

hg_9_big.jpg
Ligeti Stratos


The assymetric layout is much more complex than duplicate bodies and identical outer wings etc as for CRI CRI -- re locating the engines and props of the CRI CRI to the centre section makes sense (and the airflow effect around the canopy with one engine out is unneccesary ) --the Swedes designed an assymetrical aircraft in 1943 --very much like the well known Blohm und Voss recon design --their's was called Tungt Jaktflygplan (sounds like 'fighterplane' -drawing shows six cannon )-- it had push pull engines driving contrarotating pairs of props at each end .

Blohm&Voss-BV-141-Nazi-Experimental-Recon-Aircraft-Inflight-Rendering.jpg
Blohm&Voss


Better to go with doubled up standard components where possible -- three CRI CRI pods if you want three seats I guess Or back to back seating in one pod .... or….

Maybe readers could look at "multi body designs" and "twin Cozy" for other thoughts on older threads --the idea of reducing structure weight in a two seater by having separate pods spread along a wing was proposed by Cmdr Nick Goodhart as a way to get a workable TWO man powered aircraft by reducing structural weight, increasing span greatly and also giving yaw by differential thrust (the Toucan and Hertforshire two seat/ one fuselage MPAs hoped to get a better power to weight ratio than singles --something like the present GFC favouring multiseat aircraft in terms of economy as seat miles per gallon.
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Re: "Mini Boomer" Design, What if the Cri-Cri and a Boomeran

Postby Christian » Sun Oct 02, 2011 11:31 pm

Glenn_F_Cist.jpg


Regarding the previous post

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Postby VeTRooTVob » Thu Mar 08, 2012 8:56 am

I am sorry, that I interrupt you, but you could not give more information.
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