1947 Lifting Body Burnelli Concept Aircraft - Anatomy of a Trim Session

This film shows a few of the stages of building the 37" free-flight rubber-powered Burnelli Transport concept aircraft from 1947. It then focuses on the methodical, eleven flights of the model's first trim session, ending in a beautiful soaring flight in Wawayanda, NY, where the many curious & vocal bobolinks had a front row seat or perch. Filmed by Tom Hallman on 5.25.24 with a Canon PowerShot SX20, and iPhones 11 & 14Pro. Music via the talented musicians at ArtList.io, who breathe life into my films.

First day notes with the Burnelli:

Started at 200 winds…then methodically worked up the ladder by
100 and then 150-200 turns with each new flight. Max turns in the 1900-2000 range.
Used the same motors (2 loops x 3/16" x 40") that singularly power the 27" Seafire & 28" Cauldron. Both use a 10" EB white prop...compared to the 8-7/8" props for the Burnelli.

The quick fix was more downthrust (twice), nose weight, right rudder via
1/32" thick gurney flap, and a touch of gurney on the lower left to help hold that right
turn…although I might remove it or adjust the location after seeing what the increased torque did to the initial power burst. I’d rather see the bird climb a bit flatter thru the first circle. With 500+ turns to go, I’ll need to keep an eye on the torque effect.

Cracked a bamboo skewer prop spar...twice, when it outflew the field, landing on the hardened dirt of the neighboring crop section. I’ll resolve these issues for the future. The 1/16” dia. toothpick rivets that I use are great for holding the blades in place, but I should not have had the one closest to the hub, as it created a weak spot in a heavy stress / leverage area.

I thought I’d be OK with shrink wrap tubing for the canopy but the hours of hot, direct
sun had other intentions, so that’ll be replaced with the good stuff, PETG plastic via the vacuformer.

I have growing concern for the lack of a DT on this model. But yes, a fantastic first day out with this unusual design.

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Wiki on Vincent Burnelli: https://en.wikipedia.org/wiki/Vincent...
News reel footage of the similar design from the late 40s:    • HD Stock Footage Canada Demos CF-BEL-X Pro...  

Making props from a cheese container:    • Free-Flight Basics #11 - Making Props From...  

Here's a source for rubber: https://www.faimodelsupply.com/produc...
Generic rubber turns calculator: http://2002.hallmanstudio.com/rubber_...

Article on the use of dethermalizers: http://2002.hallmanstudio.com/DT.pdf
Badge Classic DT & spring (at the bottom of the page): http://www.starlink-flitetech.com/tim...

*** 10 steps to trimming a rubber model, by John Koptonak: http://www.flyingacesclub.com/PFFT/Tr...

Also, these tutorials from Easy Built Models: https://easybuiltmodels.com/tips.htm#...

Looking for a Flying Aces Club near you? Check out this link: http://flyingacesclub.com/wp/about-th... If you click on the map at the area closest to you, it will automatically bring up an information request link. That request goes to FAC GHQ and also to the Squadron Commander of record for that squadron.

Geneseo FAC Nats Journals from 2016 & 2018: http://www.maxfliart.com

For more info on free-flight rubber-powered models, check these websites:
https://brooklyn-balsa.square.site
http://www.easybuiltmodels.com/
https://volare-products.myshopify.com
http://www.flyingacesclub.com
National Free Flight Society - https://freeflight.org/
Mike Stuart's Flying Scale Models - http://www.ffscale.co.uk/
https://www.freeflightsupplies.co.uk

Flying Aces Club merchandise: https://www.cafepress.com/flyingacesclub
All profits support Flying Aces Club activities.
Center of Gravity merchandise: https://www.cafepress.com/centergravity