Hi everyone! Joined this site while googling information regarding the A-Plane. I have plans for that and several of the Mini-Max series before they went pay. I was going to flight school but deployments and 6 kids kind of put a stop to that...for the time being. That and we moved to northern Michigan and it is a bear of time finding a flight instructor up here! In the meantime I am going to build an ultralight just to get back into the air again. I look forward to learning from you all!
Greetings!
- Thread starter wicki1984
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Victor Bravo
Well-Known Member
Welcome! We're glad to have you here! What materials are you most comfortable working with, and what is your level/experience of mechanical ability?
Grew up woodworking and restoring Mustangs. I was then a heavy equipment mechanic for the Army for 2 years and have spent the past 16 years as builder for the Air Force. A builder for the Air Force is diverse and we do quite a bit of sheet metal fabrication and welding. So...experience with plane building, none. Comfort level of figuring it out, pretty high, lol.
Victor Bravo
Well-Known Member
Great, you have skills ! You're 3/4 of the way there... just have to calibrate yourself for the type and level of woodworking that goes into a very light aircraft. Not a biggie, just start wrapping your head around the idea that aircraft woodwork has to be a lot lighter than carpentry/construction woodworking, and makes the most strength out of a much smaller quantity of wood.
If you have woodworking equiment available and enjoy working with wood, then the Mini-Max and its related design family is a near-guarantee of a safe, well-designed, good-flying ultralight. If you already have the plans, make sure your workbench is flat and level, and you can get started today
See if you can find the Mini-Max build thread by Little Scrapper and look through that. He had several videos on that thread too. He did not progress past a certain point, but the methods and shop hacks and ideas he had were going in a really good and worthwhile direction.
If you have woodworking equiment available and enjoy working with wood, then the Mini-Max and its related design family is a near-guarantee of a safe, well-designed, good-flying ultralight. If you already have the plans, make sure your workbench is flat and level, and you can get started today
See if you can find the Mini-Max build thread by Little Scrapper and look through that. He had several videos on that thread too. He did not progress past a certain point, but the methods and shop hacks and ideas he had were going in a really good and worthwhile direction.
It sounds like you'll do just fine. ;-) What sort of ultralight do you have in mind?
robertl
Well-Known Member
Wicki, I too became interested in the A Plane years ago but eventually decided I really didn't like the construction and began to question the strength of the design. The MiniMax on the other hand has a proven track record and there are lots of them flying around the world. Personally, I like building with aluminum and there are a couple of designs like the Hummel UL and the Ultra Cruiser that are all aluminum.
Bob
Bob
I am leaning toward the A-Plane to start. I have a friend who is a structural engineer and also an aviation buff so we are going to scrutinize the design as we go through it and see what can be done to make it better while still using "off the shelf" materials. After that it will be the mini-max; I've gotta support Mini-Max since they are from my state! The ultra-lights are a stepping stone, I am hoping by the time I am done with those 2 that the Scalebird's P-36 will be in production (my personal favorite air-frame ever built). I stay in loose contact with ScaleBirds; I have been discussing using a Verner radial on the Mini-Max...even considering using it on the A-Plane. When I start the build I will make sure to catalog it. The life-goal is I want to scale down a PBY or B-25. I've always wanted either of those 2 air-frames and if Jack Bally can make the Bally Bomber then why can't I do something similar? Dreams keep us going, lol.
My grandfather was a PBY pilot so I am all for that idea! Let’s see....
A PBY-5A had 104’ span, 1,400 sq ft area, 35,420 lb gross, 2 x 1,200 hp, so about 25 lb/sq ft wing loading and 15 lb/hp power loading. A proven light amphib like a Thurston Teal TSC-1A1 had 32’ span, 157 sq ft wing area, 2,200 lb gross, 150 hp, so about 14 lb/sq ft wing loading and 15 lb/hp power loading. So basically we want to halve the wing loading and keep the power loading about the same.
The 60 hp Verner 5V is more affordable than the larger models, which would give us 120 hp and a gross weight of 1,800 lb at 15 lb/hp. The Teal is a little hot (57 mph stall) so let’s bring the wing loading down to 10 lb/sq ft like a Super Cub to get 180 sq ft. That’s about 13% of the Catalina wing area so about 36% scale for a wing span of 37’ 6” which will fit in a T-hangar.
That weight and power should give performance comparable to a PA-18-105 (O-235 Lycoming) two up with the otption of carrying baggage or a third person when desired. Cockpit would have to be non-scale (unless you are two feet tall) and you’d probably want shorter engine nacelles to keep the props away from the cockpit. Sounds like a lot of fun to me!
A PBY-5A had 104’ span, 1,400 sq ft area, 35,420 lb gross, 2 x 1,200 hp, so about 25 lb/sq ft wing loading and 15 lb/hp power loading. A proven light amphib like a Thurston Teal TSC-1A1 had 32’ span, 157 sq ft wing area, 2,200 lb gross, 150 hp, so about 14 lb/sq ft wing loading and 15 lb/hp power loading. So basically we want to halve the wing loading and keep the power loading about the same.
The 60 hp Verner 5V is more affordable than the larger models, which would give us 120 hp and a gross weight of 1,800 lb at 15 lb/hp. The Teal is a little hot (57 mph stall) so let’s bring the wing loading down to 10 lb/sq ft like a Super Cub to get 180 sq ft. That’s about 13% of the Catalina wing area so about 36% scale for a wing span of 37’ 6” which will fit in a T-hangar.
That weight and power should give performance comparable to a PA-18-105 (O-235 Lycoming) two up with the otption of carrying baggage or a third person when desired. Cockpit would have to be non-scale (unless you are two feet tall) and you’d probably want shorter engine nacelles to keep the props away from the cockpit. Sounds like a lot of fun to me!
Victor Bravo
Well-Known Member
Mr. Bally has just recently passed away, and I mean no offense whatsoever to his work or his legacy... but... there is a very important lesson in the Bally Bomber for all homebuilts enthusiasts. Before embarking on a replica of that general scale or nature, figureout what has really worked and what hasn't. The Bally aircraft should have had an incredible career, paying its own way as a star attraction at airshows worldwide, and being flown all the time. The B-17's proportions were really good, and by all rights it should have flown beautifully. Big thick blunt airfoil, very modest wing taper, great big tail for a wide CG range, great big fin and rudder. All the ingredients were there for a good flying airplane.
But apparently (from what little we heard) it didn't fly well enough, and it was not enough of an "every day" airplane to have gone on the airshow circuit. It was put up for sale very soon after it flew, and nobody was interested. The answers to why it was not enjoyable to fly, or why it wasn't everything Bally had wanted it to be... after all the time and money he had spent... need to be understood.
I would love to see a PBY or B-25 replica, I am a fan of both of those airplanes like most of us here. I just wouldn't want to see someone go down that path without a better chance of the result being successful.
But apparently (from what little we heard) it didn't fly well enough, and it was not enough of an "every day" airplane to have gone on the airshow circuit. It was put up for sale very soon after it flew, and nobody was interested. The answers to why it was not enjoyable to fly, or why it wasn't everything Bally had wanted it to be... after all the time and money he had spent... need to be understood.
I would love to see a PBY or B-25 replica, I am a fan of both of those airplanes like most of us here. I just wouldn't want to see someone go down that path without a better chance of the result being successful.
Great points, VB. Such projects do spark the imagination but their rarity should be a warning about their practicality. I have mentioned before my interest in the Shavrov Sh-2 and Dornier Libelle and an original design inspired by those two light planes and painted in PBY colors would be a much more practical proposition.
I agree with everything you have said. I find myself returning to mantra that, "If at first you don't succeed; try, try again". I was saddened the day that the news of Mr. Bally's death came across my Facebook news feed. Instead of it diminishing my desire to experiment with scaled down multi engine aircraft it only further cemented it. I am aware of the discrepancies you speak of and do not mean to sound ignorant but I want to experiment and understand the why. In this great day and age of computer simulation, combined with classic methods of wind tunnels, aqua tunnels, and r/c aircraft, the methods are there to make any aircraft dream a reality.
I found this site while googling building threads for the a-plane and it was the thread about how to make it better. I saw early on that you err on the side of caution, and known design principles and engineering. Keynote on the signed engineering, lol. I respect that very much and as I progress in my builds I will make sure to keep things posted and am looking forward to your ever cautious advise. My own ambitions can grow wild and it is nice to have someone step up and say, maybe we should think harder about this. What I have learned in the threads I have read is I guarantee you that as I start documenting my builds we will not see eye-to-eye on everything, but more importantly I welcome your criticism.
Lastly. Since you do regularly bring up getting designs approved by an engineer, would you happen to know of a company that does this in particular? I see merit in your suggestion and as I develop my plans I would like to run them by someone with much more knowledge than myself. I would be curious if there was a firm that specialized in analyzing experimental aircraft design. A google search I am sure would eventually bring up something, but if you have someone you know of and trust I would like to look into them.
Victor Bravo
Well-Known Member
Assuming that by "you" you mean me specifically, a little "calibration" is in order here. While I'm often the biggest mouth on this forum, I have little or no formal training in design. Many of the people here have a tremendous amount of formal training; they might (or might not) have much better knowledge or experience than me or anyone else.
Many times I do err on the side of caution, and that's mostly because because I lack the technical ability to identify or get close to engineering limits. That's a defense mechanism, not any notable advantage or point of honor. I appreciate real innovation and cutting edge engineering as much as the next guy.
So for the love of Roscoe Turner don't let any of my comments stop you from pursuing something really cool. Perhaps my cautious advice can simply remind you to look at something from different points of view. But once you have worked through whatever it is, go ahead and innovate, design, and push the limits as you see fit.
Many times I do err on the side of caution, and that's mostly because because I lack the technical ability to identify or get close to engineering limits. That's a defense mechanism, not any notable advantage or point of honor. I appreciate real innovation and cutting edge engineering as much as the next guy.
So for the love of Roscoe Turner don't let any of my comments stop you from pursuing something really cool. Perhaps my cautious advice can simply remind you to look at something from different points of view. But once you have worked through whatever it is, go ahead and innovate, design, and push the limits as you see fit.
Random thought...at about 50% scale you could do a late model B-25H or -J as a tandem two-seater with the pilot in the cockpit and the rear passenger's head in a possibly enlarged dorsal turret bubble.
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Victor Bravo
Well-Known Member
An earlier model B-25 with the "glass nose" would be just a little longer, the rudder pedals would be visible in the bombardier's compartment, but the airplane would scale down to perhaps an even more manageable size for a garage builder? The nosegear would swing up just in front of the pilot's seat...
I remember reading articles about that particular aircraft. Have you ever read any of the articles of the guy in England who built his own spitfire?
Spitfire enthusiast spends 28 YEARS building 'perfect' replica of plane flown by his friend during World War Two
Terry Arlow (pictured), from Lowestoft, Suffolk, built the 'perfect' replica of a Spitfire Mk. IX, despite having no engineering skills, after securing plans for the plane from the RAF museum in Hendon.
I am partial to the glass nose models. The one with the 75mm coming out of the nose is cool, but just like my sweet spot for radials I have a sweet spot for the glass nose on a bomber.An earlier model B-25 with the "glass nose" would be just a little longer, the rudder pedals would be visible in the bombardier's compartment, but the airplane would scale down to perhaps an even more manageable size for a garage builder? The nosegear would swing up just in front of the pilot's seat...
