• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $29.95/year to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction).

Smith Miniplane on CL

Snappy

Well-Known Member
Supporting Member
Joined
Jul 31, 2020
Messages
153
Reaction score
70
Location
Washington
Nice looking Miniplane with O-235 on Craigslist in Estacada OR. $12,000
I’m too far away to check it out.
 

footloose

Well-Known Member
Supporting Member
Joined
Mar 10, 2017
Messages
555
Reaction score
201
It sure is a Cutie . Standard cockpit . Better be a small guy or you'll get the sardine feeling . Don't know why Frank didn't stretch that area a bit . I feel like this is the only thing that held that design back . Fixable , ask how I know . I wonder what engine .
 

EAABipe40FF

Registered Users
Supporting Member
Joined
May 30, 2009
Messages
6,841
Reaction score
1,512
Location
Springfield, WV
Many designs are too small "today". People on average were smaller back then. Even when I learned to fly in 1971 the FAA 170# average was actually realistic which seems far from true today. I weighed 135 in 1971.........210 today. Oh well.
 

Snappy

Well-Known Member
Supporting Member
Joined
Jul 31, 2020
Messages
153
Reaction score
70
Location
Washington
Yep, I bought a project with an O290G and “most” of the welding done. Being a wood guy, the wings seemed easy! After understanding what was actually involved, I decided that with three small children, it just wasn’t the project for me at that time. It DID have an extended fuselage so I could sit in it and make motor noise 😃
 
Joined
Jan 24, 2008
Messages
3,289
Reaction score
1,717
I guess Frank Smith thought the cockpit of the Stits Playboy was too big as that's what he built prior to the Miniplane.
 

El Piloto

Registered Users
Joined
Aug 17, 2008
Messages
67
Reaction score
14
Many designs are too small "today". People on average were smaller back then. Even when I learned to fly in 1971 the FAA 170# average was actually realistic which seems far from true today. I weighed 135 in 1971.........210 today. Oh well.
People (many) do not understand the leg to torso ratio applies here....and I sure do not know why! I had men 6 feet tall who could not get into my Charger. Others 6'6" had no trouble whatsoever. So here it is....the guy 6'6'' had a long torso and short legs. The guy who was 6' was all legs and a short torso. Many designers just do not seem to get it. These days, in the "lands of milk and honey" designers say they made the cockpit larger or bigger....but they mean wider...and totally miss the leg/torso ratio. The Baby Ace and the Pitts S-2 etc. need re-design work. The Baby Ace and the Smith Miniplane are both fine designs for long torsos but not for long legs. The Baby Ace needs another six inches in cockpit length with adjustable rudder pedals to be a really good design. Ditto many others.
 

Neil

Well-Known Member
Lifetime Supporter
Joined
Nov 10, 2006
Messages
6,596
Reaction score
1,153
Location
Monroe, Louisiana
Totally agree. I'm right at 5'11" and when I sit in my Acro Sport, I drop pretty low in the cockpit but my legs are folded up even with the rudder pedals moved forward. Others of the same basic height stick up above the top of the turtle deck and can't reach the pedals.
4210-b8de4bf373c2e637a3d3390aa466f501.jpg
 

footloose

Well-Known Member
Supporting Member
Joined
Mar 10, 2017
Messages
555
Reaction score
201
The Smith can be enlarged somewhat by reclining the seat aft by whatever it takes to fit the individual (up to a certain point) of course . There is always structure and W/B considerations . I'm 5' 10'' . 240 . I reclined my seat 5'' at the shoulder and moved the rudder pedals to 5 1/2'' aft of the firewall . Feels very comfortable to me . As stated above , might mot be so comfortable for someone the same height with a different build . Just reclining the seat made a world of difference .
 

Attachments

El Piloto

Registered Users
Joined
Aug 17, 2008
Messages
67
Reaction score
14
The Smith can be enlarged somewhat by reclining the seat aft by whatever it takes to fit the individual (up to a certain point) of course . There is always structure and W/B considerations . I'm 5' 10'' . 240 . I reclined my seat 5'' at the shoulder and moved the rudder pedals to 5 1/2'' aft of the firewall . Feels very comfortable to me . As stated above , might mot be so comfortable for someone the same height with a different build . Just reclining the seat made a world of difference .
Curtis Pitts told me I could move the cross tube behind my shoulders a distance of 3 inches on the S1C.That might release some pressure on my lower spine....but would not alleviate the need for far more leg room. I did have a wonderful ride in the Pitts S2A but could not continue more than 20 minutes because my knees were jammed TIGHTLY between the back of the instrument panel and the fuel tank! A wonderful flight -but still a painful experience.
 

IanJ

Well-Known Member
Supporting Member
Lifetime Supporter
Joined
Jun 12, 2007
Messages
3,502
Reaction score
857
Location
Seattle, WA
Agreed on the leg/torso ratio. I have relatively longer legs for my height, though not extremely so. I notice it most sitting in the driver's seat of a car my dad's been driving -- we're about the same height, but he has at least three inches of torso height over me, so I'm always scooting the seat back, and adjusting mirrors. That's one of the reasons I want to make my Charger rudder pedals adjustable, to allow people with longer and shorter legs to fly it.
 

wanttaja

Registered Users
Joined
Jul 13, 2014
Messages
364
Reaction score
228
People (many) do not understand the leg to torso ratio applies here....and I sure do not know why! I had men 6 feet tall who could not get into my Charger. Others 6'6" had no trouble whatsoever. So here it is....the guy 6'6'' had a long torso and short legs. The guy who was 6' was all legs and a short torso. Many designers just do not seem to get it. These days, in the "lands of milk and honey" designers say they made the cockpit larger or bigger....but they mean wider...and totally miss the leg/torso ratio. The Baby Ace and the Pitts S-2 etc. need re-design work. The Baby Ace and the Smith Miniplane are both fine designs for long torsos but not for long legs. The Baby Ace needs another six inches in cockpit length with adjustable rudder pedals to be a really good design. Ditto many others.
The Air Force went through this in the '50s. Prior to that, planes were built toward "average" dimensions...which means few people were actually comfortable. Small people, especially women, had a really hard time. There were some accidents attributed to the plane not being well-matched to the ability of the pilot to move the controls.

Instead, the Air Force started demanding adjustability... enabling the pilot to set the seats and controls in a position best suited for them. They specified requirements on the basis of a percentile... e.g., the plane has to be adjustable enough to be efficiently controlled by a given percentage of the adult population. A lot of surveying was done to determine what the percentages were.

I worked Boeing's original Space Station proposal in the '80s, and we were required to accommodate male astronauts up to 95% of the maximum size, and female astronauts down to 5% of their minimum size. When designing the cabin, they wanted to find a 95-percentile male and a 5-percental female for quick checks. So they ran us over to an Iron Maiden-sort of setup at Boeing's Renton plant. We stood, sat, or laid down as appropriate, and our dimensions and ranges of motion were measured.

They recorded the data, and gave us summary cards of our scores. Here's mine. First column is the measurement, and the "%" column is my percentile.
Anthropometric data card002.jpg

Ron Wanttaja
 

El Piloto

Registered Users
Joined
Aug 17, 2008
Messages
67
Reaction score
14
With the Charger you might want to find a way to remove the two tubes angling down from the center radio stack in the back cockpit. This might impact the strength of the area but there are probably ways of doing this safely. In the back seat it was always difficult for me to get my feet properly on the rudder pedals (back seat) ...and in the event of a "prang" I worried about my legs being injured/broken - or my being pinned in the rear cockpit. I suggest this is a worthwhile consideration. But, it certainly is a wonderful design! Mine performed very well with a 125HP six- cylinder Continental. It sounded very good with all six cylinders running smoothly...we also added an extra hinge for the rudder.
 

mbourget

Well-Known Member
Joined
Jan 27, 2014
Messages
194
Reaction score
40
This is a physical anthropology issue. They have extensive charts on height, weight and limb length. During WWII the design fighter pilot was 5-7 to 5-8 and 145#. Many of the guys who originally designed these birds were raised in that nutrition/health etc. "era"

When (larger) guys started asking John Thorp about wider cockpits, the advice was to lose weight. But you can't lose height or limb length.

Following up with John, the solution was to increase the dimension, but this requires focus and weight and balance calculations. For something as robust as a Pitts, I'd think there wouldn't be a need to upgrade tubing structure, but it's all in the numbers.

Keep in mind, simply widening the fuselage, without taking into account possible changes in airflow, can lead to problems. The only "wide-body" T-18 (fuselage widened, but not in proportion to cross-section) I know of that was spin tested reportedly took over 10,000 feet to recover.

FWIW
 

Latest posts

Top