PB100:  The Pete Bowers Centennial
Rebooting the Fly Baby
15 May 2018

Peter M. Bowers
May 15th, 1918 - April 27th, 2003

We're re-inventing the building process!

Jump to the Construction Information

Table of Contents

Introduction

In 1958, the Experimental Aircraft Association (EAA) announced a contest to design, build, and demonstrate a new homebuilt aircraft.  The winner would have to be simple and inexpensive to build in the home shops and garages of that era.  One of the stipulations of the contest was that the winning designer would have to completely document how to build that airplane within the pages of EAA's SPORT AVIATION magazine.

Peter M. Bowers and his "Fly Baby" won.  It was an inspired selection for a number of reasons.  Not only did the Fly Baby meet the buildability and flyability criteria of the contest, in Pete Bowers they had that rarities of rarities... an engineer/aircraft designer who would actually write.  

And so, in a 14-part series in EAA SPORT AVIATION starting in December 1962 (just four months after winning the contest), Pete wrote about how to build a Fly Baby.  Thousands of EAA members started construction.  Dozens, or even hundreds of them were completed and flown.

While he worked on the articles, Pete was assembling a stand-along set of plans for sale.  The plans used the same diagrams (drawn by Jim Morrow) as the magazine articles.   The diagrams printed in SPORT AVIATION even had the figure-numbering of the plans set, rather than relative to their position among the articles.  From 1963 to 2003, Pete ended up selling around 5,000 sets of plans.  About 500 airplanes were built, either from the magazine articles or from the plans.  As you can see from the above diagram most of the planes were completed in the '60s to early '70s.

Drew Fidoe's "Stringbag" was built from the EAA Magazine Articles

So, what's the problem?

It's the 100th anniversary of Pete Bowers' birth...but the plans for his most famous creation are no longer available. 

And, in any case, the plans were written in 1963.  While there were almost a dozen revisions, they all were technical in nature--correcting dimensions, etc.  The current planes don't really doesn't reflect the realities of the 21st Century.

Think about how much has else changed in the past 50+ years, just in the homebuilding world.  Epoxy glues.  Stits fabric.  Composites.  Computer-aided laser, plasma, and water-cutting of steel and aluminum.  The latest edition of Pete's plans says you can buy a freshly overhauled Continental A65 for $500.  That'll hardly buy the overhaul gasket kit, now. 

Finally, people are different now from back then.  Back in the '60s, high school kids took shop classes, and practically anyone with a house had a table saw and did some minor woodworking.  It's just not the case, anymore.  The classic argument for a Fly Baby is that it's built just like a balsa-and-tissue model.  But how many people are actually building those, nowadays?

Safety Issues

Another aspect is safety.  Over fifty years of Fly Baby flying has revealed some problems with the design.  For the most part, nothing major... but the Fly Baby has the highest rate of in-flight structural failure among homebuilt aircraft in the US.  Almost a quarter of Fly Baby accidents involve wing failures. 

A Fly Baby properly built, properly maintained, and properly operated doesn't have a problem.  But Pietenpols are older than the Fly Baby, there are twice as many of them...but their wings don't break.  Why does the Fly Baby have such a problem?

I believe there are some changes that will provide pilots with a bit more design margin. And I'd like ensure builders know about them.

So What is "PB100" About?

We don't need band-aids to the existing instructions:  We need a REBOOT. So, to honor Pete Bowers' legacy, let's take things down to fundamentals, give the builder of the 21st century the kind of help that wasn't thought necessary in the '60s, and recommend modifications where experience shows it needs it.

Most homebuilt designs become lost to history when the plans go off the market.  But the Fly Baby has a unique advantage:  That 14-part building series in EAA SPORT AVIATION magazine.  No other homebuilt has had that level of detail published, free, for the use of the magazine's readers.  And if you're an EAA member, the entire series is available for you to download.  For free. 


That's what PB100 is all about:  Helping people build Fly Babies, whether they have an original set of plans or use the magazine articles.  PB100 support will be based on what can be downloaded for free from EAA.  I'm going to present information to help you understand them and know what kinds of changes are necessary or desired.  Each construction article has a complementary "Companion Guide."  These guides provide additional information that'll greatly assist in your construction.  Each Guide contains:
  1. Errata on what changes to the diagrams are needed.  Over the years, Pete did make some changes to the figures.
  2. Expanded detail to help you understand the tasks needed to be performed.  This will include new diagrams that illustrate aspects of the design to help you imagine how it goes together.
  3.  Key changes needed for safety
  4.  Warnings about components no longer being available, and potential alternatives
  5. Alternative approaches to some aspects of the design, as suggested by the builder community.
In addition, the section on each article includes links to key articles written by Fly Baby folks over the past twenty years.  They may not tie directly into the subject article, but they'll help with understanding it.

If you own plans...PB100 will make your building job easier.  But Pete intended that the magazine articles would be all a builder would need.

I've got Companion Guides for the first eleven of the fourteen EAA articles.  Article 12 is on assembly, and is pretty complete.  Articles 13 and 14 are on fabric covering and painting...and there are plenty of other references for these kinds of activity.  So there may not be Companion Guides for Articles 12, 13, and 14. 

I'll be modifying the Guides as suggestions are received, depending on the input from the community.  I've flown Fly Babies a lot, I've worked on them a lot, but I've never actually built a Fly Baby myself. I'm depending on the community for good info.  Each guide will include a version number to help identify when they've been updated.

Accessing the Building Series in EAA SPORT AVIATION

Construction instructions for the Fly Baby are available in the form of reprints of the original Fly Baby construction series, running from January 1963 to September 1964.  If you're an EAA member, you can download these articles FOR FREE from the EAA Archives.  If you're not an EAA Member, it costs just $40 to join, and you get a great monthly magazine.  In addition, EAA had published the articles in a SINGLE BOOK...and that book is now available for free download as well!


The first step is to download the magazine articles.  Go to the EAA Magazines page and click "EAA Sport Aviation".  At the bottom of the page, there's a link to the Archives.  Click that, and then the “View PDFs of Past Issues” button.  You'll need to log in to the site, using your EAA number.  The link here may not work all the way, because of the log-in requirement.

Enter "Building Fly Baby" in the "Exact Phase" box, and turn off all the options except "Title."

Here’s a breakdown of the EAA magazine articles vs. the organization of the plans.  Note that the articles were not published in the same sequence as the plans. 

EAA Magazine Article Part

Date of Publication

Plans Topic

1

Jan 1963

Wing Construction

2

Feb 1963

Wing Assembly

3

March 1963

Fuselage

4

April 1963

Fuselage Secondary Structure

5

May 1963

Landing Gear

6

June 1963

Tail Surfaces

7

July 1963

Power Plant and Related Installations

8

Sept 1963

Controls

9

Nov 1963

Misc Systems 1

10

Dec 1963

Misc Systems 2

11

Jan 1964

Corrections

12

May 1964

Assembly

13

Aug 1964

Covering Tail and Wing

14

Sept 1964

Covering Fuselage

There's also an "Overview" in the December 1962 issue.  This is mostly history and background.

The articles are in PDF format, and you can copy the text and paste it into a word processor for better readability.  You will have to go through the text to correct most of the fractional numbers (e.g., they come across as "1V" rather than "1/4").

EAA actually has a nice web page set up about the Fly Baby, and it includes a listing of ALL the Fly Baby articles published...not just the construction series.  You don't need to be a member to view it, either.

The EAA Web Site linked just above has added the ability for EAA members to download a PDF of EAA's "Building the Wood Airplane" book.  It contains all the Fly Baby construction articles, in one document.  You do have to be a member to download the book.

Downloading The Full Plans...for Free!

The Fly Baby community received wonderful news in February 2022.  When he passed away, Pete Bowers left his entire collection to Seattle's Museum of Flight.

The Museum has scanned in the plans, and you can read or download them for free!

This is very, VERY cool.  These are 1965 versions of the plans, which means the Companion Guides will be FULLY APPLICABLE.

Fly Baby fans now have the best of both worlds:  They can read the original articles, download the COMPLETE plans, and use these Companion Guides for amplifying information.


Finding Help

All this data is being compiled with the assistance of the Fly Baby community on Facebook and on the Fly Baby group on Groups.io.

If you have questions, feel free to ask them there.  As more information comes out, the supporting information will be upgraded.

Tony Bingelis articles

In addition to the Fly Baby articles, EAA Sport Aviation is chock-full of great information on building planes like the Fly Baby.  The late Tony Bingelis wrote many of them.  Here's a summary of useful articles in SPORT AVIATION

  • January 1972, Page 14, "Aircraft Metal Work"
  • December 1972, Page 36, "To Nail or not To Nail"
  • October 1981, Page 39, "Control System Cable Terminals and Connections"
  • September to November 1980, "Making Fittings" parts 1, 2, and 3
  • November 1979, Page 14, "You Can't Build an Airplane Without Nuts and Bolts"
  • September 1978, Page 34, "Aircraft Plywood...How to Use It"
If you're stumped about something, try searching the Sport Aviation archives.

Also, many of Bingelis' articles were re-published in book form.  "Sportplane Construction Techniques" and "The Sportplane Builder" can be purchases from the EAA.  For when you're ready to bolt on the powerplant, get "Firewall Forward" and "Tony Bingelis on Engines."

Fly Baby Bulletin

There was a newsletter for Fly Baby builders published in the 1960s.  I have received permission to include it for free download.  There's a lot of good information scattered throughout.

Templates for Parts

Ted Cannaday put together a PDF file that contains templates for all the Fly Baby steel parts.  These are the same for both the EAA Articles and the formal plans.

Jim Katz generated these CAD files (.DWG format) for getting his steel AND wood parts cut by laser/water jet/plasma systems.  In an ideal world, you should be able to take these by a commercial vendor and have them cut out quickly at a fairly low cost

FAA Advisory Circular AC43.13-1B

This Advisory Circular provides the official guidance for aircraft construction and repair.  If covers everything, from wood, to metal, to hardware, to fabric, to electrical work, and far beyond.  It provides techniques, and it provides standards.  If you follow AC43.13, no FAA inspector or Designee will object to how your airplane is constructed.

Building Information

Updated 19 July 2019 (See Update Note Section)
  • Introduction
  • Wing Construction -- Article 1,  January 1963. 
    • Companion Guide
    • Rib templates
      • Nose Ribs
      • Middle Ribs
      • Trailing Edge Ribs
      • Note that it's VERY IMPORTANT that the templates be printed out accurately.  They each contain a scale showing a ruler.  Print one template out, and measure with a ruler to ensure it's printed to the correct scale.
    • Steel part templates
      • Ted Cannaday's Overall Steel-Part Templates.  
        • For Article 1, you will need all templates labeled "W402", "W403," "W404", "W405," and "W406"
        • Note that the templates show the center point for all holes to be added, not the diameter of the holes.  You'll have to cross-reference with the original figures in Article 1.
        • Also note that it's VERY IMPORTANT that the templates be printed out accurately.  They each contain a scale showing a ruler.  Print one template out, and measure with a ruler to ensure it's printed to the correct scale.  For my Epson 830 printer, I have to print these out at 94% scale.
    • Jim Katz' Autocad Templates
      • Jim Katz generated these CAD files (.DWG format) for getting his steel AND wood parts cut by laser/water jet/plasma systems.  In an ideal world, you should be able to take these by a commercial vendor and have them cut out quickly at a fairly low cost
      • However, it's important to CHECK the dimensions youself... there's no guarantee there aren't any errors in there, nor that the various computer systems haven't distorted some of the dimensions.
      • You may want to have the shop actually put in pilot holes, rather than the full-size holes shown in these drawings.  It gives you a bit more leeway.
    • Wing ordinates for the airfoil
    • Other Pertinent Information



Update Information

1 June 2018

  • Added the draft Companion Guide for Article 2.  This currently takes the builder through the initial wing assembly.
  • Updated the guide for Article 1

26 May 2018:

  • Updated the guide for Article 1
  • Added the DWG templates
10 June 2018
  • Completed Companion Guide for Article 2
  • Updated Article 1 Companion Guide, and the Preparations material.

22 June

  • Updated first two Companion Guides
  • Added Draft Guide for Fuselage Construction

25 June

  • Article 3 Companion Guide completed and placed online
18 July
  • Updated Article 3 Companion Guide
22 July
  • Added Draft version of Article 4 Companion Guide
  • Updated Article 3 Companion Guide

23 July

  • Replaced draft with Version 1.0 of Article 4 Companion Guide

9 August

  • Added the Draft Companion Guide for Article 5

13 August

  • Replaced draft with Version 1.0 of Article 5 Companion Guide

12 November

  • Added Draft Companion Guide for Article 6
13 November
  • Replaced draft with Version 1.0 of Article 6 Companion Guide

22 December

  • Added Draft Companion Guide for Article 7
27 December
  • Replaced draft with Version 1.0 of Article 7 Companion Guide

25 February 2019

  • Added Draft Companion Guide for Article 8
9 March
  • Replaced draft with Version 1.0 of Article 8 Companion Guide

30 April

  • Added Draft Companion Guide for Article 9
2 May
  • Replaced draft with Version 1.0 of Article 9 Companion Guide
3 July
  • Added draft version of the Article 10 Companion Guide
July 4
  • Replaced draft of Article 10 with Version 1.0
July 19
  • Added Article 11 Companion Guide.