Tweedy Bird (oz5521)


Tweedy Bird (oz5521) by Joe Bridi 1975 - plan thumbnail

About this Plan

Tweedy Bird. RC Pattern plane. The Tweedy Bird (often seen spelled as Tweety Bird) was a smaller version of the classic Dirty Birdy (oz4915) design.

Direct submission to Outerzone.

Update 18/06/2014: Added supplement file with rib templates, thanks to bulldogdrummond.

Update 18/06/2014: Added a second file of rib templates, hand traced on 2 pages, thanks to JimPurcha.

Quote: "Good morning, I have two pages of traced ribs for the Bridi Tweedy Bird model. The current drawing shows only 9 ribs. There are actually 10 ribs. Thanks, Jim"

Update 08/03/2020: Added kit review from RCM, February 1977, thanks to RFJ.

Quote: "RCM Product Test. Bridi Hobby Ent Tweedy Bird.

The Tweedy Bird is a sport and pattern aircraft manufactured by Bridi Hobby Enterprises, 1611 E Sandison St, Wilmington, California 90744. Designed by well-known pattern flyer Joe Bridi, this low wing pattern and general sport aircraft has a wing span of 48-3/4 in and a total wing area of 400 square inches and is designed for .15 to .30 cubic inch displacement engines. Four channels of control are required for rudder, elevator, throttle, and ailerons.

The basic materials used in the construction are conventional balsa and hardwood. The hardware in the kit include the main landing gear, steerable nose gear with associated hardware, main gear hold-down straps and screws, motor mounts and mount screws, nuts, control horns, canopy, pre-formed epoxy cowling and aileron torque rods. There is one plan sheet measuring 50 x 30 in with building instructions included on the plan sheet in addition to a 15 page instruction manual. Parts are machine cut.

The weight of our prototype ready to fly was 56 ounces for a wing loading of 19 ounces per square foot. RCM's prototype was covered with Super MonoKote and Bridi Striping Tape. An OS Max .35 engine with Max muffler was used while the radio was a Kraft Gold Medal Series with KPS 12 servos. While this was a well-designed model with clear and precise instructions, we found the following changes necessary in our particular kit:

On page 3 of the instructions, while the plans and instructions call for the sheeting to come over the spar, the ribs were cut so that the sheeting (top front and bottom wing) fit flush to the front edge of the main spar. Either the ribs should be die-cut or the plans and instructions modified. Since that time Bridi Enterprises has machine cut all the ribs and cap strips have been added to the kit.

On page 4, the instructions should refer to the bottom leading edge sheeting rather than to the top leading edge sheeting.

On page 5, if number 5 instruction were followed, it would not be possible to glue in the dowel plate. The instructions should be modified indicating that the dowel plate should be glued in before sheeting is completed.

On page 7, the doubler has to be glued to the front edge of bulkhead number 1 or the triangular stock has to be cut out so that the sides fit flush to bulkhead number 1.

On page 9 we would recommend that the NyRod tube be anchored to the fuselage side before the bottom sheeting is completed.

On page 12 the 'U' cut-out on the cowling is not on the plans as indicated in the instructions.

Overall this is an outstanding kit with excellent instruction manual and plans with only the minor corrections previously mentioned.

In the performance category the Tweedy Bird must be ranked as outstanding - another excellent aircraft from Bridi Enterprises. It is extremely pleasant to handle and flew hands off on the first flight. It has an excellent roll rate, a fine glide pattern with no snap or tip stall tendencies noted. It performs all maneuvers with ease. We would have to rate this kit as excellent."

Supplementary file notes

Wing ribs (1).
Wing ribs (2).


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Tweedy Bird (oz5521) by Joe Bridi 1975 - model pic

  • (oz5521)
    Tweedy Bird
    by Joe Bridi
    from Great Planes
    49in span
    IC R/C Kit
    clean :)
    all formers complete :)
  • Submitted: 24/04/2014
    Filesize: 537KB
    Format: • PDFbitmap
    Credit*: sdad46, bulldogdrummond, JimPurcha

Tweedy Bird (oz5521) by Joe Bridi 1975 - pic 003.jpg

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Download File(s):
  • Tweedy Bird (oz5521)
  • Plan File Filesize: 537KB Filename: Tweedy_Bird_oz5521.pdf
  • Supplement Filesize: 2800KB Filename: Tweedy_Bird_oz5521_review.pdf
  • Supplement Filesize: 378KB Filename: Tweedy_Bird_oz5521_ribs_1.pdf
  • Supplement Filesize: 562KB Filename: Tweedy_Bird_oz5521_ribs_2.pdf
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