{"id":4392,"date":"2020-11-15T09:40:55","date_gmt":"2020-11-15T14:40:55","guid":{"rendered":"http:\/\/flymall.org\/blog\/?p=4392"},"modified":"2020-11-15T09:40:55","modified_gmt":"2020-11-15T14:40:55","slug":"bolt-in-cross-brace-explained","status":"publish","type":"post","link":"https:\/\/flymall.org\/blog\/2020\/11\/bolt-in-cross-brace-explained\/","title":{"rendered":"Bolt In Cross Brace Explained"},"content":{"rendered":"

There is indeed a bolted-in section of tubing in the upper (top) plane of the forward-most fuselage “bay”, located immediately between the firewall and the opening of the front cockpit – the area immediately above the front rudder pedals. This bolted-in section is V-shaped, with a single bolted fitting forward, at the center of the forward-most fuselage left-to-right cross tube (immediately aft of the firewall). From that centered forward fitting, two tubes welded to that fitting run diagonally toward the rear of the fuselage, one to the left and one to the right, with their rearward ends each welded to individual bolted-in fittings. These left and right fittings are secured to the upper-most left and right fore-and-aft fuselage tubes respectively, just forward of the junction of the second fuselage cross tube. The base of the forward cockpit instrument panel is clamped to that second fuselage cross-tube.<\/p>\n

All Model 75 Stearman aircraft were originally designed and built with a\u00a0single<\/u>\u00a0tube welded into the\u00a0forward-most fuselage “bay”\u00a0in that location, oriented and running diagonally from the right side of the fuselage to the left side, across the top plane of that “bay”.\u00a0 When these aircraft were “retired” from military service and were sold to the public as military surplus at the end of WW II, many were converted from their original two-cockpit configuration into a single-seat configuration in order to be used as crop dusters and sprayers.\u00a0 That single diagonal tube was cut out\u00a0without replacement<\/u>,\u00a0and\u00a0the dual controls of the front cockpit were removed in order to mount a tank or hopper into the space that was the front cockpit.\u00a0 This alternation of the fuselage was made to many Model 75 Stearman aircraft.\u00a0 In fact, it is commonly accepted that their conversion and use as dusters and sprayers is one reason why so many Model 75 aircraft survive to this day.<\/p>\n

In restoring a Model 75 Stearman to its original two-cockpit “military” configuration, a new diagonal tube was commonly welded into place to replace the cut-out diagonal tube, and the front cockpit controls re-installed.<\/p>\n\n\n

<\/p>\n\n\n\n

In the case of N49680, that single diagonal tube was not replaced to restore the original fuselage configuration, but rather, a V-shaped\u00a0two-tube replacement\u00a0was bolted into place.\u00a0 Instead of a fuselage tube running in a single diagonal direction from one side of the fuselage to the other,\u00a0two\u00a0tubes were put into place. one running diagonally in one direction (for example, from\u00a0center\u00a0to right), and a second tube running in the opposite direction (from\u00a0center\u00a0to left).\u00a0 That is, the diagonal bracing in the top plane of the forward-most bay of the front cockpit is\u00a0double\u00a0that of the original configuration, resulting in bracing of the fuselage not merely in one direction, but two opposing directions simultaneously. <\/p>\n\n\n\n

This non-standard bolted-in two-tube configuration was inspected during the restoration, and has been inspected during every annual inspection since, and found to be acceptable. <\/p>\n\n\n\n

Nevertheless, this bolted-in two-tube replacement could easily be removed, and a new single diagonal fuselage tube welded into place\u00a0to return the fuselage to its original “factory” configuration, as has been done with many “restored” Model 75 Stearman aircraft. <\/p>\n\n\n\n

Those who are “very knowledgeable” about the Model 75 Stearman aircraft, their design, configuration,\u00a0and<\/em>\u00a0history, including their extensive use as dusters and sprayers after the war, should be very familiar with this fuselage modification and its restoration.\u00a0 Indeed, it is widely known among Stearman restorers, experienced owners, and enthusiasts that a Model 75 fuselage that has\u00a0not\u00a0been cut is a true rarity. <\/p>\n\n\n\n

To substantiate my statement that this Model 75 aircraft was originally designed and built with a two-cockpit configuration, we have copies of Boeing engineering drawings, numerous published reference documents, and the military history for this serial numbered aircraft, prepared by Ken Wilson, Stearman Restorers Association Historian.\u00a0\u00a0Boeing Model A75N1 PT-17\u00a0serial numbered\u00a075-2242\u00a0was assigned to and served training military pilots at the Contract Pilot School, Bennettsville, South Carolina, after its delivery from the Boeing Wichita factory on 01 October, 1941.\u00a0 All Model 75 aircraft were originally built with a two-cockpit configuration. <\/p>\n\n\n\n

\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

There is indeed a bolted-in section of tubing in the upper (top) plane of the forward-most fuselage “bay”, located immediately between the firewall and the opening of the front cockpit – the area immediately above the front rudder pedals. This bolted-in section is V-shaped, with a single bolted fitting forward, at the center of the […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[1],"tags":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p95FsX-18Q","jetpack-related-posts":[{"id":2895,"url":"https:\/\/flymall.org\/blog\/2019\/01\/flymall-wheels-wings-january-2019-newsletter\/","url_meta":{"origin":4392,"position":0},"title":"Flymall Wheels & Wings January 2019 Newsletter","date":"January 24, 2019","format":false,"excerpt":"Welcome to the Kraemer Aviation \/ Flymall Wheels & Wings January 2019 Newsletter.\u00a0 Lots of exciting items this month.\u00a0 Click here for past newsletters.\u00a0 Click here for our January 2019 newsletter. Looking for something we covered in the past?\u00a0 Our newsletter section is searchable.\u00a0 Just use the search box (in\u2026","rel":"","context":"In "Newsletters"","img":{"alt_text":"","src":"https:\/\/i1.wp.com\/flymall.org\/blog\/wp-content\/uploads\/2019\/01\/1-300x224.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":8951,"url":"https:\/\/flymall.org\/blog\/2025\/01\/flymall-january-2025-wheels-wings-newsletter\/","url_meta":{"origin":4392,"position":1},"title":"Flymall January 2025 Wheels & Wings Newsletter","date":"January 28, 2025","format":false,"excerpt":"Welcome to the Kraemer Aviation\/Flymall.org Wheels & Wings Newsletter. Kraemer Aviation hosted their annual Christmas party on Christmas day last month. We had pilots, car collectors, bicycles collectors, plus a few international flight students. Click here for more pictures. You can view past newsletters here.\ufeff Interested in living at an\u2026","rel":"","context":"In "Newsletters"","img":{"alt_text":"","src":"https:\/\/i2.wp.com\/flymall.org\/blog\/wp-content\/uploads\/2024\/12\/54228288078_d972fed00e_c.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":47,"url":"https:\/\/flymall.org\/blog\/2010\/02\/fly-the-airplane\/","url_meta":{"origin":4392,"position":2},"title":"Fly the airplane!","date":"February 6, 2010","format":false,"excerpt":"Will \u201cFly the aircraft\u201d become a lost skill?\u00a0 With more and more technology being crammed into general aviation aircraft and pilots are taught to push a button for this or that, what is going to happen to our basic stick and rudder skills?\u00a0 I remember my first lesson, my instructor\u2026","rel":"","context":"In "Newsletters"","img":{"alt_text":"","src":"https:\/\/i0.wp.com\/flymall.org\/blog\/wp-content\/uploads\/2010\/02\/DSC_27351-300x200.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":9963,"url":"https:\/\/flymall.org\/blog\/2026\/01\/flymall-january-2026-wheels-wings-newsletter\/","url_meta":{"origin":4392,"position":3},"title":"Flymall January 2026 Wheels & Wings Newsletter","date":"January 28, 2026","format":false,"excerpt":"Welcome to the Kraemer Aviation\/Flymall.org Wheels & Wings Newsletter You can view past newsletters here. Interested in living at an airport?\u00a0\u00a0Visit our Aviation Real Estate page here. You can view price data for airport property in our Market Watch section of the Flymall.\u00a0Here is the data for all airport property.\u2026","rel":"","context":"In "Newsletters"","img":{"alt_text":"","src":"https:\/\/i0.wp.com\/flymall.org\/blog\/wp-content\/uploads\/2026\/01\/jett-2016.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":328,"url":"https:\/\/flymall.org\/blog\/2016\/01\/fly-fast-2\/","url_meta":{"origin":4392,"position":4},"title":"Fly Fast","date":"January 27, 2016","format":false,"excerpt":"Here are some simple tips to help get more speed out of your aircraft.\u00a0 Number one is to relearn what the rudder pedals are for.\u00a0 Hint, they are not foot rest.\u00a0 Anytime you are at the controls of the aircraft your feet should be on the rudder pedals, I often\u2026","rel":"","context":"In "Newsletters"","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":329,"url":"https:\/\/flymall.org\/blog\/2011\/04\/fly-fast\/","url_meta":{"origin":4392,"position":5},"title":"Fly Fast","date":"April 2, 2011","format":false,"excerpt":"Here are some simple tips to help get more speed out of your aircraft.\u00a0 Number one is to relearn what the rudder pedals are for.\u00a0 Hint, they are not foot rest.\u00a0 Anytime you are at the controls of the aircraft your feet should be on the rudder pedals, I often\u2026","rel":"","context":"In "Newsletters"","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/posts\/4392"}],"collection":[{"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/comments?post=4392"}],"version-history":[{"count":2,"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/posts\/4392\/revisions"}],"predecessor-version":[{"id":4398,"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/posts\/4392\/revisions\/4398"}],"wp:attachment":[{"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/media?parent=4392"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/categories?post=4392"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/flymall.org\/blog\/wp-json\/wp\/v2\/tags?post=4392"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}