The Double-Delta Revolution: Inside the Secret Underground Birth of the Saab 35 Draken

In late 1947, news of the world’s first supersonic flight reached a small team of engineers in Linköping, Sweden, setting in motion one of the most ambitious fighter programs of the Cold War: the Saab J 35 Draken. Haunted by the lessons of April 1940—when Nazi forces seized Oslo Airport and the United States halted warplane deliveries to Stockholm the very next day—the Royal Swedish Air Force (Flygvapnet) vowed never again to rely on foreign powers for its national survival. Following the twin-boom J 21, the swept-wing J 29 Tunnan, and the two-seat A 32 Lansen, project manager Lars Brising and 33-year-old chief designer Erik Bratt launched Project 1250 in 1949. Tasked with intercepting high-altitude transonic bombers while operating from 42-foot-wide rural highways and relying on conscript mechanics wearing heavy winter gloves, Bratt’s team pioneered the radical double-delta wing. After testing circular control-line models and flying the scaled-down Saab 210 Lilldraken in 1952, Saab began building the J 35 Draken 100 feet underground. Powered by a license-built Rolls-Royce Avon RM6 turbojet, the Draken broke Mach 1 without afterburner in 1956, integrated into the jam-resistant STRIL 60 data-link network, and gave birth to the Kort Parad—the world’s first Cobra maneuver—to counter high-alpha super stalls. Through rare archival flight-test footage, we step inside the Flygvapnet Test Center to witness high-altitude pressure suit trials, radar interception tests aboard modified Lansen aircraft, and live rocket runs climbing toward the stratosphere. The documentary then examines the Saab 37 Viggen, featuring integrated-circuit computers, encrypted fighter-to-fighter data links, and the ability to achieve radar lock on the Lockheed SR-71 Blackbird over the Baltic Sea. Finally, we trace the full history of Swedish aviation from 1914 through World War II—covering the Seversky P-35 embargo, the wooden-skinned FFVS J 22, the dive-bombing Saab B 17, the twin-engine B 18’s perilous V-1 missile tests, the J 29 Tunnan’s UN combat campaign in the Belgian Congo, and the tri-role JAS 39 Gripen operating from Base 90 highway strips. To support our work and channel, join @ https://www.youtube.com/channel/UCTTqBgYdkmFogITlPDM0M4A/join Thank you! 🙏🎖️ ➤ More aircraft and history videos: https://www.youtube.com/@Dronescapes ➤ Join the channel: https://www.youtube.com/@Dronescapes/join ➤ THREADS: https://www.threads.net/@dronescapesvideos ➤ FB: https://www.facebook.com/Dronescapesvideos ➤ Reddit: https://www.reddit.com/user/Atellani/ ➤ IG: https://www.instagram.com/dronescapesvideos ➤ BlueSky: https://bsky.app/profile/dronescapes.bsky.social ➤ Tumblr: https://www.tumblr.com/blog/dronescapesvideos ➤ X/Twitter: https://dronescapes.video/2p89vedj VIDEO SERIES: 🎥U.S. AIRCRAFT VIDEOS: https://dronescapes.video/US 🎥AVIATION VIDEOS: https://dronescapes.video/aviation 🎥GERMAN AIRCRAFT VIDEOS: https://dronescapes.video/WWIIGermany 🎥BRITISH AIRCRAFT VIDEOS: https://dronescapes.video/British 🎥ERIC BROWN VIDEOS: https://dronescapes.video/EricBrown 🎥B-29 VIDEOS: https://dronescapes.video/B29 🎥VIETNAM AND KOREA: https://dronescapes.video/Vietnam 🎥TURBOJET VIDEOS: https://dronescapes.video/Turbojet 🎥SUPERSONIC VIDEOS: https://dronescapes.video/fastest 🎥EXTREME AIRCRAFT VIDEOS: https://dronescapes.video/Extreme 🎥STRANGE PLANES VIDEOS: https://dronescapes.video/Extreme 🎥COLD WAR ERA VIDEOS: https://dronescapes.video/ColdWar 🎥 WW2 VIDEOS: https://dronescapes.video/WW2 00:00:00 The Saab 35 Draken and the 1940 Arms Embargo Lesson 00:03:20 Erik Bratt and the 1949 Project 1250 Interceptor Specification 00:07:50 Double-Delta Aerodynamics and the Saab 210 Lilldraken Testbed 00:11:45 Underground Production and First Supersonic Prototype Flights 00:15:55 J 35A Flight Characteristics, STRIL 60 Data Link, and Kort Parad 00:20:50 Draken Operational Service, Export Variants, and 45-Year Career 00:24:24 Archival Film: Flygvapnet All-Weather Tactical Flight Testing 00:27:27 Avionics Trials in the Lansen and High-Altitude Rocket Intercepts 00:33:17 The Saab 37 Viggen: Encrypted Data Links and SR-71 Radar Locks 00:38:37 Origins of Swedish Military Aviation and the Founding of Saab 00:45:10 Wartime Embargoes and the Subcontracted FFVS J 22 Fighter 00:49:18 The Saab B 17 Dive Bomber, Forest Bases, and Toss-Bombing Sight 00:55:36 The Twin-Engine Saab B 18 and Reverse-Engineered V-1 Missile Tests 01:02:31 Entering the Jet Age: The Swept-Wing Saab J 29 Tunnan 01:05:34 Swedish Air Force J 29 Tunnan Combat Operations in the Congo 01:07:32 The Saab 32 Lansen All-Weather Attack Aircraft 01:09:27 Deep Dive into the J 35 Draken, S 35E Recon, and Mountain Hangars 01:15:28 Canard Aerodynamics: Engineering the Saab 37 Viggen 01:19:55 The Tri-Role Saab JAS 39 Gripen and Base 90 Highway Strips #SaabDraken #SwedishAirForce #ColdWarAviation