# Learjet 722 Bravo Delta Crash: Mach Tuck and Tail Failure Examined - Original post: https://www.twitter.com/i/status/2117998970840776796 - Source account: [@JG_CSTT](https://x.com/JG_CSTT) - Source language: English - Duration: 2:58 - Published: 2026-11-06 - Canonical URL: https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined ## Transcript [0:00](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined) Declare emergency, 722 Bravo Delta. We are in an overspeed condition, descending 20,000 feet per minute. [0:07](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=7) Overspeed. That's what the crew of Learjet 722 Bravo Delta radioed as they fell from 35,000 feet. [0:15](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=15) 75 seconds later, it crashed, killing all nine people on board. [0:20](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=20) Did a Mach tuck bring it down? Mach is speed compared to the speed of sound. [0:26](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=26) Air flowing over the top of a wing moves faster than the air underneath. [0:31](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=31) Faster air has lower pressure, so the higher pressure below pushes the wing up. [0:37](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=37) That's lift. But go fast enough and the air on top goes supersonic and a shock wave forms. [0:43](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=43) As speed builds, the shock slides back and the lift slides back with it behind the center of gravity. [0:50](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=50) The nose drops, the jet speeds up, and the nose drops more. [0:54](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=54) That's a Mach tuck. The Learjet 60 cruises close to that edge. [1:00](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=60) Its limit is Mach .81, and before the upset, this jet was at about .75. [1:06](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=66) Learjets carry a Mach trim system that raises the nose automatically as speed builds. [1:12](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=72) Hand flying without it, the 60's limit drops to .77. [1:16](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=76) And in 1980, the NTSB warned that once earlier Learjets got into a fast, steep dive, recovery may be impossible. [1:25](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=85) The crew reported ice and turbulence and asked to climb. [1:28](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=88) Then the nose went down, wings level. In 13 seconds, the jet blew through its Mach limit and kept going past Mach .9. [1:38](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=98) Then it rolled into a steep right spiral where pulling back only tightens the turn. [1:43](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=103) We are descending 22,000 feet and we are banking 60 degrees. [1:50](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=110) Could that tear off the tail? By 9,000 feet, it was doing almost 500 knots against a limit of 340. [1:58](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=118) That's twice the air pressure on every surface. [2:01](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=121) Pushed that far, a tail can flutter and shake itself apart, or the pull to recover can snap it. [2:08](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=128) In 1985, a China Airlines 747 dove 30,000 feet and the pullout tore away pieces of its tail. [2:16](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=136) Now the NTSB has recovered the left elevator, the hinged surface on the tail that controls pitch, in three pieces, 1.3 to 3.8 miles from the crash site. [2:28](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=148) The dive began seven miles away. Those distances match the middle of the dive, between about 27,000 and 14,000 feet, when the jet was far past its limits. [2:40](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=160) So the elevator most likely came apart during the dive. [2:44](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=164) Whether that helped cause the crash or the dive tore it off, the NTSB says it doesn't know yet. [2:50](https://www.translate.mom/transcript/OI6gGl7mQ5hp/en/learjet-722-bravo-delta-crash-mach-tuck-and-tail-failure-examined?t=170) The NTSB's final report should tell us. Until then, the precise cause of the crash remains unknown.