Are Passenger Jet Engines Hitting Their Technical Limits?
They were hitting their limits by the mid 70’s.<p>The mid 70’s was golden era of supersonic research. Supersonic engines are just regular jet engines with a Turbofan. Add in wings swept further back in a Delta pattern like the Concorde and you have...supersonic aircraft that comfortably can do Mach 1.5-Mach 2.0.<p>Today, I think there is just 1 functioning wind tunnel in the US that can do supersonic research, so sad. If you live in the Bay Area you pass it, just look at Moffet Field on your way north of San Jose.<p>The Japanese and Australians, due to their remote location in part, have done most of the significant research of any last few years.<p>Why did SuperSonics not go anywhere with essentially every major civilian project being mothballed?<p>1. Materials Science: we simply don’t have reliable data for how long XYZ Metal lasts at extreme temperatures of supersonic flight. If you read Michael Crichton’s Airframe from 1996 (great novel), they mention that aircraft are designed with a lifespan of a human. 80 years. It’s insane how long these things fly. The heat is so extreme, the Concorde would fully extend 1 foot (it was made in part of titanium) during flight. Many crashes have occurred, such as Alaska Airlines Flight 261 in 1999 from Mexico to California, because the maintenance time frames of these parts is still not fully understood. And that’s for subsonics!<p>2. Noise: No way around it. The decision to build aircraft close to cities was essentially finalized in preparation for World War II. You can dampen significantly, but it is painfully loud. Landing outside the city with fast train back is best solution.<p>3. Fuel costs and burn. Supersonic research got underway right as Earth Day started. Lots of supersonic tech relies on afterburners, terrible mileage. It was bad timing.<p>4. 2003 Concorde crash where a tire was hit on the runway, and the entire aircraft exploded. This should have not happened for a tire collision. SuperSonics are fragile because of all the design tradeoffs one has to make (currently).