GE Aerospace Successfully Develops and Tests New Hypersonic Dual-Mode Ramjet

Civil aviation, fuel efficiency, and industrial base

• Several comments argue that fuel efficiency dominates commercial aviation decisions; inefficient jets are hard to sell given thin airline margins.
• Others counter that airframe makers don’t build engines and mostly depend on a tiny set of engine OEMs; competitiveness is constrained more by industrial scale, safety reputation, and integration than by fuel-burn know‑how alone.
• Discussion notes the difficulty new entrants face (Japan’s canceled Mitsubishi SpaceJet, Ukraine’s lost Antonov/Motor Sich capacity). Embraer is seen as technically capable but financially constrained, with Bombardier’s C‑Series saga cited as a warning.

Russia/China airliners and economies

• Russia’s SSJ‑100, MS‑21, Tu‑204/214 programs are described as reliant on Western parts, now being “russified” with older, less efficient domestic tech. Reliability and crash history of SSJ‑100 are criticized.
• China’s COMAC C919 is flying domestically and seeking EASA certification; engine technology is still catching up, with a domestic CJ‑1000A program mentioned.
• There is debate over Russia’s economic strength: PPP GDP and low debt vs heavy war spending, sanctions, inflation, and constrained borrowing. Several commenters argue current growth is war‑driven and not durable.

Supersonic vs hypersonic flight

• Supersonic civil flight is considered effectively dead due to sonic boom regulations, limited viable routes, and economics rather than pure technology. Concorde/Tu‑144 are used as historical examples.
• Hypersonic (≈Mach 5+) is differentiated from supersonic by extreme heating, different aerodynamics, and the need for specialized propulsion (ramjets/scramjets).

Hypersonic weapons and defenses

• One view: Russia is ahead with operational hypersonic missiles (e.g., Kinzhal); hypersonics are hard to intercept and enable maneuvering at very high speed.
• Counter‑view: many “hypersonic” systems are just fast ballistic or quasi‑ballistic missiles; speed alone isn’t new, maneuverability is limited by materials, and Ukraine has intercepted many with existing air defenses.
• Some assert the US has long-running hypersonic R&D and downplays its capabilities.

GE dual‑mode ramjet and rotating detonation

• The dual‑mode ramjet is seen as mainly relevant to missiles, drones, or a speculative SR‑72‑type platform; manned hypersonic aircraft are viewed as impractical.
• Commenters are impressed by the claimed 11‑month development but suspect it built on prior work at an acquired specialist firm and years of internal RDE research.
• Dual‑mode is explained as operating across supersonic and hypersonic regimes, though it still requires another system to accelerate to initial supersonic speed.