Masks, Smoke, and Mirrors: The story of EgyptAir flight 804

Comparisons to Other Air Disasters

• Multiple commenters compare the EgyptAir 804 fire scenario to UPS Flight 6: oxygen-fed cockpit fire, loss of visibility, and consequent loss of control.
• The 804 story is also linked conceptually to earlier EgyptAir and other crashes where investigations or conclusions were politically sensitive.

Fire Suppression: Halon, CO₂, and Replacements

• Long subthread on halon: extremely effective at interrupting combustion chemistry at low concentrations; generally safe to breathe at those levels.
• Misconception correction: halon doesn’t “remove oxygen” but terminates radical chain reactions; its boiling also provides some cooling.
• Problem: if fuel remains hot, reintroduction of oxygen can cause re-ignition, and halon pyrolysis products are toxic—but several argue that if this is a concern, the situation is already near-fatal anyway.
• Phase-out drivers are environmental (ozone depletion), not safety. Permanently installed halon systems on commercial aircraft are expected to persist for decades; portable replacements are expensive and can exhibit “subinerting” (feeding a fire).
• CO₂ systems can be lethal in confined spaces and are common in ship engine rooms; high‑pressure water mist is mentioned as a promising alternative.

Cockpit Oxygen System and Risk Analysis

• Discussion of why pure oxygen is used: necessary to maintain adequate oxygen partial pressure at altitude and minimizes tank size/weight.
• Commenters are surprised a catastrophic oxygen leak is still possible; others note its assessed probability was “extremely improbable,” but industry-wide exposure still yields occasional events.
• Debate on design trade-offs: keeping the valve always open vs risking non‑availability in emergencies.

Egyptian Investigation, Politics, and Safety Culture

• Many see the French investigators as methodical and technically rigorous and the Egyptian side as forcing a bomb narrative.
• Several argue this is less “incompetence” and more authoritarian political pressure: attributing the crash to terrorism avoids implicating state-owned airline maintenance and protects powerful interests.
• Broader reflections on low social trust, truth vs “saving face,” and the dangers of starting from a desired conclusion rather than evidence.

Author’s Background and Quality of Analysis

• Commenters describe the writer as long‑standing, meticulous, and generally accurate, with at least informal aviation experience.
• Some readers with technical backgrounds (e.g., materials/failure) report the explanations align well with their own expertise.

Smoking Policies in Cockpits

• Surprise that cockpit smoking is still at captain’s discretion in some regimes, despite cabin bans.
• Link made between onboard fires and any open flame near oxygen; others emphasize historical safety incidents tied to smoking.
• One dissenting voice calls anti‑smoking responses “hysteria,” but others counter that banning cockpit smoking is a straightforward risk reduction.

Trains, Terrorism, and Relative Risk

• Side discussion contrasts aircraft security with high‑speed trains.
• Points raised: trains are easier to stop and evacuate, less dense, more robust to small bombs, and pervasive airport‑style screening on local transit would be unworkable.
• Some note that cars or crowded venues are simpler terrorist targets than trains.