Masks, Smoke, and Mirrors: The story of EgyptAir flight 804
An in-depth reconstruction of EgyptAir Flight 804’s 2016 crash prompts debate over cockpit oxygen system design, fire suppression technologies like halon, and how “Swiss cheese” layers of small failures can align into catastrophe. Commenters contrast the French BEA’s evidence-driven investigation with Egypt’s politically constrained response, using it to highlight how authoritarian pressure, institutional face‑saving, and even ambiguous smoking rules in cockpits can undermine aviation safety. Broader points touch on the limits of current risk models, the slow transition away from halon, and why robust, independent accident investigation bodies matter.
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.