Not a professional pilot (yet). Not an engineer either. A few thoughts straight from the armchair at the risk of being censored out of hand by the totalitarian 20,000-hour-on-type forum masters…
Given all previous facts, info & speculation, what would your recommendations be for systems and procedural improvement?
Here a few shots from the hip - some (or many?) of which were mentioned before:
A. Systems Design
1. Location of onboard bombs: Can anyone clarify why pressurised bottles (apart from fire extinguishers & mobile O2 for crew) would knowingly/willingly be kept in the pressure vessel? Is it feasible to carry them on the a/c outside the pressure compartment such that depressurisation or structural damage are unlikely if they fail?
2. O2 for crew:
- There should be 2 indicators for each pilot: one indicating flow (and pressure) and the other indicating content (O2 vs. nitrogen for Qantas I guess, but you could have other contaminants as we know from scuba/technical diving).
- There should be at least one independent back-up: mobile O2 bottle for each pilot within reach of their seats if everything else fails. Again, look at scuba divers. They actually have several back-ups (Main bottle(s): regulator 1, regulator 2, some 3rd regulator; buddy: 1 or 2 spares plus buddy’s main to share; separate independent bottle as last resort giving a few minutes or if buddy is MIA. Yes they take compressed air or nitrox instead of O2 but principle is the same.)
- O2 for crew seems to have failed in previous emergencies. (1st officer on BA w/ 4 engines out due to volcanic ash – any others from the old folks?)
3. O2 for pax:
- Systems need to be designed such that pax need to do nothing apart from putting masks on. If they need to pull to trigger generator, 95% will not know or have forgotten and 5% will pull so hard that the hose separates from the system.
B. Procedures Design
1. Depressurisation crew: Great potential for refinement I think. IMHO the item ‘Establish communication’ is grand BS and wastes precious time. What if PF does not get mask working or O2 flowing? What if both pilots don’t? Their best course of action would still be to initiate immediate descent (possibly at a speed assuming structural failure) – with or without communication. Unless they have an O2 back-up in reach. But maybe not even in that case. Procedures should generally assume that 1st O2 supply does not work and comms cannot be established. How about using hand signs? What about an emergency descent button on the flight control deck that will do exactly that (taking into account GPWS and TCAS)?
2. Ground checks: Good scuba divers check their regulators/air flow/bottle pressure&contents 3 times: once when setting up their systems, once when putting them on, once when doing buddy checks. How come airline crew forget or only do it once?
3. Pax briefing: If strap has to be pulled on rubber jungle than it must be emphasised. (“Pull on strap until you feel flow or you will die.”) Also it has to be shown how hard to pull. Better to eliminate that necessity altogether as above. As mentioned by others before, the rapid descent should be described as standard emergency procedure in briefing.
Corrections & your own additions appreciated! We can then compare the pprune wish list with what the ATSB come up…
Happy landings!