[Radio Wrangler]

A number of things have been learned from that and similar crashes. Pilots are taught to not be so reticent about declaring an emergency. Higher priority, more support to take workload off of them and more direct routing can increase the chances of a positive outcome. Being less driven to get to the planned destination can help... deciding to cut a flight short at an early sign of a problem. Getthereitis still kills people today, driving non-instrument pilots into instrument met conditions. It is reckoned that a non-imc pilot starts becoming disoriented after 30 seconds. Just look up 'VFR into IMC' and you'll see one of the biggest killers of people in light aircraft. Instrument pilots don't have it easy. On many planes the basic instrument gyros are spun by an air jet powered backwards by vacuum from an ancillary pump on an engine. These pumps wear out and fail. So pilots lose horizon and pitch indications on the very instruments designed to circumvent electrical failure. In cloud this can be disastrous.

Once an emergency is declared, pilots get priority on comms as well as on routing. Not all use the opportunity to talk the ground through what they are doing and why. Cockpit voice recorders aren't much use if everyone up front stays stumm.

Then we have the 737 MAX issue where automated systems are fitted to yank controls around in the pilot's hands for one issue, and to avoid different training from earlier versions of the plane, the crew aren't told of the new system, so they don't know it has a single point of failure and what to do if it misbehaves.

Getting an aviation product certified is a very large amount of work and cost. But it has to be borne in mind that the testing is not a 100% assurance that a passing product is perfect. It never can be. It is an assurance that an honest job has been done of testing but there are still possible vulnerabilities. What certification does is provide a limitation of liability. The documents include a statement that successful completion of their prescribed tests is sufficient proof of compliance with the requirements set out. This neatly transfers responsibility onto the shoulders of the certifying body, FAA in the US and EASA in Europe (and nobody nowadays in the UK).

One aeroplane without trim tabs was Concorde. They wouldn't have survived well at those airflows and wouldn't have worked well. Instead it was trimmed by moving fuel around between tanks to control the C of G. This meant it needed spare tank capacity at the start of a flight, and needed to have fuel left towards the end.. Both of which bit into the payload/range capability.

David