climb requirements are pretty simple.
14 cfr part 25.121(d) requires the plane to be able to achieve 2.1% gradient in the conditions, with a critical engine failed, with the gear retracted.
Part 25.119 covers landing climb, all engines operating. Gradient requirement of 3.2%. That is in landing config, e.g., f30, gear down. The sub para (a) is pertinent on some aircraft, (the pw4098 was one that could be a long time between wanting and getting, but well within the required periods).
The gradients for the aircraft cover therefore approach configuration engine out, and all engines in full landing configuration. That is rational and works well.
Any assumption that after some millions of hours of operating we suddenly get a plane that cannot achieve a gradient would have to assume some extenuating circumstance well outside of normal operations. High temps are an issue, the reported temp and local temp of an airmass that the aircraft passes by are different, but you will likely find that that is not a big issue in this case. Wind shear equates directly to a change in the cas as the energy state of the aircraft alters with a time domain delay due to inertia, either increasing it or reducing it depending on the sequence of encounter. In these conditions, again they would have to be rather severe to critically affect the energy state of the aircraft. Increasing tailwind, or reducing headwind result in loss of cas. Modest shear will alter the performance outcome from an expected outcome such as a pitch attitude that is selected, the flight path then is reduced where cas is lower than expected. That may seem pretty obvious, but when you rotate you are not necessarily looking at pertinent data, and routine standards evals show that the same is true for the pm case, what they are looking at during the change in flight path is not necessarily what you may expect. Bottom line, pitching up and assuming that the plane will achieve a certain performance is human nature, reinforced by the routine expectancy being matched by reinforcing outcomes, (we don't get surprises that often, fortunately).
On any day, proceduralizing of our processes in the cockpit act as much as a threat to the operation as an enhancement. How often is a checklist item answered without the actual condition being confirmed... "clear left/right!... Without anyone looking, standard callouts being made without the requisite action being taken that is supposed to be verified/reinforced by the callout. Sucks to be human, but then humans also can do things that computers cannot do, so it really sucks to be walk-on freight. You get what you pay for...
Emirates is a compliant airline; look at any iosa audit and you will find that in fact most are. (in fact, almost all are, and that should make one ponder for a moment, and then the moment will be lost in time). Emirates has a public image that is one of competence. Airlines are obliged to balance safety and economics, no matter what
pr may say, that is not just the air transport industry, that is every human endeavour, in fact every system in nature that has a choice of actions. We are likely to find not very much was out of the ordinary here; we tend to forget due to the amazing reliability of the global air transport system that very flight involves an extraordinary confluence of things going right, with great demands for perfection. A failure can occur when a number of conditions are just sufficiently outside of normal to act together in concert to result in an unanticipated outcome. Such a failure mode comes from the reality of complex systems having potential for resonance to occur, where stochastic system behaviour of various inputs results in something that is outside of the expected occurring. Such a failure doesn't need active failures, it can occur with a number of within limit conditions just ending up at the wrong place at the wrong time. Sometimes, it just sucks. If that sounds depressing to people that may gain succour from linear or quasi linear causation, it need not be. It indicates that the most important thing we can have in operations is situational awareness, and that means, knowing when it likely to be compromised hints at how to get serious about maintaining system integrity. But, it is much easier to shoot the messenger, that cures the problem immediately, and everyone is satisfied that both justice, and system safety has been satisfied. Unfortunately, the world is not linear, nor quasi linear, and so a similar event will not be avoided.
Wonder how the emirates management will respond, insight or pavlovian responses.
If resonance appears a strange concept, one should consider their daily experience, or read up on complex systems failures as ladkin or hollnagel consider. Aircraft losses are brutal, so is a nuclear power station loss, and similar critical coupled systems.
Flight crew are not served well by rigid sops that end up affecting sa. Losing sa is just being human, yet our systems tend to belt the stuffing out of our crews for merely being so.
Never dull