Hacker News Reader

Comment by RetroTechie | Hacker News Reader

The window didn't "fall off". In article's 1st paragraph:

"debris from a dramatic engine failure caused damage to the aircraft's window"

That's high-velocity pieces of metal. Hard to prevent that from shattering a window if engine housing didn't catch it.

How much stronger, thicker & heavier you want to make those windows? Costing how much more fuel? To save how many lives per year?

I'd think airplane builders (note: not airlines!) are more qualified to make that calculation than armchair safety 'experts'.

View on HN

Well there are a lot of these airplanes going around the world all the time, and very seldom does anything like this happen. I just don’t want people thinking that airplanes aren’t safe.

Fan and turbine failures are supposed to be contained by the engine casing - it's part of certification. But as we see here, uncontained failures do occur. In general "airplane builders" do the absolute minimum to meet certification so they're not going to add reinforcement to protect against such an event until they're forced Into doing so by the authorities.

Turboprops can't, of course, contain a propellor failure which is why they have a big slab of armour in line with the prop disk. So in that case, yes, safety wins over cost and weight.

In the case of the Quantas A380 departing from Changi some shrapnel from the engine explosion did go through the aircraft's body, cutting cables, making a mess of the control-command systems. I don't know how one could contain the kind of energy imparted to these metal bits, especially on engines with so much power...

Fan blade failures are supposed to be contained. Turbine disk failures are not. This leads to several characteristics: disks are life-limited parts where they must be removed after so many cycles, no fuel tanks are within the burst axis of disks, and the flight ceiling of airliners is dictated by the fact that you can get holes and the cabin can (at >1e-9/flight hour) rapidly depressurize.

The comment you are replying to is a reference to a famous comedy skit (about the whole front of an oceanliner falling off, and the official company response).

whoosh..

Reply on news.ycombinator.com