Air France Crash - shocking

[TimberWolf]

Interesting table of travel safety statistics here.

What's your favourite death by travel measure: likelihood of death per trip, death per hour travelled or death per kilometre?

Basically motorbikes fare worse by a good margin in all measured categories, with other two wheeled or two legged forms of locomotion also being relatively deadly. Air travel scores relatively high on the deadly scale when measured in terms of death per passenger journey, but fares well by the other two measures.

[OwlHoot]

I found the series interesting not just because of the air safety aspect but interesting in how a critical situation can come about even with the most experienced pilots due to in-depth instincts taking president over logic or wrongly laid down procedures.

and not just instincts. With a major malfunction such as an engine dropping off the wing, the wiring can be so damaged that instruments start giving false readings!

You'd think they could design voltage levels or pulses etc such that severing any wire would automatically blank out the relevant instrumentation. Bad as that would look to the pilot, at least they'd know where they stood and could promptly switch to seat of the pants mode without the often fatally misguided "fighting the plane" struggle.

[SueEllen]

Interesting table of travel safety statistics here.

What's your favourite death by travel measure: likelihood of death per trip, death per hour travelled or death per kilometre?

Basically motorbikes fare worse by a good margin in all measured categories, with other two wheeled or two legged forms of locomotion also being relatively deadly. Air travel scores relatively high on the deadly scale when measured in terms of death per passenger journey, but fares well by the other two measures.

Time to travel everywhere by bus/coach. Though you are more likely to get killed on the way to and from the bus stop then on the bus journey. (I wonder if the fatalities including pedestrians run over by buses?)

[TimberWolf]

and not just instincts. With a major malfunction such as an engine dropping off the wing, the wiring can be so damaged that instruments start giving false readings!

You'd think they could design voltage levels or pulses etc such that severing any wire would automatically blank out the relevant instrumentation. Bad as that would look to the pilot, at least they'd know where they stood and could promptly switch to seat of the pants mode without the often fatally misguided "fighting the plane" struggle.

I was wondering whether switching to GPS stored in the pants mode for altitude, rate of climb, ground speed and direction information might have been a viable option if the plane lost all electrics. Seat of the pants alone might be tricky and unreliable in bad weather? But as far as engine speculation goes, I think the preliminary report indicated that they were responding to controls throughout, and that they were at take-off thrust, i.e. they were gunning the engines. Could be wrong about that though, I'm a bit unclear about the whole thing.

[doodab]

I was wondering whether switching to GPS stored in the pants mode for altitude, rate of climb, ground speed and direction information might have been a viable option if the plane lost all electrics. Seat of the pants alone might be tricky and unreliable in bad weather? But as far as engine speculation goes, I think the preliminary report indicated that they were responding to controls throughout, and that they were at take-off thrust, i.e. they were gunning the engines. Could be wrong about that though, I'm a bit unclear about the whole thing.

The lack of airspeed indication would still be a problem. That's more relevant than ground speed for actual flying I think.

[TimberWolf]

The lack of airspeed indication would still be a problem. That's more relevant than ground speed for actual flying I think.

True, and lack of airspeed information appears to be critical to the onset of the accident. But it's curious how the pilots reacted to the lack of airspeed data, unless, amongst other possibilities, other instruments were provided duff information compelling enough for them to raise the nose.

I'm a bit surprised, for example, that pressure altimeters are accurate enough in adverse conditions weather systems, but I haven't run any numbers, and given that most aircraft use them successfully I suppose they must be pretty good.


Altimeter - Wikipedia, the free encyclopedia

[Cliphead]

True, and lack of airspeed information appears to be critical to the onset of the accident. But it's curious how the pilots reacted to the lack of airspeed data, unless, amongst other possibilities, other instruments were provided duff information compelling enough for them to raise the nose.

I'm a bit surprised, for example, that pressure altimeters are accurate enough in adverse conditions weather systems, but I haven't run any numbers, and given that most aircraft use them successfully I suppose they must be pretty good.


Altimeter - Wikipedia, the free encyclopedia

Altimeter pressure setting is set to 29.92 above 18,000 ft where you're unlikely to fly into anything. If equipped with a radar altimeter it's normally used for accurate height measurement below 200 ft.

[scooterscot]

If a plane is stalled and in a nose high attitude it would be very difficult to restart the engines.

Hard to imagine an modern AC falling in the stall attitude from such a descent without the possibility of recovery. Even in the event of a single instrument failure redundant systems remain available to the DCU's with which airspeed could be measured.

[Cliphead]

Hard to imagine an modern AC falling in the stall attitude from such a descent without the possibility of recovery. Even in the event of a single instrument failure redundant systems remain available to the DCU's with which airspeed could be measured.

It can happen and seems it did. Jet wing design is not efficient at low speeds and if in storm clouds a plane could find itself descending rapidly even with full power applied if in windshear conditions with a vertical component.

[scooterscot]

It can happen and seems it did. Jet wing design is not efficient at low speeds and if in storm clouds a plane could find itself descending rapidly even with full power applied if in windshear conditions with a vertical component.

All the way from 38,000 ft? Terrifying.