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Last night I watched something I recorded from the weekend, a documentary about the Air France A330 crash enroute from Brazil to France. Pretty tense viewing, and God how I hate planes.
The cause of the crash was put down to bad weather, instrumentation failure and pilot(s) error. The pitot tubes (the right-angled things which tell you airspeed from pressure) had frozen up and were giving crazy readings for airspeed and descent speed, so the autopilot gave up and handed control back to a pilot who it turned out was too inexperienced to handle the situation. He pulled back, and kept pulled back such that the aircraft lost speed, stalled and plummeted into the sea.
I've heard of a number of cases of pitot tubes freezing up, and even one where a wasps nest in one caused some sort of problem, but I can't remember the details.
You lot look like a bright bunch, so my question is this: Why not use GPS as an extra means of determining speed? I think the argument goes that would read groundspeed, not airspeed but surely that's preferable to no valid speed at all? Had they had my SatNav on the windscreen and a second reference speed perhaps they'd have been able to make sense of the situation.
Regards,
Rob Philpott.
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I think you've answered it yourself. Aircraft have gps of course. The groundspeed could look fine but the actual airspeed could be near stall. Not good. How would you correct for that? Maybe a pitot tube. So the gps adds nothing but erroneous information.
http://www.quora.com/Do-airplanes-also-use-GPS-to-calculate-airspeed[^]
Peter Wasser
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell
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Most airliners have at least four pitot tubes, all with internal heating elements to prevent them freezing up. The biggest issue with them is usually insects making a home in them while the planes on the ground (but that's why you normally take a look down them during the pre-flight check).
To add to this, they'd also have an AOA (angle of attack) indicator which should have been sounding off alarms in the cockpit about the aircraft being too nose-up.
The biggest problem I've seen over the years is the reduction in the level of pilot training. When I learnt, we did stalls and spins and we have engines where we needed to regulate fuel/air mixture manually, constantly be aware of magneto failure and carburetor icing and practice flying with no navigation instruments except for a map, a magnetic compass and the window to simulate total instrument failure 
Modern training aircraft have GPS, glass cockpits, computer controlled fuel-injected engines, lumbar supporting seats and variable sized coffee cup holders  Most of them aren't even capable of spins (or even severe movements) and even a minor stall scares trainees out of their skins (I took a Diamond aircraft out for a flight a few years ago and the young pilot on board started panicking when I banked it past 60 degrees!).
Chances are, the co-pilot on your next flight hasn't been out of those planes long. Within a few years, they'll be the captain. Scary.
How do you know so much about swallows? Well, you have to know these things when you're a king, you know.
modified 31-Aug-21 21:01pm.
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Brent Jenkins wrote: carburetor icing
Grief! That's a phrase I haven't even thought of in fifteen years! I used to have a motorcycle which was prone to it on one cylinder out of two, and it was a PITA (until I was introduced to an additive which cured it). On an aircraft? Not good news, not at all...
Thank goodness for fuel injection, that's what I say!
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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It keeps you alert in a plane - in my time, most forced landings were down to carb icing (i.e. pilots daydreaming)
In light aircraft you had a small "carb heat" lever which you religiously moved over on a regular basis to redirect warm air taken from around the exhaust back into the carb. You'd notice around 100 rpm drop off the engine speed while it was activated.
It was a pain - and a risk - but it kept you in touch with what you were flying. I think a lot of that has been lost these days
If you make everything appear ultra-easy and ultra-reliable, then you introduce complacency.
How do you know so much about swallows? Well, you have to know these things when you're a king, you know.
modified 31-Aug-21 21:01pm.
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On that matter of self-propelling two wheel vehicles, now that hayfever season is underway, what is the correct way of dealing with sneezing whilst wearing a motorcycle helmet?
This is a genuine question. It's only a matter of time now...
Regards,
Rob Philpott.
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By preference, don't.
I wear a Shoei helmet where the chin piece "flips up" out of the way ("Multitec", I think - not certain) so it's less of a problem - I sneeze in bright light rather than as a result of hay fever, so it's a year round problem for me.
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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OriginalGriff wrote: I sneeze in bright light rather than ...
That is apparently an inherited thing. Bad news, I think we are related. [not sure who has the bad news though.]
I'm retired. There's a nap for that...
- Harvey
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It's scary enough getting into a pressurized lump of metal as it is! But I suspect you are right. As they said in the documentary last night, the pilots would normally only be flying the plane for 4 minutes of the 8 hour journey.
So, really they are there for when things go wrong, and it didn't end well in this case.
I think they said the 'pull up' alarm sounded 70 times before switching itself off, but ironically that's what they were doing which was causing the stall.
Regards,
Rob Philpott.
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I grew up about a mile from the factory where they make all the wings fitted to Airbus aircraft. Most of the guys there were the ones too thick to get a job anywhere else.
One of the team leaders there was an ex-navi who'd spent a large portion of his working life tarmacking roads around the area. I always think about them when I'm sitting on an Airbus waiting for the pilot to taxi out, looking out at the wings
Luckily I can reassure myself with the fact that most aircraft accidents are down to pilot error, so I don't need to worry too much about the wings
How do you know so much about swallows? Well, you have to know these things when you're a king, you know.
modified 31-Aug-21 21:01pm.
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Filton? If so, then I know what you mean, I've worked on that site. My experience was limited to distant assessment of the people standing outside a hanger having a fag. "yeah, they're the ones who bolt the wings on".
Regards,
Rob Philpott.
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Nah, Airbus up at Broughton just outside Chester.. I was just over the Welsh border from them
It used to be solely BAe, but then they sold off the 125 to Ratheon. They used to have a nice Mosquito there too (used to fly over our house most Saturdays during summer) but it got wrecked in a crash some years back.
https://en.wikipedia.org/wiki/Hawarden_Airport[^]
How do you know so much about swallows? Well, you have to know these things when you're a king, you know.
modified 31-Aug-21 21:01pm.
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Brent Jenkins wrote: he biggest problem I've seen over the years is the reduction in the level of pilot training. When I learnt, we did stalls and spins and we have engines where we needed to regulate fuel/air mixture manually, constantly be aware of magneto failure and carburetor icing and practice flying with no navigation instruments except for a map, a magnetic compass and the window to simulate total instrument failure
I have done a small amount of pilot training and when I insisted on not having a glass cockpit to train in, my instructor was surprised and pleased, as even pilots seem to have entered the iWhatever(Apple) generation.
Bring back the days of the flight engineer when aircraft were not computerised and as boring to fly as they can be nowadays.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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There was a good thread on here a couple of years back about this - but my search can't find it.
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And the reason[^] I thought it was a good thread is because I started it! Check the link to the full trsanscripts -it's very interesting and scary - if that's the right word?
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It is scary, very scary. It made for tense viewing, and regardless of human error when you're trying to fly a plane which is plummeting and you don't know why, well it doesn't get much worse than that.
Regards,
Rob Philpott.
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Unfortunately although the pitot tubes started the cascade of events, it was the pilot who caused the crash. The captain was not aware that the first officer was pulling back on the yoke until the last few seconds(I believe in the recordings the pilot is heard to shout something like "stop pulling back" just before impact).
Following on from the tragedy there were many changes to both aircraft and pilot communication and decision making.
It's so horrible that all those people died in what was a human error of judgement![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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Private room for rent, I am in (6)
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SUBLET ?
cheers,
Super
------------------------------------------
Too much of good is bad,mix some evil in it
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TOILET?
TO LET with I in?
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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Yep! Been busy, and only had a few moments to think of a clue....
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I thought it was a good one. Really liked it 
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Movie Quote Of The Day
When Gabriel blows his horn, I shall be playing the tuba.
Which movie?
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One Night in Paris
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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