Report on Air France 447 crash deepens mystery

Re:Report on Air France 447 crash deepens mystery by borism on Saturday May 28, 2011 @12:45PM (#2594720)

BTW, I imagine a pitot tube placed on the body of the engine would not need extra heating and would be very unlikely to ice. You can even place it inside the exhaust and compensate the reading for engine flow.

There are such things in the engines! They're used to feed the data about engine performance to FADECs (http://en.wikipedia.org/wiki/FADEC) and the crew.

But they're totally useless for airspeed calculation! Bear in mind that air flowing trough and around the engine has totally different dynamics than the air passing around the rest of the airframe. Well, that's kind of the point of the engine - to create thrust, isn't it? That's why airspeed, altitude and AoA sensors actually have to be placed further away from the engines - so that they give as accurate picture as possible.

[ Parent | on HN ]

Re:Report on Air France 447 crash deepens mystery by rbanffy on Saturday May 28, 2011 @04:20PM (#2595135)

Can't you compensate for that? Most of the time planes fly normally - data could be gathered on how to relate the readings of engine management sensors to airspeed.

I don't mean using it as a primary source for airspeed data, but backups in case other sources show weird or no data. The data that comes from those sensors already enters the cockpit, so it would make sense to use it.

[ Parent | on HN ]

Re:Report on Air France 447 crash deepens mystery by borism on Saturday May 28, 2011 @05:17PM (#2595238)

You might be able to, but I imagine the calculations will be very complex and readings will be highly unreliable in anything but ideal conditions and constant speed level flight.

But yes, I think the conclusion after AF447 investigation is completed will be that some kind of back-up speed indicator is needed beyond pitot tubes.

[ Parent | on HN ]