Wind on the PFD. How?

I actually didn’t want to make a topic because the forum is full of pilots, but after a intensive search on tje forum I couldn’t find one. So I apolsgize for making an annoying topic.

My question for the pilots or for people who also know: How is the wind (shown in the picture below marked in red) on the PFD measured. Is it taking from a radar on the ground or does the aircraft have an equipment that can measure the wind outside? If it is the second one do you also know the name of the equipment? image

A pitot-static system is a system of pressure-sensitive instruments that is most often used in aviation to determine an aircraft’s airspeed, Mach number, altitude, and altitude trend. A pitot-static system generally consists of a pitot tube, a static port, and the pitot-static instruments. Other instruments that might be connected are air data computers, flight data recorders, altitude encoders, cabin pressurization controllers, and various airspeed switches. Errors in pitot-static system readings can be extremely dangerous as the information obtained from the pitot static system, such as altitude, is potentially safety-critical. Several commercial airline disasters have been traced to a failure of the pitot-static system.

Faa_pitot_static_system

270px-StaticPort
(That’s on Airbus A330)

20080402-124833-Pitot-Static-Hand-RT-4PUB

However, I am not a pilot and may be wrong!

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That feed for the ND comes from the inertial navigation system and the GPS. It will calculate your airspeed and heading using the ADIRU and then uses your actual ground speed and track to calculate the spot wind.

The pitot static system cannot determine the spot wind without the ground speed and track input I’m afraid.

HTH

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You are wrong for this particular function. @Yuan_Tugo is correct as always.

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Fair enough, just heard about it somewhere and couldn’t remember the exact thing

No need to withdraw your post, it was a perfectly valid assumption. :)

To calculate the spot wind the aircraft systems need to be able to ascertain the difference of where the aircraft ‘is’ from where the aircraft ‘should be’. The Air Data system gives the where ‘is’ (drift and head/tail wind) and the GPS/INS gives the ‘should be’ (perfect still air conditions) the combination tells the computer what external effects have applied and therefore the spot wind.

‘Back in the day’ we used a tri-beam doppler array that was startlingly inaccurate! Especially over clouds (the beam would lock onto water droplets and give wild, false returns). Then came gyroscopic inertial nav systems (hence the lat and long co-ords on the gate number sign) which, whilst accurate, took an age to spin up and align and meant you could not move or even board the aircraft during the align procedure! Now we have ring laser gyro INS equipment which takes less than 10 minutes to align, automatically positions itself and allows small aircraft movements. How the job has changed!!!

:)

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