Airbus re-entry
 

Hi,
Excuse my ignorance in what follows, I'm a mere air traffic controller with an interest in aircraft. Living next to a VOR as I do for inbound/outbounds to STN, I occasionally hear a noise that sounds, I should imagine, rather like the space shuttle on re-entry. It's a real Star Wars 'coming out of hyperspace' type of noise, lasts a few seconds and only happens perhaps for 1 in 10 of the aircraft that fly over. I always thought it was engine related but last time I was on a jump-seat in an A319 I heard a similar noise when the spoliers were deployed, although the pilots were at a loss to explain it. Anyone have any ideas?
Cheers.
AA

It is most probably the speed brake being extended or retracted. It makes an odd whistle noise especially noticeable on the ground.

I once lived directly under a nav aid used in a STAR into MEL where last minute track shortening would often occur. Often you could tell if an A320 was high when you could hear the odd high pitched noise without actually hearing the aircraft itself.

Recovery
 

I have been flying various Airbus Aircraft for almost 10 years. I can tell you - categorically - the noise that you describe is the result of Speed Brake activation and typically occurs when the speed is above 250 KIAS, regardless of Altitude. It usually doesn't make this sound at low speeds, but is affected to some degree by outside air temperature.

Not having flown any Airbus FBW types before, it scares me to think that someone would be taking his speedbrakes at such low altitude that it can be heard from the ground. Whatever this sound is, surely it is cant be audible from 2500' agl?

It is the Airbus speed brake and it can be heard from 8000ft. Very distinctive.

Admiral
Might you be hearing the dulcet tones of a BAE 146 or Avro RJ intially setting up for LCY? - I'm assuming that you live near LAM, so apologies if not the case.

There is an amazing noise during flap retraction/extension (another poster called it "fluting") and the nearest words I can find to describe it are a banshee on steroids :}

It is indeed during the extension of speedbrakes on the A320 and can be heard at ground level with the aircraft at 8000', maybe higher. The crossing height at my house was +8000'.

It was as regular as clockwork. At 2330 the A320 from PER would wake me up as it was cleared below 8000' with "expect track shortening" for runway 16 at MEL. I never heard the plane, just the weird whistle sound as the chicken stick was used to rectify the profile.

Thanks for the replies, this tallies with the EZY A319s passing overhead, I would guess between 8000-6000ft. Cheers.

The Speed brakes can be safely extended at pretty much any altitude. They are automatically inhibited when a specific flap setting is selected, but can - and often are - used down to altitudes of 2000 or 3000 feet. Also, they can be heard from as high as 12000 feet, possibly higher.

Remember the whine when you extended the flaps on a 1-11!! That'd wake the dead.