Airbus SA: PITCH, PITCH synthetic audio

[FlightDetent]

Hello, I tried recently to look deeper into the logic behind the warning auto-call during landing. But came to almost nothing, apart from:

FCOM DSC-31-10 ECAM DESCRIPTION - AUDIO INDICATORS
PITCH, PITCH" (synthetic voice): The aircraft pitch attitude is becoming excessive during flare and landing.

and

FCOM PRO-NOR-SOP-19 LANDING - FLARE
FLARE........................................... PERFORM
ATTITUDE...................................... MONITOR
"PITCH, PITCH" auto-callout is available.

Is there any more detail available from the manufacturer on this? I assume when the feature had been introduced Airbus produced a slide presentation at least. Maybe hidden on some of the FS Conference CD's somewhere? I would be very happy if the joined wisdom of PPRuNe could help me on this one...

[Amadis of Gaul]

I don't know about a reference, but I CAN tell you that the two times this thing has activated on me so far it was completely false. There was nothing wrong neither with the pitch angle not rate of change thereof.

[G0ULI]

Just a guess but I assume this is triggered if the attitude of the aircraft presents a risk of tail strike during landing. Low altitude, high pitch reading, wheels down, etc.

[FlightDetent]

Certainly so, but what is it? There are also prescribed PM callouts for pitch, set approximately 2,8 degress below the tailstrike pitch angle for the different members of the family. For example at 7 degrees NU for A321, the human should shout out loud.

The synthetic voice is available only on the not so old models.

[G0ULI]

The ukfsc.co.uk site has information in the July 2008 copy of the Airbus Safety Magazine regarding limits and conditions for activation. There should be enough information there to answer your query. The file is in pdf format, so I can't just cut and paste the relevant section(s).

[Capt Scribble]

The synthetic pitch callout is triggered by exceeding a pitch datum or exceeding a rate of pitch during the flare, on newer aircraft.

[Goldenrivett]

Hi FlightDetent,

Please see #2 http://pitch-auto-callout-320
"Predictive pitch (pitch value reaches one second later if last pitch rate is maintained = Pitch + Pitch rate) is below a Pitch threshold"

[Candaba catfish]

In the old Flight Crew Bulletins, it's stated that there are 2 triggers:

1. Passing 6.9deg pitch attitude, AND
2. A particular pitch RATE (which I've now forgotten) which would have you reach 9.5deg within a certain time period.

I know it's not that helpful; just hoping someone else would remember (and share) the other parameter.

[FlightDetent]

Much helpful. There are useful bits and pieces in the materials people suggested, I plan to compile it together and post back soon from now.

But your post actually summarizes all of it

[Bernoulli]

On the latest A321 jets in the TCX fleet: pitch rate (degrees per second) is constantly monitored and when predicted pitch (current pitch + predicted pitch in one second) exceeds 8.25° this triggers the synthetic "Pitch Pitch" call.

Thus you can sit steadily at 8°all day without a peep out of the thing (although your colleague may have something to say on the matter) and you can also never get past 4° but still trigger the call if you flare vigourously enough (I have on a couple of occasions).

[FlightDetent]

Where did you find that 8,25°, pretty please

[Bernoulli]

After it happened to me I began looking into it. DFDR revealed a rapid change in the wind at a very late stage in the landing which I countered with a very positive flare. The touchdown was firm (but not heavy) and the synthetic "Pitch Pitch" call was heard. I didn't think that I'd overdone it on the pitch and so I got in touch with one of our engineers who was kind enough to email me the documents for our new jets and that's where I got the figure from. Quite possible that the number is different for older jets and possible that it's programmeable too. I can try and get you the document reference if you want?

[Greek God]

Think the number on a 320 is 9.25
Ie actual pitch plus rate = >9.25 gives Pich Pitch

[Goldenrivett]

Hi FlightDetent,

Where did you find that 8,25°, pretty please

See my reply 14 Aug.

* 8.25° for A321,

* 9.25° for A320 if "Lift Improvement Package " (LIP) is not installed,

* 10° for A320 if "Lift Improvement Package " is installed.

[FlightDetent]

Thanks Bernoulli, the reference "in the engineers documents" is good enough for my purpouse at the moment.
GR: