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160knots
10th Dec 2016, 22:44
Hi Guys
Just another question on the 320.
If after the RAT was deployed and for some reason at very short finals and say speed was say 110kt and ATC required you to go around, could you un stall the RAT. I say un stall the RAT, because at that speed the RAT would have stalled.
1. Is there a procedure for doing so?
2. Is there a reference?
Would really appreciate some facts on this, not just opinions.

FlyingStone
10th Dec 2016, 23:36
1. Performance for ELEC EMER CONFIG is calculated with VREF+10 or 140 kts, whichever is higher, so your approach speed wouldn't be 110 kts. Even if you do go-around from touchdown, RAT only stalls at about 125 kts, so still some margin left.

2. Since in this case you will most likely declare emergency, ATC would normally avoid situations which could result in a go-around from low altitude.

3. I imagine a very high speed could unstall the RAT, but I believe all the Airbus procedures are in place to prevent you from stalling the RAT in-flight in the first place.

160knots
10th Dec 2016, 23:48
FyingStone
What you say is common sense and I appreciate your response.
However I specifically asked if there was a procedure and a reference.
Opinions fall short of the answer. There must be something in the Maintenance Manual. I would like to know for my own knowledge.

FlightDetent
11th Dec 2016, 00:47
No. No. You're welcome.

EcamSurprise
11th Dec 2016, 01:18
No. No. You're welcome.

My thoughts exactly.
When will they learn....

vilas
11th Dec 2016, 05:30
What is RAT stall? The RPM not sufficient to generate electric power. So when speed goes past 125/140 it will start functioning again. Why an elaborate procedure required?

Fursty Ferret
11th Dec 2016, 09:22
I imagine it stalls due to excessive loading at low speed. I can't see why it wouldn't unstall pretty promptly as speed increases, particularly as the electrical load would have shifted back to the batteries. Would the emergency generator couple to the network again automatically? Dunno. So you might end up having manually select it again as per ECAM.

A RAT stall in the go-around is perhaps not as unlikely as you'd think given the aircraft may be in direct law at the time of initiation and a massive overpitch and subsequent speed loss quite plausible. Moral of the story is to select the gear up first unless close to the ground.

FlightDetent
11th Dec 2016, 09:29
What about massive overpitch on take-off? The relation of ELEV to sidestick is direct too.

Lantirn
11th Dec 2016, 10:18
It's not the same as the pitch control passes to flight mode quickly in normal law after takeoff. There is a point. Go around in direct law especially with TOGA is very funny to see if the PF is unprepared!

FlightDetent
11th Dec 2016, 10:24
Ok, agreed on that one.

Now imagine G+Y loss, same question: How do you unstall RAT to commence a G/A from 110 kt, when the RAT is said to stall at 140. No opinions, just references to manufacturer's data.

Daft.

tom775257
11th Dec 2016, 10:24
Just speed up, it unstalls. If you have an old A320 it used to stall at gear down anyway and would unstall in the go around once gear up. If you are using elec power just press the emer elec power man on to reset the gen.

Lantirn
11th Dec 2016, 10:42
FD,

This question should be for triple hyd failure. For G+Y failure there is no need to extend the RAT because the blue elec pump is energized by elec pwr.

In this tripple case I assume you have practically crashed so you don't ever let the speed below 150!

FlightDetent
11th Dec 2016, 11:06
Lantirn: 2:0
(towel, glowes, hat, coat, sunday roast)

Amadis of Gaul
11th Dec 2016, 11:25
What is RAT stall? The RPM not sufficient to generate electric power. So when speed goes past 125/140 it will start functioning again. Why an elaborate procedure required?
Some people need an "elaborate procedure" to pour coffee, too. I don't know if that's a result of "integrated" training processes that teach (or at least imply) that the book will have an answer for everything or just a banal result of mass refusal to think for oneself. Both are pretty depressing, actually.

vilas
11th Dec 2016, 14:24
I imagine it stalls due to excessive loading at low speed. I can't see why it wouldn't unstall pretty promptly as speed increases, particularly as the electrical load would have shifted back to the batteries. Would the emergency generator couple to the network again automatically? Dunno. So you might end up having manually select it again as per ECAM.

A RAT stall in the go-around is perhaps not as unlikely as you'd think given the aircraft may be in direct law at the time of initiation and a massive overpitch and subsequent speed loss quite plausible. Moral of the story is to select the gear up first unless close to the ground.Minimum approach speed is 140k executing a GA notwithstanding direct law a loss of 15k speed is poor flying.You never retract gear first in hurry. Dubai 777 is a stark reminder. Switching back and forth between batteries and Rat is not one time option it will happen as and when situation warrants automatilly.

fruitloop
12th Dec 2016, 06:53
Just restrict turning to the Right....The "wash" from the nose gear can alter the stall speed..

Capt Fathom
12th Dec 2016, 11:01
People! You need to stop overthinking this stuff.

It is not that difficult!

The Banjo
12th Dec 2016, 20:33
What is RAT stall? The RPM not sufficient to generate electric power. So when speed goes past 125/140 it will start functioning again. Why an elaborate procedure required?

Why:confused:

Because it is French...