Rat On A320

[toby320]

HI, does somebody know why if you are on electric emergency configuration and during your final approach you need to make a go around on (on msn 1132) the procedure is to push the emerg generator man on and need to fly with 180 kts???? :rolleyes:

tks toby.

[beam app]

Did you read QRH 1.05 GA????

[rudderrudderrat]

Hi toby320,

An ancient scroll copy of FCOM says
"For GA -Proc refer to the ESS BUSES ON BAT procedure."

ELEC ESS BUSES ON BAT says:
If landing gear fails to retract during GA, when in Emergency Configuration, the emergency generator can be recovered as follows:

MIN RAT SPD = 180 kts
accelerate to 180 kts to recover RAT operation with the gear down.
LGCIU 1 CB (C09)... Pull
Pull LGCIU 1 cb to simulate the landing gear up condition, in order to allow emergency generator operation.
EMER ELEC PWR .. MAN ON
Allows coupling of the emergency generator.

Sounds like a pig's breakfast.

[toby320]

hi, tks for your replyies but I wonder why need to fly at 180kts insted of 140kts??.. I really appreciate if someone provide info related or reference

tks toby :ok:

[muduckace]

The rat will not spin at optimal levels w/o 180kts (you may crash).

[PantLoad]

This applies to the "little RAT". Most of the new A/C have been fitted with the newer, larger RAT. These will operate with the gear down, as long as you're doing at least 125 kts.

How do you know which RAT is on your A/C? If the RAT door is flush with the fuselage, you have the older, smaller RAT. If there's a bulge in the fuselage, you have the big RAT. (Of course, this is how you tell when you're walking up to the A/C. A look in the MSN-specific QRH and other documents will tell you what you've got.)

The scenario you mention exists when you're in the ELEC EMER CONFIG AND you can't retract the gear in a go-around (for an unrelated reason).

Fly safe,

PantLoad

[ggofpac]

HI, does somebody know why if you are on electric emergency configuration and during your final approach you need to make a go around on (on msn 1132) the procedure is to push the emerg generator man on and need to fly with 180 kts???? :rolleyes:

i don't have that requirement on fcom procedures or QRH.:confused:

"For GA -Proc refer to the ESS BUSES ON BAT procedure."


don't have that too.....is this a common procedure for all 320s? :hmm:

[rudderrudderrat]

Hi ggofpac,

The clue was in the MSN number in the original post. That is an older aircraft (hence my reference to scroll FCOM).

The problem has been designed out with with a better RAT etc.

[ggofpac]

ah ok. many thanks rudder. :O

[toby320]

hi, well more info the complete scenario is rat was deployed on EEC on a320 (msn 1132) and during a g/a landing gear can not be retracted so the emergenci generator need to be press manually again to reconect the generator but on flight manual said the speed to maintain the rat running is 180kts, but normally with this msn when EEC you need to mantain 140kts to keep the rat running so my question is what difference make this situation to mantain diferent speed to keep the rat running.

why 180 insted of 140 please this scenario is driving me crazy :}

thk toby320.

[PantLoad]

The difference between 140 KIAS and 180 KIAS (besides 40 kts)....is, on the old-style RAT, the RAT will not run with the gear down. So, on approach, at 140 KIAS or greater, you drop the gear, and the RAT quits.

Now, when you introduce the scenario of a go-around on ELEC EMER CONFIG....and, for an unrelated reason, you cannot raise the gear, you will not be able to recover the RAT.

Again, this applies to the old style RAT.

However, there's hope on the horizon....

If you run into this problem....a go-around (hoping to recover the RAT function) but the gear is down and cannot be retracted, you can recover the RAT by pulling the LGCIU 1 CB AND flying at a speed at least 180 KIAS. (I've seen figures of 185 KIAS in some publications.)

Of course, this does not apply to the new RAT (which is larger).

Hope this helps....


Fly safe,

PantLoad

[toby320]

pantload, many tks so the reason is coz the landing gear down and old kind rat need more speed to mantain the gen operative mm ok

thank you

toby320:ok:

[PantLoad]

Yes, the old RAT needs at least 140 KIAS AND gear up to work. There is electrical logic with the LGCIU 1 also...but not to confuse the topic. (I have to look it up, to be honest.)

But, say you are on ELEC EMER CONFIG (on the RAT) AND you've also lost Green System (for whatever unrelated reason)....so, you have to crank the gear down. No problem, except in the event of a go-around....that's when you have a problem.

That's why you, in this double-failure-unrelated-event, you have to get some speed (at least 180 KIAS) AND undo the logic by pulling the LCGIU circuit breaker. By doing these two things, you'll be able to re-gain the RAT function. (Also, you'll have to reset the RAT button, as well.) But, you can actually have the RAT work with the gear down.

Again, this applies to the old, smaller-design RAT. The new, big RATs will work down to 125 KIAS and will work with the gear down, as well. Thus, the only restriction of the new RAT is to maintain at least 125 KIAS.

Fly safe,

PantLoad

[Dan Winterland]

The 140 with gear up thing is why the old RAT equipped aircraft go into flight on batteries only with gear extension.

Another good way to find out which one is fitted is to look at the overhead CB panel. If the Capt's pressure probe CBs (2 of them) have yellow collars, it''s an old RAT. These yellow collred CBs are the ones you need to find in a hurry for extended flight on batteries only if you can't restore the RAT. o yellow collars on the overhead panel = new RAT.