Agusta AW139

[dangermouse]

Ok, thanks for the clarification, I know on some designs the Tq limiter is active AEO but not OEI so will limit the power and thus droop the rotor to a point at which it has been decided that if you droop that much you really do need the power and then the Tq limiter disengages to give full available power (ie the scenario Nescafe suggested).

OEI training mode Tq limiter logic is completely different

DM

[HLCPTR]

The TQ Limiter logic is the same regardless of AEO or OEI.
It limits total Tq to 228% PI - Logically, that means 114%/114% max PI.
IF AEO, once you reach the 228 total, the Nr will droop since the EEC will not give more fuel to support Nf/Nr. TQ LIM does not "disengage".
If you go OEI, TQ LIM is still active but irrelevant. The good engine function still will give you your OEI limits.
Neither does it disengage if in OEI training. It is required in OEI training in the event of a condition (such as a real engine failure while in a low Nr condition) to prevent major engine/MGB overtorque while the EECs are pumping more fuel trying to recover the low Nr.
What does happen in OEI training is that OEI TRNG will automatically disengage under certain conditions, such as a real engine failure or a low Nr condition (<87%). The TQ LIM will still be engaged and prevent a potential overtorque until the pilot deselects it manually

[Pontius Pirate]

So basically few operators have SOPs that require TQ Limiter ON while performing daily flying duties?

I for one don't use it, if I fly correctly I'm unlikely to "bust" any limits during normal ops.

I would be interested in people's thoughts on an engine popping very short final to an offshore platform with TQ Limiter on?

Based on previous comments it sounds like having it ON would not be a factor and would therefore depend on pilot ability to hit the correct OEI profile...the aircraft performance would not be degraded as a result of TQ Limiter ON?

[HLCPTR]

I for one don't use it, if I fly correctly I'm unlikely to "bust" any limits during normal ops.

True. It seems to me that the only operators who fly with it ON all the time either don't fully understand this function or see it as protection from major overtorque. If you fly within the RFM limits, it serves no purpose.
Worst case scenario: pilot gets way behind the power curve and has to grab a big armful of collective to save the airframe. TQ LIM ON will limit the PI. Saves the MGB, but possibly not the airframe.

Based on previous comments it sounds like having it ON would not be a factor and would therefore depend on pilot ability to hit the correct OEI profile...the aircraft performance would not be degraded as a result of TQ Limiter ON?

That is correct. TQ LIM will not affect the good engine.
But again, it's only real purpose is for use during OEI training, not daily flying.

[tottigol]

Nescafe...OEI will disengage the Tq limiter, but the exact point of disengagement-not sure.
Where did you read that?

DM, BaronG and Nescafe, are y'all running a bull**** competition?

[Nescafe]

When the torque limiter function is engaged, a green TQ LIMITER ON will appear on the MFD. The All Engines Operating (AEO) total engine torque is limited to be the combined torque of TQ228% (114%/114%) when the torque limiter function is set to ON. The One Engine Inoperative (OEI) torque is not affected.

From my FSI Phase 7 notes. Maybe my initial phrasing was unclear, but as it was explained to me during ground class, if you lose an engine with the torque limiter on, the tq is not limited on the remaining engine!

[tottigol]

You said FSI, right?

OEI shall not disengage the TQ Limiter, OEI shall disengage the OEI trainin' switch.
Like HLCPTR wrote, the TQ Limiter is necessary to allow functioning of the OEI training switch.
I strongly suggest you and your course buddies review the AW139 Section 5 RFM Supplement 12 section L :"Cat A OEI Training".

The OEI TQ shall not be limited BY THE TQ LIMITER, but it shall be limited by other functions to 160% OEI, 2.5 minutes plus a 10% 5 seconds transient, after which the rotor RPMs shall droop.
BTW, 140% OEI is all you are going to get with any collective mode engaged.

I stayed at the Holiday Inn Express last night.

[ODEN]

AW 139 EGPWS

In the EGPWS manual it says there are several optional aural height calls.

smart 500, 200, 100, 50 etc

Looking for information if any operator has any other calls than the standard 150 call generated by the AWG.

Im not talking about the calls generated during autorotation but during normal operation.

Cheers

[Pilotmartymcfly]

XMSN OVTQ on AW139

My friends, I would like to know if anyone has the knowledge of this detail. In the AW139, with both motors running, the operating yellow range is up to 110% of torque. There is up to 121% transient for 5 seconds. In this case, if the pilot reaches, for example, 112% in a takeoff, but remains in that range for only 1 or 2 seconds and returns to the normal operating range, that is, below 110%, no overtorque event will be recorded?

And the second question is: Why the TQ is on 114% and not on the 110%, if the 110% is the maximum operation under the red line?

Hugs

[tottigol]

The TQ limiter is to be only used to allow the OEI training switch to function.
It is set at 114% to protect the aircraft from the pilots.
Also, the transient limit on AEO PI is NOT to be used intentionally.

[Pilotmartymcfly]

Tks tottigol.

The question is whether to reach the transient range unintentionally, whether there would be some kind of record or not.

Certainly pilots should not intentionally reach the 110% mark.

[spinwing]

Hmmmmm ....

The question is whether to reach the transient range unintentionally, whether there would be some kind of record or not.

EVERYTHING is recorded ... and can be recovered by the maintenance recording software ...

[tottigol]

Nothing records intentions, however repeated applications of PI into the transient range can definitely be interpreted as INTENTIONAL.
Just for the "record", 110% is maximum T/O AEO PI and can be held for 5 minutes.
100% is max continuous.

[Pilotmartymcfly]

I think my question was not clear enough, because no one could answer exactly what I asked. The question would be whether a torque between the transient range of 110% and 121% would be interpreted as Overtorque and there would be a need to inspect the components, as in an overtorque event. Or only if it was registered in the CAS, it would be registered as an overtorque event. But thank you for the answers.

Edit: Tottigol, you got it. Thank you.

[HLCPTR]

All values (Ng, Tq, ITT, Nf, Nr) are recorded and can be downloaded from the CMC and the engine DCU. The maintenance manuals contain charts which show the relative severity of any exceedance and the resulting maintenance requirements based upon peak value and duration. As simple as "no maintenance required" to "send it back to P&W for overhaul".

[Mark Six]

Originally Posted by tottigol

The TQ limiter is to be only used to allow the OEI training switch to function.

Tottigol, would you like to reconsider your use of the word "only" in the above quote?

[tottigol]

Originally Posted by Mark Six

Tottigol, would you like to reconsider your use of the word "only" in the above quote?

Why?
The use of the TQ limiter is associated with the use of the OEI training switch as reported in the pertinent supplement of the RFM.
Please quote for me and my failing memory where else is the TQ limiter required for use in the RFM.

[Mark Six]

It might be semantics but... you're right in that the TQ limiter MUST be used in association with the OEI training switch and that is the only situation it is REQUIRED by the RFM, but to say or imply that is the ONLY time it can be used (as you did) is misleading. For example it is often used for offshore takeoffs when the required CAT A power is 110% TQ in order to prevent the pilot accidentally pulling past 114% through to 121% and bleeding NR. At least one major EMS/SAR operator requires TQ limiter to be switched on for all operations (it's in their before T/O checks).

[Non-PC Plod]

It is not forbidden to use it in that way, but it is not recommended. (See the FCOM). If you have Tq limiter selected, it means you cannot use the extra power if you suddenly need it (maybe heavy helo & sudden downdraught etc).
Any competent crew should be able to avoid pulling over 114% on a normal takeoff!!!

[Mark Six]

Originally Posted by Non-PC Plod

It is not forbidden to use it in that way, but it is not recommended. (See the FCOM). If you have Tq limiter selected, it means you cannot use the extra power if you suddenly need it (maybe heavy helo & sudden downdraught etc).
Any competent crew should be able to avoid pulling over 114% on a normal takeoff!!!

I'm not going to get into a discussion about whether you should or should not use it. I'm well aware of the pros and cons.
"Competent crews" do a lot of things they should be able to avoid. Just look at some of the recent discussions on this forum.