AW139 Training mode
 

When training mode was deactivated with AW139 I saw the PI goes into red band and digital number of PI shows 121%.


When using training mode TQ Limiter mast be used and it limits PI up to 114%.


I wonder if PI really gpes up to 121% when training mode is deactivted?

When you landed and you reported it to your friendly engineer what did he/she say that it had actually reached?

Flying another AW family member.

When we use the training mode and we de-activate it in flight, we make sure to lower collective to a predetermined number on the FLI.
We also have a weight limit in force for using training mode, preventing unwanted exceedance of real OEI limitations.

You will find that everyone has a weight limit in force for OEI training (its is mandated in the RFM)

I'm not a fan of the AW139 training switch. It bites instructors if they relax and it's not representative training. Because it caps available power at 70/70 it droops Nr at a simulated 140 OEI where as for real with no alt holds you have 160. This is roughly the equivalent of simulating an aircraft 500 kg heavier than the one you are in. But by far it's worst feature is the safety function that kicks out the switch if Nr is drooped to 87%. In itself that is a good thing but the way it restores power is not. The training switch kicks out and the EECs instantly respond by trying to restore Nr. They accelerate the engines against no resistance until they smash into the falling Nr. It is a very violent application of power and it's no surprise that this can result in transient Tq spikes

The OP did not give enough information to answer his question.

Was the PI spike on both engines or just one side?
Was OEI TRNG manually deselected or did it do it on its own?
What was the Nr when OEI TRNG disengaged?

I'm puzzled by that statement, as the OEI training mode uses AEO (as you state), but displays OEI - unlike some types where an engine actually goes to idle and the other has an 'artificial' OEI limit but displays the real limits on the FLI etc. As the mode uses AEO, both engines are engaged and delivering a load (i.e. freewheels engaged), so isn't the real issue the fact that they will potentially go into 'blow away' power (or whatever AW/PWC call it), in an attempt to restore Nr, and use real limits?

212 - You are correct.

The issue is that when the operator uses too much collective (power demand beyond what 70/70 % PI can deliver), the Nr droops. When Nr gets below 87%, OEI TRNG is automatically disengaged. Yes, the engines are obviously driving the MGB, so there is no "smash into" and there is no equivalent to the "blow away" you mention. The EECs are trying to get Nf/Nr back to 100% by providing more fuel. What you may see, depending upon Nr and collective position, is a momentary PI/Tq transient beyond 114/114%. Without the protection of the Tq Limiter, a major overtorque would occur, potentially as high as 160/160% PI.

The OP has not given sufficient detail to explain his particular experience.

Ok, you passed your 61.58.

I guess that means I won't have to see your ugly mug for a while then.

What a relief! :-)

With respect to HLCPTR's question

Was the PI spike on both engines or just one side?
I saw both engines PI going up to red band.

Was OEI TRNG manually deselected or did it do it on its own?
What was the Nr when OEI TRNG disengaged?
Automatically disengaged as Nr falls below 87%.


The question is that Engines actually deliver power above 114% while OEI TRNG Mode is disengaed but TQ Limiter is still ON.

I saw both engines PI was going up to the red band and TRNG Mode was automatically deactivated as Nr fell down beloe 87%.


TRNG Mode was off but TQ Limiter was still on. So PI must be limited up to 114% as a function of TQ Limiter.

Twinbird, 114% per side IS in the red band. Anything above 110% TO power IS in the red band.
100% max continuous, 110% Max TO.
I hope you guys were working in accordance with the OEI training mode weight limitations set forth in the appropriate RFM supplements.

TB,
The system is designed to prevent a major overtorque but, by allowing the Nr to droop that low, you put the aircraft in a critical condition. Although EEC fuel scheduling is designed to provide 114/114% max, you should understand that when you cause such a significant demand for more power, the way the Tq sensors detect torque will result in the indications appear to "overshoot". That is simply a very momentary overshoot in the indication.
I suspect that the Tq only displayed those high values for a second or so then stabilized at a slightly lower value. Is that what you saw or were your eyeballs so large that you did not notice the details?
Regardless, did you report it and what was the determination once the CMC and the engine DCU data was downloaded?

Some interesting notes in the FCOM section on this mode - TB do you have this, because if not I suggest you request it from LH?

I thought above 114% of TQ never happened with TQ Limiter ON, but momentaly overshoot might be happened as described by HLCPTR. I'll ask mechanic to download the data and try to get FCOM from Leonard.


Thank all of u very much for really usefu information.

From the training manual:

On the AW139 helicopter, the torque limiter function is set to OFF as default.

If the pilot wants to engage the torque limiter function, the TQ LIM push-button
on the collective grip, must be pressed. After selection, the green advisory
message TQ LIMITER ON will be displayed in the CAS window.

When the torque limiter function is set to ON, the AEO total torque will be limited
to be combined torque value of TQ 228%. The OEI engine torque will not be affected.

When pressed a second time, the torque limiter function is deactivated and full power is available from engines.

To perform the OEI TRAINING, the TQ LIM function must be set to ON.

So following deactivation of OEI training mode, if one engine accelerated faster than the other, it is possible that there was a momentary split in the Tq values, with one engine reaching 121 (and the other presumably at 107) before balancing again at 114/114.

Sounds like something to save for the simulator, thus avoid any expensive mistakes.
These mind boggling modern computerised helicopters, we never had any issues like this to deal with in the old days doing single engine training in the 212.

single engine training used to be simple in the gazelle too!:ok: