AW169 AW139 with real OEI landing

[MeddlMoe]

Hello Everybody,

There is one thing I have been discussing with a collegue:

The MPM of AW169 and AW139 mention lifetime penalty factors for CAT.A training mode.

Do you know the lifetime penalty for real OEI, or even real Autorotation? Is there any effect, as long no limit is exceeded?

[casper64]

Originally Posted by MeddlMoe

Hello Everybody,

There is one thing I have been discussing with a collegue:

The MPM of AW169 and AW139 mention lifetime penalty factors for CAT.A training mode.

Do you know the lifetime penalty for real OEI, or even real Autorotation? Is there any effect, as long no limit is exceeded?

Strange… then why a „Training Mode“ H135/145 don’t have these issues as far as I know.

[Aucky]

Originally Posted by MeddlMoe

Hello Everybody,

There is one thing I have been discussing with a collegue:

The MPM of AW169 and AW139 mention lifetime penalty factors for CAT.A training mode.

Do you know the lifetime penalty for real OEI, or even real Autorotation? Is there any effect, as long no limit is exceeded?

Frustratingly it is not the time spent in training mode either, but the whole flight duration if training mode was used 🤷🏼‍♂️ What’s equally odd is that both engines are operating delivering equal torque (governed to 77%), so there is no large asymmetrical torque applied through the gearbox. Are the penalty factors due to stresses from flight at low Nr?

Not aware of a penalty for genuine OEI, but as it is forbidden by the RFM to place an ENG MODE switch to IDLE/OFF for OEI training I guess they don’t expect you to spend much time there, whereas training mode might be used extensively.

[Non-PC Plod]

Not just the stresses from the low Nr, but also remember the very sudden Nr acceleration you get if the Nr droops too low, and the OEI training mode drops out.

[Aucky]

Originally Posted by Non-PC Plod

Not just the stresses from the low Nr, but also remember the very sudden Nr acceleration you get if the Nr droops too low, and the OEI training mode drops out.

No doubt this puts significant stress on the freewheels and gearbox if it is allowed to get all the way to the 88% cut out (usually with an associated XMSN OVTQ caption unless on the ground). It would seem unfair to apply this as a penalty to every use of training mode given the rarity of it occurring, but you’re probably right. It’s a little like how they penalise the entire duration of a flight at TOW above 4.6t (169), even if it was only >4.6t for the first 5 minutes.

[Non-PC Plod]

With unknowns, its always safest to use the worst case scenario - so assume it happens every time.

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To my knowledge, the later 139s trg mode just adjusted the display figures rather than actually backing off an engine - that should mean no penalties. You have all the MFD indications of an engine failure but without the mechanical problems.