Aw139 IFR skill test/prof check
 

I recently had an answer to a problem which has been troubling me for a number of years as a TRE, which I wanted to share with the community as I expect ( and hope) it will receive some interest.
The problem was: how do you conduct the parts of an IFR skill test/ proficiency check which include mandatory simulated OEI under EASA and FAA rules ( ie- a precison approach & missed approach procedure) in a real helicopter? ( this problem does not arise in FFS). Because.....according to Leonardo ( including discussion with the programme test pilots) you can neither put one engine to idle nor can you use the OEI training switch for this purpose. The OEI trg switch is only mentioned in the OEI training part of the Cat A supplement, and is not intended or flight tested for use for example in a climb to 3000 ft as part of a published MAP. So....I am guessing a great number of checks over the past 15 years or so have been non-compliant, either with the authority's requirements, or with the manufacturers intentions.
The answer I have been given is that for this exercise, the instructor/examiner needs to physically restrict the movement of the collective to simulate the max PI available under 2.5 min or Max continuous power. There seems to be few other options, but I am concerned there is a danger that this will focus the examiner's attention on the PI at a time when he has other things to look at ( outside for example if the check is simulated IMC).
I thought I should share this, because I am not sure that this is widely understood, and this is info which the wider community needs to know.

How does that work when coupled?

I guess you can still stop the collective moving up, even if coupled. The FD just wont necessarily achieve the reference vertical speed.

Hi Non-PC
Could you perhaps argue that the Cat 'A' performance does not end at 1000ft but continues right up to MSA?
Cheers
TeeS

You can argue how you like, but the test pilots say you cannot use the OEI trg switch.

Sorry Non-PC, let me try and put it another way. If you are carrying out a PC(I) on a pilot and you brief him to carry out a Cat A departure into cloud with a departure clearance to climb to 3000ft straight ahead, the pilot calls TDP and presumably you can select training mode and the pilot will fly the continued take off profile. At what point does the Cat A supplement require you to de-select the training mode in the climb? I don't fly the 139 by the way.
Cheers
TeeS

From the AW139 RFM
ENGINE TRAINING MODE LIMITATIONS

Selection of Engine Training Mode (OEI TNG) is permitted only for Category A Training and OEI training (for conditions other than CAT A) in OEI simulated conditions.
Can't see a problem with IFR OEI Trg based on the above

Most Cat A certified helicopters with training mode will have similar limits if you asked the makers - the FMS only ever describes use in Cat A manoeuvres on all the types I’ve flown. It’s driven by the certification specs. The bare minimum is the take off and landing phases so that’s all they test. Customer demand might make them test elsewhere but I suspect that rarely happens as it’s not terribly marketable. I feel you get the most training benefit and meet the Appendix 9 LPC requirements below 1000ft anyway which is where it’s been tested so I feel perfectly comfortable using it in these conditions. Confined areas PC2 - maybe not.

I wouldn’t use a physical block on the collective by the way. There isn’t one for real and much more fun/realistic to mimic a suitable audio tone if they exceed your nominated power limit.

here’s the reference. AC29 MG 22 para e1


https://cimg9.ibsrv.net/gimg/pprune....82bb72f3e5.png

JB 123 - The problem is that the test pilots who write the RFM say you cant do it. Therefore, if you do it, you are operating outside of the OEM certification.
Gypsymagpie - exactly as you say. It aint tested for anything outside of Cat A training, , so it aint certified!
Tees - I am guessing they would say 1000 ft ATS, at the end of flight path 2 is where any Cat A profile ends?

Depends on your jurisdiction and the company you fly for. These days if you can't afford sim you can't afford a 139.

in early days we'd have to land a 212 with both hydraulics off, OEI to droop without cooking an engine was done by N1 limiting the remaining engine with partial throttle, full on autos, etc.

139 OEI in all flight regimes was always done with the training switch. For that matter we'd also do both AP off on the aircraft because the sim didn't replicate it well and real life landing profiles kept you in paint shaker mode until the APs kicked off.

I never sweated RFM limitations much in training and was supported by both my company and my regulator, and by the manufacturer's own test pilots.

Sporting, there is no dual failure case in the emergency section. Why do it? You have two systems for a reason.


https://cimg1.ibsrv.net/gimg/pprune....3575aeff84.png

https://cimg1.ibsrv.net/gimg/pprune....f83d7bcc19.png

The limit says "CAT A Operations"

Isn't the entire flight either Cat A or Cat B? If you fly to either performance requirement that applies to the entire flight? Like for instance the fuel levers in the 76 can be moved to XFEED in Cat B operations during Cruise only, but not in Cat A?

I don't fly the 139 and I don't have a bone in this fight, just curious.

The 139 RFM has no reference to Cat B like Sikorsky does. When I queried Leonardo on that they said that anything that is not CAT A is Cat B. I see your point though about the flight being CAT A since CAT A is not just about performance. That's were Class 1 enters into the picture.

Usually from a training perspective the only bit of the Cat A certification that needs training is the approach and departure. I suspect this is backed up when you read the performance section of the training supplement. I would bet the only graphs in the training supplement are ones for the landing, takeoff and path 1/2. There will not be an en route graph. Also pay attention as some aircraft cannot achieve path 2 when doing training OEI when they can for a real OEI. I feel that’s not usually a problem as you’d be brave to do a training OEI in a limiting obstacle environment in IMC.

Well in Canada you may have to demonstrate a missed approach with a failure or already failed engine, with vectors back to a single engine ILS with landing, That involves cruise flight, and can't be tested then if you can't cruise?

Being devil's advocate, I'd highlight it does not say you need to be single engine between top of climb and next approach and anyway, why would you want to be speed (OEI) limited while operating a commercial aircraft where time is money. If I can safely and sensibly lob 5 mins off a check ride then why not? Experiential training is only worth it to a point

Winnie - my point from the outset.
So, you have to find a way to simulate an engine failure that doesnt use the OEI training switch. EG, you could make a crunching noise, and say " for exercise, you have a No 1 engine out CAS message" and then make sure the candidate doesnt pull more than 80/80 twin PI.

Or.....
You could continue to use the OEI Training Switch in accordance with the RFM as we always have done:cool:

I think you are missing something - The authors of the RFM say you cannot use it like that!

I guess the question is, is this a PUBLISHED limit, or just something "they say". If they didn't publish it then you can do it the way it has always done, until they publish a limit, in which case then there will more simulator rides and less rides in the aircraft.