A.Agincourt

A long time ago we used to 'beep up' simply to increase tail rotor efficiency therefore using less pedal and reducing power bleed from the main rotor via transmission system. Used for both take off and landing - but there again that was a long time ago.

Geoffersincornwall

Owner of Dauphin C equipped with tricycle undercarriage orders skid kit to achieve a lighter airframe. The manual explains everything the guy needs to do but he cannot find the page in the manual that tells how to remove the tailwheel mounted at the base of the fenestron fairing.

Assuming this is a mistake, he uses his 'common sense' and takes the thing off. Some flying hours later the aircraft crashes with fenestron failure. The accident investigator finds that the tailwheel is used to tune the fin structure to avoid resonance.

QED

If you want to do something that is not in the manual then it is wise to check first.

'He applied his common sense' is not what you want to have on your headstone.

G.

spinwing

Mmmmm ...

Geoffers .... with respect

.... there would have been nothing in that aircrafts 'Flight Manual' to do with the removing of the tailwheel ... THAT would have been a maintenance/Engineering issue and I suspect that the maintenance manual said nothing about NOT REMOVING the assy. either.

I can see what point you are trying to make ... BUT as you know aviation safety has by and large been improved by the 'generating of f**kups' that people have then discussed and found the answers to ....

And as far as the law (in aviation) is concerned whilst you can be just as easily damned if you don't ... you can also be damned if you do ....

OR just possibly praised for NOT doing exactly by the book ... as Capt. Chesley Sullenberger discovered ...

Aser

Geoff
Regarding the 102% in the 139:

IN FLIGHT PROCEDURES
Hoist Operating Procedure
1. RPM switch — Set 102%.

Regards
Aser

Geoffersincornwall

Spin - You are absolutely right in the same way that the difference between a medal and a court-martial is sometimes nothing at all, it is the outcome that is important. Notice that in my example I was talking about a 'headstone'. This rather implies that it didn't work out. My message was meant to convey the caution required when treating the absence of prohibition as tacit permission. If in doubt - check.

Aser - Yes I believe that in an earlier post I mentioned that 102 should be used for Cat A, sling ops and hoisting.

G.

ATN

To feed the discussion:

EC 155
Use of RPM HIGH is limited to CAT A helipad or increased slope operations for IAS < Vy. (FLM section 2.4, 1.3).

AS 365 N and N2
CAT A clear area, OEI at take off after TDP, beep the rotor to 325 Nr, in the
2nd segment for the N, the 1st segment for the N2.

EC 225
OEI at take off after TDP, adjust collective pitch as necessary to maintain NR at approximately 96 % (FLM section 3.1, 6.1 page 8).

Cheers

ATN

Aser

Sorry Geoff I misread your previous post.
You made a very good point about treating the absence of prohibition as tacit permission.
We have been talking about the use of 102% in cat B, when to arm floats, the use of tq limiter etc. For years...
The question is, Is a normal procedure in the flight manual a limitation?