Radio switch to 8.33

[timprice]

Just looking at changing our radio's so we can have 8.33, but everybody we ask has a different opinion, Bendix King say they are plug and play?
Bendix King 155 to Bendix King 165a (Radio)
and at the same time
Bendix King KY76C to Bendix King KT74 (Transponder)
Some people say Fit, Form and Function under EASA others say needs minor mod, others say it needs a major mod.
CAA say up to airworthiness inspector, any idea's guys its in a Bell 206 Jetranger

[wigglyamp]

Both upgrades in this case are EASA Minor changes. No STC required as there are no failure conditions associated with the new kit that are hazardous or catestrophic and no changes to certified gross weight, C of G limits or aerodynamics (there are a few more considerations but none apply in this case).

Once EASA CS-STAN is adopted (possibly next year) then the licensed engineer or Part 145 organisation will be able to cover the change without a formal modification approval, just like an FAA minor alteration. For the time being, approved data is required as the part numbers are changing and additional functionality is being added.

[OvertHawk]

Tim

Check you PM.

[timprice]

Thanks Wigglyamp, do you have an EASA reference

[wigglyamp]

EASA 21.A.91 - classification of changes and the associated AMC and GM:

https://www.easa.europa.eu/system/fi...2012-020-R.pdf

There is no 'Form/Fit/Function' replacement without approved data under EASA other than use of PMA parts, and even then, only when the part is non-critical and the specific EASA aircraft type is listed on the component PMA approval.

[timprice]

Thanks for the reference

So reading that it's minor, but you think that will change next year?
Thank you.
Tim

[wigglyamp]

Definitely a Minor change at the moment. Once CS-STAN is adopted (probably next year), this level of upgrade will be possible without any formal design approval.


NPA 2014-24 | EASA

[Windmill Wiz]

CS-STAN not that useful for turbine helicopters

Although CS-STAN is definitely a step in the right direction, the devil is, as usual, in the detail. When you review the proposed Standard Changes, very few if any apply to turbine helicopters. For example the Standard Change relating to VHF communications equipment applies to:

Aeroplanes not being complex motor-powered aircraft with a maximum cruising speed in ISA conditions below 250 kts and any ELA 2 aircraft.

This rules out all rotorcraft.

I fully agree that a change to 8.33 spacing radios is a Minor Change on a VFR aircraft. Whether it is plug-and-play depends on the individual aircraft installation and specific radio variants (dash numbers) being exchanged. For example a change from KX165 to KX165a on a twin turbine helicopter necessitated some wiring changes.

I hope this helps.

[timprice]

Its for a Jetranger, but interestly drives a HSI and strictly speaking a 155 can't do that, so we think it is a 165 with a 155 front?
If that makes any sense as apparently 155 never had a driver for an HSI?
So max speed 130kts and VFR.