Richard,

There’s no safety concern with partially deactivating the air conditioner by removing the compressor 

drive pulley and belt. Regarding the wording of the terminating action so that it covers our possible 

solution paths we suggest only a minor addition to your statement: 

“Replacing the Air Comm pulley with Airbus output flange, part number C632A2158201, and fully or 

partially deactivating the air conditioning system (partially deactivating means the evaporator blowers 

are still operable), constitutes terminating action for this Emergency AD unless and until a future Service 

Bulletin from ACC is issued”.

Thanks,

Jim Byrnes

Air Comm Corporation

www.aircommcorp.com

1575 W. 124th Ave.

Westminster CO 80234

Phone - 303-440-4075 x248

Fax - 303-440-6355

From: Richard.R.Thomas@faa.gov [mailto:Richard.R.Thomas@faa.gov] 

Sent: Friday, April 01, 2016 11:25 AM

To: Jim Byrnes

Cc: Matthew.Bryant@faa.gov; Courtney.Liedler@ntsb.gov; Eugene.Trainor@faa.gov

Subject: Spline Coupling AD

JimWe are working on publishing AD 2015-24-51 in Federal Register as a final rule. The terminating action 

in the AD reads as follows:

Replacing the Air Comm pulley with Airbus output flange, part number C632A2158201, and fully or 

partially deactivating the air conditioning system (partially deactivating means the evaporator blowers 

are still operable), constitutes terminating action for this Emergency AD.

I know you are working on a design change to operate the compressor off of a different (less critical) 

power takeoff and that this would include replacing your pulley and reinstalling the Airbus output 

flange. That action is consistent with part of this terminating action but it would reactivate the air 

conditioning system which is slightly inconsistent with this terminating action. Rather than revise the 

AD at some future time to incorporate your design change which would reactivate the air conditioning 

system, I would like to find a way to change this statement in a manner which would consider your 

possible design change.

With this in mind, if you replace your pulley with the Airbus part, which removes the compressor drive 

belt, and take no further action to fully or partially disable the air conditioning system, would any harm 

to the air conditioning system occur if the crew attempts to operate it? More importantly, would taking 

no further action create any increased hazard to the helicopter of any of its systems if the crew attempts 
to operate it? An example, but not necessarily the only concern, would be overheating of any parts of 

the air conditioning system which could increase the possibility of fire. What I am thinking about here is 

the possibility of striking the deactivation requirement.

Please advise me at your earliest convenience so we can get this off to the Federal Register.

Respectfully,

Richard R. Thomas

Aerospace Engineer (Mechanical Systems)

ANM-100D Denver ACO

Office - 303.342.1085

Cell - 720.961.3663

Air Comm Corporation acquired Meggitt (Addison), Inc., the former Keith 

Products

as of May 22, 2013. Please update your records accordingly and visit

http://www.aircommcorp.com/acquisition/announcement/for more information.

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