From: Ing. Tomáš Novotný
To: Thomas, Richard R (FAA)
Cc: Bryant, Matthew (FAA) ; Courtney.Liedler@ntsb.gov ; emanuele.figlia@airbus.com ; donald.kramer@ntsb.gov ; kucharik@dsa.cz ; "Zakl" Subject: RE: Your Inquiry Regarding AD 2015-24-51
Date: Tuesday, March 01, 2016 6:07:52 AM
Attachments: image001.png

Dear Richard,

The removed pulley exhibited more or less left-and-right play but the up and down was observed as well, as the splines were not tighten enough. When the output flange and the brake was hold properly the spline joint has seemed to fit perfectly without play. If you would watch the video once again you should notice (at the third period when the output flange was installed again).

I do not see an issue to forward the links.

Kind regards

Tomas Novotny
Maintenance Director
DSA a.s. tel/fax : +420 495 217 010
mobil : + 420 721 221 010
mail : novotny@dsa.cz
www.dsa.cz

From: Richard.R.Thomas@faa.gov [mailto:Richard.R.Thomas@faa.gov] Sent: Monday, February 29, 2016 7:51 PM To: novotny@dsa.cz Cc: Matthew.Bryant@faa.gov; Courtney.Liedler@ntsb.gov; emanuele.figlia@airbus.com; donald.kramer@ntsb.gov Subject: RE: Your Inquiry Regarding AD 2015-24-51

Dear TomasFirst, I noticed a very slight amount of clockwise/counter-clockwise play per your latest video when you installed the new Airbus Output Flange on the Output Wheel spline. Was there any up-anddown and/or left-and-right play when the new Airbus Output Flange was installed on the splines? The damaged Air Comm Pulley had substantially more clockwise/counter-clockwise play per your original video. Did the removed Air Comm pulley exhibit any up-and-down and/or left-and-right play?

Second, could I forward your two videos to another operator in Australia for comparison to their
observations. They also noted a slight amount of play when they installed a new Airbus Output Flange on a new Output Wheel Spline and I would like to see if their observations were consistent with yours.Thanks.

Respectfully,

Richard R. Thomas Aerospace Engineer (Mechanical Systems) ANM-100D Denver ACO Office - 303.342.1085 Cell - 720.961.3663

From: Ing. Tomáš Novotný [ mailto:novotny@dsa.cz ] Sent: Friday, February 26, 2016 4:22 AM To: Thomas, Richard R (FAA) Cc: Bryant, Matthew (FAA); Courtney.Liedler@ntsb.gov ; JByrnes@aircommcorp.com ; emanuele.figlia@airbus.com ; kucharik@dsa.cz ; fiser@ldap.cz ; Garcia, Maria (FAA); Trainor, Eugene (FAA) Subject: RE: Your Inquiry Regarding AD 2015-24-51

Dear Richard,

When the Airbus output flange have been installed there have been no observation of any rotation looseness or backlash, see a video (enclosed link below) which compares it with used pulley
installation.

https://www.youtube.com/watch?v=vlIkU-Nl7dY&feature=youtu.be

Once more thanks for your significant support.

Yours sincerely

Tomas Novotny
Maintenance Director
DSA a.s. tel/fax : +420 495 217 010
mobil : + 420 721 221 010
mail : novotny@dsa.cz
www.dsa.cz

From: Richard.R.Thomas@faa.gov [ mailto:Richard.R.Thomas@faa.gov ] Sent: Thursday, February 25, 2016 6:14 PM To: novotny@dsa.cz Cc: Matthew.Bryant@faa.gov ; Courtney.Liedler@ntsb.gov ; JByrnes@aircommcorp.com ; emanuele.figlia@airbus.com ; kucharik@dsa.cz ; fiser@ldap.cz ; Maria.Garcia@faa.gov ; Eugene.Trainor@faa.gov Subject: RE: Your Inquiry Regarding AD 2015-24-51Dear TomasPer the original pictures it appeared the output wheel splines were no longer of uniform crosssection along their length whereupon the output wheel would need to be replaced. Per your response below, I concur that you have correctly inspected the output wheel for wear and, in the absence of wear, it would reasonable to replace only the drive pulley. Per your input we will consider revising the AD to make allowance for the output wheel to remain in service if it meets the wear criteria of both the AD and Airbus EC120 AMM 63-22-00, 6-12B. Presently it states that, both parts must be replaced if any play exists in paragraph (i) below. Please let me know if any play exists when you install the Airbus output flange.

I am happy to support and thanks for contacting us.

Respectfully,

Richard R. Thomas Aerospace Engineer (Mechanical Systems) ANM-100D Denver ACO Office - 303.342.1085 Cell - 720.961.3663

From: Ing. Tomáš Novotný [ mailto:novotny@dsa.cz ] Sent: Thursday, February 25, 2016 5:39 AM To: Thomas, Richard R (FAA) Cc: Bryant, Matthew (FAA); Courtney.Liedler@ntsb.gov ; JByrnes@aircommcorp.com ; emanuele.figlia@airbus.com ; 'Filip Kuchařík'; 'Zdenek Fiser' Subject: RE: Your Inquiry Regarding AD 2015-24-51

Dear Richard,

Exactly it was the reason I have contacted you for the first time to clarify this AD requirements. Please let me repeat our statement. The ACC pulley is not available as FAA quarantined those parts.

According to AD, see quotation below from 2 nd page: 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.

...we are going to replace the ACC pulley with Airbus output flange. The output wheel (drive shaft – see enclosed photo) is passed thru the inspection according to AIRBUS EC120 AMM 63-22-00, 6- 12B. Per this criteria, the measured dimensions are not underneath the minimum allowable dimension. The splines are straight, no material pick up observed neither deformation.Furthermore the output flange was not installed yet as we will received tomorrow.

Please could you confirm that if the output wheel passed the inspection it will not be necessary to be replaced as the pulley will be replaced with AIRBUS output shaft.

Thanks for your support.

Yours sincerely

Tomas Novotny
Maintenance Director
DSA a.s. tel/fax : +420 495 217 010
mobil : + 420 721 221 010
mail : novotny@dsa.cz
www.dsa.cz

From: Richard.R.Thomas@faa.gov [ mailto:Richard.R.Thomas@faa.gov ] Sent: Wednesday, February 24, 2016 7:23 PM To: novotny@dsa.cz Cc: Matthew.Bryant@faa.gov ; Courtney.Liedler@ntsb.gov ; JByrnes@aircommcorp.com ; emanuele.figlia@airbus.com Subject: FW: Your Inquiry Regarding AD 2015-24-51

Dear TomasI took another look at the AD. See below. The AD also includes inspection/replacement criteria for the Airbus drive shaft (in addition to EC120 AMM 63-22-00, 6-12B). Per this criteria, and based on

your picture, the AD requires the Airbus drive shaft be replaced as well.

Respectfully,

Richard R. Thomas Aerospace Engineer (Mechanical Systems) ANM-100D Denver ACO Office - 303.342.1085 Cell - 720.961.3663From: Thomas, Richard R (FAA) Sent: Wednesday, February 24, 2016 10:38 AM To: 'Ing. Tomáš Novotný' Cc: 'Liedler Courtney'; Bryant, Matthew (FAA); JByrnes@aircommcorp.com ; emanuele.figlia@airbus.com Subject: RE: Your Inquiry Regarding AD 2015-24-51

Dear TomasThanks so much for your further report, particularly the video as we have never seen the actual play observed on other helicopters reporting the same damage.

I would strongly suggest you contact airbus regarding whether the Airbus drive shaft is acceptable
for continued service. It seems per your pictures that the splines on the shaft no longer have a
uniform cross section? Also, was any play apparent when you installed the Airbus output flange?

Again, thanks so much. If you require any further assistance with regards to the AD please let me
know.

Respectfully,

Richard R. Thomas Aerospace Engineer (Mechanical Systems) ANM-100D Denver ACO Office - 303.342.1085 Cell - 720.961.3663

From: Ing. Tomáš Novotný [ mailto:novotny@dsa.cz ] Sent: Wednesday, February 24, 2016 5:24 AM To: Thomas, Richard R (FAA) Cc: Courtney.Liedler@ntsb.gov ; Bryant, Matthew (FAA); JByrnes@aircommcorp.com ; emanuele.figlia@airbus.com ; 'Filip Kuchařík' Subject: RE: Your Inquiry Regarding AD 2015-24-51

Dear Richard ,

Regarding the issued AD 2015-24-51 we have observed play between pulley and drive shaft, see
video https://www.youtube.com/watch?v=_cCmCXk-Aeg&feature=youtu.be Furthermore there were not found any significant damage of the parts except the corrosion of spline joint.

As there is not possible order new ACC pulley (regarding the provided information from ACC) weare going to replace it with AIRBUS output flange. In according with Airbus EC120 AMM 63-22-00, 6-12B the drive shaft is acceptable for further operation.

Report of required information:
1. The splined joint was corroded – see enclosed pictures with and without corrosion.
2. FH since AC kit installed 477:25 H
3. EC120B S/N1579

4. Pulley S/N 1880

5. Splined drive shaft S/N M775
6. Primary operating location middle of Europe

7. Probably 100% in used of flight
8. Our maintenance service (contact below), Operator: Letecke muzeum Tocna s.r.o., Radlicka 605/2, Praha 5, Czech Republic
9. As ACC pulley is quarantined and there is not another solution how to keep the air condition system operable (no parts for replacing], the system is going to be partially
deactivated.

In addition I would like to confirm that if the output wheel is iaw Airbus AMM inspection it does not require replacement and the action of installing output flange is constituted terminating action
for this AD.

Please do not hesitate to contact me for further inquires.

Thanks for your support.

Kind regards

Tomas Novotny
Maintenance Director
DSA a.s. tel/fax : +420 495 217 010
mobil : + 420 721 221 010
mail : novotny@dsa.cz
www.dsa.cz

From: Richard.R.Thomas@faa.gov [ mailto:Richard.R.Thomas@faa.gov ] Sent: Tuesday, February 23, 2016 10:51 PM To: novotny@dsa.cz Cc: Courtney.Liedler@ntsb.gov ; Matthew.Bryant@faa.gov ; JByrnes@aircommcorp.com ; emanuele.figlia@airbus.com Subject: Your Inquiry Regarding AD 2015-24-51

Tomas-If play is found, the output wheel (also known as the output pinion shaft) could remain in service upon replacement of the Air Comm compressor pulley drive if it meets the criteria of the Airbus inspection procedure. If you do not have the procedure please contact Airbus at http://www.airbushelicopters.com/website/en/ref/Tech-Support-&-Publications_73.html

. Note that, in all of the incidents of play observed to date both the Air Comm pulley drive and the output wheel (pinion shaft) have required replacement.

Regarding your particular aircraft, which was previously unknown to us, could you please provide the following information requested by the AD to assist us in our root cause investigation:

(1) Condition of the splined joint. Document any damage found with photographs. (2) Flight hours since the air-conditioning kit was installed. (3) Aircraft serial number. (4) Pulley serial number (etched on the pulley’s face). (5) Output Pinion serial number from main gearbox, MAIN MODULE hard card. (6) Primary operating location of the aircraft. (7) Approximate average percentage of time the air conditioner is used. (8) Operator and maintenance facility contact information. (9) If parts are replaced, will air conditioning system remain fully or partially operable?

Also, if you have damaged parts please hold onto them.

Thank you so much for contacting us. I hope this response addresses your concerns. If there is anything else we can assist you with please let us know.

Respectfully,

Richard R. Thomas Aerospace Engineer (Mechanical Systems) ANM-100D Denver ACO Office - 303.342.1085 Cell - 720.961.3663

From: Ing. Tomáš Novotný [ mailto:novotny@dsa.cz ] Sent: Tuesday, February 23, 2016 10:39 AM To: Thomas, Richard R (FAA) Subject: AD 2015-24-51 Importance: High

Good morning Richard,

I would like to ask you for a clarification regarding the terminating action of this AD. There is stated as Required Action no. 3 replacing Air Comm pulley with Airbus output flange and deactivating theair condition constitutes terminating action.

Do I understand that correctly that if the play would have been discovered between pulley and pinion, the terminating actions would require to replace the pulley with output flange only and the pinion could stay if it complies Aribus AMM.

Thanks for your support.

Kind regards

Tomas Novotny
Maintenance Director
DSA a.s. tel/fax : +420 495 217 010
mobil : + 420 721 221 010
mail : novotny@dsa.cz
www.dsa.cz