U.S. Department 

of Transportation 

Federal Aviation 

Administration 

Small Airplane Directorate 

Wichita Aircraft Certification Office 

1801 Airport Road, Room 100 

Wichita, Kansas 67209 

In Reply, refer to: L115W-15-7 

Mr. Randolph Shields 

Director, Safety & Certification B099-A02 

Beechcraft Corporation 

JAN · .. 'J 20!5 10511 E Central Ave 

Wichita, KS 67206 

Subject: AD 2014-21-06 Beechcraft Undocumented Comments in the AD Docket 

Dear Mr. Shields: 

Tllis letter addresses comments from Shawn Kohr/Beechcraft Corporation, posted 

September 11,2014, to Docket FAA-2014-0345, Directorate Identifier 2013-NM-230-AD. 

These comments can be found at: http://www.regulations.gov/#!documentDetail;D=F AA2014-0345-0003. The following italicized sentences are issues noted in Mr. Kohr's 

comments, followed by the FAA's responses. 

1. However, at no point has Whippany Actuation Systems recommended 

replacement of the jackscrew other than on an "on condition" basis. Mandat01y 

replacement of the jackscrew assembly regardless of condition is unnecessmy. 

FAA Response: The FAA disagrees with this statement. During discussions 

with Beechcraft regarding this issue, it was brought to light that GE had proposed 

a safety action to recall26 high time PTA's (21 commercial; 5 military) to 

replace ACME nuts and jackscrew as required per the CS Repair Shop Lead 

directive. Based upon these discussions, replacement of the ACME nut and 

jackscrew are required per the repair shop lead directive. To our knowledge, this 

directive is not a published document but is a verbal direction that was provided 

to those personnel overhauling these units at GE Aviation. This understanding is 

also consistent with the Beech Safety Review Board minutes dated May 12, 

2011 , which state "HBC requested (20 1 0) that GE revise their overhaul 

requirements to change both the jackscrew and ACME nut at overhaul." 

The FAA had to conservatively select the replacement life for the ACME nut 

and jackscrew of 1800 hours since Beechcraft has not provided any engineering 

data to support a longer life. The FAA worked with Beechcraft engineers to see 

if there was a way to extend the 1800 hour life, but we could not fmd a way 

without generating a fatigue spectrum for the ACME nut and jackscrew. 

2. Of the units involved in the investigation, which was the basis for this NP RM, 

two units were identified as being improperly installed while improper 
Page 3 

replacement of the Acme nut and jackscrew every 1800 hours. Also, the ALM 

has not been mandated by an AD, so it is not a requirement for all airplanes. An 

AD is the appropriate vehicle for mandating the replacement. 

5. The proposed AD is in effect requiring the replacement of parts within the 

appliance at the established overhaul interval and Beechcraft C01poration 

believes an appliance AD may be a more appropriate vehicle to enforce this 

requirement. 

FAA Response: The FAA disagrees with this statement. The PTA does not 

have a separate design approval. For this component and its installation, HBC is 

the design approval holder and the approval was accomplished under the 

certification procedures for the Beechjet type certificate. Also perF AA-IR-M8040.1 C, the Airworthiness Directives Manual, because the unsafe condition 

results from the installation of the appliance on an aircraft, the AD action is to be 

issued against the aircraft, engine, or propeller (not the appliance). 

If you have any questions or comments regarding this subject, please contact Ann Johnson at 

(316) 946-4105 or ann.jolmson@faa.gov. 

Sincerely, 

;J ,n 

C-'D

Robert 

. 

P. 

~ Busto 

[)'-Associate ACO Manager, Continued Operational Safety 

Wichita Aircraft Certification Office