The First Edition of SEA Tech Talk


We are introducing a weekly post that expands on the avionics technical topics that we’ve encountered during the week.

This week’s Tech Talk includes: KT-74 ADS-B STC,  KHF-950 SB notes, Cage Locking Attitude Indicators.


Bendix/King is shipping and SEA has started selling the KT-74 transponder. The KT-74 is described as “ADS-B Ready” and the install manual provides instructions to install it as such.

However, at this time the KT-74 is only a Mode S Transponder replacement for the KT-76A & KT-76C. Although the KT-74 has ADS-B capabilities, there is no STC currently available for the transponder.

Bendix/King has informed us that an AML-STC will be issued soon. SEA will announce the KT-74 as ADS-B Ready once the STCs have been released.

A Few Notes on the KHF-950 SB

Why is the mod level important on the KTR-953 and KAC-952 HF components?

Previously, SEA answered the FAQ: “Can the KTR-953 and KAC-952 be mounted in different locations in an aircraft?“. The answer to that question details the service bulletin (mod) levels that each unit must have incorporated for this installation scenario to be possible.

In addition to what these service bulletins offer in the way of installation flexibility, improper performance and actual unit failure can occur if the units are mismatched. That is, using a KTR-953 unit without SB 8 connected to a KAC-952 unit with SB 9,10 is not ideal. Southeast Aerospace has actually seen units fail in the field when mismatched in this manner as well.

Cage Locking Attitude Indicators

Should all cage-able attitude indicators be locked when handled, transported, or stored?

No, not all and they could be damaged if you do.

Many legacy electromechnical attitude gyroscopic instruments include a caging device to hold the gimbals in place and ‘force’ the gyro gimbals to return to their home position. This instantly erects or resets the unit by pulling the caging knob. Some caged gyros include a cage lock mechanism, some do not. Some people believe that a cage-able gyro should always be in the locked position when handling, transportation, or storage takes place. This is not always the case. Continue Reading>>


Visit SEA @ Heli-Expo 2014!

Our bags are packed and the SEA Team is headed to Anaheim for Heli-Expo 2014!  Be sure to visit us at Booth #5008 from February 25-27 at the Anaheim Convention Center.

“Serviceable” Defined

Although the term “Serviceable” is widely used within the aviation industry, a common misconception persists.

While the industry has adapted the trade term “Serviceable” to imply a general “condition” of the unit, the designation is absent from FAA Form 8130-3.

According to FAA Order 8130.21H, the following terms are approved for use in Block 11 on FAA Form 8130-3 for a Return to Service:


So, what does “Serviceable” mean?

For parts sales purposes, “Serviceable,” more or less, differentiates between “Overhauled” parts and all other non-New parts that still included a Return to Service. “Serviceable” parts with the appropriate Return to Service fall within the manufacturer’s operational specs and can be legally installed on an aircraft for which they’re certified.

TSA Repair Station Security Rule: What you Need to Know –

The TransportatiTSA_logoon Security Administration has issued regulations to improve security at repair stations located within and outside the United States as required by the Aviation Reauthorization Act.

The regulations apply to all repair stations certificated by the FAA under 14 CFR Part 145, except repair stations located on a U.S. or foreign government military base. All repair stations are subject to inspection as provided in the rule and to security directives, should there be a security need. However, the rule requires only certain repair stations to carry out specific security measures on a regular basis.


To determine if action is required, you need to answer a few questions:

Are you a Federal Aviation Administration Part 145 repair station? If “NO,” this rule does not apply to you. If “YES,” continue.

In general, each repair station must allow TSA and other authorized Department of Homeland Security officials, at any time and in a reasonable manner, without advance notice, to enter, conduct any audits, assessments or inspections of any property, facilities, equipment and operations; and to view, inspect and copy records as necessary to carry out TSA’s security-related statutory or regulatory authorities.

Additional security measures are as follows:

For specific repair stations located on or adjacent to airports that regularly serve commercial (Part 119) aircraft with a TSA security program, the repair station must provide TSA with the name and means of contact on a 24-hour basis of a person or persons designated by the repair station with security responsibility. Many members have recently received a letter notifying them of the new repair station security regulations.

  • If the letter arrived and it was addressed to the correct person, no additional communication with TSA is required.
  • If the letter arrived but you choose to designate someone else (or additional persons) to TSA with security responsibility for the repair station, simply send a letter to the TSA office identified on the letter informing them of the correction.

IF you are working on an airport with TSA security program with commercial service AND you are working on aircraft with a gross takeoff weight of greater than 12,500 pounds, there are additional security requirements that include:

  • The prevention of unauthorized operation of all large aircraft under your control, which are capable of flight.
  • Background checks of those individuals who are designated as the TSA point(s) of contact.
  • Background checks for those who have access to any keys or other means used to prevent the operation of large aircraft.

This new repair station security rule will become effective on Feb 27, 2014.

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To view the complete text of the rule, Click Here