Attn:    All Customers / Operators / Mod Centers / Repair Stations


Date:    November 7, 1998


The following part number appliances manufactured by Avionics Engineering Services are subject to the following maintenance requirements:


  1. All part numbers listed below are classified as "ON CONDITION" with no preventative maintenance required. No overhaul time limitations apply.
  2. No scheduled inspections to determine operational status are required for any of the part numbers listed below.
  3. In the event of a failure of any of the part numbers listed below, the operator or cognizant maintenance facility shall remove the appliance and return it to AES for the repair or replacement


Items 1 through 3 above applies to all part numbers of appliances manufactured by AES from calendar year 1989 to present.


Autopilot Interface Unit (AIU)

P/N 89-7007-1 (GII)

P/N 89-7007-2 (B727-100)

P/N 89-7007-3 (P3-B)


L35 LRN Steering Interface Unit (SIU)

P/N 92-7009-1 (Lear 35/36 with FC-200 Autopilot)


Annunciator Dim/Test Unit (ADU)

P/N 92-7001-1

P/N 92-7001-2

P/N 92-7001-3


Roll Steering Conditioner Unit (RSCU)

P/N 89-7007-70-1

P/N 89-7007-70-2 (Pitch - P3B)

P/N 89-7007-70-3 (Yaw - P3B)

P/N 89-7007-70-4 (B737)

(Original signed by)

John Goswick



(Original signed by)

Scott Billings

Project Engineer


Click here to download an official signed copy of

Instructions for Continued Airworthiness

(Adobe Acrobat .pdf)

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