84-03-09 SUNDSTRAND DATA CONTROL, INC.: Amendment 39-4809. Applies to Sundstrand Model 573A, Digital Flight Data Recorder (DFDR) Part Numbers 981-6009-001/010/011/012/013/014. To prevent loss of recorded data, accomplish the following within the next 2,000 hours time in service or 1 year after the effective date of this AD, whichever occurs later, unless already accomplished:
A. Inspect the DFDR to determine modification status. For DFDR's which have Mod 8 accomplished, but not Mod 15, accomplish Sundstrand Service Bulletin No. 23, (Document No. 012-0118-123), (Mod 15), dated August 2, 1982, or later FAA approved revisions.
B. Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.
This amendment becomes effective March 19, 1984.