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Propellers

STC SP1521SO

FAA DRS lists SP1521SO as Current · Amended, held by Northwest Propeller Services Inc., for Hamilton Standard Division 12D40 and Hamilton Standard Division 2D30. Recorded change: Install Northwest Propeller Service Counterweight Thrust Bearings in place of the Hamilton Standard Counterweight Thrust Bearings. Snapshot dated June 30, 2026.

Aircraft configurations
2
FAA revision date
FAA status
Current · Amended

Recorded modification

What the FAA record covers

Install Northwest Propeller Service Counterweight Thrust Bearings in place of the Hamilton Standard Counterweight Thrust Bearings.

SP1521SO identifies the approval, recorded holder, named aircraft, and modification scope. It does not confirm kit availability, serial-number effectivity, data rights, price, or installation authority.

Applicability

Aircraft named in FAA DRS

Named aircraft: Hamilton Standard Division 12D40 and Hamilton Standard Division 2D30. Confirm the approved model list, serial effectivity, configuration, and certificate revision.

Buyer checks

Confirm before sourcing

  1. 01Does it cover the exact Hamilton Standard Division 12D40 and Hamilton Standard Division 2D30 model, serial range, and configuration?
  2. 02Which propeller, governor, spinner, engine, and vibration limits apply?
  3. 03Who can legally supply the design data, kit, instructions, and ICAs?
  4. 04What parts, labor, conformity, and return-to-service work are excluded?