# AD 84-26-02: Paper Induction Air Filters

- Type: Airworthiness directive
- Status: Current
- Products: Induction Air Filters Paper Induction Air Filters
- Effective: January 29, 1985
- Published: December 19, 1984
- Issued: December 11, 1984
- Superseded by: Nothing supersedes this AD
- Product type: Appliance, Small airplane
- Amendment: 39-4966
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2BA8EAB12B8CE12186256A380049C63B.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/84-26-02

## The airworthiness directive

84-26-02 INDUCTION AIR FILTERS: Amendment 39-4966. Applies to all paper induction air filters used in small airplanes.

Compliance: Required as indicated, unless already accomplished.

To prevent possible engine power loss or stoppage caused by engine ingestion of fragments of a deteriorated induction air filter, accomplish the following:

Within the next one hundred hours time-in-service after the effective date of this AD or prior to the accumulation of 500 hours time-in-service on the filter, whichever occurs later, and thereafter at intervals not exceeding 500 hours time-in-service on the filter:

  (a) Replace the air filter with a new filter that is FAA approved for the airplane installation.

  (b) Within 100 hours time-in-service replace any filter on which the time-in-service cannot be determined utilizing the airplane maintenance records for this determination. NOTE: This AD does not alter current maintenance procedures which require inspection of paper induction air filters at 100 hours time-in-service and annual inspections and replacement as necessary based on filter condition.

This amendment becomes effective January 29, 1985.

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

## NTSB investigations that cite this AD (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB SEA05FA124](https://openairdocs.org/ntsb/SEA05FA124), Jun 21, 2005: Cessna 320E (N3438Q), Missoula, MT, destroyed. Probable cause: Terrain clearance was not possible as a result of a right engine failure. Factors contributing to the accident included the rising terrain, foreign material being ingested into the engine's…

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