AD 74-10-01

Airworthiness directive · Outboard Flap Hinge · Piper PA-23-250 (Navy UO-1)

Effective
December 31, 1975
Published
December 30, 1975
Issued
December 19, 1975
Model
PA-23-250 (Navy UO-1)
Data sheet
TCDS1A10
Registered aircraft
899 matched by model
Product
Aircraft · Small airplane
Amendment
39-2480

Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed November 21, 2025.

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The airworthiness directive

74-10-01 PIPER: Amendment 39-1830 as amended by Amendment 39-2480. Applies to model PA-23-250, Aircraft Serial Numbers 27-3050, 27-3154 to 27-7405330, certificated in all categories.

Unless already accomplished within the last 75 hours in service, to prevent possible asymmetric flap conditions attributed to cracks developing in the outboard flap hinge, the following must be performed within the next 25 hours in service after the effective date of this airworthiness directive, and every 100 hours thereafter:

1. Using the hydraulic hand pump, lower the flaps to full-down position.

2. Clean outboard hinges, part numbers 17103-04 (left) and 17103-05 (right). Using a 10-power magnifying glass, inspect these parts (outboard flap hinges) for cracks. An equivalent inspection method approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may be used.

3. If cracks are found, replace, before further flight, any cracked part with unused hinges,part number 17103-04 (left) and/or 17103-05 (right) or equivalent parts approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

Compliance with this AD is not required upon incorporation of Piper Kits 760 861 (right flap) and 760 817 (left flap) or equivalent parts approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

Upon request with substantiating data submitted through an FAA maintenance inspector, the compliance time specified in this AD may be increased by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region. Service Bulletin 408B pertains to the same subject.

Amendment 39-1830 was effective May 7, 1974.

This amendment 39-2480 is effective December 31, 1975.

Affected TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

Registered aircraft · 899

Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.

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19531995
Registered aircraft by year built: 724 aircraft
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196839
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197019
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197227
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197449
197536
197652
197735
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198011
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