Airworthiness Directive · Amendment 39-18965 · Air conditioning
Piper Aircraft, Inc. Airplanes
This AD applies to Piper Aircraft, Inc. Models PA-23, PA-23-160, PA-23-235, PA-23-250, PA-E23-250, and PA-30 airplanes, all serial numbers, certificated in any category.
We are superseding Airworthiness Directive (AD) 69-13-03 for all Piper Aircraft, Inc. Models PA-23, PA-23-160, PA-23-235, PA-23-250, PA-E23-250, and PA-30 airplanes. AD 69-13-03 required inspection of the heater exhaust extension, replacement of the extension as necessary, and overhaul of the combustion heater assembly. This AD retains the inspection of the heater exhaust extension with replacement of the extension as necessary and removes the overhaul requirement of the combustion heater assembly. This AD was prompted by a recently issued AD that applies to the Meggitt (Troy), Inc. combustion heaters, and the combustion heater AD incorporates corrective actions for the heater that contradict the overhaul requirement of AD 69-13-03. We are issuing this AD to continue to address the unsafe condition on these products and avoid potential contradiction of actions.
Within the next 25 hours time-in-service (TIS) after December 14, 1973 (the effective date retained from AD 69-13-03 as amended by AD 69-13-03, Amendment 39-785 (38 FR 33765, December 7, 1973)), remove the heater exhaust tube shroud and by means of a magnet determine if Stewart-Warner part number (P/N) 486238 exhaust extension (Piper P/N 754-708) is mild steel (magnetic) or stainless steel (non-magnetic). If the exhaust extension is stainless steel, then no further action is required by this AD.
If there is a mild steel Stewart-Warner P/N 486238 exhaust extension (Piper P/N 754-708) installed on the airplane, within 25 hours TIS after August 28, 2017 (the effective date of this AD), you must do one of the following actions found in paragraph (h)(1) through (3) of this AD.
(1) Replace the mild steel exhaust extension with a stainless steel exhaust extension.
(2) Visually inspect the mild steel exhaust extension for deterioration (cracks, corrosion, rust, and/or flaking) and repetitively thereafter visually inspect the exhaust extension at intervals not to exceed 25 hours TIS or until the mild steel exhaust extension is replaced with a stainless steel exhaust extension.
(3) Disable or remove the combustion heater.
If deterioration (cracks, corrosion, rust, and/or flaking) of the extension is found during any of the inspections required in paragraph (h)(2) of this AD, before further flight, you must do one of the following actions in paragraph (i)(1) or (2) of this AD.
(1) Replace the exhaust extension with a stainless steel exhaust extension or a mild steel P/N 486238 exhaust extension that has been inspected per paragraph (h)(2) of this AD and was found free of deterioration. If you install a mild steel P/N 486238 exhaust extension, you must continue the repetitive visual inspections required in paragraph (h)(2) of this AD.
(2) Disable or remove the heater.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
