AD 81-01-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Piper Aircraft Inc. | PA-31T | Airworthiness Directives; Piper Model PA-31T and Piper PA-31T1 Airplanes |
| aircraft | Piper Aircraft Inc. | PA-31T1 | Airworthiness Directives; Piper Model PA-31T and Piper PA-31T1 Airplanes |
Unsafe Condition
Loss of propeller and intake lip deicing functions due to improper installation of DC relay PRD7DYD (24 VDC).
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Required Actions
Inspect for proper propeller and intake lip deice power relay per Piper telegraphic form letter #31-28 dated December 22, 1980, or equivalent approved by Chief, Engineering and Manufacturing Branch. If P/N 484247 relay is installed, check for correct DC relay PRD7DYD (24 VDC). If not installed, remove and install proper relay prior to further flight in known icing conditions.
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Compliance Time
Prior to further flight in known icing conditions
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Affected Aircraft
Piper Model PA-31T (S/N 8120008, 8120009, 8120010, 8120013) and PA-31T1 (S/N 8104007, 8104008, 8104009, 8104010, 8104011, 8104012, 8104013)
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Federal Register Abstract
Propeller Deice Relay
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_81-01-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 81-01-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Piper Model PA-31T and Piper PA-31T1 Airplanes Subject: Propeller Deice Relay Status: Current Citation: This information is not available. Citation Publish Date: 02/26/1981 Effective Date: 02/27/1981 Make: Piper Aircraft Inc. Model: PA-31T | PA-31T1 Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: AIR-700: Compliance & Airworthiness Division Office of Primary Responsibility: AIR-720: Operational Safety Branch CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 81-01-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4051 AD NUMBER: 81-01-01 SUBJECT HEADING: Airworthiness Directives; Piper Model PA-31T and Piper PA-31T1 Airplanes ACTION: SUMMARY: DATES: Effective February 27, 1981. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 81-01-01 PIPER: Amendment 39-4051. Applies to Piper PA-31T S/N 8120008, 8120009, 8120010, and 8120013, and Piper PA-31T1 airplanes S/N 8104007, 8104008, 8104009, 8104010, 8104011, 8104012, and 8104013. Compliance required as indicated, unless already accomplished. To prevent loss of the propeller and intake lip deicing functions, comply as follows: Prior to further flight in known icing conditions, inspect for proper propeller and intake lip deice power relay in accordance with Piper telegraphic form letter #31-28, dated December 22, 1980, or equivalent, approved by Chief, Engineering and Manufacturing Branch. If (P/N 484247) relay is installed, check to insure that correct D.C. relay PRD7DYD (24 VDC) is installed. If the latter relay is not installed, remove and install proper relay prior to further flight in known icing conditions. This amendment is effective February 27, 1981, and was effective upon receipt by all recipients of the letter dated December 24, 1980. FOOTER:
Document Text
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AD Final Rules - DRS_81-01-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 81-01-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Piper Model PA-31T and Piper PA-31T1 Airplanes Subject: Propeller Deice Relay Status: Current Citation: This information is not available. Citation Publish Date: 02/26/1981 Effective Date: 02/27/1981 Make: Piper Aircraft Inc. Model: PA-31T | PA-31T1 Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: AIR-700: Compliance & Airworthiness Division Office of Primary Responsibility: AIR-720: Operational Safety Branch CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 81-01-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4051 AD NUMBER: 81-01-01 SUBJECT HEADING: Airworthiness Directives; Piper Model PA-31T and Piper PA-31T1 Airplanes ACTION: SUMMARY: DATES: Effective February 27, 1981. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 81-01-01 PIPER: Amendment 39-4051. Applies to Piper PA-31T S/N 8120008, 8120009, 8120010, and 8120013, and Piper PA-31T1 airplanes S/N 8104007, 8104008, 8104009, 8104010, 8104011, 8104012, and 8104013. Compliance required as indicated, unless already accomplished. To prevent loss of the propeller and intake lip deicing functions, comply as follows: Prior to further flight in known icing conditions, inspect for proper propeller and intake lip deice power relay in accordance with Piper telegraphic form letter #31-28, dated December 22, 1980, or equivalent, approved by Chief, Engineering and Manufacturing Branch. If (P/N 484247) relay is installed, check to insure that correct D.C. relay PRD7DYD (24 VDC) is installed. If the latter relay is not installed, remove and install proper relay prior to further flight in known icing conditions. This amendment is effective February 27, 1981, and was effective upon receipt by all recipients of the letter dated December 24, 1980. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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