AD 81-25-03
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | DC-9-11 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-12 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-13 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-14 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-15 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-15F | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-21 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-31 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-32 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-32 (VC-9C) | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-32F | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-32F (C-9A) | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-32F (C-9B) | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-33F | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-34 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-34F | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-41 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-51 | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-81 (MD-81) | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-82 (MD-82) | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-83 (MD-83) | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
| aircraft | The Boeing Company | DC-9-87 (MD-87) | Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes |
Unsafe Condition
PPG Industries windshield panels manufactured between November 1, 1978, and December 31, 1980, may have out-of-tolerance heating element resistance, which could compromise bird impact protection and anti-ice functions.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect windshield panels to determine manufacturer and year of manufacture. For PPG panels with November 1, 1978, through December 31, 1980, manufacturing dates, perform heating element resistance checks using an ohmmeter. Depending on resistance readings, install placards restricting airspeed or icing conditions, or replace panels with LOF-manufactured or non-PPG 1978-1980 panels. Repetitive inspections at 50-hour intervals until 200 flight hours may be required, followed by 1,500-hour intervals if within tolerance.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within six months from the effective date of this AD
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
McDonnell Douglas Model DC-9-10, -20, -30, -40, -50, and -80 series airplanes, including C-9A, C-9B, and VC-9C airplanes, fuselage numbers 894 through 1021, and those with left, center, or right windshield panels replaced since November 1, 1978.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Windshield Heat Generation
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_81-25-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 81-25-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B...Show more Subject: Windshield Heat Generation Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/04/1982 Make: The Boeing Company Model: DC-9-11 | DC-9-12 | DC-9-13 | DC-9-14 | DC-9-15 | DC-9-15F | DC-9-21 | DC-9-31 | DC-9-32 | DC-9-32 (...Show more Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 81-25-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4271 AD NUMBER: 81-25-03 SUBJECT HEADING: Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes ACTION: SUMMARY: DATES: Effective January 4, 1982. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 81-25-03 McDONNELL DOUGLAS: Amendment 39-4271. Applies to McDonnell Douglas Model DC-9-10, -20, -30, -40, -50, and -80 series airplanes, including C-9A, C-9B, and VC-9C airplanes, certificated in all categories. Compliance required within six months from the effective date of this AD, unless already accomplished. To assure that proper windshield heat generation is available for bird impact protection and anti-ice functions on aircraft fuselage numbers 894 through 1021 and on aircraft that have had left, center, or right windshield panels replaced since November 1, 1978, accomplish the following: A. Inspect windshield panels to determine manufacturer and year of manufacture. Windshield panels may be identified by the manufacturer's logo "PPG" or "LOF" in large capital letters with part number, specification, and serial number adjacent to logo. These are located at the top of the panel on the left and right-hand windshield panels, and at the bottom or top of the center windshield panel. 1. Panels manufactured by Libbey Owens Ford (LOF), no further action is required. 2. Panels manufactured by PPG Industries: a. Determine the year of manufacture, which is contained in the serial number. Serial number samples are shown below: 8-H-10-20-220-315 (first digit indicates year of manufacture, 1978; third digit indicates month, October) 9-H-5-21-315-373 (first digit indicates year of manufacture, 1979; third digit indicates month, May) 0-H-4-6-219-215 (first digit indicates year of manufacture, 1980; third digit indicates month, April) 1-H-3-6-317-212 (first digit indicates year of manufacture, 1981; third digit indicates month, March) b. Windshield panels with an October 1978 or prior manufacturing date coded, or January 1981 or subsequent manufacturing date coded, no further action is required. c. Aircraft with less than 200 flight hours since new or on aircraft with less than 200 flight hours on replacement panel(s), accomplish the following heating element resistance check on PPG November 1, 1978, through December 31, 1980, date coded windshield panels: (1) Open anti-ice circuit breaker on lower electrical panel center for windshield to be checked. (2) Disconnect electrical connector from windshield panel to be checked. (3) Using an ohmmeter, check resistance between Pins L and P at receptacle on left (right) windshield panel. Resistance reading should measure 61.2-82.8 ohms. (4) Using an ohmmeter, check resistance between Pins E and G at receptacle on center windshield panel. Resistance should measure 67.5-92.5 ohms. (5) If windshield resistance is: (a) Within tolerance on all three panels, aircraft may be continued in service, and panels must be repetitively inspected at 50-hour intervals until the accumulation of 200 flight hours. (b) Within tolerance after the accumulation of 200 flight hours, no further action is required. (6) If resistance is out of tolerance on one or more of the three windshield panels: (a) Center panel out of tolerance, install the following placard in full view of the pilot: "Do Not Exceed 260 kts IAS Below 10,000 Feet Altitude." (b) Only side panel(s) out of tolerance, install the following placard in full view of the pilot: "Do Not Exceed 285 kts IAS Below 10,000 Feet Altitude." (c) If windshield resistance of any panel, left, right, or center is greater than 130 ohms, install the following placard in full view of the pilot: "Flight into known icing conditions is prohibited." If left (right) windshield panel(s) resistance is 82.9 to 130 ohms, and/or center windshield panel resistance is 92.6 to 130 ohms, the panel(s) must be repetitively inspected at 50-hour intervals until the accumulation of 200 flight hours to ascertain that resistance remains at or below 130 ohms. After the accumulation of 200 flight hours, the repetitive inspection interval can be extended to 1,500 flight hours. (d) The above restrictions can be removed when the out-of-tolerance panel(s) is/are replaced with panel(s) manufactured by LOF or any PPG manufactured panel(s) with a date code other than November 1, 1978, through December 31, 1980. (7) Reconnect electrical connector to windshield panel and close circuit breakers. d. For November 1, 1978, through December 31, 1980, date coded windshield panels which have over 200 flight hours, accomplish the following: (1) Perform heating element resistance check, as outlined in paragraphs c(1) through c(4). If windshield resistance is within tolerance on panel(s), reconnect electrical connector to panel(s). No further action is required. (2) If resistance is out of tolerance on any of the three panels, accomplish the instructions as outlined under paragraph c(6). B. Alternate inspections, repairs, or other action to be accomplished on or after the effective date of this AD, which provide an equivalent level of safety, may be used when approved by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Mountain Region. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. This amendment becomes effective January 4, 1982. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_81-25-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 81-25-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B...Show more Subject: Windshield Heat Generation Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/04/1982 Make: The Boeing Company Model: DC-9-11 | DC-9-12 | DC-9-13 | DC-9-14 | DC-9-15 | DC-9-15F | DC-9-21 | DC-9-31 | DC-9-32 | DC-9-32 (...Show more Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 81-25-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4271 AD NUMBER: 81-25-03 SUBJECT HEADING: Airworthiness Directives; McDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and -80 Series, C-9A, C-9B, and VC-9C Airplanes ACTION: SUMMARY: DATES: Effective January 4, 1982. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 81-25-03 McDONNELL DOUGLAS: Amendment 39-4271. Applies to McDonnell Douglas Model DC-9-10, -20, -30, -40, -50, and -80 series airplanes, including C-9A, C-9B, and VC-9C airplanes, certificated in all categories. Compliance required within six months from the effective date of this AD, unless already accomplished. To assure that proper windshield heat generation is available for bird impact protection and anti-ice functions on aircraft fuselage numbers 894 through 1021 and on aircraft that have had left, center, or right windshield panels replaced since November 1, 1978, accomplish the following: A. Inspect windshield panels to determine manufacturer and year of manufacture. Windshield panels may be identified by the manufacturer's logo "PPG" or "LOF" in large capital letters with part number, specification, and serial number adjacent to logo. These are located at the top of the panel on the left and right-hand windshield panels, and at the bottom or top of the center windshield panel. 1. Panels manufactured by Libbey Owens Ford (LOF), no further action is required. 2. Panels manufactured by PPG Industries: a. Determine the year of manufacture, which is contained in the serial number. Serial number samples are shown below: 8-H-10-20-220-315 (first digit indicates year of manufacture, 1978; third digit indicates month, October) 9-H-5-21-315-373 (first digit indicates year of manufacture, 1979; third digit indicates month, May) 0-H-4-6-219-215 (first digit indicates year of manufacture, 1980; third digit indicates month, April) 1-H-3-6-317-212 (first digit indicates year of manufacture, 1981; third digit indicates month, March) b. Windshield panels with an October 1978 or prior manufacturing date coded, or January 1981 or subsequent manufacturing date coded, no further action is required. c. Aircraft with less than 200 flight hours since new or on aircraft with less than 200 flight hours on replacement panel(s), accomplish the following heating element resistance check on PPG November 1, 1978, through December 31, 1980, date coded windshield panels: (1) Open anti-ice circuit breaker on lower electrical panel center for windshield to be checked. (2) Disconnect electrical connector from windshield panel to be checked. (3) Using an ohmmeter, check resistance between Pins L and P at receptacle on left (right) windshield panel. Resistance reading should measure 61.2-82.8 ohms. (4) Using an ohmmeter, check resistance between Pins E and G at receptacle on center windshield panel. Resistance should measure 67.5-92.5 ohms. (5) If windshield resistance is: (a) Within tolerance on all three panels, aircraft may be continued in service, and panels must be repetitively inspected at 50-hour intervals until the accumulation of 200 flight hours. (b) Within tolerance after the accumulation of 200 flight hours, no further action is required. (6) If resistance is out of tolerance on one or more of the three windshield panels: (a) Center panel out of tolerance, install the following placard in full view of the pilot: "Do Not Exceed 260 kts IAS Below 10,000 Feet Altitude." (b) Only side panel(s) out of tolerance, install the following placard in full view of the pilot: "Do Not Exceed 285 kts IAS Below 10,000 Feet Altitude." (c) If windshield resistance of any panel, left, right, or center is greater than 130 ohms, install the following placard in full view of the pilot: "Flight into known icing conditions is prohibited." If left (right) windshield panel(s) resistance is 82.9 to 130 ohms, and/or center windshield panel resistance is 92.6 to 130 ohms, the panel(s) must be repetitively inspected at 50-hour intervals until the accumulation of 200 flight hours to ascertain that resistance remains at or below 130 ohms. After the accumulation of 200 flight hours, the repetitive inspection interval can be extended to 1,500 flight hours. (d) The above restrictions can be removed when the out-of-tolerance panel(s) is/are replaced with panel(s) manufactured by LOF or any PPG manufactured panel(s) with a date code other than November 1, 1978, through December 31, 1980. (7) Reconnect electrical connector to windshield panel and close circuit breakers. d. For November 1, 1978, through December 31, 1980, date coded windshield panels which have over 200 flight hours, accomplish the following: (1) Perform heating element resistance check, as outlined in paragraphs c(1) through c(4). If windshield resistance is within tolerance on panel(s), reconnect electrical connector to panel(s). No further action is required. (2) If resistance is out of tolerance on any of the three panels, accomplish the instructions as outlined under paragraph c(6). B. Alternate inspections, repairs, or other action to be accomplished on or after the effective date of this AD, which provide an equivalent level of safety, may be used when approved by the Chief, Los Angeles Area Aircraft Certification Office, FAA Northwest Mountain Region. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. This amendment becomes effective January 4, 1982. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
Related Airworthiness Directives
2025-09-11
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: The discovery of jammed elevators during takeoff could result in the inability of the airplane to rotate at rotation speed V<NF>R<INF>, and lead to a rejected takeoff and high-speed runway excursion.
2024-20-02
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: cracked and severed structure found in the aft fuselage cant bulkhead at STA 1178.225 and vertical stabilizer rear spar installation, on a Boeing Model 717-200 airplane, and similar structure on Bo...
2023-12-15
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: 5G C-Band interference can cause radio altimeters to not perform their intended function, resulting in increased flightcrew workload while on approach with the flight director, autothrottle, or aut...
2023-10-02
final ruleAirworthiness Directives; Transport and Commuter Category Airplanes
Unsafe Condition: Radio altimeter anomalies that are undetected by the automation or pilot, particularly close to the ground (e.g., landing flare), could lead to loss of continued safe flight and landing. Additional...