AD 80-19-09 R1

final rule

Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes

AD Number
80-19-09 R1
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Learjet Inc. 23 Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24 Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24A Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24B Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24B-A Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24C Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24D Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24D-A Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24E Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24F Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 24F-A Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 25 Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 25A Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 25B Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 25C Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 25D Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 25F Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 28 Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 29 Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 35 Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 35A (C-21A) Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 36 Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
aircraft Learjet Inc. 36A Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes

Unsafe Condition

Fuel contamination and ignition sources in the tailcone service area due to deterioration, damage, leakage, or blockage of fuel, hydraulic system components, batteries, electrical equipment, vents, and drains.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Within 25 hours time-in-service after May 8, 1980: inspect fuel/hydraulic components, batteries, electrical equipment, vents, and drains for deterioration, damage, leaks, stains, or blockages; replace leaking motive flow shutoff valves. Install updated Temporary Airplane Flight Manual Supplement (Figure 1A). By February 13, 1981, install motive flow valve shrouds and drain lines per Modification Kit No. AMK 80-7. Remove temporary supplement after modification.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within the next 25 hours time-in-service after May 8, 1980 for initial inspections and replacements; on or before February 13, 1981 for installation of shrouds and drain lines.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Gates Learjet Model 23 (equipped with jet pumps, serial 23-003-23-099), 24 (24-100-24-357), 25 (25-003-25-319), 28 (28-001-28-005), 29 (29-001-29-002), 35 (35-001-35-348), and 36 (36-001-36-045).

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Jet Pumps

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_80-19-09_R.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
80-19-09 R1
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
Subject:
Jet Pumps
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/11/1980
Make:
Learjet Inc.
Model:
23 | 24 | 24A | 24B | 24B-A | 24C | 24D | 24D-A | 24E | 24F | 24F-A | 25 | 25A | 25B | 25C | 25D | 2...Show more
Product Type:
Aircraft
Product Subtype:
Small/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: 80-19-09 R1
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3998

AD NUMBER:   80-19-09 R1

SUBJECT HEADING:   Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 11, 1980.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
80-19-09 R1 GATES LEARJET: Amendment 39-3913 as amended by Amendment 39-3998. Applies to the following Model 23, 24, 25, 28, 29, 35 and 36 series airplanes certificated in all categories:

Model	Serial Numbers
*23 (equipped with jet pumps)	23-003 thru 23-099
24	24-100 thru 24-357
25	25-003 thru 25-319
28	28-001 thru 28-005
29	29-001 and 29-002
35	35-001 thru 35-348
36	36-001 thru 36-045
*NOTE: Model 23 airplanes were not equipped with jet pumps when manufactured. Model 23 airplanes which have been retrofitted with jet pumps in the field will be so identified on the title page of the Airplane Flight Manual.

COMPLIANCE: Required as indicated unless already accomplished.

To reduce the possibility of fuel contamination and/or the presence of ignition sources in the tailcone service area, accomplish the following:

A) Within the next 25 hours time-in-service after May 8, 1980:

1. Run each engine to takeoff thrust momentarily, shut down and immediately open the access cover under the tailcone service area and make the following visual inspections:

a. Inspect the fuel and hydraulic system components for deterioration or damage, leakage and stains indicating leakage, paying particular attention to the exterior of the P/N AV16E1182 motive flow shutoff valves.

b. Inspect the batteries and electrical equipment for deterioration or damage and conditions which may cause arcing.

c. Inspect all vents and drains for obstruction or blockage.

d. Before further flight, correct any of the above-noted unsatisfactory conditions. Do not disassemble or reassemble motive flow shutoff valves in the field. Replace leaking valves with a new or factory rebuilt part.

2. Remove the Temporary Airplane Flight Manual Supplement, included in AD 80-09-06 as Figure 1, in the existing Airplane Flight Manual and in place thereof, install Temporary Airplane Flight Manual Supplement, included in this AD as Figure 1A, and comply with its instructions.

B) On or before February 13, 1981, install Gates Learjet motive flow valve shrouds and drain lines per Modification Kit No. AMK 80-7. After accomplishing this modification, remove the Temporary Airplane Flight Manual Supplement required by Paragraph A)2.

C) Airplanes may be flown in accordance with FAR 21.197 to a location where the provisions of this AD can be accomplished.

D) Any equivalent method of compliance with this AD must be approved by the Chief, Aircraft Certification Program Office, Room 238, Terminal Building 2299, Mid-Continent Airport, Wichita, Kansas 67209; Telephone (316) 942-4285.

This AD supersedes AD 80-09-06, Amendment 39-3764.
Amendment 39-3913 became effective September 15, 1980.
This amendment 39-3998 becomes effective December 11, 1980.

FIGURE 1A


TEMPORARY AIRPLANE FLIGHT MANUAL SUPPLEMENT


FOR GATES LEARJET MODELS


23, 24, 25 , 28, 29, 35 AND 36 SERIES AIRPLANES

(AD 80-19-09 requires this supplement to remain in the below designated Airplane Flight Manual until replaced by an equivalent Gates Learjet Company Flight Manual Supplement.)

Model ________ N ________ S/N ________

In addition to the presently specified post-flight procedures, immediately after the engines are shut down, open the access cover under the tailcone service area and accomplish the following, using a flashlight or supplemental light as necessary for adequate illumination.

1. Check the motive flow valves for leaks or stains indicating leaks.

2. Check all vents and drains to assure that they are clean and free from obstruction.

3. Any leaking motive flow valve must be replaced with a new or factory rebuilt part prior to further flight.

4. Secure access cover.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_80-19-09_R.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
80-19-09 R1
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes
Subject:
Jet Pumps
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/11/1980
Make:
Learjet Inc.
Model:
23 | 24 | 24A | 24B | 24B-A | 24C | 24D | 24D-A | 24E | 24F | 24F-A | 25 | 25A | 25B | 25C | 25D | 2...Show more
Product Type:
Aircraft
Product Subtype:
Small/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: 80-19-09 R1
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3998

AD NUMBER:   80-19-09 R1

SUBJECT HEADING:   Airworthiness Directives; Gates Model 23, 24, 25, 28, 29, 35 and 36 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 11, 1980.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
80-19-09 R1 GATES LEARJET: Amendment 39-3913 as amended by Amendment 39-3998. Applies to the following Model 23, 24, 25, 28, 29, 35 and 36 series airplanes certificated in all categories:

Model	Serial Numbers
*23 (equipped with jet pumps)	23-003 thru 23-099
24	24-100 thru 24-357
25	25-003 thru 25-319
28	28-001 thru 28-005
29	29-001 and 29-002
35	35-001 thru 35-348
36	36-001 thru 36-045
*NOTE: Model 23 airplanes were not equipped with jet pumps when manufactured. Model 23 airplanes which have been retrofitted with jet pumps in the field will be so identified on the title page of the Airplane Flight Manual.

COMPLIANCE: Required as indicated unless already accomplished.

To reduce the possibility of fuel contamination and/or the presence of ignition sources in the tailcone service area, accomplish the following:

A) Within the next 25 hours time-in-service after May 8, 1980:

1. Run each engine to takeoff thrust momentarily, shut down and immediately open the access cover under the tailcone service area and make the following visual inspections:

a. Inspect the fuel and hydraulic system components for deterioration or damage, leakage and stains indicating leakage, paying particular attention to the exterior of the P/N AV16E1182 motive flow shutoff valves.

b. Inspect the batteries and electrical equipment for deterioration or damage and conditions which may cause arcing.

c. Inspect all vents and drains for obstruction or blockage.

d. Before further flight, correct any of the above-noted unsatisfactory conditions. Do not disassemble or reassemble motive flow shutoff valves in the field. Replace leaking valves with a new or factory rebuilt part.

2. Remove the Temporary Airplane Flight Manual Supplement, included in AD 80-09-06 as Figure 1, in the existing Airplane Flight Manual and in place thereof, install Temporary Airplane Flight Manual Supplement, included in this AD as Figure 1A, and comply with its instructions.

B) On or before February 13, 1981, install Gates Learjet motive flow valve shrouds and drain lines per Modification Kit No. AMK 80-7. After accomplishing this modification, remove the Temporary Airplane Flight Manual Supplement required by Paragraph A)2.

C) Airplanes may be flown in accordance with FAR 21.197 to a location where the provisions of this AD can be accomplished.

D) Any equivalent method of compliance with this AD must be approved by the Chief, Aircraft Certification Program Office, Room 238, Terminal Building 2299, Mid-Continent Airport, Wichita, Kansas 67209; Telephone (316) 942-4285.

This AD supersedes AD 80-09-06, Amendment 39-3764.
Amendment 39-3913 became effective September 15, 1980.
This amendment 39-3998 becomes effective December 11, 1980.

FIGURE 1A


TEMPORARY AIRPLANE FLIGHT MANUAL SUPPLEMENT


FOR GATES LEARJET MODELS


23, 24, 25 , 28, 29, 35 AND 36 SERIES AIRPLANES

(AD 80-19-09 requires this supplement to remain in the below designated Airplane Flight Manual until replaced by an equivalent Gates Learjet Company Flight Manual Supplement.)

Model ________ N ________ S/N ________

In addition to the presently specified post-flight procedures, immediately after the engines are shut down, open the access cover under the tailcone service area and accomplish the following, using a flashlight or supplemental light as necessary for adequate illumination.

1. Check the motive flow valves for leaks or stains indicating leaks.

2. Check all vents and drains to assure that they are clean and free from obstruction.

3. Any leaking motive flow valve must be replaced with a new or factory rebuilt part prior to further flight.

4. Secure access cover.

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.