AD 78-26-10 R1

final rule
Data completeness: 70%

Airworthiness Directives; Great Lakes Model 2T-1A-1 and 2T-1A-2 Airplanes

AD Number
78-26-10 R1
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Great Lakes Aircraft Company, LLC (John Duncan) 2T-1A-1 Airworthiness Directives; Great Lakes Model 2T-1A-1 and 2T-1A-2 Airplanes
aircraft Great Lakes Aircraft Company, LLC (John Duncan) 2T-1A-2 Airworthiness Directives; Great Lakes Model 2T-1A-1 and 2T-1A-2 Airplanes

Unsafe Condition

Contamination of cockpit heater air with carbon monoxide due to cracks in the support plates of the heat exchanger at both ends between the five tube cluster.

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

Required Actions

Within 25 hours time-in-service after the effective date, determine if the airplane has P/N 50146 heater system; if equipped, install a walk around inspection in the Flight Manual, and inspect support plates for cracks every 25 hours time-in-service. If cracks found, replace heat exchanger or comply with Paragraph B. Paragraph B requires removing the heater system, installing specified parts, blocking valves and openings, and removing AFM revision if installed.

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 the effective date of this AD, and within each 25 hours time-in-service thereafter for recurring inspections.

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

Affected Aircraft

Great Lakes Model 2T-1A-1 and 2T-1A-2 airplanes equipped with P/N 50146 cockpit heater system.

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

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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