AD 91-06-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airbus Helicopters Deutschland GmbH | MBB-BK 117 A-1 | Airworthiness Directives; MESSERSCHMITT-BOLKOW-BLOHM (MBB) Model BK-117 Series Helicopters |
| aircraft | Airbus Helicopters Deutschland GmbH | MBB-BK 117 A-3 | Airworthiness Directives; MESSERSCHMITT-BOLKOW-BLOHM (MBB) Model BK-117 Series Helicopters |
| aircraft | Airbus Helicopters Deutschland GmbH | MBB-BK 117 A-4 | Airworthiness Directives; MESSERSCHMITT-BOLKOW-BLOHM (MBB) Model BK-117 Series Helicopters |
| aircraft | Airbus Helicopters Deutschland GmbH | MBB-BK 117 B-1 | Airworthiness Directives; MESSERSCHMITT-BOLKOW-BLOHM (MBB) Model BK-117 Series Helicopters |
Unsafe Condition
Uncontrolled fuel vapor ignition which could result in an explosion, fire, and subsequent loss of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Modify and retrofit the bonding jumpers on the landing gear per ASB-MBB-BK 117-90-104. Install electrostatic dischargers and modify fuel vent outlet parts per ASB-MBB-BK 117-90-105 with specified changes. Remove fuel return lines per ASB-MBB-BK 117-60-107. Inspect fuel supply tank vent outlet ports per SB-MBB-BK 117-60-108 to ensure no paint blockage.
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Compliance Time
Within the next 50 hours' time in service or within 28 days after the effective date of this AD, whichever comes first.
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Affected Aircraft
MBB Model BK-117 series helicopters with serial numbers 7001 up to and including 7261, 7241, 7215 (per referenced service bulletins).
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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