AD 99-23-24
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B2-1A | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B2-1C | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B2-203 | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B2K-3C | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B4-103 | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B4-203 | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B4-2C | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B4-601 | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B4-603 | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
| aircraft | Airbus | AlliedSignal | The Boeing Company | A300 B4-605R | Airworthiness Directives; AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes |
Unsafe Condition
The ILS navigation receiver incorrectly indicates signals from the glideslope ground station during final approach due to improperly sized resistors, leading to inaccurate glideslope data and potential landing short of the runway or runway overrun.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace three resistors in the ILS navigation receiver with higher ohm resistors and replace the nameplate with a new nameplate within 6 months after the effective date of the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 6 months after the effective date of this AD
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Affected Aircraft
AlliedSignal ILS navigation receivers installed on Airbus Model A300 series and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP series airplanes.
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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