AD 77-13-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Textron Aviation Inc. | BH.125 Series 400A | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | BH.125 Series 600A | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 1A | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 1A-522 | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 1A/R-522 | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 1A/S-522 | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 3A | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 3A/R | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 3A/RA | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
| aircraft | Textron Aviation Inc. | DH.125 Series 400A | Airworthiness Directives; HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 Airplanes |
Unsafe Condition
Failure of the knife edges of the emergency brake reducing valve, P/N AC.61516, leading to complete loss of emergency braking capability without advance warning.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the emergency brake control valve knife edges with new parts per Service Bulletin 32-167 Part A or replace the entire emergency brake reducing valve (P/N AC.61516) with a valve fitted with new knife edges per Service Bulletin 32-167 Part B, followed by recurring compliance at intervals not exceeding 4500 landings since last compliance.
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Compliance Time
Prior to the accumulation of 4500 landings, 200 landings, or as specified based on existing records and landing counts as detailed in the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
HAWKER SIDDELEY AVIATION, LTD Model DH/BH-125 airplanes, all series, certificated in all categories.
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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