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89-18-13: AFM Changes - APU

FAA order 89-18-13 is an airworthiness directive in force since September 28, 1989. The FAA's subject line: AFM Changes - APU. It names British Aerospace BAE 125, Hawker Siddeley HS.125 SERIES 700A: about 82 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: engine.

What it applies to as the FAA lists it

Kind of product
Aircraft
Makes
Textron Aviation Inc.
Models
BAe.125 Series 1000A, BAe.125 Series 1000B, BAe.125 Series 800A, BAe.125 Series 800A (C-29A), BAe.125 Series 800A (U-125), BAe.125 Series 800B, BH.125 Series 400A, BH.125 Series 600A, DH.125 Series 1A, DH.125 Series 1A-522, DH.125 Series 1A/R-522, DH.125 Series 1A/S-522, DH.125 Series 3A, DH.125 Series 3A/R, DH.125 Series 3A/RA, DH.125 Series 400A, HS.125 Series 1B, HS.125 Series 1B-522, HS.125 Series 1B/R-522, HS.125 Series 1B/S-522, HS.125 Series 3B, HS.125 Series 3B/R, HS.125 Series 3B/RA, HS.125 Series 3B/RB, HS.125 Series 3B/RC, HS.125 Series 400B, HS.125 Series 400B/1, HS.125 Series...
On this site
British Aerospace BAE 125 75 registered
Hawker Siddeley HS.125 SERIES 700A 7 registered

Dates and paperwork

In force since
September 28, 1989
Docket
89-NM-24-AD
Status
Current
The FAA's document
Read the order on the FAA's site

The order itself the regulatory text, as published

Show the full text (2,178 characters)
89-18-13 BRITISH AEROSPACE: Amendment 39-6309. (Docket No. 89-NM-24-AD) Applicability: Model DH/HS/BH/BAe 125 series airplanes certificated in any category, equipped with Sundstrand Turbomach Titan Gas Turbine Auxiliary Power (APU) Unit, Model T- 62T Series, installed in the aft equipment compartment of the airplane. NOTE: Installation of the subject APU's has been in accordance with, but are not limited to, the following Supplemental Type Certificates (STC): SA674CE SA1143EA SA1176EA SA1196EA SA440NE SA1173EA SA4710SW SA1923SW This AD applies to all Sundstrand Turbomach Titan APU installations in the aft equipment compartment. Compliance: Required as indicated unless previously accomplished. To prevent a fire in the aft equipment compartment, puncture of the aft pressure bulkhead, and severance of the control cables, due to an uncontained APU rotor failure, accomplish the following: A. Within the next 10 days after the effective date of this AD: 1. Revise the Limitations Section in the FAA-approved Airplane Flight Manual (AFM) Supplement to include the following statement. This may be accomplished by inserting a copy of this AD in the AFM Supplement Limitations Section: "OPERATION OF THE APU DURING FLIGHT IS PROHIBITED, EXCEPT DURING AN EMERGENCY." 2. Install a placard next to the APU start switch in the cockpit to state: "OPERATION OF THE APU DURING FLIGHT IS PROHIBITED, EXCEPT DURING AN EMERGENCY." B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region, Transport Airplane Directorate. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Standardization Branch, ANM-113. C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of modifications required by this AD. This amendment (39-6309, AD 89-18-13) becomes effective on September 28, 1989.

Related safety bulletins advice on the same designs, not orders

2015-09-29NM-15-24 · Landing Gear
2013-11-27NM-14-05 · Wing: Ailerons
2011-09-29NM-11-60 · Landing Gear

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 30, 2026. Connections as data: /graph/directive/89-18-13.json · aircraft systems.