99-22-08: Pneumatic Augmentation Valve
FAA order 99-22-08 is an airworthiness directive in force since November 30, 1999. The FAA's subject line: Pneumatic Augmentation Valve. It names Douglas DC-9, Mcdonnell Douglas Aircraft Co MD-88, Mcdonnell Douglas DC-9: about 110 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
- The Boeing Company
- Models
- DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A), DC-9-32F (C-9B), DC-9-33F, DC-9-34, DC-9-34F, DC-9-41, DC-9-51, DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), MD-88
- On this site
- Douglas DC-9 7 registered
Mcdonnell Douglas Aircraft Co MD-88 10 registered
Mcdonnell Douglas DC-9 93 registered
Dates and paperwork
- In force since
- November 30, 1999
- Published
- October 26, 1999 (signed October 15, 1999)
- Docket
- 98-NM-382-AD
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The FAA's summary their words, unchanged
This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9, DC-9-80 and C-9 (military) series airplanes, and Model MD-88 airplanes, that requires revising the wiring of the air conditioning pneumatic supply control, if applicable, and revising the wiring of the pneumatic augmentation valve. This amendment is prompted by a report indicating that the pneumatic augmentation valve may go fully open when an engine fails during initial climb prior to deactivation of the second segment climb switch. The actions specified by this AD are intended to prevent opening of the pneumatic augmentation valve, which could result in significant loss of thrust from the remaining engine and consequent inadequate initial climb performance of the airplane.
The order itself the regulatory text, as published
Show the full text (3,840 characters)
Related safety bulletins advice on the same designs, not orders
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/99-22-08.json · aircraft systems.
