| AD Number | 59-12-03 | Status | Active |
| Effective Date | Not specified | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | N/A |
| Product Type | ["Aircraft"] | Product Subtype | ["Large Airplane"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Vickers-Armstrongs (Aircraft Limited) |
| Model(s) | Viscount 745D Viscount 810 |
59-12-03 VICKERS: Applies to All Viscount 745D and 810 Series Aircraft.
Compliance required by October 31, 1959.
Two cases have occurred of the Graviner fire extinguisher cartridge types A216 and A217 failing to operate at altitudes exceeding 20,000 feet. The failures were due to a combination of altitude and temperature affecting the gunpowder charge. To preclude such failures the Graviner Manufacturing Company has issued Modification AU 393 introducing improved firing units type A716 (replacing type A216) and type A717 (replacing A217). The new units have a modified bridge wire arrangement and may be identified by a blue plastic band around the neck of the cartridge. The British Air Registration Board considers the embodiment of this modification mandatory.
(Graviner Manufacturing Company Modification No. AU 393 and Vickers-Armstrongs PTL205 and Modification D.2926 (700 Series) and PTL 73 and Modification FG.1695 (800/810 Series) covers this subject.)