Aircraft emergency equipment repair.

Aircraft emergency equipment includes aircraft escape slides but also safety equipment to be used by passengers in the event of emergency.

Inflatable lifejackets and liferafts are subject to general deterioration due to aging. Experience has indicated that such equipment may be in need of replacement at the end of 5 years due to porosity of the rubber-coated material. Wear of such equipment is accelerated when stowed on board aircraft because of vibration which causes chaffing of the rubberised fabric. This ultimately results in localized leakage.

Leakage is also likely to occur where the fabric is folded because sharp corners are formed. When these corners are in contact with the carrying cases, or with adjacent parts of the rubberized fabric, they tend to wear through due to vibration.

Lifejackets inspection and lifejacket repair.

Aircraft lifejackets should be inspected at 3-month intervals for cuts, tears, or other damage to the rubberized material. Check the mouth valves and tubing for leakage, corrosion, and deterioration. Remove the carbon dioxide cylinder and check the discharge mechanism by operating the lever to ascertain that the pin operates freely.

Check the gaskets and salve cores of the cylinder container and the pull cord for deterioration. If no defects are found, inflate the preserver with air to a 2  pound pressure and allow to stand for 12 hours. If the preserver still has adequate rigidity at the end of that time, deflate and fit with C02 cylinders having weights not less than that indicated on them by the manufacturer. All cylinders made in accordance with joint Army/Navy Specification MIL-C-00601D are stamped in this way and have a minimum permissible weight shown on them. The use of such CO2 cylinders is recommended.

These cylinders have the 5/32-inch end disc sealed by an electric welding process, which is intended to provide a superior seal compared to the older type, which have a similar disc surrounded by a thin rubber seal. Inasmuch as the rubber is subject to deterioration, its ability to maintain pressure will possibly be affected. Leaky electrically welded seals will probably be discovered upon final inspection at the manufacturer's plant. If such a cylinder is up to weight at the end of 3 months in all probability it will remain so until used; whereas, the old type with the rubber seal is apt to lose its pressure with age.

Having fitted the preserver with an adequately charged cylinder, mark the preserver to indicate the date of inspection and pack into its container. It is recommended that the aforementioned procedure be repeated every 12 month period, using the CO2 cartridge for inflation. Carbon dioxide permeates the rubberized fabric at a faster rate than air and will indicate if the porosity of the material is excessive.