MS27215-2 Dehydrator Plug — Reusable Engine Desiccant Plug

The MS27215-2 Dehydrator Plug is designed to screw into 18 mm spark plug holes of aircraft piston engines and is filled with MIL-D-3716 desiccant. This plug protects against moisture and corrosion during periods of inactivity. It is reusable, with the desiccant color changing from blue (dry) to pink (saturated), indicating when replacement or reactivation is needed.

• ✅ Fits 18 mm spark plug holes
• ✅ Replaces AN4062-1
• ✅ Reusable — bake the desiccant beads to recharge
• ✅ Sold in multiples of 8 (80 plugs per can)
• ✅ Dimensions: 3.25 x 0.88 x 0.88 inches
• ✅ No shelf life limit when stored in the can

Why Use Dehydrator Plugs?

Engines that are flown infrequently are more likely to develop internal corrosion—especially freshly overhauled engines or aircraft stored in humid environments. The MS27215-2 plug is an affordable way to prevent expensive engine damage during:

• Flyable storage (7–30 days)
• Temporary storage (up to 90 days)
• Indefinite storage (90+ days)

Per NTSB and manufacturer guidelines, these plugs are an essential part of any aircraft engine preservation strategy, especially when humidity and salt air are present. Install dehydrator plugs in the top spark plug holes and check the desiccant color regularly.

When to Replace or Recharge?

• Blue: Dry and ready to use
• Pink: Saturated — bake to reactivate

Simply remove the plug, bake the silica gel beads until they return to blue, and reinstall. These plugs are durable and intended for repeated use.

Installation & Storage Recommendations

According to FAA and OEM guidelines:

• Install in each top spark plug hole
• Support leads with AN-4060 protectors
• Seal all other engine openings with tape or additional desiccant bags
• Inspect every 30 days during indefinite storage
• Replace or reactivate if half or more of the plugs change color

Refer to Continental’s Service Bulletin M89-3 and Lycoming SI 515 for detailed preservation procedures.

Trusted by Aircraft Owners & Engine Shops

Whether you’re a pilot preparing for winter storage or a maintenance shop protecting customer engines, dehydrator plugs are a must. Air Power, Inc. offers same-day shipping, volume availability, and expert support.