MIL-PRF-87937

What is MIL-PRF-87937?

MIL-PRF-87937 is a United States military performance specification that establishes the requirements for biodegradable, water-dilutable, and environmentally safe cleaning compounds designed for use on aerospace equipment.

The compound is critical for routine maintenance and pre-treatment of military and civilian aircraft. It is formulated to be effective on various soils, including greases, oils, hydraulic fluids, and carbon exhaust, while ensuring compatibility with sensitive aircraft materials like painted aluminum surfaces, conversion coatings, and acrylic plastics (when used correctly).

The cleaning compounds meeting MIL-PRF-87937 are used on:

Aircraft Exteriors: Routine cleaning and removing various soils.
Aerospace Ground Equipment (AGE): Cleaning associated support equipment and engines.
Surface Preparation: Removing contaminants prior to the application of primers, topcoats, sealants, and adhesives.

Variations of MIL-PRF-87937

The MIL-PRF-87937 specification covers four distinct types of cleaning compound, classified by their chemical composition and intended duty level:

Type	Description & Base	Primary Use
Type I	Terpene Based (often D-Limonene), Solvent Emulsion, Water Dilutable	Light to Heavy Cleaning and degreasing. Effective for removing greases and hydraulic oil.
Type II	Water Dilutable Compound	Light to Medium Cleaning, intended for general surface cleaning and not for heavy soils.
Type III	Gel-Type Cleaning Compound	Medium to Heavy Cleaning for exterior aircraft surfaces. The gel form allows for longer dwell time on vertical surfaces.
Type IV	Heavy Duty, Water Dilutable Cleaning Compound	Heavy Duty Cleaning and degreasing of oil residues and carbon stains, often used in steam cleaning applications.

All types are designed to be biodegradable and water-dilutable to varying degrees. Users must adhere to specific dilution ratios and ensure the correct type is used for the coatings on the equipment (e.g., Type I may not be suitable for lacquer coatings).

Equivalent Specifications & Codes

MIL-PRF-87937 doesn't have a single common international NATO Code but is widely referenced by commercial aviation specifications due to its environmental focus and effectiveness.

Code Type	Equivalent	Notes
NATO Code	MIL-C-87937	Prior specification
Commercial Aviation References	Boeing (e.g., D6-17487), Douglas (e.g., CSD #1)	Products meeting this spec often meet these commercial requirements

It's crucial to consult the Qualified Products List (QPL-87937) for the latest approved products and the equipment manufacturer's Technical Orders for required dilution rates.