MIL-STD-810 Icing/Freezing Rain Testing Method 521

The purpose of the MIL-STD-810 icing test is to evaluate the effect of icing on materials. As a MIL-STD-810 certified lab, we realize the importance of icing/freezing rain method 521 testing. Meeting the MIL 810 test method 521 icing test requirements can be difficult. Keystone Compliance understands the challenges and guides companies through the process.

Keystone takes a consultative approach throughout the entire test program. When products do not meet the requirements, we assist with finding solutions. Keystone Compliance partners with customers to achieve MIL-STD-810 product compliance. We are in constant communication throughout the entire test process. Keystone provides the peace of mind that all of your needs will be met.

Request a quote and find out first hand about our competitive pricing, timely process, and outstanding reputation. Ready to get started? We are. Contact us to see why so many companies work with us to achieve their military standard testing needs.

The Importance of Icing/Freezing Compliance Testing

This enclosure seal test provides testing for the evaluation of the effectiveness of de-icing equipment and techniques. This includes prescribed means to be used in the field.

The application of this MIL-STD 810 compliance method is to develop ice accretion from sea splash or spray. However, the ice thickness may need to be modified to reflect the lower density of the ice.

How MIL-810 Method 521 Affects Products

After examining the purpose and application of this 810-test method, the tailoring process will determine where icing/freezing rain is anticipated to occur within the materials life cycle. When ice removal is required before operation, use integral deicing equipment or expedients normally available within the field.

Evaluate the deicing equipment to assess the effectiveness and potential for damage. This damage may degrade the materials performance.

Ice formation can prevent material operation and survival. Ice formation may also affect the safety of operating personnel. The following typical problems listed below help determine if this method is appropriate for the material being tested. Note that this icing lab testing list is not intended to be all-inclusive.

  • Binds moving parts together
  • Adds weight to radar antennas, aerodynamic control surfaces, helicopter rotors, etc.
  • Increases footing hazards for personnel
  • Interferes with clearances between moving parts
  • Induces structural failures
  • Reduces airflow efficiency as in cooling systems or filters
  • Impedes visibility through windshields and optical devices
  • Affects transmission electromagnetic radiation
  • Provides a source of potential damage to material from employment of mechanical, manuel, or chemical ice removal measures
  • Reduces efficiency of aerodynamic lifting and control surfaces
  • Reduces aircraft stall margins

Information on this MIL-STD 810 Lab and Military Standard Testing Method

Use the anticipated life cycle sequence of events as a general sequence guide. However, there are two approaches to using this MIL-810 test method among other methods.

The first approach to the icing method 521 is to conserve the test item by applying the least damaging environments first. For the first approach, apply the icing and freezing rain following the rain tests but prior to the salt fog tests.

The second approach consists of applying environments to maximize the likelihood of disclosing synergistic effects. For this approach, subject the icing test item to the dynamic tests prior to conducting the icing/freezing test.

Though this MIL-STD 810 test method only has one procedure, there are various conditions that may be selected. Before conducting this ip code test, it is important to select specific procedure variations based on the requirements documents.

A buildup of ice occurs in four principal ways. First, from rain, drizzle, or fog falling on the material whose temperature is at or below freezing. Second, from sublimation. From freezing rain or freezing drizzle falling on material. Lastly, from sea spray and splash that coats material when the material temperature is below freezing.

Types of ice – There are two types of ice commonly encountered when proceeding with this icing freezing rain lab test.

Rime Ice – is a white or milky and opaque granular deposit of ice formed by a rapid freezing of supercooled water drops as they fall upon the exposed object. Rime ice is lighter, softer and less transparent than glaze with two variations: hard rime and soft rime.

Glaze Ice – This coating of ice is generally clear and smooth but usually contains some air pockets formed on exposed objects by the freezing of a film supercooled water vapor. Since glaze ice is more difficult to remove, it is structurally a more significant factor.

Water Delivery Rate –  The objective of this MIL-810 icing test variation is to produce a clear, uniform coating of glaze ice. Any delivery rate that produces such ice is acceptable. However, the water delivery rate is suggested at 25mm/h

Water Delivery Method – Nozzle arrays that direct spray to the top, sides, front and rear of the test item, a single nozzle directing spray over the appropriate surfaces of the test item. Nozzle arrays that spray straight down onto the test item are all acceptable. However, it is acceptable as long as the water is delivered in a uniform way.

Droplet Size – The droplet size may vary and range from 1.0 mm to 1.5 mm diameter.

Ice Thickness – Unless specifically measured data is available, the following ice thicknesses are recommended:

6 mm – represents general conditions, light loading

13 mm – represents general conditions, medium loading

37 mm – represents heaving ground loading and marine mast loading

75 mm – represents extremely heavy ground loading and marine deck loading

Limitations of the Icing Compliance Method

Within this MIL-810 standard method, some limits are imposed and must be noted when applying the tailoring process. This method is not supposed to simulate snow conditions or ice buildup on aircraft through supercooled clouds. Though frost occurs naturally, these effects are considered less important. They are not expected to be addressed within test method 521, icing freezing rain test.

This MIL-STD-810 standard may also not be suitable for the assessment of aerial/antenna performance. Lastly, other conditions that are not included within this MIL-810 icing freezing rain test are the icing effects from falling, blowing or recirculating snow, wet snow or slush.

Keystone Compliance Provides Icing/Freezing Rain Compliance Testing Standards

Our team strives to give our customers more time and energy on product development instead of testing. Keystone has a full military testing lab of equipment which permits us to provide short lead times on scheduling. In addition to MIL-STD-810 ingress protection testing and enclosure testing, Keystone has a full scope of expertise including solar radiation, fungus, and rain

Ready to get started? We are. Contact us to see why so many companies work with us to achieve their military standard testing needs.