5.4 Environmental Specifications

The following DO-160D categories will be used for the MARK III:

Temperature and Altitude (DO-160D Section 4.0)

Category A2, Partially controlled temperature, Pressurized to 15,000 feet

Operating temperature

-15C TO +70C

Short time high operating temp

+70C

Loss of cooling

+40C

Ground Survival

-55C to +85C

Altitude

15,000 feet

Decompression

55,000 feet

Overpressure

-15,000 feet

Category F2, Non-controlled temperature, Non-pressurized, 55,000 feet maximum

Operating temperature

-55C TO +70C

Short time high operating temp

+70C

Loss of cooling

+40C

Ground Survival

-55C to +85C

Altitude

55,000 feet

Decompression

N/A

Overpressure

N/A

In-Flight Loss of Cooling (DO-160D Section 4.5.4)

Category W, 90 minutes minimum

The MARK III shall be able to operate with no forced cooling air at an ambient of +40° Celsius for a period of 90 minutes.

Temperature Variation (DO-160D Section 5.0)

Category B, Non-controlled temperature, Equipment mounted internal in aircraft

The maximum temperature variation rate is 5° Celsius per minute.

Humidity (DO-160D Section 6.0)

Category B, Severe Humidity environment

The unit shall withstand a 95% humidity, 10 day cycle.

Shock (DO-160D Section 7.0)

Category – B

Vibration (DO-160D Section 8.0)

Category – (UFF1)(SCLMY)

Explosion Proofness (DO-160D Section 9.0)

Category E

Non hermetically sealed equipment which meets the test requirements of environment I.

HONEYWELL Aerospace Electronic Systems

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Honeywell Mark III manual Environmental Specifications