01 — Public chapter: component, system and installed boundaries

DO-160 Display Qualification | A-P02 — Draft / Not Released

Learning objective: Allocate evidence to the display boundary that actually experiences the condition.

Define the display boundary before selecting tests

For planning purposes, use three levels. These are engineering boundaries, not separate DO-160 certification classes.

A “display module” sold as an enclosed, directly aircraft-powered unit may already be the equipment under test. A bare panel driven from a regulated internal rail is a different boundary. The supplier’s product name does not decide the test allocation.

Upstream inputs may be represented by controlled simulators. The display still needs tests for correct presentation, timing, validity indication and response to missing or malformed inputs. That verifies the display’s interface behavior; it does not qualify the equipment that normally generates those inputs.

Component testing reduces risk before qualification

Component work is most useful when it finds weaknesses before the final assembly is committed. Characterize cold response, hot luminance, dimming behavior, uniformity, color, touch performance and power demand. Exercise the optical bond, seals and flex connections through relevant temperature, moisture and mechanical exposures.

The conditions need to represent the component’s actual environment. A panel inside a sealed display usually does not see the same water exposure as the front surface. A backlight bonded to a heat spreader does not have the thermal boundary conditions of a bare module in free air. A fixture can either reproduce the intended support or create an artificial glass stress.

Supplier evidence should identify the part and revision, sample configuration, mounting, electrical drive, exposure, measurements, criteria and results. A temperature range on a data sheet does not explain whether an image remained usable throughout the range.

Qualification credit must be justified. DO-160G §2.9 ties results to the tested configuration, and §3 addresses representative connections, operating modes and test arrangements. Review differences in enclosure, glass, bonding adhesive, panel, backlight drive, firmware, grounding and cables before reusing evidence. Retest affected requirements where applicability cannot be demonstrated. DO-160G publisher information.

Exercise: place the disturbance

A bonded LCD uses an internal 5 V rail. The complete display accepts aircraft 28 VDC. A supplier offers a bare-panel temperature report and says no power-input test is needed. Identify the missing argument.

Worked response: the panel report may support the panel's allocated temperature requirement if configuration and conditions match. It does not evaluate the aircraft input, power converter, internal rail behavior, enclosure cooling or complete display reset behavior. Apply the allocated aircraft power tests at the complete display's aircraft interface and observe the internal consequences and visible function. Preserve the panel report as supporting evidence with a defined limit of applicability.

Boundary worksheet

Record what is physically supplied, what is needed to operate it, and what the aircraft supplies. Identify separate display controllers, remote power modules or dedicated cooling equipment that are part of the display architecture. Record cable ownership and whether each connection is internal to the display system or an aircraft interface. That distinction determines test points and representative harness arrangements.

Fixed-wing aircraft and helicopters

The same component, complete-system and installation boundaries apply to both. The environmental allocation changes with the aircraft, location and intended function. A fixed-wing report does not automatically qualify a display for a helicopter, and a helicopter label does not establish suitability for every rotorcraft.

Planning input	Fixed-wing application	Helicopter application
Vibration	Identify propulsion type and installation zone; select the applicable standard or robust method and any required abnormal-condition test.	Use the helicopter robust approach; establish rotor-related frequencies or the applicable unknown-frequency method and location limits.
EMI and EMC	Account for enclosure, airframe shielding, bonds, harnesses, antenna proximity and display function.	Use the same evidence chain; assess the specific airframe, wiring and installed equipment. Do not assign an automatic helicopter RF severity multiplier.
Pressure and exposure	A pressurized flight deck and an unpressurized light aircraft can require different allocations.	Establish the actual pressure and exposure environment; do not transfer a pressurized-airplane decompression assumption by default.
Crew interaction	Verify installed viewing, dimming, controls and the relevant operating conditions.	Include operational vibration and control usability, plus mission-specific gloves, lighting or NVIS requirements where applicable.

These are planning distinctions. The adopted DO-160 revision, aircraft requirements and accepted compliance plan determine the actual tests. Chapters 11 and 14 develop the vibration and EMC comparison; Chapter 22 applies it to a second capstone case.