22 — Capstone: plan qualification for a complete aircraft display

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

Learning objective: Assemble a reviewable plan and identify the inputs that prevent premature category selection.

Scenario — all values are teaching assumptions

You are buying a 10-inch bonded touch display with an internal LCD module, graphics processor, backlight, heater and metal enclosure. The complete assembly takes nominal 28 VDC; the panel uses an internal 5 V rail. The proposed installation is a pressurized flight-deck location with four structural mounts and conduction plus local airflow cooling. The customer asks for −40 °C to +70 °C operation, −55 °C to +85 °C unpowered survival, Section 5 Category B variation and a decompression test described only as 65,000 ft. No power-input, RF, lightning or vibration categories have been agreed.

The example intentionally contains incomplete allocations. Do not assume a Section 4 category from these numbers alone, and do not claim the proposed high-altitude endpoint is a universal DO-160 requirement.

Task 1 — define and question the boundary

Draw or describe the complete display architecture and supplied cables. Identify controlled interface simulators. List missing installation inputs: aircraft maximum operating altitude, pressure profile, local thermal environment, cooling failure conditions, vibration location, electrical power characteristics, shielding/bonding and functional criticality. State who must provide each input.

Task 2 — create the matrix

Consider Sections 4–26. For each applicable section give the candidate method and the information needed to finalize it. Use unresolved rather than a guessed category where input is missing. Document exclusions with a rationale. For the component panel, state which development data can support the complete-display plan and where it cannot.

Task 3 — write two procedure outlines

Prepare a cold-operation outline with explicit survival/conditioning separation, stabilization, timing and startup checks. Prepare a Section 5 outline using the complete adopted Category B sequence. Compute the ideal one-way −40 to +70 °C transition time at the minimum stated rate: 22 minutes. Identify the additional stages that prevent using 22 minutes as a total test duration.

For decompression, request initial and final absolute pressures, final altitude basis, transition time, hold, power/mode and acceptance. Explain the relationship between the proposed customer endpoint and the aircraft maximum operational altitude. Keep the Section 9 decision separate.

Task 4 — define monitoring and criteria

Write measurable requirements for startup, dynamic image continuity, luminance/contrast under defined conditions, controls, validity indications, resets and recovery. Classify each as during exposure, after exposure or survival. Specify synchronized observations and the uncertainty decision rule. Proposed numbers are design inputs until agreed; label them.

Task 5 — buy and hand over evidence

Prepare a deliverable list, configuration record, article allocation/sequence, deviation/retest process and installation-verification checklist. Include the source and report identifiers needed for another engineer to review every closed requirement. State any limits on evidence reuse for other panels, covers, touch controllers or harnesses.

Review rubric — 100 points

Suggested learning target: at least 80/100 and no unresolved misconception that survival proves operation, a component report qualifies the full assembly, or a chamber pass establishes installation approval. This is a teaching rubric, not an aviation qualification or personnel authorization.

Model-review highlights

A strong plan refuses to invent the missing power, vibration and lightning categories. It preserves the customer's temperature requests as explicit requirements while checking their relationship to Section 4. It treats 65,000 ft as a requirement needing clarification and reconciliation with the aircraft environment. It includes optical/control performance during the required exposures, a real configuration record and the integrator's installed-verification duties.

Second capstone case — helicopter installation

Now propose the same display for an assumed unpressurized helicopter, with an isolator-mounted instrument panel and a different harness route. This is a teaching scenario, not an AW139 specification. Do not carry over the first case’s pressurization, altitude, vibration, EMC or cooling assumptions without review.

1. Ask the integrator for the aircraft model/configuration, intended location, mounting and bonding drawings, relevant rotational frequencies and blade counts, and measured local vibration data if available. Explain when the known-frequency, unknown-frequency or agreed tailored approach could be considered.
2. Compare the new harness, shield terminations and bonds with the tested arrangement. Identify the evidence needed for equipment EMC, onboard compatibility, HIRF and lightning separately.
3. Revisit pressure, temperature, water/dust exposure, power behavior and installed viewing/control use against the mission. Treat NVIS and gloved touch operation as explicit requirements when specified.
4. Produce a two-application qualification matrix showing justified common evidence, additional work and unresolved inputs. Identify the contractual owner of each missing input.

Model-review point: “Use Category U2 and the highest RF category” is not an adequate answer. The method must fit the installation and intended coverage, while RF requirements depend on the function, environment and installation evidence. The existing 100-point rubric applies to either case; assess the aircraft-specific reasoning under boundary, applicability, monitoring and handover.