High-Definition Aircraft Bulkhead Display: Design, Certify and Manufacture
Fanless hardware design, embedded OS & video processing firmware, and mechanical design for Business Class bulkhead display that passed RTCA DO-160 and DO-178 Qualification testing.
An aviation electronics solutions company that serves customers in the commercial aerospace and defense industries.
The client needed a custom-designed, high-definition bulkhead display unit (BDU) for business aircrafts. A single intelligent circuit board would handle various formats of incoming data streams and be paired with three different sizes of monitors: 19, 22 and 24 inches. All units had to play all video formats (H.264, MPEG, NTSC, etc.) at any resolution (640x480, 1024x768, 1080x760, 1920x1080, etc.). The client wanted to outsource all aspects of the project, including engineering design in hardware, software and mechanical enclosure; tooling; development of prototype units; DO-160 and DO-178 qualification; and production.
Among the hundred pages of specifications for the units were some very specific requirements that turned out to be much more challenging than they first appeared:
- Consistent color temperature and brightness across all display units
- Brightness of 500 nits (candelas per square meter)
- Ruggedized front panel with no screen glare from unshaded airplane windows
- Optimal video quality for seated viewers watching from a low viewing angle
The customer also wanted a fanless solution, which would reduce system size and weight, but did not believe this was truly possible. In addition, the entire unit needed to be qualified to RTCA DO-160 and DO-178 specifications.
This project was extraordinary for two reasons: First, it required every engineering discipline of RightHand Technologies to create a very elegant, multifaceted solution. Second, it had several particularly challenging product requirements.
By using its years of experience in embedded electronic systems design and problem-solving skills, along with tight integration among all company departments—including electrical engineering, software engineering, mechanical engineering, qualification and manufacturing—RightHand Technologies successfully developed a complex, high-quality in-flight entertainment product suitable for the cabins of executive jets, with all FAA qualifications and documentation. The resulting displays give no inkling of the underlying complexity and technical challenges of the project.
Every department at RightHand Technologies contributed to the project:
- Hardware: Off-the-shelf LCD panel modifications for brightness and ruggedness, and an intelligent processor circuit board for video encoding and decoding.
- Software: Board support software including Linux operating system and drivers, on-screen display configuration application, bootloader for field upgrades, and manufacturing test and calibration utilities.
- FPGA: I/O mapping and video manipulation for optimal viewing from a low angle.
- Mechanical: Heat dissipation and EMI suppression and containment in an attractive, lightweight aluminum enclosure.
- Quality: 100% functional testing outlined in detailed Assembly and Test Instructions (ATI), automated Acceptance Test Procedure (ATP) and computer controlled uniform color calibration.
- Manufacturing: Assembly tools and fixtures to ensure the manufactured units conform 100% to the qualified design.
Working together, RightHand Technologies’ engineers used their extensive experience in developing complex embedded electronics, their in-depth knowledge of high-speed video processing and FPGAs, and their ingenuity to develop creative and innovative solutions that met all of the customer’s product requirements, including:
- Consistent color temperature and brightness: Wrote color calibration software and developed a custom calibration test apparatus for use during manufacturing tests that measure and store unique calibration parameters for every device.
- Brightness: Replaced the LCD panels’ fluorescent tubes with custom-developed circuit boards containing bright white LEDs. This also improved the monitors’ reliability and durability in harsh conditions.
- Panel ruggedness and glare: Optically bonded a strong, protective glass shield with anti-glare film onto the LCDs’ screens. This had the added benefit of reducing electrical emissions from the panel.
- Optimal video viewing angle: Inverted the display to optimize video quality for viewers in a seated position and then coded the FPGA to invert the video image before displaying.
- Fanless: Used the entire back of the enclosure as a heat sink for the high-speed electronics through the strategic placement of precision-machined contact surfaces and ceramic thermal transfer tape to wick the heat away from the chips and dissipate it into the enclosure.
To ensure that the finished product qualified to FAA-required RTCA DO-160 and DO-178 specifications, RightHand engineers also used their knowledge, resourcefulness and experience to:
- Effectively create a Faraday cage around the components by connecting the conductive surface of the glass to the bezel with a clever implementation of silver ink, copper tape and a conductive elastomer, which sealed the glass to the bezel.
- Perform 100% functional testing.
- Develop assembly tools and test fixtures to ensure that all manufactured products—which were produced in the company's dedicated, state-of-the-art AS9100:2009 Certified specialized manufacturing facility—conformed 100% to the qualified design.
RightHand Technologies delivered this project within three days of the projected target date and exceeded every aspect or parameter of the client’s requirements—including developing a fanless design, which the customer did not expect could be achieved.
In addition, the systems qualified to the FAA-required RTCA DO-160 and DO-178 specifications with ease. RightHand Technologies prepared and delivered all of the documentation required for the testing, accompanied the units to the testing labs, obtained FAA certification in nine days, and then delivered a completely qualified product to the customer.
The customer is extremely pleased with the BDUs and with RightHand Technologies. The product line has been very well received and is selling much faster than the customer originally anticipated. Plus, the customer subsequently has awarded RightHand Technologies several additional projects needing qualification to FAA-required specifications.