- 08 Jun 2020
- Brian Wilson
- Jet Connectivity
Ken Elliott reviews cabin electronics upgrades, with a focus on retrofit. Here he covers the planning phase. Future articles will focus on the implementation of various cabin systems.
What's the best way to plan and undertake an upgrade to your aircraft's cabin electronics? Ken Elliott reviews, starting with a focus on the planning phase...
Assuming you are catering to passengers and not cargo, your aircraft’s appearance is crucial to those who own, charter or share it. That appearance is experienced on several different levels, including:
To a degree, all levels of experience are pertinent to this article. To meet experience objectives, any improvements to the cabin should be well studied. Essentially, changes to cabin electronics should not be considered in isolation.
Cabin modifications are extremely complex, requiring input from several disciplines. So, while this series is electronics-related it will address integration with respect to the overall cabin, beginning with planning.
Cabin Electronics Upgrade: Where to Start Planning…
Starting with the cabin’s occupants is always a good place to commence planning. It’s important to hear primary user desires and keep an open mind. It could be that a minor malfunction with an existing system triggered the CEO’s decision to upgrade, so this will be a good time to plan a strategy and do it right.
Have all your ducks in a row to upgrade the cabin. Why? Because it makes sense on so many levels… While downtime and cost will always be primary drivers, they should be weighed against the downsides of a compromised cabin.
Perhaps the biggest reason for planning an interior upgrade, including the electronics, is because you don’t want to access the interior more than you need to. Interiors are expensive and while improvements have been made to expedite removal and reinstallation (R&R) over the years, it is still a ‘process’ to access wire runs, equipment and component mounting.
Most major MROs have interior teams that specialize in access and the professional handling of storage, but this is still a vulnerable time for aircraft interiors and other aircraft substructures.
Even small cabin upgrades should have a plan, and this process can be applied to many levels of cabin improvement. Following are the major subsets of the plan, as a set of questions, and not in order of priority:
Weight, Power and Cost?
What is Your Accomplishment Goal?
Consider how everything interacts when looking at overall accomplishment. There will be inter-dependency in the cabin where physical activity within small spaces can interact across zones. Start planning from the CEO seat.
The CEO seat will have the primary controls with the most choice, allowing an override of selections made by others. Moreover, plan goals by dividing the cabin into zones, i.e. by seat groupings, galley, vestibule, bathroom and storage.
Take a minimalist approach to de-clutter the cabin design and prevent confusion over multiple selections of the same function. Accomplishment is a satisfied customer, and if it means a sales engineer visiting the aircraft at its home-base to hear and visualize a customer’s plan, then you will be glad that occurred. (After all, photographs help but only tell half the story.)
The completion facility should ask and verify with the operator the following three significant questions:
What are your expectations of when the aircraft is complete? On the first two questions, a typical pre-owned aircraft with higher airframe hours will likely have a potpourri of cabin modifications, differently aged, while missing some of its custom prints, weight and balance, and electrical load amendments.
Regarding the third question, communication on the front-end (cockpit) dictates the degree of anticipated functionality on the back-end (cabin). Equipment providers should be included in the discussion at this early stage. Finally, as a goal consider cabin functionality with respect to typical flight times, the size and layout of the cabin, and the anticipated level of comfort and convenience desired.
What are the Non-electrical Impacts?
There are four key questions when it comes to the non-electrical impacts of a cabin electronics upgrade. These are:
A good approach at this stage is to use layout diagrams for the cabin showing all potential integration, including wire routing. It may be necessary to access both sides of the cabin, including the aft bulkhead behind the lavatory for route wiring between components on both sides.
Footprint is so crucial in the cabin. This is exacerbated in side ledges and narrow spaces. Never assume a replacement product will fit where an existing product is located, or that there is space if you are simply adding new. You should also plan for cooling distance around components that need it, and allow access for future servicing or software uploads.
What are the Access Considerations?
There is a valid argument to complete a major cabin upgrade in stages, phasing downtime, budget and other factors over several manageable visits. However, before completing that assessment you should consider the impact of ‘open and close’ with each shop visit, and the impact of phasing certification, including sign-off provisions. Access can be very painful for the completion facility and the operator, so you should try to keep it to a minimum.
Plan access very carefully, ensuring proper protection and storage for anything removed, while remembering that the center of gravity can shift on the fuselage after a complete interior is removed.
Size, weight and power, with an eye on cost, is so important, because an aircraft represents very limited real estate with a capacity for only so much weight and current-draw. While the size of new cabin electronics is likely to be less, the form and fit may be different.
Most changes will result in a weight reduction as heavy power amps and monitors are replaced, but you should never assume. Note, too, the overall impact of projected weight change on the Center of Gravity.
Power considerations are very important. Although a new current load may be less, the current draw on any single aircraft power bus may be an issue, especially if the utility buss is already at maximum capacity.
Another common issue for cabins is power outlets for carry-on devices. Make sure the aircraft bus or power converters are capable of providing the right current load at each location. There also may not be enough physical breaker locations, requiring additional engineering and build requirements to the project.
While cost is a driver in product selection, and compromise may be necessary, always try to do the right thing regarding SWaP-C – consider the safety, reliability, practicality, ergonomics and quality.
The FAA and other aviation authorities delegate certification authority to Designated Engineering/Airworthiness Representatives (DERs/DARs). These are the folks who should be consulted before you turn a wrench, or pin a new wire. Most completion facilities will have DERs and DARs on staff, or as regular consultants. They know what is necessary to ensure approvals for cabin upgrades.
When you reach out to a DER, they will ask questions and focus attention on important certification requirements. When planning, make sure you’re including all supporting documentation needed, how and who will generate it, and how – throughout and upon completion – the facility will demonstrate compliance to airworthiness requirements.
Unless you are undertaking an aircraft manufacturer’s standard and proven cabin system upgrade, try to avoid the embarrassment of delivering a new cabin electronics system with incomplete functionality. Of course, it is highly likely that with any change, functionality may end up being different to that existing. The key is to have that discussion during the planning phase.
Here it is also essential to include others. For example, conducting an aircraft survey that includes the systems providers early on can save you so much time and money!
Lastly, make sure new equipment for the cabin is in itself certifiable. This means it may need a Technical Standard Order (TSO) number, issued to the manufacturer by the certification authority.
As with most avionics systems, those created for the cabin will come with standard features and permit options. When planning it’s essential to ensure the owners of the aircraft are aware of all options available to them. Understand, though, that options may themselves have limitations, including incompatibility with aircraft type and other equipment.
Specific new or existing systems may require a level of software, a hardware modification or even a complete replacement. Be careful when reviewing sales material as it is designed to sell a product. It may not necessarily include all the integration requirements you will need to get there.
That’s why it’s essential to have an equipment provider involved early in planning. Either or both, owner and completion facility, can engage with the provider(s), the DER(s) and customer’s consultant conversant with the aircraft model.
Be prepared to review several different cabin electronic suites and not just the one that comes recommended. There is no harm in evaluating different options for equipage, completion facility and future subscriptions provider.
Figure B (above) shows a simplified block diagram of a modern entertainment system. It assumes (North American) continental operations with ATG Wi-Fi. Apart from some of the familiar legacy interfaces, it also relies on Bluetooth and walk-on devices, saving on wiring and providing personalized familiar interfaces, as if operating at your favorite coffee shop or home office.
When I had a custom home built, it took double the estimated time. The quality was amazing and attention to detail stunning. Assume your cabin upgrade will, at least to some degree, be customized. The mere mention of the word custom seems to stretch time.
Be prepared for extra downtime and understand that, in most cases, completion centers have your best interests at heart. They truly want to get you delivered so another hangar slot becomes available. Nevertheless, it is the nature of the business that completions rarely deliver precisely on time.
Downtime planning should include extra time for interior R+R, system performance checks, and to undertake corrections. Be prepared to update downtime after the aircraft has been fully accessed. At this point a completion center should review the work scope with the owner’s representative present, to assess for additional requirements.
It is rare that a legacy aircraft is found to be exactly as represented. Items and wire routes are not always as, or where, prints and drawings specify. Downtime is driven by accurate data that is only available when the aircraft is open and the work scope is compared against reality.
Never forget the peripherals of a cabin electronics upgrade, some of which are:
Test and Delivery
No cabin upgrade is complete until verified. Plan on carving out time to train the flight department on full system capability, while making sure everyone understands that Air to Ground (ATG) internet and communications function differently in three ways, including on the ground; airborne below 10,000ft: and then above 10,000ft (for example).
A test flight, even if not required, is always advisable. Some flight check items should be:
A common flight test practice is to ensure the customer representative is on-board, as well as having some seats filled by technicians to test ergonomics and functionality. Next time we will address considerations for the actual installation of the cabin electronics. Stay tuned!