Avionics News July 2012 - 40

Tips for a Smooth Retrofit
1. Planning is key. Even for what you think will be a simple install, perform an electrical load analysis, a complete inventory of avionics actually in the airplane (not just what’s in the records) and do a flight test to verify the autopilot works. Look carefully at HIRF/EMI requirements for the new equipment (especially PFDs) and the aircraft instructions for continuing airworthiness to verify that it meets the STC requirements. Bringing a legacy airplane up to modern EMI standards can be a significant issue. Identify existing avionics that will be retained to the serial number (model and sub-type) level to assure compatibility and avoid unpleasant surprises. Follow all the manufacturer’s instructions, including surveys and forms, before pulling equipment out of the airplane. Consider a block diagram to identify all major components connected to the new glass avionics. It can be included in the flight manual supplement, and will be helpful to you (and others) when troubleshooting problems. If you spend more than one hour chasing a problem, call tech support for whatever component you’re working on. They may have seen the problem before and can save you hours of wasted time. For custom installations that involve deviations from an AML/STC (and on heavy airplanes, where every install is a custom job), get the certification people involved early. If you finish the airplane before contacting them, you’re setting yourself up for a long delay. Training the flight crew on glass is more than just a five-minute conversation and handing them the manual. Make sure the operator has a training plan. Glass avionics are complex: Consider building a reserve into your quote to handle unexpected trouble – especially the first time you install a particular unit. RETROFIT INSTALLATIONS
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10. Ask the operator (and yourself): What’s your Plan B? These installs involve much more than just pulling a radio and replacing it. If you find corrosion in the airframe, or discover major issues in existing wiring that lead to a lengthy delay, what’s the impact on the operator? 
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There can be additional issues when dealing with business-class aircraft. Mark Wilken, avionics sales director for Elliott Aviation, noted that reduced vertical separation minimum certiﬁcation can present a challenge when upgrading higher-end ﬂight decks. “We learned that the hard way while installing a Universal 890R upgrade in a Citation,” he said. “The airplane had Honeywell air data computers driving the old round-gauge ﬂight instruments and was certiﬁed for RVSM. When we put in the Universal display, we found that one of the low-speed indications out of the air data computer was wrong. Honeywell told us their ADC wasn’t designed to drive an airspeed indicator; reprogramming it would cost $200,000. Ultimately, Universal revised its software – and STCs – to allow programming the speeds instead of getting them from the ADC. You’ll ﬁnd a lot of problems like this when doing a non-integrated installation – in a fully integrated system where everything was made to work together and all components come from one company, these problems don’t exist – it’s an easier, less risky way to go.” “I can’t stress enough that the dealer must get the certiﬁcation agency involved early in the process, especially for Part 25,” added Grady Dees, Universal Avionics director of technical sales. “If you just do the install and then call the FAA and expect a sign off, you’re asking for trouble. On transport-category aircraft, there’s a lot more involved than just the local FSDO. Sequencing is an issue – if you send an STC project request to the ACO, they’ll ask if it takes more than 40 hours. For displays, the answer is always yes, and it’s automatically bounced to FAA HQ with at least a 90-day delay.” Dees said that in extreme cases, he’s seen installations that had to be referred back to the FAA three times for a total delay exceeding nine months. This can be a big problem with corporate customers. “Business class aircraft are tools for the owner – if it’s sitting on the ground, it costs them money,” Wilken agreed. “You need to understand the risks involved before doing anything that might leave the customer without that tool to do business. It can get into legal and ﬁnancial penalties. Some things are beyond your control. If you’re going to the FAA for certiﬁcation, you can’t control its schedule. The customer needs to understand that. Plan for the worst-case scenario in your quote and downtime estimates. If you think the job will take three months, bid four.” One way to minimize such problems is to understand that

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JULY

2012

Avionics News July 2012

Table of Contents for the Digital Edition of Avionics News July 2012