On Top of the Turboprop Retrofit Avionics Market

Sandel's 5-day glass panel retrofit

Can shops really retrofit Sandel’s new Avilon integrated flight deck, which includes an advanced autopilot—in a King Air—in five working days? Gerry Block at Sandel Avionics believes so. I’m skeptical because it’s challenging to install a single-screen Aspen PFD in a Skyhawk in one shop week, especially for smaller shops. Tearing down (and building back up) a King Air isn’t easier. I was once on a team that retrofitted a Garmin MFD, TAWS-B and a satellite phone in an old E90 and it took the better part of three weeks, including FAA paperwork, flight testing and a DER signoff.

Sandel Avionics front deck

Sandel’s new Avilon, with its prefab design, hints that the labor effort for large projects could be changing for the better. You don’t have to own a turboprop to appreciate the benefits of getting the project off the hangar floor quickly. As we report in the aircraft appraisal article on page 8 of this issue, the hit you’ll take on the labor portion of an avionics project when you sell is enough to make you cry.

The labor-gobbling realities of most upgrades means shops are bogged down with repairing existing old wiring harnesses (spaghetti, as we called it in the shop), building new ones, plus the gutting of the cabin to gain access and lay it all in. After all that, it’s time to put it all back together. Sandel attempts to tame that dragon, supplying the Avilon suite mostly assembled, with prefabricated wiring harnesses wrapped in protective sheathing and even sending new drop-in replacement instrument panels. Rather than large remote mounted processors, the Avilon architecture is made of small LRUs, or line replaceable units running across a common databus.

Sandel Avionics turboprop retrofit LRU

LRUs aren’t new and they’ve been the backbone of Garmin’s G1000 and G500/600 integrated avionics for years, often scattered about the airframe. And that’s where the intense labor comes into play—running harnesses here and there—while relocating existing systems to accommodate large AHRS processors, air data computers and other accessories. But Sandel designed its weight-saving LRUs to be self-contained in one small area and easily accessible by folding down a hinged door on one of the instrument panels, or containing the LRUs in one central location in an existing avionics bay.

Sandel designed its network to work with other brands of vintage avionics, but that isn’t necessarily a time saver, since shops will have to work with existing wiring. The Avilon’s autopilot utilizes the existing autopilot servos, saving the effort of pulling the old servos and rigging new ones deep within the airframe. The system is also compatible with Garmin’s GWX-series weather radars (and others), since Garmin utilizes an Arinc bus for interconnection with the display and AHARS pick-off. Software compatibility remains a concern when mixing brands.

There is growing competition in the turboprop avionics retrofit market, with Sandel boldly advertised a fly-away price of $175,000 (the system is still in the STC process, so it’s still early to tell just how realistic that price is.) What is realistic is the $300,000 fly-away price for Garmin’s G1000 King Air retrofit. Elliott Aviation’s Mark Wilken told me the G1000 doesn’t sell itself. In other words, at this price point, the sales department works hard. His shop completes G1000 King Air retrofits in three weeks, but all harnesses are ready before the aircraft even arrives, plus the aircraft is crewed by large teams in two shifts. Like me, Wilken thinks Sandel is underestimating the time required for reassembly, paperwork, configuration and testing. Even BendixKing told me it might require 1200 hours of labor to install its AeroVue glass suite (still in certification) in a King Air. For this reason, all eyes are on Sandel for an easier way.

– Larry Anglisano