L-3 Avionics Systems anticipates gaining STC approval for its Iris enhanced-vision system (EVS) this month after the successful conclusion of flight testing in a King Air C90. FAA parts manufacturing approval should follow soon afterward, clearing the way for installations in customer airplanes.

The initial focus for follow-on Iris certifications will likely be on a number of popular single-engine turboprops, including the Cessna Caravan, Pilatus PC-12 and Socata TBM 700, according to Shelly Buckley, manager of aftermarket products for L-3 Avionics Systems in Grand Rapids, Mich. “We’re close to formalizing agreements with a number of dealers and should be announcing the first two very soon,” she said.

The STC in the King Air C90 will cover the Iris camera systems and the link to the airplane’s Honeywell KMD 850 multifunction display, which is part of the STC approval. L-3 has been working with an FAA designated engineering representative to explore the possibility of expanding the STC to cover other cockpit displays, but Buckley said it is unclear at this point whether that will be possible.

Iris uses a special barium strontium titanate (BST) sensor tuned to the long-wave portion of the infrared spectrum to create its EVS image on a cockpit display. The display itself must be RS-170 (standard black-and-white video source) compatible, and that limits Iris use to just a handful of MFDs and cockpit video screens. The KMD 850 and 550 displays from Honeywell include the RS-170 capability, as do displays from Rosen, Sagem, Sandel, Op Technologies and Flight Display Systems. Popular displays from Garmin and Avidyne, however, are not RS-170 compatible.

Price for the Iris camera system is $15,000 plus the cost of the STC kit, consisting of the camera fairing and wiring. Downtime should be fairly minimal, Buckley said, because the installation requires only minor changes inside and outside the airplane. In the King Air C90, for example, engineers fitted the camera in a fairing near the air-conditioning vent on the nose, where there is extra room for the additional hardware.

The Iris camera’s video feed is advisory only and doesn’t provide information that pilots can use to fly to lower minimums as is the case with more expensive EVS products. But it does capture infrared energy from anything within the sensor’s 24- by 18-degree field of view, as far as the eye can see, thereby providing useful imaging cues for pilots flying in certain low-visibility conditions such as haze. Like other enhanced-vision systems, Iris doesn’t do a good job of seeing through solid clouds, especially if they contain lots of moisture, Buckley noted.

L-3 Avionics obtained the BST technology from sister company L-3 Communications Infrared Products, which sells the Thermal-Eye camera used in Nightdriver IR systems for automobiles, as well as for military, public service and safety applications. As well as adding aviation-type electrical connectors and modifying the camera so it will function with 28-volt electrical systems, L-3 Avionics incorporated electronic circuitry that continuously recalibrates the BST sensor hundreds of times a second to prevent blooms of light when the sensor points at a bright infrared source. This recalibration allows the Iris camera to provide a clear image even when pointed at the sun. 

Potential markets for Iris include helicopters, high-end piston airplanes and possibly business jets. The system’s DO 160 environmental testing limits its use to below 25,000 feet, so additional testing would be needed before Iris could be fitted in jets. But Buckley said L-3 has provided flight demos to the major OEMs, and that interest is high. L-3 has also begun helicopter vibration testing and is close to identifying initial STC targets for that market.