Honeywell "Vet" Retires to Museum after Seven Decades of Service

The “veteran” we’ll be talking about here is the venerable Convair 580, initially certified in 1952 and now taking its unique place in the history of aviation safety. As we pointed out in an April blog post, this particular 50-seat commuter was first put in service by United Airlines, its original owner, Sept. 2 of that year.

The CV580, to use its shortcut moniker, was designed as a two-engine, low-wing medium-range commercial transport with a maximum range of 1,250 nautical miles. It was initially manufactured by Convair as a CV340 or CV440, and then converted to propjet power.

The aircraft type itself has a storied history with more than 30 civil and military operators past and present, out-surviving many of the airlines—like the original Frontier Airlines and North Central Airlines—it first served.

The particular aircraft that eventually sported the jaunty tail number N580HW joined Honeywell in 1992 and has logged an amazing number of flight hours as a workhorse for both flight testing and demonstrating major safety innovations.

Ethan Schell, Honeywell flight test program manager in Seattle, and Markus Johnson, a retired Honeywell chief test pilot out of Everett, Wash., listed some of the major programs:

• Traffic Alert and Collision Avoidance System (TCAS)
• Enhanced Ground Proximity Warning System (EGPWS), aka, “ground prox”
• Weather radar
• Runway Awareness and Advisory System (RAAS)—addressing the billion-dollar worldwide concern for runway incursions
• Datalink products
• Radar altimeters
• Aircraft Environmental Surveillance System (AESS)—integrating weather, traffic and terrain awareness

But how does a single aircraft test something like TCAS, which by definition involves two aircraft heading for each other?

“With great care,” said Johnson. “It’s actually a very strict, highly choreographed, highly scripted maneuver. And of course, we have a second company aircraft, like a suitably equipped King Air.”

Mid-air collisions were a terror of the sky for everyone, back in the day. But thanks to TCAS and a carefully structured flight testing program on the Convair 580, the incidence is very low these days, Johnson reports.

EGPWS, which reduces the risk of controlled flight into terrain, is another life-saving technology developed and tested by Honeywell using the CV580. Unlike, TCAS, ground prox detection doesn’t require a second aircraft but still requires a very strict flight regime—especially when potential customers are onboard for a demonstration. Johnson points out that hundreds of product demo flights were made on the Convair with thousands of passengers, all told, during its time of duty. “With the procedures, we have in place, no one gets hurt.”

Don’t tell the aircraft, but one of the benefits of the Convair 580 is its big nose!

Honeywell was able to develop the RDR-4B weather radar (predecessor to today’s RDR-4000 IntuVu 3D weather radar system) thanks to the Convair’s nose cone which was large enough to accommodate a larger antenna. The CV580 with RDR-4B was the world’s first aircraft with forward-looking windshear detection capability. “Thankfully, windshear-related accidents are very rare these days,” Johnson says.

According to Schell, there was a lot of work in the early 2000s on developing systems to alert pilots to runway incursions and excursions. The original Honeywell RAAS evolved into today’s SmartRunway/SmartLanding thanks to the CV580 which was the first aircraft certified with RAAS.

At times, N580HW was hauling around as many as 30 to 40 systems, along with toolboxes, spare parts and multiple versions of TCAS, weather radar, as well as radar altimeters, navigation and data link products. “We had to cut the number of seats down to 24 or 26 to get everything and everyone on board,” Johnson says. “Fortunately, we kept the lavatories.”

Of course, not everything being tested makes it out of development. In addition to validating new technologies actually flying today, Honeywell engineers and scientists used the CV580 to check products and systems that couldn’t cut the mustard. But that’s exactly what a test aircraft is supposed to do.

Honeywell’s Convair 580 took its last flight for us in April and is making its way to Kelowna, British Columbia in Canada, where Barry Lapointe of KF Aerospace is planning an aviation museum.