Hawker Beechcraft chief Bill Boisture says a Honeywell Epic avionics software problem that has shut down deliveries of the company's flagship $20 million Hawker 4000 super-midsize business jet this summer is fixed, and awaits US and European regulator approvals.

The quandary is linked to problems with the so-called "Load 20" update to the 4000's Honeywell-built Primus Epic integrated avionics. Load 20, originally slated to be complete by early 2011, includes required navigation performance (RNP) operations, down to RNP0.1. It also includes localizer performance with vertical guidance (LPV) approaches, using wide area augmentation system (WAAS)-enabled GPS', electronic checklists and Honeywell's runway awareness and advisory system.

Hawker had delivered four Hawker 4000s with previously certified Load 19 software in the first and second quarter this year, but had recently switched over to Load 20 for new deliveries. Boisture said three aircraft were not delivered due to the problem as of the end of June.

During testing of Load 20 for the Hawker 4000, Honeywell said it "identified software issues involving a wrong turn on a missed approach procedure" that delayed certification of the system.

 © Hawker Beechcraft

Improper turn problems with Honeywell-built Primus Epic flight management systems are affecting more than just the Hawker 4000, however, with more than 13 aircraft models in the business aviation and airline sectors affected by similar issues.

In a Honeywell service information letter published on 1 July, the company informed operators of a wide range of aircraft using Epic-based flight management systems (FMS) that the US Federal Aviation Administration requires that hundreds, and in some cases, thousands, of terminal area procedures be removed from their databases.

Aircraft affected range from the AgustaWestland AW139 helicopter to the Embraer E190 regional jet.

Honeywell said: "Due to recently discovered issues dealing with the way procedure legs with turn directions indicated are handled in the FMS, the FAA has required Honeywell to remove procedures that could potentially result in incorrect turn directions. There are a few other issues as well, but this is the bulk of the reason these actions have been taken."

Examples provided by Honeywell in its June FMS newsletter show that the error could cause the FMS to command a turn in the opposite direction from an approved procedure like a missed approach, potentially putting the aircraft in danger of hitting terrain or other aircraft.

For the Hawker 4000, Honeywell says it modified the FMS software "to correct the issue", but did not provide details on whether operators would have access to all terminal procedures.

"This has been a point of intense focus by our senior leadership and Honeywell senior management," said Boisture of the Load 20 problem during the company's second-quarter earnings call on 4 August.

He added that Hawker Beechcraft had "a line of sight" on FAA certification for the corrected Load 20 "in the next few weeks", and European Aviation Safety Agency (EASA) approval before the end of the year.

Boisture said Hawker 4000s are going "predominately" to European customers in the second half of the year, "so EASA approval is important". "We're optimistic we'll see our way out of this in the third or fourth quarter," he added.

The delivery lag and corresponding loss of revenue from progressive payments by customers on those aircraft is compounding an already tough quarter for the Wichita-based company, with flat business and general aviation sales for the first half of the year down by nearly 20% from the second quarter of 2010.

Other manufacturers are seeing similar performances. According to data from the General Aviation Manufacturers Association, business jet deliveries in the first six months of 2011 dropped by 26.5%, compared to the first half of 2010.

"Ongoing market concerns in Europe and around the globe continue to dampen confidence of buyers worldwide, which is evidenced by continued softness in our primary segments, especially the light and mid-jet market," Boisture said. "Our decreased jet deliveries are reflective of this and are not dissimilar to what is being experienced throughout the industry."

Source: Flight International