September 03, 2012
Why am I bouncing around in a 60-year-old aircraft, somewhere over southern Virginia? Because I am on a demo flight, in Honeywell's Convair 580 radar testbed, to see the latest in weather hazard-avoidance technology.
And the improvements become clear within seconds of lifting off from Washington Dulles International Airport as Honeywell's RDR-4000 IntuVue weather radar probes the clouds ahead of us. On the workstation screen in front of me, the radar display (see image) shows a swath of magenta indicating turbulence in the clouds.
But also on the display are new symbols indicating the likely presence of hail and lightning in the storm. And in the radar “shadow” beyond the clouds, which on a normal display could look deceptively dark and quiet, magenta cross-hatching warns the crew that the attenuated radar returns from the region are not reliable, and storms could exist there.
The flight is showcasing an enhanced version of the RDR-4000, which includes predictive hail and lightning detection as well as extended-range turbulence detection. Certified this year, the enhanced radar has entered service with a “large airline” launch customer, which is equipping Boeing 737NGs with the system.
Flight demonstrations to additional potential forward-fit and retrofit customers are underway using the twin-turboprop Convair 580, first flown in 1962 and the oldest of its type still flying, but used because its capacious nose makes it ideal as a radar testbed.
The radar enhancements are a result of a detailed analysis of inadvertent weather encounters resulting in hail and lightning damage or injuries caused by turbulence. This showed that a key factor was the crew's failure to gain weather situational awareness in time to reroute or avoid hazards, says Ratan Khatwa, Honeywell senior chief engineer for human factors.
Poor antenna tilt management and misinterpretation of radar returns were revealed as major factors, as well as a lack of knowledge of radar fundamentals and large variability in pilots' use of radar and in training standards. Honeywell has approached the identified programs in two steps.
“Part 1 was to simplify operation of the radar,” says Khatwa. This led to introduction of the RDR-4000 pulse-compression radar in the early 2000s. “Part 2, in 2012, is to make it easier to interpret the data,” with a software-only upgrade to add hail and lightning indication and increase turbulence-detection range by 20 nm to 60 nm.