Radar Confidence Check

Having doubts about your radar? You need a confidence check! The Honeywell procedure given below is for the Primus 660, an earlier version than what is on the G450. But it works for the Primus 880 too.

Everything here is from the references shown below, with a few comments in an alternate color.

Primus 660 Radar Confidence Check

Figure: Radar confidence check, from Honeywell Radar Training, Part 7, Slide 36.

Example:

Figure: Radar confidence check, from Honeywell Radar Training, Part 7, Slide 37.

Since this radar paints ground to 150 nm and the charts says 115 nm is the minimum, it passes the check.

Gulfstream Notes

It has been my experience that nobody at Boeing, Bombardier, or Gulfstream understands radar and what to do if it isn't working:

• While flying brand new GIII's for the Air Force I was frustrated by the radar's poor performance. Everyone at Gulfstream blamed it on the extra coats of paint we had. A year into my tenure there I was watching a mechanic work under the radome and noticed three missing wires from the R/T unit to the radar dish. We discovered that all ten of our Gulfstreams were missing the wires. We reconnected them and the radars started working brilliantly.
• One of our CL-604's seemed to have an on again/off again temper that finally led one of our crews into a hail storm. On a clear day I noticed there were ten blind spots randomly spread across the presentation it put onto a multifunction display. Bombardier gave us a test procedure which it passed. It was, they said, flight worthy. In a flight department of eight pilots, all eight refused to fly the aircraft. They pulled the unit and sent it to the manufacturer who found nearly a third of its circuits were burnt out.
• Our brand new G450 seemed only able to paint weather on one side. Tech Ops said that was impossible. After whining to anyone willing to listen we found there was indeed a calibration that somehow got skipped when the airplane was delivered.

There, I got that off my chest. But there are two lessons here. First, when dealing with radar problems, don't forget to check with those who built the thing in the first place. Second, in the case of the G450, you have resources available to you that many in Tech Ops seem to have forgotten:

• G450 Maintenance Manual §34-44-00 — Weather Radar System - Adjustment / Test
• G450 Maintenance Manual §34-44-01 ¶1 — Stabilization Trim Adjustment
• G450 Maintenance Manual §34-44-01 page 501 — Return to Service Test
• Honeywell Primus 880 Pilot's Guide Chapter 5, page 5-25 — Roll Stabilization Check
• Honeywell Primus 880 Pilot's Guide Chapter 5, page 5-28 — Pitch offset adjustment
• Honeywell Primus 880 Pilot's Guide Chapter 5, page 5-29 — Roll gain adjustment
• Honeywell Primus 880 Pilot's Guide Chapter 5, page 5-30 — Pitch gain adjustment
• Honeywell Primus 880 Pilot's Guide Chapter 7 — In-flight Troubleshooting

Attenuation

Beam Width

Calibration

Energy

Gain

How it Works

Operational Examples

REACT

Techniques

Tilt

Portions of this page can be found in the book Flight Lessons 1: Basic Flight, Chapter 28.

Gulfstream G450 Maintenance Manual, Revision 18, Dec 12, 2013

Honeywell Airborne Weather Radar Training, Rev E, 12/09/02, Honeywell Inc. Commercial Flight Systems Group, Phoenix, AZ.

Honeywell Primus 880 Pilot's Guide, Pub. No. A28-1146-102-03, Revised January 2006, Honeywell International Inc. Commercial Electronic Systems, Glendale, AZ.