Reader Correspondence: February, 2022

GARMIN RADAR INSTALLS

Regarding the article authored by Larry Anglisano in the August 2021 Aviation Consumer, WX Radar Upgrades: Garmin’s GWX 75 Is Top, the article mentions the Cessna 210 and also includes a photo of a Cessna T210 with a 10-inch radar pod.

The article never explicitly states that Garmin’s GWX 75 will play we’ll with the Cessna wing pod, but the implication/assumption is clearly there. A 10-inch radar mated with a 10-inch wing pod—what can possibly go wrong? 

Unfortunately, the 10-inch Garmin GWX 75 will not fit in the 10-inch Cessna pod. The GWX 75’s (Mod Level 2) base assembly is 9.80 inches high and 9.67 inches wide. The antenna has a 9.85-inch diameter. Unfortunately, the mount point is off-center, so the overall required height of the complete assembly is 10.60 inches, which is too much for the Cessna wing pod. 

Garmin has indicated that they are not working on this issue and they have no current plans to address this problem.

Michael Howard – via email

You’re mostly correct, but it’s not impossible to make this installation work. We asked Garmin’s aviation technical support group about this, and they gave the following explanation and provided useful drawings of the GWX 75 physical installation:

“The short of it is Garmin doesn’t explicitly test each and every one of the possible radar wing pods that can be used on the market. Instead, we provide specific drawings in our install manuals which outline the size and scan angles for the antenna units with the flat plats installed. Installers should reference specific drawings from the installation manual, which shows the 10-inch GWX 75 system with and without Mod 2. We hope that dealers are making very good measurements when it comes to price-quoting these installations so they can be sure whether or not the radar will fit in the existing radome.

“Early on before we had Mod 2, we found that the radar heat sink was causing the radar to not fit into a smaller 10-inch wing pod (reported mostly with the Pilatus and Socata airframes), so we then incorporated Mod 2, which removes this heat sink from the outside of the unit allowing it to fit properly in more smaller radomes. Recently, however, we’ve had a few reports of problems on the 210 airframes, and even with units with Mod 2, the radar flat plate was hitting on the sides of the radome housing. In these cases we found these radomes were recessed in the area where the radar sits, and the edges of the flat plate were hitting on the sides. The fix would take a complete redesign of the flat plate, which could alter the radar’s performance.

We agree with Garmin—it’s up to the shop to research each install for compatibility. Still, Garmin also shared images of a GWX 75 installation where the shop (with FAA DER approval) modified the wing pod to extend the radar’s mounting points out of the recessed area, which worked fine.

BENDIXKING AUTOPILOTS

I recently had a quote for the BendixKing factory repair of the KAP150 autopilot computer in my 1995 Mooney. It includes the payment (by my Australian avionics shop) of a 20 percent surcharge on the service parts and labor that they say is required to pass along to BendixKing. Are you aware of BendixKing trying to enforce a similar policy in the United States?

John Hillard – via email

We followed up on this and asked BendixKing if there are any surcharges in place for these repairs, and we were told there absolutely are not. However, it’s not uncommon for shops to mark up outside repairs above and beyond the vendor’s flat-rate repair pricing. Get a firm quote (including freight and troubleshooting charges) before committing to avoid any surprises. 

OXYGEN TANK REFILLS

Thank you for the well-researched and worthwhile article in the January 2022 Aviation Consumer on O2 tank refills. After dealing with the hassles of getting my tanks filled, your article convinced me to build my own refilling farm. Keep up your top-notch coverage. 

John Demers -via email

Editor in Chief Larry Anglisano has been a staple at Aviation Consumer since 1995. An active land, sea and glider pilot, Larry has over 30 years’ experience as an avionics repairman and flight test pilot. He’s the editorial director overseeing sister publications Aviation Safety magazine, IFR magazine and is a regular contributor to KITPLANES magazine with his Avionics Bootcamp column.