Back to Cat 1 Approaches?

[Stephanie Belser]

AvWeb is reporting that the rollout of 5G cell-towers will mess up instrument approaches that require radar altimeters.

[Russell Holton]

More detail: www.aviationtoday.com

[Terry Carraway]

So it seems that the radar altimeter makers cheapened out and put a VERY wide band front end in.

[Russell Holton]

So it seems that the radar altimeter makers cheapened out and put a VERY wide band front end in.

Sure looks that way to me. 200MHz is 5% of the frequency. That would be like an AM radio tuned to 1000 KHz and picking up stations at 940 and 1040.

[Stephanie Belser]

So it seems that the radar altimeter makers cheapened out and put a VERY wide band front end in.

Why wouldn't they if there was no reason to put in a more expensive part?

[Terry Carraway]

Why wouldn't they if there was no reason to put in a more expensive part?

Because wide open front ends are sloppy work.

[Russell Holton]

Digging though the documents, RTCA is claiming there's interference from both the primary intended signal as well as spurious emissions from the cell towers. Since those signals are in the aviation band, just adding better filters to the radar altimeters isn't going to do it.

But this also impacts the carriers. AT&T and Verizon delay 5G service rollout until January—giving rival T-Mobile a competitive edge

[Stephanie Belser]

Because wide open front ends are sloppy work.

Are you familiar with the concept of pointy-haired bosses? Or management by MBAs?

[Ray Tackett]

Are you familiar with the concept of pointy-haired bosses? Or management by MBAs?

At a former, now-defunct employer, the motto was "Save a buck no matter what it costs."

[Russell Holton]

I think this helps explain it.

[Terry Carraway]

I think this helps explain it.

The 5G filtering depends on where that spurious emission level is an issue if the radar altimeter front end rejected the main signal frequency band.

IOW, if the rad alt front end cut off was at 4000 MHz, would there be a problem.