Glideslope Error

The glideslope currently is telling me that I am to high on cruise. The ILS I am tuned into is rwy 31L at KJFK. It tells me that I am too low when I am 37:19 ETE to Dest, 311nm Dist to Dest. This was the first time this happened to me. From flying into other airports like SFO, LAX, DEN, etc, the ILS works fine. Help would be appreciated.

The glideslope can definitely say that until you get closer. It’s not intended to be used that way, that far out & high.

1 Like

Uhh…why are you tuning into an ILS on cruise? 😅
It’s bound to show inaccurate readings.

I tend to forget.

ok. thx. And… when should I tune in?

When you’re on approach :)
But it’s fine to be tuned in that early, but the glideslope is not something to care about that early.


ok. thank u.

You can rely on the localiser about 10-18 NM out from the runway, and the glideslope at roughly 10 NM.

The glideslope is usually considered to be accurate inside of the final approach fix (FAF).

As a rule of thumb, be in the vicinity of the “red cone” on IF to rely on ILS signals.


thamk u. i didn’t know.

Op flagged for closure