EMB190 Erroneous Radio Altimeter Indications
 

Hello to all of you,

i observed quite a few times now on different EMB190's that the L/H Radio Altimeter is Indicating some unreasonable Heights while on the Ground at Parking Position while the R/H RA is fine (E.G 800FT L/H 0FT R/H). This is accompanied by Advisory Messages "Steep Approach not Avail" and "APPR 2 not Avail" ... In all cases there have been no complains from the Flight Crew at all. This is why i wonder if this is some Kind of Known Issue on the E-Jets? I'am new on this Type so i'am lacking experience. Maybe somebody can bring up some light into this?

Greetings and Thanks

Hi,
Not just the L/H, can happen occasionally with the R/H. Happens a lot, usually rapid fluctuations around the 760 ft mark, after power up.
Various theories, including reflections off the painted lines, especially in the wet.
Nobody worries about it, the crews are used to it. It usually stops after a while. never happens in flight.
Hope that helps.
Cheers!
From the FIM :
NOTE Objects (for example: tools, tool carts/boxes, stairs, drainage grates, pipes, metal covers on the ground, etc.) or structures near the Rad Alt antennas can cause the Rad Alt system to oscillate and show values different from 0 ft with the aircraft on the ground..

NOTE:Objects (for example: tools, tool carts/boxes, stairs, drainage grates, pipes, metal covers onthe ground, etc.) or structures near the Rad Alt antennas can cause the Rad Alt system tooscillate and show values different from 0 ft with the aircraft on the ground.FAULT ISOLATIONMANUALEmbraer 195 - FIM 321134-31-00810-813-A/200Page 2 of 17Rev 49 - Jul 22/22Copyright © by Embraer S.A. All rights reserved - See title page for details.

General, not EMB specific

On ground; possible reflections from surface - puddles, reflective paint markings.

In the air; possible cracked aerial mounting / cover, or poor insulation / bonding with structure, usually when wet.