EMB145 first officer reports the EICAS displayed left/G air ground fail message during initial climb...

Narrative:

While climbing out the departure the EICAS displayed left/G air ground fail message an aural warnings that seemed to indicate that aircraft's logic was indicating the aircraft on ground instead of in the air. We completed the after takeoff items and informed ATC that we will need some delay vectors. I (first officer) pulled out the QRH and located the page related to that EICAS message. Meanwhile the captain asked ATC to level off at 6;000 and we switched the controls. We performed the required QRH items and captain contacted operations and informed them of the gate return. Captain informed the ATC about an air return and we set up for an ILS approach. After landing when the speed went below 10 KTS we got a stick shaker and other sps messages associated with it. While at the gate when captain switched to gpu power more system stopped working such as sat; tat; fuel quantity etc.; indications stopped working. The list of messages on EICAS exceeded one page. The gust lock did not lock the elevator; so we secured with a seat belt and left the aircraft with maintenance personnel.

Original NASA ASRS Text

Title: EMB145 First Officer reports the EICAS displayed L/G Air Ground Fail message during initial climb. After complying with QRH procedures crew elects to return to the departure airport. Many anomalous EICAS messages and stick shaker activation are reported during taxi in and shut down at the gate.

Narrative: While climbing out the departure the EICAS displayed L/G Air Ground Fail message an aural warnings that seemed to indicate that aircraft's logic was indicating the aircraft on ground instead of in the air. We completed the after takeoff items and informed ATC that we will need some delay vectors. I (First Officer) pulled out the QRH and located the page related to that EICAS message. Meanwhile the Captain asked ATC to level off at 6;000 and we switched the controls. We performed the required QRH items and Captain contacted Operations and informed them of the gate return. Captain informed the ATC about an air return and we set up for an ILS approach. After landing when the speed went below 10 KTS we got a stick shaker and other SPS messages associated with it. While at the gate when Captain switched to GPU power more system stopped working such as SAT; TAT; Fuel quantity etc.; indications stopped working. The list of messages on EICAS exceeded one page. The gust lock did not lock the elevator; so we secured with a seat belt and left the aircraft with Maintenance personnel.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1037745
Time
Date	201209
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	EMB ERJ 145 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Component
Aircraft Component	Squat Switch
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

EMB145 first officer reports the EICAS displayed left/G air ground fail message during initial climb. After complying with QRH procedures crew elects to return to the departure airport. Many anomalous EICAS messages and stick shaker activation are reported during taxi in and shut down at the gate.