EMB145 flight crew reports an FMC anomaly crossing aldan on the aldan 1 arrival to rdu. Although the...

Attributes
ACN	1069050
Time
Date	201302
Local Time Of Day	1201-1800
Place
Locale Reference	RDU.Airport
State Reference	NC
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	EMB ERJ 145 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR ALDAN1
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

During descent into rdu; on the ALDAN1 RNAV arrival; we were given the 'landing southwest' transition. The FMS was programmed for the ILS to runway 23R. The FMS was reviewed and the waypoints were correct with no multiple waypoints. Upon crossing the aldan fix; the flight guidance went from LNAV to roll mode. We immediately put the FGC into heading mode and turned to the next fix. ATC was notified and we were subsequently given direct to a fix on the ILS approach. The FMS seemed to sequence to the next fix correctly; but the FGC did not. This particular aircraft's FMS was software version 4.8.

Original NASA ASRS Text

Title: EMB145 flight crew reports an FMC anomaly crossing ALDAN on the ALDAN 1 arrival to RDU. Although the FMC was programmed for the Runway 23 transition the Flight Guidance went into roll mode at ALDAN and was quickly corrected.

Narrative: During descent into RDU; on the ALDAN1 RNAV arrival; we were given the 'landing southwest' transition. The FMS was programmed for the ILS to Runway 23R. The FMS was reviewed and the waypoints were correct with no multiple waypoints. Upon crossing the ALDAN fix; the Flight Guidance went from LNAV to ROLL mode. We immediately put the FGC into HDG mode and turned to the next fix. ATC was notified and we were subsequently given direct to a fix on the ILS approach. The FMS seemed to sequence to the next fix correctly; but the FGC did not. This particular aircraft's FMS was software version 4.8.

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.

EMB145 flight crew reports an FMC anomaly crossing aldan on the aldan 1 arrival to rdu. Although the FMC was programmed for the runway 23 transition the flight guidance went into roll mode at aldan and was quickly corrected.