After a B737-700 first officer flying the mem bluzz 1 RNAV changed landing runways the FMC put the a...

Narrative:

We were given a descend via clearance on the arrival with a runway assignment. On descent; we were given the option of landing on 36L; a more favorable runway. I programmed in the new runway and briefed the approach. I extended out the approach to a waypoint that was higher than the lowest point on the arrival. The FMC didn't like this and it took a little while to identify that this was the problem. After it was corrected; we finished the descent checklist. I realized that the aircraft was not descending correctly on the arrival. When I had selected a new runway; the FMC put the arrival back in but with a discontinuity as the next waypoint. As a result; the aircraft didn't know where it was on the arrival. I then selected level change to get the aircraft back onto VNAV path. I believe the crossing restrictions at both mrcel and dasac were missed. Approach control then gave us an unrestricted descent to 3;000 ft. This occurred at a very busy time on the arrival. We started the descent checklist; changed runways; tried to correct an altitude problem on the approach; returned to the descent checklist; and then realized we were not on VNAV path. After reprogramming the new runway; the FMC responded in an unanticipated way. I did not monitor the automation to the level that it required.

Original NASA ASRS Text

Title: After a B737-700 First Officer flying the MEM BLUZZ 1 RNAV changed landing runways the FMC put the arrival back in but with a discontinuity at the next waypoint; disconnected VNAV and caused the aircraft to miss at least two crossing restrictions.

Narrative: We were given a descend via clearance on the arrival with a runway assignment. On descent; we were given the option of landing on 36L; a more favorable runway. I programmed in the new runway and briefed the approach. I extended out the approach to a waypoint that was higher than the lowest point on the arrival. The FMC didn't like this and it took a little while to identify that this was the problem. After it was corrected; we finished the Descent Checklist. I realized that the aircraft was not descending correctly on the arrival. When I had selected a new runway; the FMC put the arrival back in but with a discontinuity as the next waypoint. As a result; the aircraft didn't know where it was on the arrival. I then selected Level Change to get the aircraft back onto VNAV PATH. I believe the crossing restrictions at both MRCEL and DASAC were missed. Approach Control then gave us an unrestricted descent to 3;000 FT. This occurred at a very busy time on the arrival. We started the Descent Checklist; changed runways; tried to correct an altitude problem on the approach; returned to the Descent Checklist; and then realized we were not on VNAV PATH. After reprogramming the new runway; the FMC responded in an unanticipated way. I did not monitor the automation to the level that it required.

Data retrieved from NASA's ASRS site 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	1164417
Time
Date	201404
Local Time Of Day	1801-2400
Place
Locale Reference	MEM.Airport
State Reference	TN
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR BLUZZ 1
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Pilot Not Flying First Officer
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

After a B737-700 first officer flying the mem bluzz 1 RNAV changed landing runways the FMC put the arrival back in but with a discontinuity at the next waypoint; disconnected VNAV and caused the aircraft to miss at least two crossing restrictions.