Distracted by the failure of their autoflight system to comply with the constraints of the fnchr RNA...

Narrative:

During descent on the fnchr arrival to mem; the aircraft didn't seem to be descending enough to meet the programmed restrictions so the first officer elected to use level change and extend speed brakes to get on the proper profile. After this; he reselected profile to let the jet fly the profile but; once again; it didn't seem to be slowing at the programmed rate to meet the next restriction so the he again selected level change in order to slow. At the same time we needed to descend after fnchr for loonr. We both focused on the beginning of descent and didn't realize as we passed 10;000 MSL that we were still at 290 KIAS. As soon as we noticed it; we slowed immediately to 250 KIAS for jesti; then 210 KIAS for loonr. We made all the altitude restrictions and slowed to 250 KIAS below 10;000 as soon as we noticed our error.one of our conclusions was that if we needed to revert to level change for any reason; we should perhaps leave it there for the remainder of the arrival to avoid confusing ourselves or the jet. I've noticed that; on more than one occasion; the jet doesn't want to slow to the programmed speeds in a timely manner on the mem arrivals. At other times it works fine. Perhaps the arrivals could also be revised to be a little straighter forward in their design for smoothness of operation.

Original NASA ASRS Text

Title: Distracted by the failure of their autoflight system to comply with the constraints of the FNCHR RNAV STAR into MEM; the flight crew of an A300 descended below 10;000 MSL prior to reducing to 250 KIAS.

Narrative: During descent on the FNCHR arrival to MEM; the aircraft didn't seem to be descending enough to meet the programmed restrictions so the First Officer elected to use Level Change and extend speed brakes to get on the proper profile. After this; he reselected Profile to let the jet fly the profile but; once again; it didn't seem to be slowing at the programmed rate to meet the next restriction so the he again selected Level Change in order to slow. At the same time we needed to descend after FNCHR for LOONR. We both focused on the beginning of descent and didn't realize as we passed 10;000 MSL that we were still at 290 KIAS. As soon as we noticed it; we slowed immediately to 250 KIAS for JESTI; then 210 KIAS for LOONR. We made all the altitude restrictions and slowed to 250 KIAS below 10;000 as soon as we noticed our error.One of our conclusions was that if we needed to revert to Level Change for any reason; we should perhaps leave it there for the remainder of the arrival to avoid confusing ourselves or the jet. I've noticed that; on more than one occasion; the jet doesn't want to slow to the programmed speeds in a timely manner on the MEM arrivals. At other times it works fine. Perhaps the arrivals could also be revised to be a little straighter forward in their design for smoothness of operation.

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	1060916
Time
Date	201301
Local Time Of Day	0601-1200
Place
Locale Reference	MEM.Airport
State Reference	TN
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	A300
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	Autoflight System
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural FAR Deviation - Speed All Types

Distracted by the failure of their autoflight system to comply with the constraints of the fnchr RNAV STAR into mem; the flight crew of an A300 descended below 10;000 MSL prior to reducing to 250 KIAS.