A B757 crew reported that new company procedures for the mia quito arrival accompanied with changing...

Narrative:

On arrival into the mia area; we were cleared for the ILS 9 and told to cross gritt at 3;000 ft. We were attempting to use the new VNAV arrival procedures. Approach asked us to keep up our speed and while concentrating on this we descended approximately to 2;700 ft about a mile to half a mile from gritt. We noticed this and corrected back to 3;000 ft immediately. There was no TCAS alert nor did ATC ask about the altitude. Additionally; approach asked us to maintain 170 KTS to the final approach fix. This complicated the situation by trying to comply with the speed and be configured and stabilized by 1;000 ft without using the speed brakes with flaps 25. The VNAV arrival procedures works fine until ATC starts giving speed changes; also we were on a vector to intercept the localizer; which we did just outside gritt. Trying to comply with configuration; speed; altitude requirements along with rarely used VNAV procedures resulted in too many distractions. Perhaps we should adjust VNAV procedures to be used only when shooting a full arrival to ensure enough time to be configured and on speed by final.

Original NASA ASRS Text

Title: A B757 crew reported that new Company procedures for the MIA QUITO arrival accompanied with changing ATC procedures left the flight crew unable to slow and descend the aircraft comfortably.

Narrative: On arrival into the MIA area; we were cleared for the ILS 9 and told to cross GRITT at 3;000 FT. We were attempting to use the new VNAV arrival procedures. Approach asked us to keep up our speed and while concentrating on this we descended approximately to 2;700 FT about a mile to half a mile from GRITT. We noticed this and corrected back to 3;000 FT immediately. There was no TCAS alert nor did ATC ask about the altitude. Additionally; approach asked us to maintain 170 KTS to the final approach fix. This complicated the situation by trying to comply with the speed and be configured and stabilized by 1;000 FT without using the speed brakes with flaps 25. The VNAV arrival procedures works fine until ATC starts giving speed changes; also we were on a vector to intercept the localizer; which we did just outside GRITT. Trying to comply with configuration; speed; altitude requirements along with rarely used VNAV procedures resulted in too many distractions. Perhaps we should adjust VNAV procedures to be used only when shooting a full arrival to ensure enough time to be configured and on speed by final.

Data retrieved from NASA's ASRS site as of April 2012 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	890529
Time
Date	201005
Local Time Of Day	1201-1800
Place
Locale Reference	MIA.Airport
State Reference	FL
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	STAR CURSO
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Person 2
Function	Captain Pilot Flying
Events
Anomaly	Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy

A B757 crew reported that new company procedures for the mia quito arrival accompanied with changing ATC procedures left the flight crew unable to slow and descend the aircraft comfortably.