B737 captain laments ATC 'meddling' in charted RNAV arrivals; believing that they should be flown as...

Narrative:

Flying the lyndi arrival into san; la center held us up higher than charted; no reason given. We were told to expect jackk at 10;000; and we advised ATC that we would be high. FMC already was indicating 5;000 feet above the descent profile. Center cleared us to cross jackk at 10;000; and we again told them that we would be unable. We were given a 90 degree turn off course; and a descent to 10;000. This whole evolution was avoidable; inefficient; and I do not believe traffic was an issue. This only serves to increase cockpit workload and increase the possibility of an error. ATC continues to intervene in charted RNAV arrival procedures for no apparent reason. Two of the worst; the eagul arrival to phx and the endee arrival to mdw; consistently have points added; altitudes and speeds changed. If these changes are needed; the procedure needs to be modified to reflect the change. This constant meddling by ATC introduces the possibility of error by increasing pilot workload; increasing the chance of an FMC programming error; and increasing the opportunity for a deviation. It simply decreases safety by introducing an increased probability for error and should be stopped immediately.

Original NASA ASRS Text

Title: B737 Captain laments ATC 'meddling' in charted RNAV arrivals; believing that they should be flown as published. If constant adjustments are necessary then they should be part of the procedure and flown as published.

Narrative: Flying the LYNDI Arrival into SAN; LA Center held us up higher than charted; no reason given. We were told to expect JACKK at 10;000; and we advised ATC that we would be high. FMC already was indicating 5;000 feet above the descent profile. Center cleared us to cross JACKK at 10;000; and we again told them that we would be unable. We were given a 90 degree turn off course; and a descent to 10;000. This whole evolution was avoidable; inefficient; and I do not believe traffic was an issue. This only serves to increase cockpit workload and increase the possibility of an error. ATC continues to intervene in charted RNAV arrival procedures for no apparent reason. Two of the worst; the EAGUL arrival to PHX and the ENDEE arrival to MDW; consistently have points added; altitudes and speeds changed. If these changes are needed; the procedure needs to be modified to reflect the change. This constant meddling by ATC introduces the possibility of error by increasing pilot workload; increasing the chance of an FMC programming error; and increasing the opportunity for a deviation. It simply decreases safety by introducing an increased probability for error and should be stopped immediately.

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	1186739
Time
Date	201407
Local Time Of Day	0601-1200
Place
Locale Reference	SAN.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR LYNDI
Flight Plan	IFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 191 Flight Crew Type 13500
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

B737 captain laments ATC 'meddling' in charted RNAV arrivals; believing that they should be flown as published. If constant adjustments are necessary then they should be part of the procedure and flown as published.