A B737-700 flight crew took exception to the phraseology utilized by approach control when clearing ...

Narrative:

While attempting to fly the RNAV rnp to runway 13C; approach control vectored us toward the IAF but never clear us to the IAF. The phraseology used was 'intercept the approach course; maintain 180 KTS'. At this point; we were still restricted to 4;000 and not cleared the approach. Pilot not flying queried ATC asking; 'are we cleared the RNAV rnp 13C approach?' ATC stated that we were cleared the RNAV rnp 13C approach. ATC should have cleared us initially to the IAF with subsequent clearance for the approach. Instead; we received confusing instructions and a speed restriction which was counter to the speeds directed in the rnp system. We missed the 2;500 altitude restriction because of the confusion of the ATC instruction. Unfortunately; we see approach control too often attempt to use the rnp approaches but use improper terminology; add additional non-standard altitude and speed instructions overlapping the directives of the published rnp approaches. These approaches do not work if ATC insists on overriding the details of the approaches.

Original NASA ASRS Text

Title: A B737-700 flight crew took exception to the phraseology utilized by Approach Control when clearing their flight to intercept and fly the RNAV (GPS) Z Runway 13C approach to MDW.

Narrative: While attempting to fly the RNAV RNP to Runway 13C; Approach Control vectored us toward the IAF but never clear us to the IAF. The phraseology used was 'intercept the approach course; maintain 180 KTS'. At this point; we were still restricted to 4;000 and not cleared the approach. Pilot not flying queried ATC asking; 'Are we cleared the RNAV RNP 13C approach?' ATC stated that we were cleared the RNAV RNP 13C approach. ATC should have cleared us initially to the IAF with subsequent clearance for the approach. Instead; we received confusing instructions and a speed restriction which was counter to the speeds directed in the RNP system. We missed the 2;500 altitude restriction because of the confusion of the ATC instruction. Unfortunately; we see Approach Control too often attempt to use the RNP approaches but use improper terminology; add additional non-standard altitude and speed instructions overlapping the directives of the published RNP approaches. These approaches do not work if ATC insists on overriding the details of the approaches.

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	1052654
Time
Date	201212
Local Time Of Day	1201-1800
Place
Locale Reference	MDW.Airport
State Reference	IL
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 223 Flight Crew Type 10000
Events
Anomaly	ATC Issue All Types Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Published Material / Policy

A B737-700 flight crew took exception to the phraseology utilized by approach control when clearing their flight to intercept and fly the RNAV (GPS) Z runway 13C approach to mdw.