When they misinterpreted approach control's clearance to intercept 'the final approach course at 8;0...

Attributes
ACN	1201869
Time
Date	201409
Local Time Of Day	0601-1200
Place
Locale Reference	DEN.Airport
State Reference	CO
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 152
Person 2
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Airspace Violation All Types Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

Den approach cleared us on a vector to intercept the ILS 35R final at 8000 ft MSL; and cleared to cross deane at 8000 ft and contact tower. I deleted the crossing restrictions of 9000 ft at deane and drumm since our clearance was at 8000 ft. We intercepted final at 8000 ft and set 7000 ft in the MCP altitude window which was FAF altitude. After passing deane; PF announced and began descent to 7000 ft MSL. We had not passed drumm when den tower stated; 'low altitude alert; the MVA is 7500 ft .' we initiated an immediate climb to 7500 ft MSL; passed drumm and then resumed the ILS 35R arrival without further incident.when vectored below a fix required altitude; it would be a good idea to set that altitude as a hard altitude until the earliest fix we can descend from; which in this case was drumm. ATC's clearance led me down the path of deleting hard altitude requirements we were already below. Den approach control could have also stated maintain 8000 ft until drumm which would have been a better clearance.

Original NASA ASRS Text

Title: When they misinterpreted Approach Control's clearance to intercept 'the final approach course at 8;000 FT; cross DEANE at 8;000 FT' as a clearance to fly the DEN ILS 35R approach the flight crew of a B737NG began a descent to the glideslope intercept altitude after passing DRUMM.

Narrative: DEN Approach cleared us on a vector to intercept the ILS 35R final at 8000 FT MSL; and cleared to cross DEANE at 8000 FT and contact Tower. I deleted the crossing restrictions of 9000 FT at DEANE and DRUMM since our clearance was at 8000 FT. We intercepted final at 8000 FT and set 7000 FT in the MCP ALT window which was FAF Altitude. After passing DEANE; PF announced and began descent to 7000 FT MSL. We had not passed DRUMM when DEN Tower stated; 'Low Altitude alert; the MVA is 7500 FT .' We initiated an immediate climb to 7500 FT MSL; passed DRUMM and then resumed the ILS 35R Arrival without further incident.When vectored below a fix required altitude; it would be a good idea to set that altitude as a hard altitude until the earliest fix we can descend from; which in this case was DRUMM. ATC's clearance led me down the path of deleting hard altitude requirements we were already below. DEN Approach Control could have also stated maintain 8000 FT until DRUMM which would have been a better clearance.

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.

When they misinterpreted approach control's clearance to intercept 'the final approach course at 8;000 ft; cross deane at 8;000 ft' as a clearance to fly the den ILS 35R approach the flight crew of a B737NG began a descent to the glideslope intercept altitude after passing drumm.