Enroute controller described a MVA infraction when issuing a descend to an emergency air carrier wit...

Narrative:

A B757 was an overflight who I believe departed enroute to the east at FL370. I was working [sector X] and [sector Y] combined which is a low sector that feeds [the airport]. Aircraft reported emergency with a possibly fire in the galley and smoke in the cabin with the controller working the sector above me. They called me and notified me of the emergency. I told the controller to turn [the B757] direct to [the airport] and radar contact. I then called TRACON to coordinate the emergency and told them the aircraft would be descending to 100 and released control on contact. Later when the B757 checked on descending to FL240 I descended him to 100 and gave him an altimeter setting and got some other information. [The airport] descended at a very rapid rate and descended through a 10;200 MVA block in my sector. By the time I realized this; he was just about out of the block. I should have been more aware of his descent rate and also should have assigned [the B757] 11;000 until laterally clear of the MVA of 10;200. I assumed the aircraft would clear the MVA but I shouldn't have assumed anything.

Original NASA ASRS Text

Title: Enroute Controller described a MVA infraction when issuing a descend to an emergency Air Carrier with a possible cabin fire. The reporter did not expect the rapid descent toward the diversion airport.

Narrative: A B757 was an overflight who I believe departed enroute to the east at FL370. I was working [Sector X] and [Sector Y] combined which is a low sector that feeds [the airport]. Aircraft reported emergency with a possibly fire in the galley and smoke in the cabin with the controller working the sector above me. They called me and notified me of the emergency. I told the Controller to turn [the B757] direct to [the airport] and RADAR contact. I then called TRACON to coordinate the emergency and told them the aircraft would be descending to 100 and released control on contact. Later when the B757 checked on descending to FL240 I descended him to 100 and gave him an altimeter setting and got some other information. [The airport] descended at a very rapid rate and descended through a 10;200 MVA block in my sector. By the time I realized this; he was just about out of the block. I should have been more aware of his descent rate and also should have assigned [the B757] 11;000 until laterally clear of the MVA of 10;200. I assumed the aircraft would clear the MVA but I shouldn't have assumed anything.

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	1094951
Time
Date	201306
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Aircraft 1
Make Model Name	B757-300
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Person 2
Function	Pilot Not Flying Captain
Experience	Flight Crew Last 90 Days 149 Flight Crew Total 19474
Events
Anomaly	ATC Issue All Types Aircraft Equipment Problem Critical Airspace Violation All Types Deviation - Procedural Published Material / Policy

Enroute controller described a MVA infraction when issuing a descend to an emergency air carrier with a possible cabin fire. The reporter did not expect the rapid descent toward the diversion airport.