Heavy jet flight crew was unable to comply with unrealistic ATC instructions.

Attributes
ACN	1393285
Time
Date	201610
Local Time Of Day	0601-1200
Place
Locale Reference	ZME.ARTCC
State Reference	TN
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Deviation - Altitude Undershoot Deviation - Altitude Crossing Restriction Not Met

Narrative:

ATC issued a decent clearance to cross 10 miles prior to brbbq at 17;000 or below. Pm (pilot monitoring) plugged restriction into FMS. We quickly realized it was going to be tight. I deployed speed brakes to full and increased speed. We missed the restriction by about 800 feet. We told ATC we were unable and ATC gave us a heading 30 degrees left. We felt it was an unattainable restriction.

Original NASA ASRS Text

Title: Heavy jet flight crew was unable to comply with unrealistic ATC instructions.

Narrative: ATC issued a decent clearance to cross 10 miles prior to BRBBQ at 17;000 or below. PM (Pilot Monitoring) plugged restriction into FMS. We quickly realized it was going to be tight. I deployed speed brakes to full and increased speed. We missed the restriction by about 800 feet. We told ATC we were unable and ATC gave us a heading 30 degrees left. We felt it was an unattainable restriction.

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.