After being issued a speed restriction by ATC along with the advice; 'expect short approach;' B737-7...

Narrative:

On downwind for runway xxl; approach instructed us to slow from assigned 310 knots to 250 knots and descend from 14;000 feet to 7;000 feet and advised 'expect a short approach'. The PF slowed to 250-240 knots and asked for flaps 5 to expedite the descent. Shortly thereafter; we were given further descent to 3;000 feet and once again advised 'expect a short approach'. Since we were still high; PF slowed to 200-210 knots and asked for flaps 10 to help get down quicker; thinking he was going to turn us on a base soon. A couple of minutes later; ATC asked our speed and I told him 200 knots. Another carrier's flight was closing from behind; and although minimum separation was never compromised; ATC gave us a 20 degree vector to the right to increase spacing. The other carrier was re-assigned to runway xy and we continued receiving vectors to xxl where we landed uneventfully; but just as we were exiting the runway the tower gave us 'possible pilot deviation notice from approach control; let me know when you're ready to copy a phone number'. The controller's comments about making a short approach several times led us to believe he wanted us to descend and slow for the approach rather than fly fast away from the airport.there is no specific speed assignment on this arrival; and nothing on the 10-7 page under 'arrival' that mandates maintaining a certain speed.

Original NASA ASRS Text

Title: After being issued a speed restriction by ATC along with the advice; 'Expect short approach;' B737-700 flight crew slowed below assigned speed due to their high; in close position. ATC advised of a possible violation.

Narrative: On downwind for Runway XXL; Approach instructed us to slow from assigned 310 knots to 250 knots and descend from 14;000 feet to 7;000 feet and advised 'expect a short approach'. The PF slowed to 250-240 knots and asked for flaps 5 to expedite the descent. Shortly thereafter; we were given further descent to 3;000 feet and once again advised 'expect a short approach'. Since we were still high; PF slowed to 200-210 knots and asked for flaps 10 to help get down quicker; thinking he was going to turn us on a base soon. A couple of minutes later; ATC asked our speed and I told him 200 knots. Another carrier's flight was closing from behind; and although minimum separation was never compromised; ATC gave us a 20 degree vector to the right to increase spacing. The other carrier was re-assigned to Runway XY and we continued receiving vectors to XXL where we landed uneventfully; but just as we were exiting the runway the Tower gave us 'possible Pilot deviation notice from Approach Control; let me know when you're ready to copy a phone number'. The Controller's comments about making a short approach several times led us to believe he wanted us to descend and slow for the approach rather than fly fast away from the airport.There is no specific speed assignment on this arrival; and nothing on the 10-7 page under 'Arrival' that mandates maintaining a certain speed.

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	1214813
Time
Date	201411
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 139 Flight Crew Type 7000
Person 2
Function	Pilot Flying First Officer
Experience	Flight Crew Last 90 Days 160 Flight Crew Type 3500
Events
Anomaly	ATC Issue All Types Deviation - Speed All Types Ground Incursion Taxiway

After being issued a speed restriction by ATC along with the advice; 'expect short approach;' B737-700 flight crew slowed below assigned speed due to their high; in close position. ATC advised of a possible violation.