Unable to complete a necessary communication with approach control regarding a descent clearance int...

Narrative:

While being vectored for landing and palm springs 13 right; ATC asked us to descend 2;000 feet from our present altitude. At the time; we were closely in trail of another aircraft 2;000 feet below us. In addition; we had an aircraft at our 4 o'clock position overtaking us and below us. We advised ATC we were unable to comply with their instruction because of conflicting traffic. The area was extremely heavy with traffic and the ATC controller seemed to be overwhelmed. We told the controller multiple times we were unable to comply with his instructions due to conflicting traffic but never received a response. We then received an RA and complied with the RA. We informed ATC that we were leaving our altitude responding to an RA. ATC responded; then gave us new instructions and we complied and landed without further incident.I believe the root cause was heavily congested airspace and an extremely busy air traffic controller. There was an event in palm springs that weekend which probably increased traffic significantly.possibly add an additional controller with an additional frequency when traffic gets that busy; or maybe have arrival slots when an event is going on. Another possibility would be to use flow control into the area to avoid such congestion.

Original NASA ASRS Text

Title: Unable to complete a necessary communication with Approach control regarding a descent clearance into busy PSP traffic below them; an EMB-120 flight crew delayed their descent; but then received a TCAS 'descend' RA to which they complied.

Narrative: While being vectored for landing and Palm Springs 13 right; ATC asked us to descend 2;000 feet from our present altitude. At the time; we were closely in trail of another aircraft 2;000 feet below us. In addition; we had an aircraft at our 4 o'clock position overtaking us and below us. We advised ATC we were unable to comply with their instruction because of conflicting traffic. The area was extremely heavy with traffic and the ATC controller seemed to be overwhelmed. We told the controller multiple times we were unable to comply with his instructions due to conflicting traffic but never received a response. We then received an RA and complied with the RA. We informed ATC that we were leaving our altitude responding to an RA. ATC responded; then gave us new instructions and we complied and landed without further incident.I believe the root cause was heavily congested airspace and an extremely busy air traffic controller. There was an event in Palm Springs that weekend which probably increased traffic significantly.Possibly add an additional controller with an additional frequency when traffic gets that busy; or maybe have arrival slots when an event is going on. Another possibility would be to use flow control into the area to avoid such congestion.

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	1241774
Time
Date	201502
Local Time Of Day	1201-1800
Place
Locale Reference	PSP.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Altitude Excursion From Assigned Altitude

Unable to complete a necessary communication with approach control regarding a descent clearance into busy psp traffic below them; an emb-120 flight crew delayed their descent; but then received a TCAS 'descend' RA to which they complied.