B737 captain expressed concern regarding frequency congestion at ZID.

Attributes
ACN	602695
Time
Date	200312
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : vxv.vortac
State Reference	TN
Altitude	msl single value : 29000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	cruise : level
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 220 flight time total : 12000
ASRS Report	602695
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Airspace Structure
Primary Problem	Ambiguous

Narrative:

While on indy center frequency 128.22, I noticed 23 blocked communication transmissions in less than 10 mins. We were unable to check in for 3 mins and had to make 4 calls to do it. The area was too saturated with traffic for safe travel. The controller was obviously overworked. I notice this happening more and more, especially in the midwest and east coast areas.

Original NASA ASRS Text

Title: B737 CAPT EXPRESSED CONCERN REGARDING FREQUENCY CONGESTION AT ZID.

Narrative: WHILE ON INDY CTR FREQUENCY 128.22, I NOTICED 23 BLOCKED COMMUNICATION TRANSMISSIONS IN LESS THAN 10 MINS. WE WERE UNABLE TO CHK IN FOR 3 MINS AND HAD TO MAKE 4 CALLS TO DO IT. THE AREA WAS TOO SATURATED WITH TFC FOR SAFE TRAVEL. THE CTLR WAS OBVIOUSLY OVERWORKED. I NOTICE THIS HAPPENING MORE AND MORE, ESPECIALLY IN THE MIDWEST AND EAST COAST AREAS.

Data retrieved from NASA's ASRS site as of July 2007 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.