Radio frequency congestion.

Attributes
ACN	293472
Time
Date	199501
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mnl
State Reference	FO
Altitude	msl bound lower : 33000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : stl
Operator	common carrier : air carrier
Make Model Name	Super DC-8 All Series
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Route In Use	enroute : pacific enroute airway : rpmm
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 5000
ASRS Report	293472
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Flight routing from singapore to taipei along airways G577 and R471 is conducted in a non-radar environment with position reports made on HF radio to the appropriate facility. No less than 5 facilities utilize 1 frequency during peak traffic times (singapore, hochihminh, bangkok, manila, and hong kong). This results in something beyond frequency congestion where position reports and ATC instructions are blocked by other xmissions, and at best, repeated numerous times, and worse -- never copied! In an emergency, communication may be impossible! Perhaps a suggestion to the appropriate authority/authorized on relieving this problem would be in order. In the meantime, crews in this region should use extreme caution.

Original NASA ASRS Text

Title: RADIO FREQ CONGESTION.

Narrative: FLT ROUTING FROM SINGAPORE TO TAIPEI ALONG AIRWAYS G577 AND R471 IS CONDUCTED IN A NON-RADAR ENVIRONMENT WITH POS RPTS MADE ON HF RADIO TO THE APPROPRIATE FACILITY. NO LESS THAN 5 FACILITIES UTILIZE 1 FREQ DURING PEAK TFC TIMES (SINGAPORE, HOCHIHMINH, BANGKOK, MANILA, AND HONG KONG). THIS RESULTS IN SOMETHING BEYOND FREQ CONGESTION WHERE POS RPTS AND ATC INSTRUCTIONS ARE BLOCKED BY OTHER XMISSIONS, AND AT BEST, REPEATED NUMEROUS TIMES, AND WORSE -- NEVER COPIED! IN AN EMER, COM MAY BE IMPOSSIBLE! PERHAPS A SUGGESTION TO THE APPROPRIATE AUTH ON RELIEVING THIS PROB WOULD BE IN ORDER. IN THE MEANTIME, CREWS IN THIS REGION SHOULD USE EXTREME CAUTION.

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.