Air carrier flight crew experiences lost communications while on vectors to the ILS 12 at bzn in nig...

Attributes
ACN	1153857
Time
Date	201403
Local Time Of Day	0601-1200
Place
Locale Reference	BZN.Airport
State Reference	MT
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 25000 Flight Crew Type 6000
Person 2
Function	Pilot Not Flying First Officer
Experience	Flight Crew Last 90 Days 230 Flight Crew Total 9000 Flight Crew Type 6000
Events
Anomaly	ATC Issue All Types

Narrative:

While on ATC assigned heading of 300; for an ILS 12 approach in visual conditions at night; approach control [communication] became very weak and was lost. We decided to turn toward final approach course to stay away from terrain; and contacted the tower; and told them what happened. Tower told us to go to 118.97 and advise approach control what we were doing and that we could no longer hear them on the previously assigned frequency of 119.55. Approach controller told us to be sure to file a report on this because of the hazard of lost comm in high terrain; and said he would be filing a report as well. [I] used captain's emergency authority to maintain a safe condition of flight. [We] returned to tower and were cleared to land.

Original NASA ASRS Text

Title: Air Carrier flight crew experiences lost communications while on vectors to the ILS 12 at BZN in night VMC. The Captain elects to turn inbound to the airport to avoid terrain and contact Tower. Tower advises to try a different frequency which is successful.

Narrative: While on ATC assigned heading of 300; for an ILS 12 approach in visual conditions at night; Approach Control [communication] became very weak and was lost. We decided to turn toward final approach course to stay away from terrain; and contacted the Tower; and told them what happened. Tower told us to go to 118.97 and advise Approach Control what we were doing and that we could no longer hear them on the previously assigned frequency of 119.55. Approach Controller told us to be sure to file a report on this because of the hazard of lost comm in high terrain; and said he would be filing a report as well. [I] used Captain's emergency authority to maintain a safe condition of flight. [We] returned to Tower and were cleared to land.

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.

Air carrier flight crew experiences lost communications while on vectors to the ILS 12 at bzn in night VMC. The captain elects to turn inbound to the airport to avoid terrain and contact tower. Tower advises to try a different frequency which is successful.