Narrative:

A flight of 4 F16s was heading into IR416. Cys main and standby frequencies were OTS; buecs were being used. The r-side cleared the flight into IR416. When asking for the exit fix estimate and altitude; communications became hard to understand. The F16's possibly mistook the request for his information for some sort of denial of IR416 or was unsure if his clearance was valid. While trying to sort out communications with the flight other aircraft on other frequencies were congesting the controller's radio. By the time communications cleared up between the controller and the flight of F16's; the flight started to hold at point alpha without approval or advisement. Although he was holding low enough to be clear of all IFR traffic departing from denver on the laramie transition on YELLO6 departure and also low enough to be below the IFR traffic on the laramie transition on the ramms arrival; he was not above an mia; (14;000); approximately 20 miles to the west of point alpha which he crossed into while holding. The mia was in sector 13. The controller caught his deviation and pointed the aircraft out to sector 13 he was holding at approximately 12;500; for one full rotation before finally entering ir 416. There were also two VFR aircraft out by the 14;000 mia that the aircraft came close to although he had them depicted on his on board radar. The safety situations that concern me here are: overlapping frequencies causing congestion. Main and standby frequencies being worked on during a period of moderate traffic as opposed to during slow times at night resulting in difficulty communication to pilots. The F16's choice to hold at a point of his choosing without being cleared or advising the center. I do not believe this particular situation was unsafe; but had the flight held a different point; a different altitude; or a safety situation occurred while the communications were in such a poor state; a problem could have quickly arose. The overlapping frequency is a consistent problem on sector 21 and 22 and leaves many controllers helpless to communicate while aircraft check on and step over one another.

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Original NASA ASRS Text

Title: ZDV Controller described an airspace incursion event when a flight of military fighters enroute to a training area entered holding unexpectedly; the reporter claiming frequency problems as one causal factor.

Narrative: A flight of 4 F16s was heading into IR416. CYS main and standby frequencies were OTS; BUECS were being used. The R-Side cleared the flight into IR416. When asking for the exit fix estimate and altitude; communications became hard to understand. The F16's possibly mistook the request for his information for some sort of denial of IR416 or was unsure if his clearance was valid. While trying to sort out communications with the flight other aircraft on other frequencies were congesting the controller's radio. By the time communications cleared up between the controller and the flight of F16's; the flight started to hold at point Alpha without approval or advisement. Although he was holding low enough to be clear of all IFR traffic departing from Denver on the Laramie transition on YELLO6 departure and also low enough to be below the IFR traffic on the Laramie transition on the RAMMS arrival; he was not above an MIA; (14;000); approximately 20 miles to the West of Point Alpha which he crossed into while holding. The MIA was in Sector 13. The controller caught his deviation and pointed the aircraft out to Sector 13 He was holding at approximately 12;500; for one full rotation before finally entering IR 416. There were also two VFR aircraft out by the 14;000 MIA that the aircraft came close to although he had them depicted on his on board RADAR. The safety situations that concern me here are: Overlapping frequencies causing congestion. Main and standby frequencies being worked on during a period of moderate traffic as opposed to during slow times at night resulting in difficulty communication to pilots. The F16's choice to hold at a point of his choosing without being cleared or advising the center. I do not believe this particular situation was unsafe; but had the flight held a different point; a different altitude; or a safety situation occurred while the communications were in such a poor state; a problem could have quickly arose. The overlapping frequency is a consistent problem on Sector 21 and 22 and leaves many controllers helpless to communicate while aircraft check on and step over one another.

Data retrieved from NASA's ASRS site as of April 2012 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.