What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The accident occurred on Saturday, June 2, during the gunfighter skies air and space celebration (airshow) at Mountain Home air force base (afb), Idaho.
Dan Buchanan airshows presented the hanglider act which consisted of a pilot, winch operator and tow driver.
According to statements from the winch operator and driver, the intended routine was to make three passes down runway 12-30 including two 180 degree turn arounds with the glider under tow. On the third pass, the pilot would disconnect from the tow line, perform manuevers and then land.
The launch, first pass (into the wind), first 180 degree turn around and second pass (down wind), appeared normal, at an approximate altitude of 1000'-1500' above ground level (AGL), according to the crew and witnesses.
Before the last turn the pilot told the winch operator to "joe give me five more pounds" meaning increase line tension. In addition it appeared that the glider had decended by approximately 400'-600' of altitude, but was maintaining the runway heading of 30.
As the pilot approached the second turn around point (taxiway hotel intersection), he asked the driver via the two way communications radio, to make the turn "driver get going" and "give me 5/0", meaning 50 mph. This was the last communication from the pilot.
The driver made a right hand 180 degree turn on the runway and accelerated to 50 mph as instructed by the pilot.
The afb control tower video footage shows the pilot making a right hand turn, then an abrupt decending left turn followed by a pop up and finally a left wing over in which the hanglider impacted the ground, vertically, nose first.
The winch operator stated that he monitors the azimuth angle of the tow line rather than the gliders altitude to determine that the tow is going ok. He said that an azimuth angle between 72-75 degrees is normal. When he noticed the azimuth angle between 30-45 degrees and the steep decending left turn, that's when he immediately released the brake on the tow line winch reel, which releases the tow line tension. He then shouted at the driver to stop the truck and turn around.
Upon post accident examination, it appeared that the quick disconnect the pilot uses to normally release the tow line had not been actuated, but rather the safety break away string loop had broke thereby releasing the tow line from the pilot's harness. The safety break away loop is a small piece of string that is designed to break at about 10-20 lbs above the normal tow line tension.
First responders said that the tow line was not connected to the pilot's harness when they arrived. This would indicate that the safety loop broke apparently during impact allowing the tow line to be released.
The FAA iic was not on scene but several FAA inspectors were on scene due to their participation with the airshow.
As the FAA filed it
THE ACCIDENT OCCURRED ON SATURDAY, JUNE 2, DURING THE GUNFIGHTER SKIES AIR AND SPACE CELEBRATION (AIRSHOW) AT MOUNTAIN HOME AIR FORCE BASE (AFB), IDAHO.
DAN BUCHANAN AIRSHOWS PRESENTED THE HANGLIDER ACT WHICH CONSISTED OF A PILOT, WINCH OPERATOR AND TOW DRIVER.
ACCORDING TO STATEMENTS FROM THE WINCH OPERATOR AND DRIVER, THE INTENDED ROUTINE WAS TO MAKE THREE PASSES DOWN RUNWAY 12-30 INCLUDING TWO 180 DEGREE TURN AROUNDS WITH THE GLIDER UNDER TOW. ON THE THIRD PASS, THE PILOT WOULD DISCONNECT FROM THE TOW LINE, PERFORM MANUEVERS AND THEN LAND.
THE LAUNCH, FIRST PASS (INTO THE WIND), FIRST 180 DEGREE TURN AROUND AND SECOND PASS (DOWN WIND), APPEARED NORMAL, AT AN APPROXIMATE ALTITUDE OF 1000'-1500' ABOVE GROUND LEVEL (AGL), ACCORDING TO THE CREW AND WITNESSES.
BEFORE THE LAST TURN THE PILOT TOLD THE WINCH OPERATOR TO "JOE GIVE ME FIVE MORE POUNDS" MEANING INCREASE LINE TENSION. IN ADDITION IT APPEARED THAT THE GLIDER HAD DECENDED BY APPROXIMATELY 400'-600' OF ALTITUDE, BUT WAS MAINTAINING THE RUNWAY HEADING OF 30.
AS THE PILOT APPROACHED THE SECOND TURN AROUND POINT (TAXIWAY HOTEL INTERSECTION), HE ASKED THE DRIVER VIA THE TWO WAY COMMUNICATIONS RADIO, TO MAKE THE TURN "DRIVER GET GOING" AND "GIVE ME 5/0", MEANING 50 MPH. THIS WAS THE LAST COMMUNICATION FROM THE PILOT.
THE DRIVER MADE A RIGHT HAND 180 DEGREE TURN ON THE RUNWAY AND ACCELERATED TO 50 MPH AS INSTRUCTED BY THE PILOT.
THE AFB CONTROL TOWER VIDEO FOOTAGE SHOWS THE PILOT MAKING A RIGHT HAND TURN, THEN AN ABRUPT DECENDING LEFT TURN FOLLOWED BY A POP UP AND FINALLY A LEFT WING OVER IN WHICH THE HANGLIDER IMPACTED THE GROUND, VERTICALLY, NOSE FIRST.
THE WINCH OPERATOR STATED THAT HE MONITORS THE AZIMUTH ANGLE OF THE TOW LINE RATHER THAN THE GLIDERS ALTITUDE TO DETERMINE THAT THE TOW IS GOING OK. HE SAID THAT AN AZIMUTH ANGLE BETWEEN 72-75 DEGREES IS NORMAL. WHEN HE NOTICED THE AZIMUTH ANGLE BETWEEN 30-45 DEGREES AND THE STEEP DECENDING LEFT TURN, THAT'S WHEN HE IMMEDIATELY RELEASED THE BRAKE ON THE TOW LINE WINCH REEL, WHICH RELEASES THE TOW LINE TENSION. HE THEN SHOUTED AT THE DRIVER TO STOP THE TRUCK AND TURN AROUND.
UPON POST ACCIDENT EXAMINATION, IT APPEARED THAT THE QUICK DISCONNECT THE PILOT USES TO NORMALLY RELEASE THE TOW LINE HAD NOT BEEN ACTUATED, BUT RATHER THE SAFETY BREAK AWAY STRING LOOP HAD BROKE THEREBY RELEASING THE TOW LINE FROM THE PILOT'S HARNESS. THE SAFETY BREAK AWAY LOOP IS A SMALL PIECE OF STRING THAT IS DESIGNED TO BREAK AT ABOUT 10-20 LBS ABOVE THE NORMAL TOW LINE TENSION.
FIRST RESPONDERS SAID THAT THE TOW LINE WAS NOT CONNECTED TO THE PILOT'S HARNESS WHEN THEY ARRIVED. THIS WOULD INDICATE THAT THE SAFETY LOOP BROKE APPARENTLY DURING IMPACT ALLOWING THE TOW LINE TO BE RELEASED.
THE FAA IIC WAS NOT ON SCENE BUT SEVERAL FAA INSPECTORS WERE ON SCENE DUE TO THEIR PARTICIPATION WITH THE AIRSHOW.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.