Narrative:

I was assisting an ATP candidate in performing confined area operations in the general vicinity of the airport/training facility at which I am employed. After an initial high altitude reconnaissance was made and a wind evaluation accomplished, I allowed the ATP candidate to perform the maneuver to the confined area that we frequently use for training purposes. When we terminated the approach in the confined area, I determined that, due to particular WX (heat) and performance limitations, the only safe way to depart from that area was to fly directly under a row of power lines to an area that provided a safe landing zone in the event of an engine failure during the departure. Although a normal departure from the confined area could be accomplished by paralleling the power lines and then gaining enough ht to clear them, I felt that due to the proximity of the power lines and a row of trees that were in the departure path, that it would be best to minimize the time factor in the ht/velocity curve of the helicopter being flown as well as being able to safely land in an emergency. The total amount of time spent crossing under the power lines was less than 10 seconds. There was adequate clearance separating the pwrlines from the main rotor of the helicopter. I have selected a better area to perform confined area operations and use it exclusively to reduce the threat to the safety of flight.

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Original NASA ASRS Text

Title: A HELI INSTRUCTOR PLT FELT THAT HE HAD TO FLY UNDER WIRES ON A HOT DAY.

Narrative: I WAS ASSISTING AN ATP CANDIDATE IN PERFORMING CONFINED AREA OPS IN THE GENERAL VICINITY OF THE ARPT/TRAINING FACILITY AT WHICH I AM EMPLOYED. AFTER AN INITIAL HIGH ALT RECONNAISSANCE WAS MADE AND A WIND EVALUATION ACCOMPLISHED, I ALLOWED THE ATP CANDIDATE TO PERFORM THE MANEUVER TO THE CONFINED AREA THAT WE FREQUENTLY USE FOR TRAINING PURPOSES. WHEN WE TERMINATED THE APCH IN THE CONFINED AREA, I DETERMINED THAT, DUE TO PARTICULAR WX (HEAT) AND PERFORMANCE LIMITATIONS, THE ONLY SAFE WAY TO DEPART FROM THAT AREA WAS TO FLY DIRECTLY UNDER A ROW OF PWR LINES TO AN AREA THAT PROVIDED A SAFE LNDG ZONE IN THE EVENT OF AN ENG FAILURE DURING THE DEP. ALTHOUGH A NORMAL DEP FROM THE CONFINED AREA COULD BE ACCOMPLISHED BY PARALLELING THE PWR LINES AND THEN GAINING ENOUGH HT TO CLR THEM, I FELT THAT DUE TO THE PROX OF THE PWR LINES AND A ROW OF TREES THAT WERE IN THE DEP PATH, THAT IT WOULD BE BEST TO MINIMIZE THE TIME FACTOR IN THE HT/VELOCITY CURVE OF THE HELI BEING FLOWN AS WELL AS BEING ABLE TO SAFELY LAND IN AN EMER. THE TOTAL AMOUNT OF TIME SPENT XING UNDER THE PWR LINES WAS LESS THAN 10 SECONDS. THERE WAS ADEQUATE CLRNC SEPARATING THE PWRLINES FROM THE MAIN ROTOR OF THE HELI. I HAVE SELECTED A BETTER AREA TO PERFORM CONFINED AREA OPS AND USE IT EXCLUSIVELY TO REDUCE THE THREAT TO THE SAFETY OF FLT.

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.