Bh 206 instructor pilot reported near midair collision with a light aircraft in the pattern at dto.

Attributes
ACN	1049761
Time
Date	201210
Local Time Of Day	1201-1800
Place
Locale Reference	DTO.Airport
State Reference	TX
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Jet/Long Ranger/206
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	Other GPS RNAV 18
Flight Plan	None
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	None
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 22000 Flight Crew Type 6000
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 300 Vertical 0

Narrative:

This was a training flight. I was acting as cfii; ip; the pilot flying was under the hood. We were executing the GPS/RNAV 18 at dto. At 5 mile final; I was handed off to tower. Dto tower cleared me to land. Tower advised me of traffic on the downwind leg and asked if I had the [aircraft] in sight. I replied 'I have the cessna on downwind in sight.' tower turned the cessna; which was higher in altitude; in front of me on his base leg. I lost sight of the cessna in the clutter.this put my helicopter and the cessna on a collision course. At about 1;000 ft AGL and 1 mile from the runway; I had to take evasive action to avoid a collision. The closure rate was approximately 100 KTS. When the two [aircraft] were approximately 1;000 ft apart I rapidly decelerated the helicopter to 25 KTS allowing the cessna to complete his turn to final in front of me. The aircraft separation was about 300 ft. At this same time that I was taking evasive maneuvers the tower instructed me to break off the approach and sidestep to the east. Tower instructions were too late to avoid a collision.

Original NASA ASRS Text

Title: BH 206 instructor pilot reported NMAC with a light aircraft in the pattern at DTO.

Narrative: This was a training flight. I was acting as CFII; IP; the pilot flying was under the hood. We were executing the GPS/RNAV 18 at DTO. At 5 mile final; I was handed off to Tower. DTO Tower cleared me to land. Tower advised me of traffic on the downwind leg and asked if I had the [aircraft] in sight. I replied 'I have the Cessna on downwind in sight.' Tower turned the Cessna; which was higher in altitude; in front of me on his base leg. I lost sight of the Cessna in the clutter.This put my helicopter and the Cessna on a collision course. At about 1;000 FT AGL and 1 mile from the runway; I had to take evasive action to avoid a collision. The closure rate was approximately 100 KTS. When the two [aircraft] were approximately 1;000 FT apart I rapidly decelerated the helicopter to 25 KTS allowing the Cessna to complete his turn to final in front of me. The aircraft separation was about 300 FT. At this same time that I was taking evasive maneuvers the Tower instructed me to break off the approach and sidestep to the East. Tower instructions were too late to avoid a collision.

Data retrieved from NASA's ASRS site as of July 2013 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.