While on a right base for for runway 25R at dvt; pilot is instructed to orbit north of the center li...

Narrative:

I was landing at deer valley airport in phoenix; arizona. I initially contacted the north runway tower as advised on ATIS for arriving aircraft. I reported approximately 10 miles north of the airport and was instructed to enter a right base for runway 25L as runway 25R was closed for construction. When on approximately a 2-3 mile right base to runway 25R; I was instructed to orbit north of the center line of runway 25R. I did not fully understand the request to orbit north of runway 25R. I made a left 270 to a heading of approximately 270 to establish a pattern just northeast of runway 25R. This left turn resulted in a near miss with another aircraft on base to runway 25L. At this time the tower instructed me to fly southwest to approximately the center of runway 25R. I then was changed from the north tower frequency to the south tower frequency on right base for runway 25L. When contacting ground frequency I was instructed to call the tower.misunderstanding of orbit north of runway 25R centerline. 1) clarify misunderstanding or confusion with tower as soon as possible 2) utilize communication via e-mail to local pilots by the deer valley pilot association to alert the pilot as to the anticipated traffic pattern changes occurring with closure of runway 25r3) clarification of phraseology by tower e.g. 'Make right hand turns north of runway 25R rectangular pattern' or 'turn right to enter rectangular orbit with right hand turns north of runway 25R'.

Original NASA ASRS Text

Title: While on a right base for for Runway 25R at DVT; pilot is instructed to orbit north of the center line of the Runway. A left turn is initiated resulting in a NMAC with another aircraft on base for Runway 25R.

Narrative: I was landing at Deer Valley Airport in Phoenix; Arizona. I initially contacted the North Runway Tower as advised on ATIS for arriving aircraft. I reported approximately 10 miles north of the airport and was instructed to enter a right base for Runway 25L as Runway 25R was closed for construction. When on approximately a 2-3 mile right base to Runway 25R; I was instructed to orbit north of the center line of Runway 25R. I did not fully understand the request to orbit north of Runway 25R. I made a left 270 to a heading of approximately 270 to establish a pattern just northeast of Runway 25R. This left turn resulted in a near miss with another aircraft on base to Runway 25L. At this time the Tower instructed me to fly southwest to approximately the center of Runway 25R. I then was changed from the North Tower frequency to the South Tower frequency on right base for Runway 25L. When contacting ground frequency I was instructed to call the Tower.Misunderstanding of orbit North of Runway 25R centerline. 1) Clarify misunderstanding or confusion with Tower as soon as possible 2) Utilize communication via e-mail to local pilots by the Deer Valley Pilot Association to alert the pilot as to the anticipated traffic pattern changes occurring with closure of Runway 25R3) Clarification of phraseology by Tower e.g. 'make right hand turns North of Runway 25R rectangular pattern' OR 'turn right to enter rectangular orbit with right hand turns North of Runway 25R'.

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.

Attributes
ACN	1049891
Time
Date	201211
Local Time Of Day	1201-1800
Place
Locale Reference	DVT.Airport
State Reference	AZ
Environment
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	VFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 12 Flight Crew Total 1300 Flight Crew Type 300
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 200 Vertical 200

While on a right base for for runway 25R at dvt; pilot is instructed to orbit north of the center line of the runway. A left turn is initiated resulting in a near midair collision with another aircraft on base for runway 25R.