GA flight instructor reported a near miss with a subsequent light twin aircraft departing apa. ATC's...

Attributes
ACN	1468485
Time
Date	201707
Local Time Of Day	0601-1200
Place
Locale Reference	APA.Airport
State Reference	CO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft High Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Climb
Flight Plan	None
Aircraft 2
Make Model Name	Small Aircraft Low Wing 2 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Instructor
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 1278 Flight Crew Type 50
Events
Anomaly	ATC Issue All Types Conflict NMAC Deviation - Track / Heading All Types
Miss Distance	Horizontal 100 Vertical 20

Narrative:

We were cleared for takeoff on runway 17L from centennial; and instructed to fly straight out. Before we were even airborne the local 1 controller cleared a light twin for takeoff and also told them to fly straight out/runway heading. I was watching the aircraft on my ads-B traffic display and saw them approaching us from the rear at high speed. Tower instructed me to turn right and proceed on course; and I responded 'unable' as there was an aircraft passing me on the right. I was taking evasive action and turning to the left away from the conflict. The tower controller had no idea about the proximity of the two aircraft. I don't believe proper spacing was given between both of us for takeoff; and tower absolutely lost separation between the two aircraft. A thorough review of centennial towers air traffic procedures is a must. Near misses in similar situations are a regular occurrences at this airport and many are not reported.

Original NASA ASRS Text

Title: GA flight instructor reported a near miss with a subsequent light twin aircraft departing APA. ATC's right turn instructions were ignored because of the overtaking aircraft.

Narrative: We were cleared for takeoff on Runway 17L from Centennial; and instructed to fly straight out. Before we were even airborne the Local 1 Controller cleared a light twin for takeoff and also told them to fly straight out/runway heading. I was watching the aircraft on my ADS-B traffic display and saw them approaching us from the rear at high speed. Tower instructed me to turn right and proceed on course; and I responded 'unable' as there was an aircraft passing me on the right. I was taking evasive action and turning to the left away from the conflict. The Tower Controller had no idea about the proximity of the two aircraft. I don't believe proper spacing was given between both of us for takeoff; and tower absolutely lost separation between the two aircraft. A thorough review of Centennial towers air traffic procedures is a must. Near misses in similar situations are a regular occurrences at this airport and many are not reported.

Data retrieved from NASA's ASRS site 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.

GA flight instructor reported a near miss with a subsequent light twin aircraft departing apa. ATC's right turn instructions were ignored because of the overtaking aircraft.