A saab 2000 flight crew has an near midair collision with a VFR cessna on approach to dto.

Attributes
ACN	735488
Time
Date	200704
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dto.airport
State Reference	TX
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dto.tower
Operator	general aviation : corporate
Make Model Name	Saab 2000
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer & glide slope : 17 other
Flight Phase	descent : approach
Route In Use	approach : instrument precision
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : dto.tower
Operator	general aviation : personal
Make Model Name	Cessna 340/340A
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Flight Plan	VFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine pilot : instrument pilot : cfi
Experience	flight time total : 6500 flight time type : 1200
ASRS Report	735488
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Experience	flight time total : 5000
ASRS Report	735281
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Miss Distance	horizontal : 0 vertical : 100
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

As we were approaching dto; we were speaking with ft worth approach control. Approach cleared us for the visual approach to runway 17 in dto (we were approximately 9-10 mi out at this time). We had the airport in sight and also had the ILS tuned up for runway 17. The autoplt was on and the approach mode was active once we were cleared for the approach. The approach controller then switched us to dto tower. We checked in with the tower and he asked us to report our position. We reported that we were 8 mi out; straight in for runway 17. Tower then asked a twin cessna to say his position. The cessna reported that he was on a 6 mi final. Tower reported that he had the cessna in sight. We started to slow and asked the tower what he would like us to do. He said that we were #2 behind the cessna. We did not see the cessna and did not have him on TCAS. We were discussing making a 360 degree turn for spacing. I brought the power levers to idle and reduced the descent rate in search of the cessna. Then I saw the nose of his airplane coming out from directly under us and in front of us. I would estimate that we were within 300 ft or less of the cessna. I immediately started a 360 degree turn to the left and when we told the tower that we needed a left 360 degrees; he replied that he had to clear it with approach (we were already in the turn). We were halfway through the turn when tower called and reported us in sight and wanted to know if we still had the field. Once we rolled around and saw the field again; we reported it and we were cleared to land. At no time did we ever get any TCAS alerts or even an identify on the screen in the area that the cessna was located. After the cessna landed; the tower told him we were on a 1 mi final and to turn left and stay with him. We were actually on a 3 mi final. I believe the incident was caused due to the lack of radar at denton tower and the lack of communication between the tower and the approach control.

Original NASA ASRS Text

Title: A SAAB 2000 FLT CREW HAS AN NMAC WITH A VFR CESSNA ON APPROACH TO DTO.

Narrative: AS WE WERE APCHING DTO; WE WERE SPEAKING WITH FT WORTH APCH CTL. APCH CLRED US FOR THE VISUAL APCH TO RWY 17 IN DTO (WE WERE APPROX 9-10 MI OUT AT THIS TIME). WE HAD THE ARPT IN SIGHT AND ALSO HAD THE ILS TUNED UP FOR RWY 17. THE AUTOPLT WAS ON AND THE APCH MODE WAS ACTIVE ONCE WE WERE CLRED FOR THE APCH. THE APCH CTLR THEN SWITCHED US TO DTO TWR. WE CHKED IN WITH THE TWR AND HE ASKED US TO RPT OUR POS. WE RPTED THAT WE WERE 8 MI OUT; STRAIGHT IN FOR RWY 17. TWR THEN ASKED A TWIN CESSNA TO SAY HIS POS. THE CESSNA RPTED THAT HE WAS ON A 6 MI FINAL. TWR RPTED THAT HE HAD THE CESSNA IN SIGHT. WE STARTED TO SLOW AND ASKED THE TWR WHAT HE WOULD LIKE US TO DO. HE SAID THAT WE WERE #2 BEHIND THE CESSNA. WE DID NOT SEE THE CESSNA AND DID NOT HAVE HIM ON TCAS. WE WERE DISCUSSING MAKING A 360 DEG TURN FOR SPACING. I BROUGHT THE PWR LEVERS TO IDLE AND REDUCED THE DSCNT RATE IN SEARCH OF THE CESSNA. THEN I SAW THE NOSE OF HIS AIRPLANE COMING OUT FROM DIRECTLY UNDER US AND IN FRONT OF US. I WOULD ESTIMATE THAT WE WERE WITHIN 300 FT OR LESS OF THE CESSNA. I IMMEDIATELY STARTED A 360 DEG TURN TO THE L AND WHEN WE TOLD THE TWR THAT WE NEEDED A L 360 DEGS; HE REPLIED THAT HE HAD TO CLR IT WITH APCH (WE WERE ALREADY IN THE TURN). WE WERE HALFWAY THROUGH THE TURN WHEN TWR CALLED AND RPTED US IN SIGHT AND WANTED TO KNOW IF WE STILL HAD THE FIELD. ONCE WE ROLLED AROUND AND SAW THE FIELD AGAIN; WE RPTED IT AND WE WERE CLRED TO LAND. AT NO TIME DID WE EVER GET ANY TCAS ALERTS OR EVEN AN IDENT ON THE SCREEN IN THE AREA THAT THE CESSNA WAS LOCATED. AFTER THE CESSNA LANDED; THE TWR TOLD HIM WE WERE ON A 1 MI FINAL AND TO TURN L AND STAY WITH HIM. WE WERE ACTUALLY ON A 3 MI FINAL. I BELIEVE THE INCIDENT WAS CAUSED DUE TO THE LACK OF RADAR AT DENTON TWR AND THE LACK OF COM BTWN THE TWR AND THE APCH CTL.

Data retrieved from NASA's ASRS site as of January 2009 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.