Near midair collision between 2 small aircraft aircraft in traffic pattern. Pilot deviation.

Attributes
ACN	180260
Time
Date	199106
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sjt
State Reference	TX
Altitude	agl bound lower : 1000 agl bound upper : 1050
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sjt
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other other
Aircraft 2
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	climbout : takeoff climbout : intermediate altitude
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
ASRS Report	180260
Person 2
Affiliation	Other
Function	flight crew : single pilot
Events
Anomaly	conflict : nmac non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 300 vertical : 50
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Small aircraft X departed runway 18, in left closed traffic. Small aircraft Y was released next with 6000 ft runway separation. Then small aircraft Z was released behind Y with 6000 ft runway separation. Small aircraft Z made a steep left turn before mid field and rolled out in a steep nose up angle. I then told Z 'traffic 12 O'clock less than 1/2 mi (aircraft X) in left closed traffic runway 18'. Small aircraft Z said he saw small aircraft X and before I could give X the traffic small aircraft Z passed less than 300 ft behind and maybe 50 ft above X. Before I issued the takeoff clearance to small aircraft Z the pilot gave no indication of what he was going to do.

Original NASA ASRS Text

Title: NMAC BTWN 2 SMA ACFT IN TFC PATTERN. PLTDEV.

Narrative: SMA X DEPARTED RWY 18, IN L CLOSED TFC. SMA Y WAS RELEASED NEXT WITH 6000 FT RWY SEPARATION. THEN SMA Z WAS RELEASED BEHIND Y WITH 6000 FT RWY SEPARATION. SMA Z MADE A STEEP L TURN BEFORE MID FIELD AND ROLLED OUT IN A STEEP NOSE UP ANGLE. I THEN TOLD Z 'TFC 12 O'CLOCK LESS THAN 1/2 MI (ACFT X) IN L CLOSED TFC RWY 18'. SMA Z SAID HE SAW SMA X AND BEFORE I COULD GIVE X THE TFC SMA Z PASSED LESS THAN 300 FT BEHIND AND MAYBE 50 FT ABOVE X. BEFORE I ISSUED THE TKOF CLRNC TO SMA Z THE PLT GAVE NO INDICATION OF WHAT HE WAS GOING TO DO.

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.