Mgm tower and TRACON controllers described a uncertain separation event when an aircraft departed VF...

Narrative:

Airport was reporting IFR conditions with 2-1/2 SM visibility. Tower visibility was not reported as it was probably more than 4 SM. Local control scanned two departure strips; with the first one apparently being SVFR and the next one IFR. The rules on SVFR are somewhat vague and always the subject to interpretations; but the last one that I heard indicated that if an aircraft was operating under special VFR in a class delta surface area; then it could be the only aircraft airborne in the cdsa. I think that is excessive; but that is the way I understand the last interpretation of the rules that I was briefed on. I called local control and asked if the aircraft was on a special VFR clearance; and he replied that I was correct; although the tone in his voice suggested that he had forgotten that until I posed the question. The SVFR aircraft had been fanned left to a 210 degree heading off of runway 28 and the subsequent IFR departure had been fanned right to 300 degrees. This was much more separation than would be required of two ifrs. The reported visibility was suspect as aircraft were reporting the field in sight from 7 or more miles away. I continued to work the two aircraft out of the class D as it appeared to be an incredibly safe operation. Recommendation: review and simplify the ATC requirements for SVFR. They are overly restrictive in many situations.

Original NASA ASRS Text

Title: MGM Tower and TRACON Controllers described a uncertain separation event when an aircraft departed VFR when in fact the weather had changed to IFR conditions.

Narrative: Airport was reporting IFR conditions with 2-1/2 SM visibility. Tower visibility was not reported as it was probably more than 4 SM. Local Control scanned two departure strips; with the first one apparently being SVFR and the next one IFR. The rules on SVFR are somewhat vague and always the subject to interpretations; but the last one that I heard indicated that if an aircraft was operating under Special VFR in a Class Delta Surface Area; then it could be the only aircraft airborne in the CDSA. I think that is excessive; but that is the way I understand the last interpretation of the rules that I was briefed on. I called Local Control and asked if the aircraft was on a Special VFR clearance; and he replied that I was correct; although the tone in his voice suggested that he had forgotten that until I posed the question. The SVFR aircraft had been fanned left to a 210 degree heading off of Runway 28 and the subsequent IFR departure had been fanned right to 300 degrees. This was much more separation than would be required of two IFRs. The reported visibility was suspect as aircraft were reporting the field in sight from 7 or more miles away. I continued to work the two aircraft out of the Class D as it appeared to be an incredibly safe operation. Recommendation: review and simplify the ATC requirements for SVFR. They are overly restrictive in many situations.

Data retrieved from NASA's ASRS site as of April 2012 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	913252
Time
Date	201010
Local Time Of Day	1201-1800
Place
Locale Reference	MGM.Airport
State Reference	AL
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Flight Phase	Initial Climb
Flight Plan	SVFR
Person 1
Function	Departure Approach
Qualification	Air Traffic Control Fully Certified
Person 2
Function	Flight Data / Clearance Delivery Local Ground Supervisor / CIC
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

Mgm tower and TRACON controllers described a uncertain separation event when an aircraft departed VFR when in fact the weather had changed to IFR conditions.