Jnu controller concerned with new wake turbulence separation criterion and its application.

Attributes
ACN	522367
Time
Date	200108
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : jnu.airport
State Reference	AK
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : jnu.tower
Operator	common carrier : air taxi
Make Model Name	Beech 1900
Operating Under FAR Part	Part 135
Flight Phase	climbout : intermediate altitude climbout : initial
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : jnu.tower
Operator	general aviation : personal
Make Model Name	PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	climbout : initial
Flight Plan	VFR
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : radar
ASRS Report	522637
Person 2
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : separated traffic controller : issued advisory controller : issued new clearance other
Supplementary
Problem Areas	FAA Flight Crew Human Performance ATC Human Performance Environmental Factor Aircraft
Primary Problem	ATC Human Performance

Narrative:

Beech 1900 departed from full length runway 8 with approximately 10 KT wind out of east. 1 min 10 seconds later, I cleared a piper cherokee for takeoff from an intersection -- 2100 ft from the end (runway 8 at taxiway B). Approximately 2 mins 15 seconds from the time the beech 1900 departed, I cleared an islander from the same intersection. The islander was also an air taxi passenger aircraft. By the time the islander rolled, there may have been 3 mins between him and the beech 1900, but I am not sure. There was not 3 mins between the cherokee and the beech 1900. 3 mins is the required separation between a small plus category aircraft departing full length and a small aircraft departing from an intersection. There was no concern from any of the pilots, and there was no incident or wake turbulence encountered. Separating a small aircraft and a large aircraft is easy and very clear cut. However, with this new small plus category, it is very confusing who is a small plus and who isn't one type of king air is a small and another series of king air is a small plus. It is difficult for controllers and pilots to keep straight. It is not obvious looking at the size of the aircraft.

Original NASA ASRS Text

Title: JNU CTLR CONCERNED WITH NEW WAKE TURB SEPARATION CRITERION AND ITS APPLICATION.

Narrative: BEECH 1900 DEPARTED FROM FULL LENGTH RWY 8 WITH APPROX 10 KT WIND OUT OF E. 1 MIN 10 SECONDS LATER, I CLRED A PIPER CHEROKEE FOR TKOF FROM AN INTXN -- 2100 FT FROM THE END (RWY 8 AT TXWY B). APPROX 2 MINS 15 SECONDS FROM THE TIME THE BEECH 1900 DEPARTED, I CLRED AN ISLANDER FROM THE SAME INTXN. THE ISLANDER WAS ALSO AN AIR TAXI PAX ACFT. BY THE TIME THE ISLANDER ROLLED, THERE MAY HAVE BEEN 3 MINS BTWN HIM AND THE BEECH 1900, BUT I AM NOT SURE. THERE WAS NOT 3 MINS BTWN THE CHEROKEE AND THE BEECH 1900. 3 MINS IS THE REQUIRED SEPARATION BTWN A SMALL PLUS CATEGORY ACFT DEPARTING FULL LENGTH AND A SMALL ACFT DEPARTING FROM AN INTXN. THERE WAS NO CONCERN FROM ANY OF THE PLTS, AND THERE WAS NO INCIDENT OR WAKE TURB ENCOUNTERED. SEPARATING A SMALL ACFT AND A LARGE ACFT IS EASY AND VERY CLR CUT. HOWEVER, WITH THIS NEW SMALL PLUS CATEGORY, IT IS VERY CONFUSING WHO IS A SMALL PLUS AND WHO ISN'T ONE TYPE OF KING AIR IS A SMALL AND ANOTHER SERIES OF KING AIR IS A SMALL PLUS. IT IS DIFFICULT FOR CTLRS AND PLTS TO KEEP STRAIGHT. IT IS NOT OBVIOUS LOOKING AT THE SIZE OF THE ACFT.

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.