Flight crew of an mdt cpr aircraft exceeded SID clearance limit during climb after takeoff.

Attributes
ACN	258598
Time
Date	199312
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sjc
State Reference	CA
Altitude	msl bound lower : 3000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : oak
Operator	general aviation : corporate
Make Model Name	Medium Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Route In Use	departure other departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 20000
ASRS Report	258598
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	non adherence : clearance non adherence : published procedure other anomaly other other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

The loupe 8 departure for runway 30L at sjc specifies that you should not exceed 4 DME when turning from runway heading to 120 degrees. This turn is to be started at 1.8 DME. We followed the procedure, turning at 1.8 DME and at 250 KIAS. During the turn, the DME from sjc VOR exceeded the 4 DME limit. We went to 4.8 DME. There are a number of variables that make the restr impossible to comply with. I.e., at 3000 ft outside air temperature 26 degrees C, 224 KIAS, 25 degrees bank, the diameter of a 360 degree turn is 3.61 NM or 1.805 radius. This departure is very difficult to comply with, making it a hazard if traffic separation is based on its compliance.

Original NASA ASRS Text

Title: FLC OF AN MDT CPR ACFT EXCEEDED SID CLRNC LIMIT DURING CLB AFTER TKOF.

Narrative: THE LOUPE 8 DEP FOR RWY 30L AT SJC SPECIFIES THAT YOU SHOULD NOT EXCEED 4 DME WHEN TURNING FROM RWY HDG TO 120 DEGS. THIS TURN IS TO BE STARTED AT 1.8 DME. WE FOLLOWED THE PROC, TURNING AT 1.8 DME AND AT 250 KIAS. DURING THE TURN, THE DME FROM SJC VOR EXCEEDED THE 4 DME LIMIT. WE WENT TO 4.8 DME. THERE ARE A NUMBER OF VARIABLES THAT MAKE THE RESTR IMPOSSIBLE TO COMPLY WITH. I.E., AT 3000 FT OUTSIDE AIR TEMP 26 DEGS C, 224 KIAS, 25 DEGS BANK, THE DIAMETER OF A 360 DEG TURN IS 3.61 NM OR 1.805 RADIUS. THIS DEP IS VERY DIFFICULT TO COMPLY WITH, MAKING IT A HAZARD IF TFC SEPARATION IS BASED ON ITS COMPLIANCE.

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.