An A310 crew, with loss of DME unable to ascertain where departure turn is to commence.

Attributes
ACN	498040
Time
Date	200101
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : sna.airport
State Reference	CA
Altitude	msl single value : 1000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : sct.tracon tower : slc.tower
Operator	common carrier : air carrier
Make Model Name	A310
Operating Under FAR Part	Part 121
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	498040
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On takeoff, I lost my DME localizer readout and so went my reference to turn at appropriate time. DME inoperative for a few seconds, then came back on. Unsure as to when to turn, so I turned to heading required and flew remainder of SID. Noise rule for departure causes unnecessary workload which distracts from flying aircraft.

Original NASA ASRS Text

Title: AN A310 CREW, WITH LOSS OF DME UNABLE TO ASCERTAIN WHERE DEP TURN IS TO COMMENCE.

Narrative: ON TKOF, I LOST MY DME LOC READOUT AND SO WENT MY REF TO TURN AT APPROPRIATE TIME. DME INOP FOR A FEW SECONDS, THEN CAME BACK ON. UNSURE AS TO WHEN TO TURN, SO I TURNED TO HDG REQUIRED AND FLEW REMAINDER OF SID. NOISE RULE FOR DEP CAUSES UNNECESSARY WORKLOAD WHICH DISTRACTS FROM FLYING 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.