An A320 taxiing for takeoff at mia was cleared to hold short of the merge. The flight crew was unabl...

Attributes
ACN	717433
Time
Date	200611
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mia.airport
State Reference	FL
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	717433
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Chart Or Publication Airport ATC Human Performance
Primary Problem	Ambiguous
Situations
Chart	airport : mia.airport

Narrative:

No violations or near misses or anything like that. More a concern with mia ground controller procedures/techniques. Upon changing frequency from miami gates to miami ground; we were cleared to taxi to runway 8R; 'hold short of the merge' and follow a B737. By the 'merge;' we assumed he meant the confluence of taxiways Q; P; M; and north; which all come together at the approach ends of runways 12 and 8R. Problem is; I can't find a specific ground reference point on the 10-9 defining exactly what this means (like in ord where points like 'penalty box' and 'scenic hold pad' are clearly marked). There is an inset which shows 'hold for departure' lines; but does not label the area with any lingo like 'the merge.' today was clear and a million; and we heard other aircraft being similarly cleared; so we constructed an educated guess as to the controller's intent. I still believe that nobody should ever have to guess; surmise; or assume anything where aircraft clearances are concerned. At night; in a rush; in low weather; in unfamiliar surroundings; distracted by checklist duties; distracted by searching the 10-9 for a definition of the controller's statement. Any of these can lead to 'insufficient spacing' between two jets.

Original NASA ASRS Text

Title: AN A320 TAXIING FOR TAKEOFF AT MIA WAS CLRED TO HOLD SHORT OF THE MERGE. THE FLT CREW WAS UNABLE TO FIND ANY REFERENCE TO THE MERGE ON THE MIA COMMERCIAL CHART 10-9 TAXI CHART.

Narrative: NO VIOLATIONS OR NEAR MISSES OR ANYTHING LIKE THAT. MORE A CONCERN WITH MIA GROUND CONTROLLER PROCEDURES/TECHNIQUES. UPON CHANGING FREQUENCY FROM MIAMI GATES TO MIAMI GROUND; WE WERE CLEARED TO TAXI TO RWY 8R; 'HOLD SHORT OF THE MERGE' AND FOLLOW A B737. BY THE 'MERGE;' WE ASSUMED HE MEANT THE CONFLUENCE OF TAXIWAYS Q; P; M; AND N; WHICH ALL COME TOGETHER AT THE APPROACH ENDS OF RWYS 12 AND 8R. PROBLEM IS; I CAN'T FIND A SPECIFIC GROUND REFERENCE POINT ON THE 10-9 DEFINING EXACTLY WHAT THIS MEANS (LIKE IN ORD WHERE POINTS LIKE 'PENALTY BOX' AND 'SCENIC HOLD PAD' ARE CLEARLY MARKED). THERE IS AN INSET WHICH SHOWS 'HOLD FOR DEPARTURE' LINES; BUT DOES NOT LABEL THE AREA WITH ANY LINGO LIKE 'THE MERGE.' TODAY WAS CLEAR AND A MILLION; AND WE HEARD OTHER AIRCRAFT BEING SIMILARLY CLEARED; SO WE CONSTRUCTED AN EDUCATED GUESS AS TO THE CONTROLLER'S INTENT. I STILL BELIEVE THAT NOBODY SHOULD EVER HAVE TO GUESS; SURMISE; OR ASSUME ANYTHING WHERE AIRCRAFT CLEARANCES ARE CONCERNED. AT NIGHT; IN A RUSH; IN LOW WEATHER; IN UNFAMILIAR SURROUNDINGS; DISTRACTED BY CHECKLIST DUTIES; DISTRACTED BY SEARCHING THE 10-9 FOR A DEFINITION OF THE CONTROLLER'S STATEMENT. ANY OF THESE CAN LEAD TO 'INSUFFICIENT SPACING' BETWEEN TWO JETS.

Data retrieved from NASA's ASRS site as of January 2009 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.

An A320 taxiing for takeoff at mia was cleared to hold short of the merge. The flight crew was unable to find any reference to the merge on the mia commercial chart 10-9 taxi chart.