ATC mix-up when 2 air carrier aircraft start to move into position and hold on runway 22L at mdw, il...

Attributes
ACN	544882
Time
Date	200204
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mdw.airport
State Reference	IL
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : taxi
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : mdw.tower
Operator	common carrier : air carrier
Make Model Name	SF 340A
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	544882
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 180 flight time total : 5500 flight time type : 1700
ASRS Report	544884
Events
Anomaly	incursion : runway non adherence : required legal separation non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	flight crew : took precautionary avoidance action other
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

We were holding short of runway 22L at mdw on north side of runway. Tower cleared us into 'position and hold on runway 22L' and the first officer read back the exact clearance. I repeated the clearance to 'position and hold runway 22L' and called for the below the line items on the pre takeoff checklist. As I started to taxi onto runway 22L, I noticed a saab 340 taxiing onto runway 22L from the south side of the runway (nose-to-nose with us). I stopped the aircraft just past the hold line and still clear of the solid white runway line as the saab 340 continued and asked the first officer to clarify the situation with the tower. Tower replied that they canceled our clearance. Neither myself, my first officer, or our jump seat rider heard the cancellation. No interference with landing or departing aircraft actually occurred, and we were subsequently cleared for takeoff after the saab 340. Since we all 3 heard the clearance and it was a very busy, high traffic period at mdw, I can only suspect that if the clearance was subsequently rescinded, it may have been covered by our acknowledgement or some other transmission.

Original NASA ASRS Text

Title: ATC MIX-UP WHEN 2 ACR ACFT START TO MOVE INTO POS AND HOLD ON RWY 22L AT MDW, IL.

Narrative: WE WERE HOLDING SHORT OF RWY 22L AT MDW ON N SIDE OF RWY. TWR CLRED US INTO 'POS AND HOLD ON RWY 22L' AND THE FO READ BACK THE EXACT CLRNC. I REPEATED THE CLRNC TO 'POS AND HOLD RWY 22L' AND CALLED FOR THE BELOW THE LINE ITEMS ON THE PRE TKOF CHKLIST. AS I STARTED TO TAXI ONTO RWY 22L, I NOTICED A SAAB 340 TAXIING ONTO RWY 22L FROM THE S SIDE OF THE RWY (NOSE-TO-NOSE WITH US). I STOPPED THE ACFT JUST PAST THE HOLD LINE AND STILL CLR OF THE SOLID WHITE RWY LINE AS THE SAAB 340 CONTINUED AND ASKED THE FO TO CLARIFY THE SIT WITH THE TWR. TWR REPLIED THAT THEY CANCELED OUR CLRNC. NEITHER MYSELF, MY FO, OR OUR JUMP SEAT RIDER HEARD THE CANCELLATION. NO INTERFERENCE WITH LNDG OR DEPARTING ACFT ACTUALLY OCCURRED, AND WE WERE SUBSEQUENTLY CLRED FOR TKOF AFTER THE SAAB 340. SINCE WE ALL 3 HEARD THE CLRNC AND IT WAS A VERY BUSY, HIGH TFC PERIOD AT MDW, I CAN ONLY SUSPECT THAT IF THE CLRNC WAS SUBSEQUENTLY RESCINDED, IT MAY HAVE BEEN COVERED BY OUR ACKNOWLEDGEMENT OR SOME OTHER XMISSION.

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.