Air carrier departure from mdw on runway 22L questioned takeoff clearance because of aircraft in pos...

Narrative:

While taxiing to runway 22L; another aircraft with similar call sign was given line up and wait instructions on [runway] 31C. We were then given takeoff clearance from runway 22L as we approached the hold short. The transmission was slightly garbled due to radio interference; so my first officer read back the entire clearance which included our flight number; our runway; and our turn instructions clearly and precisely to make sure of no miscommunication. We then made our required call outs stating the runway and clear in both directions. I felt uncomfortable knowing that there was another aircraft in position on the intersecting runway and with the multiple radio transmissions covering each other. I knew in my heart that we were cleared to go; but I wanted to make sure that everyone was on the same page. I asked my first officer to confirm that we were cleared to takeoff from 22L. When he did this; tower responded with a stop instruction; we stopped. Then tower gave us position and hold. Then tower gave the other aircraft takeoff clearance and shortly thereafter; gave us clearance to takeoff. Preventive measures: less general aviation traffic in congested areas and heads-up given for similar call signs.

Original NASA ASRS Text

Title: Air Carrier departure from MDW on Runway 22L questioned takeoff clearance because of aircraft in position on Runway 31C with similar flight number; resulting in a 'cancel takeoff' instruction from Local Control.

Narrative: While taxiing to Runway 22L; another aircraft with similar call sign was given line up and wait instructions on [Runway] 31C. We were then given takeoff clearance from Runway 22L as we approached the hold short. The transmission was slightly garbled due to radio interference; so my First Officer read back the entire clearance which included our flight number; our runway; and our turn instructions clearly and precisely to make sure of no miscommunication. We then made our required call outs stating the runway and clear in both directions. I felt uncomfortable knowing that there was another aircraft in position on the intersecting runway and with the multiple radio transmissions covering each other. I knew in my heart that we were cleared to go; but I wanted to make sure that everyone was on the same page. I asked my First Officer to confirm that we were cleared to takeoff from 22L. When he did this; Tower responded with a stop instruction; we stopped. Then Tower gave us position and hold. Then Tower gave the other aircraft takeoff clearance and shortly thereafter; gave us clearance to takeoff. Preventive measures: less general aviation traffic in congested areas and heads-up given for similar call signs.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	964748
Time
Date	201108
Local Time Of Day	1201-1800
Place
Locale Reference	MDW.Airport
State Reference	IL
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Person 1
Function	Captain
Experience	Flight Crew Last 90 Days 200 Flight Crew Type 200
Events
Anomaly	ATC Issue All Types Conflict Ground Conflict Less Severe Deviation - Procedural Published Material / Policy

Air carrier departure from mdw on runway 22L questioned takeoff clearance because of aircraft in position on runway 31C with similar flight number; resulting in a 'cancel takeoff' instruction from local control.