On June 3, 2009 at approximately 3:15 pm, Southwest Airlines (SWA) flight 1080, a Boeing 737, aircraft number N299WN, and Continental Express (BTA) flight 2491, call sign Jetlink 2491, an Embraer 145, aircraft number N16963, were involved in a runway incursion at Cleveland/Hopkins International Airport (CLE), Cleveland, Ohio. The incident occurred during daytime visual meteorological conditions. SWA1080 was on a scheduled part 121 flight from CLE to Chicago Midway International Airport (MDW) Chicago, Illinois. SWA1080 had a crew of 5 which included the pilot, first officer, 3 flight attendants, and 111 passengers on board. BTA2491 was on a scheduled part 121 flight from CLE to Chicago O'Hare International Airport (ORD) Chicago, Illinois. BTA2491 had a crew of 3 which included the pilot, first officer, one flight attendant and 44 passengers on board. At the time of the incident, there was a developmental controller on the local control position being monitored by a certified controller. The incident occurred during daytime visual meteorological conditions. At approximately 3:00 pm, SWA1080 requested taxi instructions from the CLE air terminal. The CLE tower ground controller issued progressive taxi instructions to SWA1080 to taxiway N at runway 6R and did not advise the crew they would be departing from runway 6L. After reaching taxiway N, the ground controller directed SWA1080 to monitor the tower local control frequency. This was the standard taxi procedure when departing runway 6L at CLE with 6R also an active runway. The local controller was responsible for all aircraft and vehicle movement on runways 6R and 6L and all taxiways in between the runways. The traditional taxi route for aircraft departing runway 6L was the ground controller directed aircraft to taxi via taxiway L, to taxiway N and then the local controller directed across runway 6R on taxiway N to a left turn on taxiway G to the approach end of runway 6L. The developmental local controller directed BTA2941 to taxi up to and hold short of runway 6R at taxiway N. The local controller directed SWA1080, waiting at taxiway N behind BTA2941 at runway 6R, to taxi to taxiway T at runway 6R. The controller then instructed BTA2941 to cross runway 6R at taxiway N. After a B773 crossed the landing threshold for runway 6R, the developmental controller directed SWA1080 to cross runway 6R at taxiway T. Thirty seconds after directing BTA2941 to cross runway 6R at taxiway N, the developmental controller transmitted “Jetlink 2941 wheels up in 1 minute sir. Turn left heading 360 runway six left cleared for takeoff.” BTA2941 acknowledged the clearance. One minute and 15 seconds after clearing BTA2941 for takeoff, the developmental controller directed SWA1080, who was still on taxiway T, to taxi into position and hold on runway 6L. SWA1080 taxied onto runway 6L at taxiway T when BTA2941, on runway 6L at the approach end, queried the developmental controller, “hey tower, 2941, I thought we were cleared to go”. The developmental controller stated he was writing down the call sign of an inbound flight and did not see SWA1080 go into position on the runway. The local controller responded with “SWA1080 hold short of [runway] six right, I’m sorry hold short of [runway] six left”. SWA1080 responded immediately with “we were told to position and hold”. Local controller directed BTA2941 to hold his position. SWA1080 asked the tower “what do you want us to do, SWA1080”. The local controller directed SWA1080 to make a 180 degree turn and turn right on taxiway G. The local controller then re-cleared BTA2941 for takeoff. SWA1080 called the tower to clarify that they had been directed to position and hold. The local controller responded affirmatively but added “not from the intersection”. SWA1080 was sequenced with two other aircraft waiting to depart and departed from the approach end of runway 6L without further incident. 2. ATC Facility Information CLE was a level 10 ATC tower and radar facility responsible for ATC services for aircraft arriving and departing CLE and for aircraft overflying and transiting through CLE airspace that operated 24 hours a day, seven days a week. CLE conducted 245,000 tower operations in 2007, 240,000 tower operations in 2008 and 67,000 tower operations in 2009 as of June 1, 2009. CLE had three runways: 6L/24R, 6R/24L and 10/28. Runway 6L/24R was 9000 feet long by 150 feet wide. Runway 6R/24L was 9955 feet long by 150 feet wide with a displaced landing threshold on runway 6L 2000 feet from the approach end. Runway 10/28 was 6017 feet long and 150 feet wide. Runway 6L/24R and 6R/24L were separated by 1241 feet between centerlines. 3. ATC Equipment CLE was equipped with airport movement and surveillance system (AMASS). The AMASS was designed to provide a visual indication when a runway is unusable due to other aircraft arriving or departing the runway. AMASS will also provide a visual and aural alarm when the system logic senses a potential collision on a runway. To prevent nuisance alerts, the AMASS will alarm if conflict aircraft and/or vehicles are moving a speed of approximately 44 miles per hour or greater. In both runway incursions discussed in this report, the AMASS did not alarm. CLE ATCT was equipped with three AMASS displays, one each suspended above the LC1 and LC2 positions and a tabletop display at the GC position.