Narrative:

[We were] cleared to 'line up and wait' on runway 1L at las and asked to report in sight on runway 1R a departing B737; which we did. We were then cleared for takeoff and told to keep [the B737] in sight and 'maintain visual separation.' our departure clearance was the las vegas 4 departure which calls for a right turn to 050 at 2500 feet MSL. As the captain turned to a heading of 050; he noted he was turning in the same direction as [the B737] and was just under its altitude. The captain thought this strange and became concerned about low altitude wake turbulence and the possibility of hitting [the B737]. The beechjet was outperforming the B737 and was climbing higher than the B737 and getting closer. Both eyes were now outside the aircraft. The captain retarded the thrust to slow the climb and the IAS. Shortly thereafter; ATC stated to [us]; 'do not overtake [the B737].' [the B737] was getting harder to see as it was beginning to disappear under [our] nose because of [our] nose attitude. The captain queried the first officer (first officer) as to what altitude we were climbing on the SID and the first officer stated; 'FL240'; put it into the altitude selector; and then immediately went eyes outside. After we climbed through 7000 feet; ATC queried our altitude. The first officer responded; 'climbing through 8600 on the SID.' ATC then queried; 'confirm you are on the mccarren 4 departure.' the first officer responded; 'negative. We are on the las vegas 4.' ATC then said; 'the altitude is 7000 on both departures. What altitude are you climbing to?' the first officer responded with; 'what altitude do you want?' we were then assigned an altitude of FL190 and a heading of 070. We were then given a number and asked to call upon landing.the captain called the number and was given the tower number to call instead. The captain was told that they had made mistakes and no further action would take place.the crew was distracted with avoiding a mid-air collision due to a misunderstanding by ATC of what the departure clearance was. They allowed [us] to turn into an aircraft on the same SID and an almost simultaneous parallel departure. If we had done the mccarren 4 departure; our headings would have been divergent instead of convergent. We inadvertently busted an altitude; but with our attention focused outside; we avoided a tragedy.

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Original NASA ASRS Text

Title: BE40 flight crew reported climbing through an altitude restriction departing LAS when they became distracted by a conflict with a preceding B737.

Narrative: [We were] cleared to 'Line Up and Wait' on Runway 1L at LAS and asked to report in sight on Runway 1R a departing B737; which we did. We were then cleared for takeoff and told to keep [the B737] in sight and 'maintain visual separation.' Our departure clearance was the Las Vegas 4 departure which calls for a right turn to 050 at 2500 feet MSL. As the Captain turned to a heading of 050; he noted he was turning in the same direction as [the B737] and was just under its altitude. The Captain thought this strange and became concerned about low altitude wake turbulence and the possibility of hitting [the B737]. The BeechJet was outperforming the B737 and was climbing higher than the B737 and getting closer. Both eyes were now outside the aircraft. The Captain retarded the thrust to slow the climb and the IAS. Shortly thereafter; ATC stated to [us]; 'Do not overtake [the B737].' [The B737] was getting harder to see as it was beginning to disappear under [our] nose because of [our] nose attitude. The Captain queried the FO (First Officer) as to what altitude we were climbing on the SID and the FO stated; 'FL240'; put it into the altitude selector; and then immediately went eyes outside. After we climbed through 7000 feet; ATC queried our altitude. The FO responded; 'Climbing through 8600 on the SID.' ATC then queried; 'Confirm you are on the McCarren 4 Departure.' The FO responded; 'Negative. We are on the Las Vegas 4.' ATC then said; 'The altitude is 7000 on both departures. What altitude are you climbing to?' The FO responded with; 'What altitude do you want?' We were then assigned an altitude of FL190 and a heading of 070. We were then given a number and asked to call upon landing.The Captain called the number and was given the tower number to call instead. The Captain was told that they had made mistakes and no further action would take place.The crew was distracted with avoiding a mid-air collision due to a misunderstanding by ATC of what the departure clearance was. They allowed [us] to turn into an aircraft on the same SID and an almost simultaneous parallel departure. If we had done the McCarren 4 Departure; our headings would have been divergent instead of convergent. We inadvertently busted an altitude; but with our attention focused outside; we avoided a tragedy.

Data retrieved from NASA's ASRS site 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.