B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 189; Flight Crew Type 15000
Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Human Factors
Hobby was using one Controller for Clearance; Ground; and Tower. It was extremely busy with multiple Company aircraft pushing and arriving; plus Maintenance aircraft on frequency as well as several general aviation aircraft needing clearances. We had problems getting a pushback clearance and clearance to taxi. We received a clearance to taxi via Echo; cross 12L and 17 and hold short 12R. This is unusual because at HOU normally you are told to hold short of 12L; contact Tower. In this case; this was Tower; so we proceeded. As we crossed 12L; we heard a transmission state someone is crossing the runway we are landing on. I looked right in time to see a Lear (outside First Officer's window) crossing overhead. I looked left out my window to see it continue over us and descend to 10-20 feet over runway; fly down runway to departure end; and finally execute a go-around. I estimate the aircraft went over the top of us 20-30 feet above the fuselage. We were crossing the numbers; and due to the short length of 12L he had to be aiming for the approach end of the runway. Tower stated we were correct and had been cleared to cross; and there was a disagreement between the Tower and the Lear as to which runway he was cleared to land on. It is way too busy at Hobby for only one Controller for everything including using crossing runways.There was obviously some miscommunication as to which runway the other aircraft was cleared to land on. I think a significant contributing factor was the exceptional amount of radio activity due to Ground and Tower frequencies being combined. [Both crewmembers] commented that it seemed like there was too much going on to have the frequencies combined like that. For my part; while I had turned on the wing and logo lights; I don't recall if I had turned on the strobes. At times in the past; I have refrained from doing this at night so as not to 'distract' other nearby taxiing aircraft. From now on; I will always turn on the strobes at night when crossing a runway.
[Report narrative contained no additional information.]
B737 flight crew reported a Learjet flew about 20-30 feet over their aircraft as they crossed the runway with a valid clearance.