Check the carotid pulse for 5-10 seconds. If you feel no pulse within 10 seconds, start CPR cycles of 30 chest compressions then 2 breaths. Compress the center of the chest hard and fast (atleast 2 acheiving at least 100 compressions per minute) Allow for full chest recoil after each compression.
Carriers are required to provide adequate food and potable drinking water for passengers within two hours of the aircraft being delayed on the tarmac and to maintain operable lavatories and, if necessary, provide medical attention.
If you include this extra time on the tarmac, the average total elapsed time from gate to gate flying from Los Angeles, CA to New York, NY is 5 hours, 14 minutes.