Narrative:

I finished fueling my aircraft at the self service island off of taxiway xx and within a short time started my taxi towards runway xx to cross onto taxiway xy. Upon reaching runway xx I noticed a [tanker aircraft] turning what appeared to be a fairly tight right base to final and decided to hold short of runway xx at taxiway xx; I also noticed another small aircraft on right downwind. While waiting for the [tanker] to land I heard someone say 'I'll depart after the tanker lands'. The [tanker] had landed and started his left turn off runway xx onto taxiway xy; at this time I took note of where the light aircraft was in the pattern and looked down the runway to check for traffic; I then radioed my intention to cross runway xx and follow the [tanker]. Within several seconds I was crossing and noticed what appeared to be a cessna citation flying low (gear up) and headed towards me; I stopped momentarily while he flew overhead. I had been listening carefully before starting my taxi across runway xx and did not hear the cj announce taking [the] runway for departure. I wish I had taken more time to look for departing traffic and will not make that mistake again.

Google
 

Original NASA ASRS Text

Title: C-172 Single Pilot reported a critical ground conflict while taxing across the runway with a aircraft executing a departure over the runway.

Narrative: I finished fueling my aircraft at the self service island off of Taxiway XX and within a short time started my taxi towards Runway XX to cross onto Taxiway XY. Upon reaching Runway XX I noticed a [tanker aircraft] turning what appeared to be a fairly tight right base to final and decided to hold short of Runway XX at Taxiway XX; I also noticed another small aircraft on right downwind. While waiting for the [tanker] to land I heard someone say 'I'll depart after the tanker lands'. The [tanker] had landed and started his left turn off Runway XX onto Taxiway XY; at this time I took note of where the light aircraft was in the pattern and looked down the runway to check for traffic; I then radioed my intention to cross Runway XX and follow the [tanker]. Within several seconds I was crossing and noticed what appeared to be a Cessna Citation flying low (Gear Up) and headed towards me; I stopped momentarily while he flew overhead. I had been listening carefully before starting my taxi across Runway XX and did not hear the CJ announce taking [the] runway for departure. I wish I had taken more time to look for departing traffic and will not make that mistake again.

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.