Kalmar “Tsarin jirgi” yawanci tana nufin ƙunƙutun takarda ko robobi da masu kula da zirga-zirgar jiragen sama ke amfani da shi don yin rikodi da bin diddigin bayanan da suka shafi jirgin. Tushen yakan ƙunshi cikakkun bayanai kamar lambar tantance jirgin, lokacin tashi da isowa, tsayi, hanya, da duk wani bayani mai dacewa. Ana amfani da tulin jirgin don sarrafa zirga-zirgar jiragen sama, sauƙaƙe sadarwa tsakanin masu kula da zirga-zirgar jiragen sama, da tabbatar da aminci da ingantaccen zirga-zirgar jiragen sama ta sararin samaniya.