Range of E32 433T20DC

Hi I am planning to utilize Lora module in my rocket project. I have 3 km apogee. Then the farthest distance between two modules will be 4-5 km. Launching area is totally bare. I've made a calculation assuming no use of antennas and I've found receiving sensitivity of -86 dBi. This value sounds too much. I mean in datasheet it is written down to -144 dBm. However without an antenna my calculation shows -86 dBi. Is there a mistake or this module easily communicate between 5 km? Thanks