So Graham arrives 11am Friday morning in Kiev, so he was afaik there Saturday afternoon, why such a short trip? there is no swift way to get from Kiev to Poland, unless you risk a helicopter, a train will still take 9-11 hours.
Flying an executive jet from Poland to Washington, D.C. takes between 8.5 to 10 hours This assumes an average flight speed for a commercial airliner of 500 mph, It also adds an extra 30 minutes for take-off and landing. Your exact time may vary depending on wind speeds.
It's not hard to construct a reasonable timeline for this.
July 9 morning: Departs Dulles (~7–9am ET). Arrives Warsaw/Poland afternoon local.
July 9–10: Short layover/ground transport → Possible charter or expedited onward movement. Arrives Kyiv early–mid morning July 10.
July 10, morning–afternoon: Meetings with Zelenskyy + drone factory visit + public statements in Kyiv (widely reported and photographed).
July 10 afternoon/evening: Departs Kyiv (likely by van/helicopter to Polish border or direct charter flight from a secure airfield near Kyiv). VIP congressional travel often uses Polish airbases or expedited hops.
July 10 late / July 11 early: Arrives Poland → Quick turnaround to transatlantic flight (military/executive jet, ~9–11 hours westbound). Possible departure Poland ~6–10pm local July 10.
July 11 morning–midday: Lands Dulles or nearby D.C.-area airport (e.g., 8am–2pm ET is realistic with a night departure from Europe).
July 11 afternoon–evening: Arrives home on Capitol Hill. Rested minimally or handled briefings.
~8:00–8:30pm ET July 11: Medical emergency (aortic dissection/cardiac arrest) at residence → 911 call. EMS response documented. 
10:23pm ET: Pronounced dead at hospital.