Upvote:4
The safest answer and the best answer are two different things. The best answer is for him not to travel until the pandemic is over. His age puts him in a very high risk category.
The safest way to travel would be for him to book a first-class ticket on a non-stop flight to the airport to which you can drive the quickest. You will need to pick him up. It may mean an extended car ride for both of you. Since, he may not be able to get a non-stop flight to the airport geographically closer to you. But, that will limit the number of people to whom he is exposed.
He needs to wear a mask and gloves from the time he leaves his house to the time he enters yours. There will be times, like at security checkpoints, where he will have to remove the mask. Try to minimize exposure at those times. This means that he will have to avoid eating, drinking and using the restroom as much as possible. And of course, sanitize his hands, and everything that he will touch, often.
Upvote:6
If the question is the safest, then the answer can only be: charter a plane. The chartering agency will help picking airports: some money can be saved by leaving from a smaller airport and the destination is a bit tricky. Not only vicinity is a requirement but he needs to meet CBP to admit him into the country (which they will, citizens can't be denied). The list of Ports of Entry in Kansas is one entry long: Wichita airport. Obviously Kansas City airport in Missouri is another possibility. I do not know whether it's possible to pay the CBP to meet him at an airport where they are typically not present. The chartering agency will be very well versed in this.
Note this is ~4500 nautical miles and so you need to charter a large or even a long range jet. I ran a random date for this route through a few private jet search engines google found me, one said "Long Range Jet from β¬ 85 090" the other said "$117,100 to $133,200". It's very likely chartering a somewhat smaller jet to do it in two hops, refueling in Gander will be cheaper (flying transatlantic like this was very popular in the 1950s because there were no bigger jets yet). With the longest leg only 2518nm there are several mid sized jets which have the range. Also, it's possible a mid sized jet will be able to take off from an airport a long range jet wouldn't be able to which again is likely to save money. For example, the balanced field length for the mid sized Legacy 450 is 3800 ft, for the large Gulfstream 500 it is 5385 ft which means the 5249ft long runway at Aix-en-Provence is enough for the Legacy 450 to take off but the G500 won't be allowed to (allowed to -- what's possible in an emergency is entirely different). You are still renting an entire jet, pay for the fuel and the crew hours but it'll be cheaper -- somewhat. Indeed, same search as above quoted me β¬ 66 970 for the one stop option indicating a mid sized jet as I expected. These numbers are pretty much in line with my wild guesstimates, so despite these are not formal quotes, this is what I would budget: 100-130 000 USD nonstop, 80 000 USD with one stop. Roughly.
But you asked for safest and this is it. Whether it's worth it, that's a different question and one that we can not help with.