SQL SERVER
You will need a function if you are trying to find the furthest one from each airport. But since you said FCO, I did it for FCO.
--temp table for testing
select 'FCO' as code, 'Fiumicino' as name, 'Rome' as city, 'Italy' as country, 41.7851 as latitude, 12.8903 as longitude into #airports
union all
select 'VCE', 'Marco Polo','Venice','Italy',45.5048,12.3396
union all
select 'NAP', 'capodichino','Naples','Italy',40.8830,14.2866
union all
select 'CDG', 'Charles de Gaulle','Paris','France',49.0097,2.5479
--create a point from your LAT/LON
with cte as(
select
*,
geography::Point(latitude,longitude,4326) as Point --WGS 84 datum
from #airports),
--Get the distance from your airport of interest and all others.
cteDistance as(
select
*,
Point.STDistance((select Point from cte where code = 'FCO')) as MetersToFiuminico
from cte)
--this is the one that's furthest away. Remove the inner join to see them all
select d.*
from
cteDistance d
inner join(select max(MetersToFiuminico) as m from cteDistance where MetersToFiuminico > 0) d2 on d.MetersToFiuminico = d2.m