What is the sum of speed in km per hour reached by John Egginton?
CREATE TABLE "aircraft" (
  "category" text,
  "speed_km_h" real,
  "speed_mph" real,
  "vehicle" text,
  "pilot" text,
  "date" text
);
SELECT SUM("speed_km_h") FROM "aircraft" WHERE "pilot"='john egginton';