hi sherri! we just flew in september with my 10 month old swcah son. i DID have a letter from my endo (a standard emergency one, not one specifically for travelling) and brought the syringes and all meds on the plane. i was not once asked to explain. went through ALL checkpoints with out one security person asking me what the syringes were even for. but, i did have the letter with me just in case. my son did just fine. i did have LOTS of juice with us b/c long airplane rides tend to be dehydrating. best of luck!!

louise