ftp-rfc: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/ftp-rfc - from package: expect

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/ftp-rfc - from package: expect

You may install the required package with command apt-get install {package}

Error in other languages:
ftp-rfc: bevel nie gevind nie
ftp-rfc: comandă negăsită
ftp-rfc: comando não encontrado
ftp-rfc: commande introuvable
ftp-rfc: command not found
ftp-rfc: käsku ei ole
ftp-rfc: không tìm thấy lệnh
ftp-rfc: komanda nerasta
ftp-rfc: Kommando nicht gefunden.
ftp-rfc: kommandot finns inte
ftp-rfc: komut yok
ftp-rfc: nie znaleziono polecenia
ftp-rfc: níor aimsíodh an t-ordú
ftp-rfc: no se encontró la orden
ftp-rfc: no s'ha trobat l'ordre
ftp-rfc: opdracht niet gevonden
ftp-rfc: parancs nem található
ftp-rfc: perintah tidak ditemukan
ftp-rfc: príkaz nenájdený
ftp-rfc: příkaz nenalezen
ftp-rfc: команда не найдена
ftp-rfc: командата не е открита
ftp-rfc: 命令找不到
ftp-rfc: コマンドが見つかりません