expect_ftp-rfc: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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 Debian possible default full paths are:

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

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