jets3t-cockpit: 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
/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 Debian possible default full paths are:

/usr/bin/jets3t-cockpit - from package: jets3t

You may install the required package with command apt-get install {package}
Error in other languages:
jets3t-cockpit: bevel nie gevind nie
jets3t-cockpit: comandă negăsită
jets3t-cockpit: comando não encontrado
jets3t-cockpit: commande introuvable
jets3t-cockpit: command not found
jets3t-cockpit: käsku ei ole
jets3t-cockpit: không tìm thấy lệnh
jets3t-cockpit: komanda nerasta
jets3t-cockpit: Kommando nicht gefunden.
jets3t-cockpit: kommandot finns inte
jets3t-cockpit: komut yok
jets3t-cockpit: nie znaleziono polecenia
jets3t-cockpit: níor aimsíodh an t-ordú
jets3t-cockpit: no se encontró la orden
jets3t-cockpit: no s'ha trobat l'ordre
jets3t-cockpit: opdracht niet gevonden
jets3t-cockpit: parancs nem található
jets3t-cockpit: perintah tidak ditemukan
jets3t-cockpit: príkaz nenájdený
jets3t-cockpit: příkaz nenalezen
jets3t-cockpit: команда не найдена
jets3t-cockpit: командата не е открита
jets3t-cockpit: 命令找不到
jets3t-cockpit: コマンドが見つかりません