pilot-install-user: 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/pilot-install-user - from package: pilot-link

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

On Debian possible default full paths are:

/usr/bin/pilot-install-user - from package: pilot-link

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

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