pilot-undelete: 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-undelete - from package: pilot-link-perl

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

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