d52: 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/d52 - from package: d52

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

On Debian possible default full paths are:

/usr/bin/d52 - from package: d52

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

Error in other languages:
d52: bevel nie gevind nie
d52: comandă negăsită
d52: comando não encontrado
d52: commande introuvable
d52: command not found
d52: käsku ei ole
d52: không tìm thấy lệnh
d52: komanda nerasta
d52: Kommando nicht gefunden.
d52: kommandot finns inte
d52: komut yok
d52: nie znaleziono polecenia
d52: níor aimsíodh an t-ordú
d52: no se encontró la orden
d52: no s'ha trobat l'ordre
d52: opdracht niet gevonden
d52: parancs nem található
d52: perintah tidak ditemukan
d52: príkaz nenájdený
d52: příkaz nenalezen
d52: команда не найдена
d52: командата не е открита
d52: 命令找不到
d52: コマンドが見つかりません