aa3d: 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 Debian possible default full paths are:

/usr/bin/aa3d - from package: aa3d

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

Error in other languages:
aa3d: bevel nie gevind nie
aa3d: comandă negăsită
aa3d: comando não encontrado
aa3d: commande introuvable
aa3d: command not found
aa3d: käsku ei ole
aa3d: không tìm thấy lệnh
aa3d: komanda nerasta
aa3d: Kommando nicht gefunden.
aa3d: kommandot finns inte
aa3d: komut yok
aa3d: nie znaleziono polecenia
aa3d: níor aimsíodh an t-ordú
aa3d: no se encontró la orden
aa3d: no s'ha trobat l'ordre
aa3d: opdracht niet gevonden
aa3d: parancs nem található
aa3d: perintah tidak ditemukan
aa3d: príkaz nenájdený
aa3d: příkaz nenalezen
aa3d: команда не найдена
aa3d: командата не е открита
aa3d: 命令找不到
aa3d: コマンドが見つかりません