equa.itt: 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/lib/eso-midas/13SEP/systab/bin/equa.itt - from package: eso-midas

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

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