stairs.itt: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/stairs.itt - from package: eso-midas

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