Why node.js can not find the avconv?

Why using the exec in node.js:

child = exec("avconv -i " + result.params.fullDestinationFilename + " -ab 128k -vcodec libx264 -vb 2000k -r 24 -s 1280x720 " + convertedFileName720p + ".mp4", function (error, stdout, stderr) {
    sys.print('stdout: ' + stdout);
    sys.print('stderr: ' + stderr);
    if (error !== null) {
        console.log('exec error: ' + error);
    }
    console.log("CONVERTED!");
});

I get an error:

  exec error: Error: Command failed: /bin/sh: avconv: command not found

In bash I can execute it normally. For node.js development I use nodeclipse.

For reference

var exec = require('child_process').exec;
exec("ls -la");    

Since feature requests to mark a comment as an answer remain declined, I copy the above solution here.

what's the difference in your own $PATH and the PATH of node? It would be safer to give the full path of avconv – glenn jackman

it is empty as I see in preferences. but the full path was the only quickest solution. thank you – static