This fork supports request headers and returns text data if the request fails.

jquery-ajax-blob-arraybuffer.js

/**
 * Register ajax transports for blob send/recieve and array buffer send/receive via XMLHttpRequest Level 2
 * within the comfortable framework of the jquery ajax request, with full support for promises.
 *
 * Notice the +* in the dataType string? The + indicates we want this transport to be prepended to the list
 * of potential transports (so it gets first dibs if the request passes the conditions within to provide the
 * ajax transport, preventing the standard transport from hogging the request), and the * indicates that
 * potentially any request with any dataType might want to use the transports provided herein.
 *
 * Remember to specify 'processData:false' in the ajax options when attempting to send a blob or arraybuffer -
 * otherwise jquery will try (and fail) to convert the blob or buffer into a query string.
 */
$.ajaxTransport("+*", function(options, originalOptions, jqXHR){
    // Test for the conditions that mean we can/want to send/receive blobs or arraybuffers - we need XMLHttpRequest
    // level 2 (so feature-detect against window.FormData), feature detect against window.Blob or window.ArrayBuffer,
    // and then check to see if the dataType is blob/arraybuffer or the data itself is a Blob/ArrayBuffer
    if (window.FormData && ((options.dataType && (options.dataType === 'blob' || options.dataType === 'arraybuffer')) ||
        (options.data && ((window.Blob && options.data instanceof Blob) ||
            (window.ArrayBuffer && options.data instanceof ArrayBuffer)))
        ))
    {
        return {
            /**
             * Return a transport capable of sending and/or receiving blobs - in this case, we instantiate
             * a new XMLHttpRequest and use it to actually perform the request, and funnel the result back
             * into the jquery complete callback (such as the success function, done blocks, etc.)
             *
             * @param headers
             * @param completeCallback
             */
            send: function(headers, completeCallback){
                var xhr = new XMLHttpRequest(),
                    url = options.url || window.location.href,
                    type = options.type || 'GET',
                    dataType = options.dataType || 'text',
                    data = options.data || null,
                    async = options.async || true,
                    key;

                xhr.addEventListener('load', function(){
                    var response = {}, status, isSuccess;

                    isSuccess = xhr.status >= 200 && xhr.status < 300 || xhr.status === 304;

                    if (isSuccess) {
                        response[dataType] = xhr.response;
                    } else {
                        // In case an error occured we assume that the response body contains
                        // text data - so let's convert the binary data to a string which we can
                        // pass to the complete callback.
                        response.text = String.fromCharCode.apply(null, new Uint8Array(xhr.response));
                    }

                    completeCallback(xhr.status, xhr.statusText, response, xhr.getAllResponseHeaders());
                });

                xhr.open(type, url, async);
                xhr.responseType = dataType;

                for (key in headers) {
                    if (headers.hasOwnProperty(key)) xhr.setRequestHeader(key, headers[key]);
                }
                xhr.send(data);
            },
            abort: function(){
                jqXHR.abort();
            }
        };
    }
});

I have encountered problem with IE11 (maybe this also happens on IE10) when server returns 500. Code throws exception thus not calling error handler of the AJAX request.

Passing response data using [] on line 51 resolved it, ie:

response.text = String.fromCharCode.apply(null, new Uint8Array([xhr.response]));

Hope it helps someone