Academic experience with a very light aircraft-dedicated flight test instrumentations system

A. Rolando, Dipartimento di Ingegneria Aerospaziale - Politecnico di Milano, Milano
C. Cardani, Dipartimento di Ingegneria Aerospaziale - Politecnico di Milano, Milano
Paolo Chimetto, Flight Test & Experimental Flight Line Manager of Alenia Aermacchi S.p.A.

Abstract

In the recent years a new class of aircraft has attained a tremendous commercial success. The defnition of these machines is different around the world - Ultra Light Machine, Very Light Aircraft, etc - but will eventually converge to some kind of generally accepted category.

A deep market analysis is beyond the scope of the present work, but to give just a rough idea on the figures of such a rapidly growing phenomenon, the last special buyer guide issue of one of the many Italian magazines dedicated to Ultra Light Machines (ULMs), lists a total of 225 different models (not to mention the variants of every model) available to the buyer.

Among the reasons for the mentioned success, the unique combination of enjoyable, real airplane like performances and low total cost of ownership can be considered preeminent.

One of the main contributions in keeping costs calm is the very relaxed - or in some cases (like Italy) totally absent - authority requirements for the certifcation of the machine. For this reason no systematic Flight Testing activity is normally planned by the manufacturing companies as a part of the design, development and production process of, and therefore no suitable Commercial Of The Shelf Flight Test Instrumentation (FTI) system is available on the market.

An activity involving the project to design, develop and test of a Very Light Aircraft tailored FTI system has therefore been launched as the main topic of a PhD[1] [2], and the MNEMOSINE system is the result of such efforts. It consists in a federated architecture data acquisition system, composed of a number of independent nodes sharing information on a dual 1 MBit/s Controller Area Network (CAN) based digital data bus.

Given the positive outcomes from both educational and research activities based on the DIA-PoliMi owned and operated Very Light Aircraft, and taking into account a few difficulties gradually arisen in the in-house operation of the aircraft, a decisive step has been taken in the past months to empower this branch of DIA-PoliMI activities. In particular, a co-operative effort is currently ongoing, involving a ying school and Nando Groppo, one of the major Italian VLA manufacturers.- This has led to the availability of a more complete Flight Line, which is professionally operated and maintained.

The present paper focuses on the in-house built FTI system's architecture, its development, and testing and performance evaluation. In addition, an overview on the recently added features-the acquisition of the pilot's force on Flight Controls-is given.

Initial results on the current year students Flight Test campaign are also presented. These have been performed on the pre-series machine of Nando Groppo's brand new XL aircraft, and are intended to be the preliminary Flight Test activity that will eventually lead to some kind of certification-oriented procedures and test reports.