Case Studies

Leonardo Aircraft Slashes Wiring Testing Manhours by More Than 90% on the M-346 Trainer 


Leonardo Aircraft (formally known as Alenia Aermacchi).


Drastically reduce time and manpower needed to test electrical systems of new production aircraft.


DIT-MCO Model 2650 with Fault Locator, Random Hookup and new Cable Management System.


Manpower needed for testing reduced by half. Connection and testing time cut by 80%. Manhours required for testing each aircraft slashed by 90%

How do you dramatically reduce the time needed for wiring testing on an aircraft bristling with more than 700 connectors?

That was the problem facing Giorgio Cagnin and his team at Leonardo Aircraft (formally known as Alenia Aermacchi) as production of the company’s new M-346 advanced jet trainer began. The aging test system they had in place was already causing delays.

Leonardo Aircraft is the only aircraft manufacturer that offers products covering every phase of military pilot training, from ground-based training systems to advanced jet trainer aircraft. Their Training Systems division produces the M-346 – and their new M-345 HET primary jet trainer – at the company’s plant in Venegono Superiore, Italy.

Sales of the M-346 have been brisk. With orders in from four countries and deliveries scheduled to ramp up sharply from one aircraft per month to four, it was clear their existing system would soon become a bottleneck that could put millions of Euros worth of milestone payments at risk.

A Problem of Complexity

That system – a DIT-MCO Model 2503 – had been used successfully to test the prototypes of the M-346. But with the new plane’s large number of test points, the hook-up and testing process was proving extremely labor-intensive.

Housed in four large cabinets, the Model 2503 was very difficult to move. This necessitated the use of long, heavy adapter cables to reach the aircraft. Each cable was in three sections which had to be unrolled and connected each time a new aircraft was rolled in for testing.

On earlier, less complex aircraft, and on the prototypes (when there was more time), this had never been a problem. Now it was. Cagnin says it would take six to seven technicians – working two shifts – two to three days just to connect each new M-346.

To make matters worse, the adapter cables – in use for ten years on the prototypes – had become unreliable. Broken wires, resulting in failed tests, were common. Time was lost waiting for repairs. Plus, the adapters were the same color as the aircraft wiring harnesses, which often caused confusion during hookup and troubleshooting.

Operators were constantly in doubt. Were faults found actually in the aircraft wiring? In the adapter cables? Or caused by an incorrect adapter connection? Testing was slowed by excessive troubleshooting. It was taking three to four weeks to test each production M-346.

“Operators couldn’t adequately concentrate on the aircraft,” says Cagnin. “Real wiring faults might be obscured by test system failures. It was a dangerous situation.”

Finding a solution became Cagnin’s top priority.

Four Requirements for a Next-Generation Tester

Cagnin and his team discussed their needs with several vendors. They examined available systems, features and customization options. It soon became clear they wanted four things in their new tester:

  1. Modular architecture
  2. Significantly reduced adapter cable length and movement
  3. Drastically reduced connection time
  4. Tests completed in minutes rather than hours

A modular architecture – small, portable units rather than huge cabinets – would make it easier to move the tester closer to the aircraft. This in turn would allow using shorter adapters.

“Often on projects like these, the adapter cables are the greatest single expense, greater than the tester itself.”

Craig Edgar
Manager for Europe
DIT-MCO International

With shorter cables and easier connection procedures, Cagnin and his colleagues believed, the likelihood of broken wires and bent pins in the adapter cables would be greatly reduced. This, in turn, would increase test reliability and reduce troubleshooting time.

Shortening the adapters would also greatly reduce the cost of the new system. “Often on projects like these, the adapter cables are the greatest single expense, greater than the tester itself,” says Craig Edgar, European Manager for DIT-MCO. “Since the tests are run at high voltages, they’re using PTFE-style Teflon cable, which is very expensive.”

Above all, Leonardo Aircraft had to make sure the new system wouldn’t be a bottleneck for production. Their goal was to reduce the manpower needed to connect and operate the system by half, while also halving set-up and test time.

A System Built for Speedy Connection

Leonardo Aircraft chose the DIT-MCO Model 2650 as the basis of their new system. The Model 2650’s portable, switching modules receive power and control signals through a single cable, in daisy chain fashion, so they can easily be placed where needed.

Cagnin and his team selected two of the Model 2650’s optional features – Fault Locator and Random Hookup – and also commissioned DIT-MCO to create some new features for them.

Fault Locator is a diagnostic tool that isolates detected faults to a specific portion of a circuit. It thus reduces troubleshooting time by focusing the search.

Random Hookup allows adapter cables to be plugged into any connector of any Model 2650 switching module. An embedded chip in each tester-side connector identifies the adapter to the test controller, which configures the test program automatically. Random Hookup saves testers time, because there’s no need to consult a procedure when hooking adapters to the tester.

“The system is very adaptable and scalable. If necessary, we just buy more modules and cables, and the system will adapt almost automatically.”

Giorgio Cagnin
Systems Engineer
Leonardo Aircraft 

To speed connection on the aircraft side, Cagnin asked DIT-MCO to create a new software utility: the Cable Management System (CMS). CMS imports all adapter/connector mapping from the test database and permits up to 5 images to be associated with each test connector. The first image shows the general aircraft location of the test port. Succeeding images allow the operator to zoom in on the connector and view it relative to nearby equipment.

To make CMS practical, DIT-MCO configured the test controller of Leonardo Aircraft’s system with a ruggedized tablet computer fitted with a barcode reader. The tablet interfaces with the controller via wireless networking, so technicians can carry it with them while connecting cables or troubleshooting faults.

Each adapter is tagged with a barcode. The technician simply reads the barcode with the tablet, and CMS shows exactly where to plug in the adapter. Combined with Random Hookup, CMS eliminates the need for any printed connection procedures

Adapting the Test System to the Aircraft

Cagnin and his colleagues, Gabriele Isella and Fabio Orizio, started from the CAD drawings used to design the M-346 and designed their new test system around it. To keep the adapters short, they positioned 17 switching modules at strategic points near the fuselage. The modularity of the Model 2650 made it easy to adapt the system to the aircraft.

They then designed the adapter cables, giving them a bright yellow color to make it easy for the operators to distinguish them from the aircraft wiring harnesses. This has significantly reduced confusion during troubleshooting of faults, according to Cagnin.

Finally, they designed stands and walkways to support the modules and allow operators easy access to all test connection points. In all, it took just over a year to build the new system.

Cagnin says they experienced a few problems along the way, but nothing out of the ordinary for a project of this size. As one might expect, there were some problems with the initial software loads, but Cagnin says DIT-MCO addressed these in a timely manner, and each was resolved to Leonardo Aircraft’s satisfaction.

Testing Time Cut by a Factor of Five

Testing with the Model 2650 began in March 2014. It was immediately obvious the new system was a big improvement over the old one, or as Cagnin calls it, “A different world.”

With short, easy-to-move cables and increased system reliability, Leonardo Aircraft were able to cut testing time by a factor of five.

Before the Model 2650 system came on line, Cagnin explains, it was taking 6 or 7 operators 3 to 4 weeks – working two shifts – to test the first M-346 production aircraft. “With the new system, we only need 3 operators,” he says. “And they can connect, test and disconnect an aircraft in just 3 to 4 days.” That’s more than a 90% reduction in test manhours per aircraft.

Wireless Tablet Improves Communication

DIT-MCO’s wireless tablet feature has also been a big plus. Besides helping to speed up connection of the adapter cables, it also aids communication between technicians during troubleshooting. “With the old system, the operators working the tester and those on the aircraft had to shout back and forth. It was hard for them to understand each other,” says Cagnin. “Now they can take the tablet right up to the aircraft. It’s much, much easier.”

The Phone Stops Ringing

Cagnin says operators are very happy and confident with the new system. So much so, they rarely seek him out for support. “Before, my phone was ringing continuously. Now, almost never,” he says. “For me, that’s a much better situation. If the test department doesn’t have a problem, I don’t have a problem.”

Best of all, the test department can now keep pace with the production line. The feared bottleneck has been eliminated.

Ready for the Future

Cagnin says Leonardo Aircraft has no immediate plans to expand the system, but he feels confident they are well prepared to cope with any new aircraft that comes down the production line.

“Before, my phone was ringing continuously. Now, almost never. For me, that’s a much better situation.”

Giorgio Cagnin
Production Engineering
Leonardo Aircraft

“As new variants of the M-346 come into production, we know we’ll make more use of the Random Hookup and CMS facilities,” he says. “Plus, the system is very adaptable and scalable. If necessary, we just buy more modules and cables, and the system will adapt almost automatically.”