CAVU Café: Royboy’s Prose & Cons

*Note: The views expressed in CAVU Café: Royboy’s Prose & Cons blog are those solely of the writer and are not necessarily shared by the Aviation Suppliers Association or the Association’s staff, members, or Board of Directors.

   About Roy Resto


Like many of you, I enjoy history and staying abreast of current events. From time to time I’ll read something or see a TV report and tell myself, ‘wow, I don’t think that commentator understood the significance of what just happened; a tick mark in history just occurred.’  In this prose I hope to share some events which to some may seem routine or minor, but that nonetheless are significant, understated ‘firsts’, and therefor noteworthy.


‘Apps’ for Aircraft Operating Systems:

For those of you who have read my blog titled “Autonomic Logistics”1, you’ll notice that I make mention of the fact that the F-35 is being fielded with many technologically advanced systems, which, as is usual for advanced military systems, will find their way trickling down to civilian applications. And so it is with what’s being metaphorically characterized as installing an app on the Aircraft Operating System; yup, just like on your smart phone.

Your iPhone has an operating system called iOS. It runs everything and hosts all the apps you install. For the F-35, the equivalent of the iOS is called OMS, Open Missions System. Israel will be the first country to install its own proprietary ‘app’ consisting of highly customized C4 (Command, Control, Communication, Cyber) and Electronic Warfare applications peculiar to its own national needs. Facilitating all this is the aircraft’s open-architecture software design by Lockheed2; another significant first. Industry users of airborne software have long clamored for open-architecture systems, and here it will debut on this aircraft. Writers of history will chronical that the first use of open-architecture software and ‘apps’ onboard aircraft operating systems occurred on the F-35. It won’t be long before the collateral ‘issues’ (such as who owns and controls the distribution rights of the apps) triggered by this new way of operating are settled and standardized, and it finds its way onboard new commercial designs, with airlines being offered ‘apps’ for installation. 

Software issues caused crash of A400M

As a self-proclaimed ‘avionics geek’ I distinctly recall those heady days of aviation when microprocessors started showing up in Avionics ‘boxes’. As a bench technician, when I started working on the first generation of Ground Proximity Warning Systems (GPWS) with microprocessors in them, I thought I was hot stuff. It took time but I learned a hard lesson: I could fix hardware problems, but not software problems. It turns out those early models exhibited many nuisance warnings to the aircrew, which were then written up by the pilots - the GPWS subsequently removed and replaced by flight line technicians - and the subsequent shop findings (me), repeated No Faults Found. In fact many of those units ended up on chronic removal programs, but had no failures! It took time to discover it was really the software, not the hardware, which was causing the removals! This got fixed over time by the OEM and follow-on product evolutions.

Today nearly every major system on board modern commercial aircraft is run by software; it dominates aircraft design, and is a major challenge for the integrators of an aircraft’s various systems. Because of this, a recent headline got my attention: “Airbus: Software Caused A400M Crash.3 If so, this is the first time I’m aware of that a software issue was at fault for the loss of life.

In the past, pilot’s unfamiliarity with how software runs the aircraft contributed to accidents, but the software itself was not at fault. In fact, software development for airborne applications is understandably subjected to very high standards of Quality Control with safety considerations commensurate with the criticality of the application. RTCA DO-178 is commonly cited as thee standard by which to develop such software. In my opinion, although this was a ‘first’, the lessons will be learned, and reoccurrences rare.

Faulty soldering cited as root cause in aircraft crash

The typical commercial aircraft easily has thousands of solder connections, mostly within the many Electronic boxes found throughout the aircraft. Every chip, transistor, diode, capacitor, inductor, transformer, and resistor is soldered into place. As any bench technician knows, faulty solder joints are a common reason for outright or intermittent failures.

Many decades ago, NASA recognized that soldering needed to be raised to a higher level of craftsmanship in order to prevent such failures which had the potential to strand astronauts in space; this simply would not be tolerated. NASA created a standard for soldering (NASA-STD-8739.3) and imposed the standard on its suppliers in order to attain the highest possible level of component reliability. Persons performing soldering had to be ‘certified’ as conforming to the standard, and if you met this standard you were a craftsman indeed. The NASA standard was subsequently replaced by IPC-J-STD-001, commonly called the “J” Standard in the industry. Today, many manufacturers and repair stations use this standard to train their technicians, and the standard is referred to in many contracts as a document that must be followed. There are other standards which accomplish the same.

Knowledge of all this grabbed my attention when it was determined that the root cause cited in the crash of an Air Asia aircraft with fatalities to all aboard, was initiated by a faulty solder joint4. This too is a ‘first’ as far as I know; that the faulty solder joint directly contributed to loss of life.

As of this writing, it has not been made publicly known if the faulty solder joint occurred during the manufacturing process or during a repair, but suffice it to say, manufacturers and repair stations should re-examine the vigor of their soldering systems and/or training, and use this unfortunate occurrence as a poster child for improvement efforts.

Aircraft collision with a drone

It had been initially reported that a British Airways flight on approach had collided with a drone, but that has since been discounted. Regardless, many continue to worry about this inevitability, and if it occurs, mark it in your history books.

Over ‘n out

Roy ‘Royboy’ Resto


2 Apps for the F-35, Has Israel set a precedent?; Aviation Week & Space Technology; April 25-May 8, 2016; Page 22


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Posted By Roy Resto | 6/1/2016 1:56:36 PM

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