Legislating Common Sense

In certain situations that appear to be devoid of rationality, we may discover a chunk of rules and regulations that attempt to try do the thinking for us – or at least speak to the lowest common denominator among us.

‘A Certificate of Airworthiness (C of A) is valid for the entire life of the aircraft.’

Mike Gough

Of course, without saying if there ever was an industry that requires the most attention to regulation, aviation is it.  This does however allow for certain situations, where the competence of the regulators may not exactly be up to the task, with a resultant overflow of verbose and tedious rules.

Aviation is intrinsically a regulation intensive industry, and some regulations must of necessity be complex. It’s then perhaps inevitable that the competence of the regulators may not quite be up to the task, with a resultant overflow of verbose and tedious rules.

As I find myself spending most of my time back in the General Aviation environment, the ‘real’ environment of operations and regulations reminded me how cocooned we can sometimes become in the airline world. Several of my ex-colleagues have spent a lot of time with me at Lanseria doing initial ratings or reviving long-expired instructor ratings, and the discussions we have had has highlighted the relationship between practicality, reality and the figments of some bureaucratic imaginations.

While conducting an initial instructor rating, I do my best to test for understanding of the various concepts associated with aerodynamics and procedural aspects.  I certainly do not claim to be any form of guru in either department, but I have been around the patch a few times in this regard.

Having said that, I have a confession to make, and I am going to open the Lift Theory can of worms yet again.  We do teach the Equal Transit or Longer Flow theory, which is by far the easiest lie to perpetuate in this regard.

Once the Bernoulli discussion is done, everyone goes off to the kitchen to try the spoon trick.

This is the much-maligned explanation that the upper surface flow of an aerofoil has to travel faster so the air molecules, traumatised by being separated at the leading edge of the aerofoil into upper and lower surface flow, are hell-bent on getting to the trailing edge simultaneously, thus forcing the longer flow to accelerate, with the attendant pressure drop, a la Bernoulli.

Anyone who has had to wash dishes in their lives has witnessed the turning or displacement force as a practical experiment when holding a serving spoon’s curved surface in a laminar water flow from the kitchen tap.  In this case there is no lower surface flow at all, and the resultant force as a result of the deflected flow is noticeably strong and visually revealing.

This can be clearly broken up into the upwash at the leading edge of the spoon, and the marked downwash at the trailing edge. Thus, once the Bernouilli discussion is done, everyone goes off to the kitchen in our hangar.

As this aspect is firmly in the CAA syllabus, we are stuck with it.  I don’t, however, think anyone is a poorer pilot as a result, after decades of technically inaccurate information.

Getting back to the instructor evaluation – a discussion on certification criteria is relevant.  Why specifically?  Well, there’s a definite method to the madness when an aircraft, large or small is designed, tested and certified.  These sets of rules are referred to as Federal Aviation Regulation (FAR) Part 23 and FAR 25, for little ones and big ones respectively.

FAR 23 pertains to light aircraft, up to 5,700kgs, or in the commuter category, up to 19 seats.  Beyond this is the transport category, and everyone needs to sit up and pay more attention as things get a little more stringent.

A primary difference between the two categories is the G Load limit.  Part 23 requires 3.8G positive limit, while Part 25 only requires 2.5G limit, as the rest of the package that goes with it is highly regulated and building in unnecessary structural strength adds weight.

Airbus has an absolute bank limit of 67 degrees as that is the 2.5G maximum load.

For those who may be familiar with Airbus and its various control laws, there is a very definite and non-negotiable maximum bank angle of 67 degrees.  Full and sustained side stick deflection while in Normal Law will not produce any bank angle greater than this.

This brings us around to certification limits, as ‘n’ or G load, is calculated by 1 over Cosine of Bank angle and using 67 degrees in this formula results in a ‘n’ factor of 2.5G.

My favourite Air Exercise briefing is the little-visited exercise of Side Slipping. This is now incorporated into the Descending exercise.  An Air Exercise briefing is meant to be completed after the talk-and-chalk part of the briefing and outlines what will be accomplished in the General Flying area to complete the exercise.

These ‘little’ briefings are often reduced to a short chat while walking out to the aircraft prior to the flight, often animated by swooping hands, which is not the idea at all.

How many of us remember, during our PPL training, how one determines when the side slip limit of an aircraft has been reached?  I thought so… your instructor did not consult the Instructor Training Procedures manual (formerly AIC 14.3), which has in depth air exercise material.

Students need to understand why the static port is on the left side of the fuselage.

This brings me around to another certification question for that nervous instructor candidate.  Why is the static port on single-static source aircraft (such as the Cessna 172) on the left side of the fuselage?

It didn’t end up there by accident. Slipping to the left results in an elevated static value for the same given pitot value.  This results in an under read on Indicated Air Speed (IAS). The distracted pilot glances back inside and sees a speed lower than planned and the natural reaction is to push the nose down, which is a safe tendency – especially with crossed controls and reduced airspeed.

Should the port be on the right, the opposite would occur, with the tendency to pull back on the control column.  This could well result in a stall / spin scenario, which would end badly if close to the ground.

All of these certification rules come together to allow a Type Certificate to be issued, which indicates a particular design conforms to its Type Design.  The regulating authority (for example the Federal Aviation Administration – FAA, or the European equivalent, EASA) issues this certificate.  When each example of a particular type is rolled off the production line, it is issued with a Certificate of Airworthiness (C of A), which is valid for the entire life of the aircraft, provided it complies with its Type Certificate – in other words, no unapproved modifications or damage occurs.

‘Unless of course you are in South Africa.’

Our Civil Aviation Authority feels that a fee to maintain the airworthiness certificate is required, and as a result has decided that an absolute mountain of paperwork is required to be submitted to them every year.  Every single maintenance aspect must be re-submitted annually, even if it is a once-off item that is required by the manufacturer to be accomplished, to the extent that they require the actual Type Certificate number to be declared each time – in case we have wickedly re-designed the aircraft between submissions.

On top of a massively tedious process, there is also a highly likely possibility that more than sixty days will elapse after submission, with no sign of the new certificate, which grounds the aircraft.

Thus, the addition of a date to the C of A renders the aircraft to be non-conforming to its original Type Design.

Another uniquely local requirement, contained in our regulations, pertains to how quickly the all-knowing authority expects a candidate to be ready for his or her first solo flight.  For some reason, there is a restriction that is in place which requires a solo recommendation in the training file prior to completing thirty hours.

Passing this arbitrary total requires an entire intervention which involves the Chief Flight Instructor and then a Designated Flight Examiner.  If forty hours total now elapse, it becomes the exclusive domain of the Director of Civil Aviation to decide if this person is allowed to continue flying.

Without doubt, forty hours with no solo is a significant amount of flying without a ‘normal’ progression rate.  What is completely lacking with this regulation, is context.  If one did twenty-five hours, ten years ago, and now want to re-start (probably from the beginning), one has to be kicked out of the nest within five hours.

Talk about legislating a major safety hazard into the regulations.

Similarly, many years ago in Nelspruit I had an elderly candidate, whose retirement mission was to attain his PPL.  To say we spent quality time together would be an understatement.  I finally sent him on his first solo with a total of 74 hours in his logbook.  He was so delighted with his first landing as pilot-in-command that he stopped on the runway, with the engine idling, and did not move.

I eventually walked up the runway to see what was happening, and he was sitting there, with an ear-to-ear grin, while being a thousand miles away, utterly caught up in the moment.  He went on to complete his PPL, and flew for many years, accident and incident free.

I have subsequently learned that this piece of legislation will be reviewed or removed, but it should not have been there in the first place.

It is impossible to regulate human performance and ability through the statutes – but that doesn’t prevent ‘authorities’ from trying.

By the way – the side slip limit is reached when one has full rudder applied to the stop, and further application of aileron will cause the aircraft to turn into the direction of the side slip – also a certification requirement.

But you knew that.

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