Commentary

This is opinion only – it is NOT legal advice

Qualitative vs. Quantitative

Published in the Daily Bugle, November 17, 2023

Qualitative vs. Quantitative

As mentioned before, the regulations have a plethora of parametric thresholds–numbers, fancy units, and the occasional squiggly math.  As a rule, it’s best to avoid qualitative thresholds, because one person’s All You Can Eat is another’s hors d’oeuvre.  Terms like “advanced,” “lightweight,” “fast,” and “spiffy[1]” can creep in and cause all sorts of problems when it comes to J&C.

When used properly, such adjectives are conveniently illustrative, as in 3A229.c which describes a “fast” switching function, but also includes a turn-on time parameter.  “Lightweight” is a problematic term used by itself, but in the EAR and ITAR it at least includes a parameter.  ECCNs 6A004.a.2 and .3 call out “lightweight” mirrors, but the threshold is set by both density and total mass; the term “lightweight” could vanish and the control interpreted just fine, a nice test.  USML XIII(g)(4) calls out “lightweight” materials, but the parameter is 2 pounds/square foot.  That unit is great for pressure, but as there are no two-dimensional radar absorbing materials.  I have no idea how to determine if a particular batch of gunk is lightweight based on incomplete units – it needs another length somewhere.  Give the USML partial credit because removing “lightweight” from XIII(g)(4) won’t change the entry’s clarity.

As an aside, a shoutout to 6A004.c.1 for the creative verb “lightweighted.”  I’d give a kidney[2] to have been in the room to hear the alternatives.

The following story combines both undefined terms and unintended consequences – a volatile mix worthy of Category V control if there ever was one.

Before the turn of the century, the Missile Technology Control Regime (MTCR) controlled missile turbofan and turbojet engines completely qualitatively – “Lightweight turbojet and turbofan engines….that are small and fuel-efficient.”  It included commentary to the effect of “They are similar in design and operation to the engines that power civilian aircraft, just smaller in size and power.  Somebody realized this was incomplete, so they later added “usable in missiles.”  Wow, thanks!

Smaller in size and power is correct.  Non-rocket missile engines typically produce between 50 to 500 pounds of thrust, weight under 200 pounds and run 12 to 18 inches in diameter.  In comparison, the engines on an A380 or 787 can produce over 80,000 pounds of thrust, weigh over seven tons, and have fans 117 inches in diameter.  Close to 1000 times the thrust, seventy times the weight, up to ten times the diameter. We’re talking Cadillac Escalade versus a Lime scooter.   Given that radar cross-section is critical to missiles, a 10 foot diameter engine is use-able in a missile, but not very use-ful.

In 1997, MTCR 3.A.1.a (EAR 9A101) added parameters – a maximum thrust of 2000 pounds[3] and a well-defined fuel efficiency.[4]  All was adequate until 2007, when the Powers That Be decided to remove the terms “lightweight” and “usable in missiles,” likely because the terms are notably undefined and parameters were added a decade before.  Per the commentary in the Federal Register Notice, “This amendment will result in a more focused control on these engines, but this change is expected to have no impact on licensing activity.”  [Narrator– It Did.]

Something else that might not have been considered – the bigger the engine, the more fuel-efficient it is.  While the fuel efficiency threshold was a differentiator for a small missile engine, any viable large commercial engine beat that limit by a mile[5].

MTCR 3.A.1/ECCN 9A101 has an odd quirk[6] on the thrust upper limit – it only applies to civil certified engines.  There is no upper limit for pre-certified engines.  When developing a new or updating an existing engine, it’s typical to have engines in the pre-certified state moving around the world for years.  And while such pre-certified engines are controlled under 9A001 for NS, the lack of an upper thrust limit means they inherit the 9A101 MT control.  That means additional license reviews, no license exceptions, and unlike the FR promise, an overall negative impact on licensing activity.  Under the pre-2007 language one could argue that a three-ton, eight-foot diameter development engine was neither lightweight nor usable in a missile, but with those words gone, it was no longer an option.  License exception STA (740.20) showed up in 2011, but the MT control kept it out of reach.  See unintended consequence[7], above.   

The straightforward[8] solution was to reinsert the concepts of “lightweight” and “small,” just using numbers this time.  The 2015 proposal to the MTCR was a weight limit of 500 kg and a maximum diameter of 750 mm, but was bumped up to 750 kg (1650 pounds) and 1 meter to get buy-in from the other MTCR members.  It only took until 2017 for MTCR approval[9], and the EAR updated a year later.  

“Lightweight,” “fast,” and “advanced” are all great advertising terms, but don’t belong in a regulation.  Those are the obvious ones.  The EAR and USML have many other terms where everyone agrees on the meaning – as long as they don’t compare notes.  Homework –find at least other qualitative terms unaccompanied by a parameter in the CCL or USML.

Got J&C questions? – please reach out to me at ArtOfJC@arinovis.com.  


[1] Not (presently) on the CCL or USML, but one can dream.  

[2] Not my kidney – there are limits.

[3] About the size of a business jet engine.

[4] Although “Kg N- 1 h-1 ” is a bit confusing.

[5] We just found the missing dimension from the XIII(g)(4) entry!

[6] More accurately, Yet Another Odd Quirk.

[7] Ample Benefit of the Doubt included at no extra charge.

[8] “Straightforward” in the update the regulations context of “as straightforward as Gravity’s Rainbow.”

[9] Blazingly fast by MTCR standards.  Missiles move fast, MTCR updates don’t.


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