Rotor & Wing NVG Article- Army Minimums

[TheVelvetGlove]

The most recent Rotor & Wing issue has an article on NVG's and NVG training. The article mentions that in extremely low light environments, the US Army has the following lunar illumination requirements: 23% disc illumination and at least 30 degrees above the horizon.

The article mentioned this in contrast to civilian HEMS operations, which typically make no mention of the moon at all, when setting limitations for NVG use.

My program utilizes NVG's in areas that have no terrestrial illumination whatsoever, and also over water at night.

Does anyone know where I can find a copy of the Army's weather and terrestrial/celestial illumination requirements for NVG use?

Thanks.

[mfriskel]

23% and 30 degrees has been around for a long time. It does not restrict you from flying in less light levels, but required you to have operational "pink light" installed on the acft. This was a requirement for Army training and operations which are tactical low altitude operations.
Civil HEMS does not perform tactial NVG covert operations. You probably have enroute minimum altitude of 500 feet AGL or higher and can only go below that after performing your high recon of the scene. Totally different environments. You also will have 2 or 3 unfiltered lights to help illumintate the area and if you feel you don't have good enough vision with the NVG, de-goggle and land unaided. NVG are a tool to make your job safer, enroute and at the scene, if you feel that unaided is safer, take the NVG off and proceed unaided. The really nice thing about NVG is you can flip them up and down as you wish and need. You are not limited to only aided or unaided. Get in the air and see which mode is safest for the conditions.
For your overwater oeprations at night, the NVG won't provide you much help unless oil rigs are not lit. I would recommend night overwater be primarily via instruments with altitude alerter set and resume NVG when approaching the shoreline.

[TwinHueyMan]

The Army does not restrict you from flying NVGs for any illumination conditions currently... IIRC it would only elevate your Risk Assesment level and require a briefing from a higher ranking commander to OK you to fly (a practice done on every flight). That being said, I've flown NVGs on many, many zero-illum nights in featureless environments in both training and actual operations, and found that while it is a huge help to have the goggles, the missions we performed would have been able to be performed unaided, with the goggles simply allowing a greater safety margin and more efficiency of flight (sans of course the blacked-out combat type missions). Goggles aren't as much a tool to allow you to fly when you could not, but rather they allow you to fly safer when you would have already been flying anyways.

Besides, when you turn even the dimmest landing light on at low level, you create your own moon... and then some.

-Mike

[TheVelvetGlove]

Thanks for clarifying that.

I don't agree with the idea that a landing light can be used to illuminate the way while enroute, however....if that was what you were getting at. In my experience, while flying in an area of high humidity over the ocean at night with no moon, the last thing I want to do is turn on an exterior light.

Besides, the landing light does nothing to help you create a visual horizon where the horizon has been lost due to dark water and no moon.... and I do not have IFR to back me up.

I think that the NVG's are a great tool, but for night overwater operations, they are not capable of at producing a horizon 100% of the time.

And there are no off-shore stuctures where I am.:suspect:

[Scorpygixxer]

NVGs over water are a bit of a problem especially when out in zero light. Unfortunately, you are left with the IFR / NVG blend to keep things safe. Many times over water you may be left with a single target point of reference such as a single distant vessel which is essentially a single point of light on the goggs. This can create gyrosomatic illusions leading to the leans. I know that much of the time the RN will rely on IFR procedures for transit and winching ops.

In fact I've experienced problems in daytime VFR SAR scenarios with reasonable visibility, solid overcast, calm water and no horizon, and little IFR experience to back me up. The only thing that prevented me losing references was back to basics, trust the instruments and find a land reference as soon as possible. These scenarios are very similar to the NVG op, but you have fewer cues and a bigger head scan to complete with the NVGs. Nothing else for it! Get the IFR training and if you can, engage and manage your autopilot at the first possible opportunity.

It's really important to realise that if there is no light there, and you cannot provide your own illumination, you may as well be IFR, for all of the use the NVGs are over featureless terrain or water. Any limitations that the army provides are primarily designed for desert operations, good meteorological visibility and low humidity with few ground references and a high liklihood of recirculation. They are not designed for over water ops.

You don't say what you do with the NVGs over water... or is it so cool you can't talk about it?

[[email protected]]

I think that the NVG's are a great tool, but for night overwater operations, they are not capable of at producing a horizon 100% of the time. Nothing will give you that horizon 100% of the time if the weather is bad - just like during the day.

You say you don't have an IFR option, does that mean you are not instrument trained or don't have an IFR equipped/capable aircraft or have other constraints that prevent you flying on instruments?

We operate low level over the sea day and night in all weathers but we have the advantage of a very good radar and radar operator which will allow us to keep clear of vessels/windfarms/land. We also have a very good AP and fly 2 pilot.

If you are flying overwater at night on goggles without a horizon because the weather is so bad then you are effectively in actual conditions. I trust you have a 4 axis autopilot with a rad alt hold and audio warner - plus a second pilot.

[TheVelvetGlove]

No- the aircraft is single pilot VFR only (nicely equipped, and with radar, but no autopilot).

I am not saying that the weather is bad- generally, it is good- it's just very dark without a moon, most of the time.

Plan B is to turn around before encountering IMC- be that a loss of horizon, or clouds/low viz. Trouble is, it is sometimes darker behind you than in front of you.

What are we doing? Just moving people from Point A to Point B- nothing spectacularly interesting...other than this being a fairly uncommon operation.

[Bertie Thruster]

Good luck, Velvet. :sad:

[busdriver02]

Very dark nights flying goggles can at times be IMC while flying VFR (no clouds but no horizon either). NVG flight is much more on the instruments than day flight. I'd be very careful flying in those conditions single pilot/ single person with access to the controls.

[[email protected]]

Velvet - I can only presume that you are doing something that is either covert, illegal or both since single pilot, VFR flight in an unstabilised helicopter over water on NVG with fare paying passengers is unlikely to be condoned by any Aviation Authority in the world. Is it single engined as well?

[TheVelvetGlove]

Well, nothing covert here- and it's a twin. We are never more than 45 miles from a land mass, but that land mass is rock, and mostly uninhabited (no light).

If anyone can provide me with a reference that states that under FAA Part 135, single pilot, twin engine, VFR, NVG, no autopilot, over water, at night, with fare paying passengers is illegal- I would really like to see that.

[Sven Sixtoo]

Dont know about FAR, but in the UK, rule 20 of the Rules of the Air prohibits VFR flight at night.

I really think that VFR ops overwater at night in an aircraft without automatic height hold acting through a fast-acting input to the collective channel of a 4-axis autopilot is asking for trouble. And using NVG is not a way to convert night to day. The RAF operates a variety of helicopters with an assortment of APs using NVG. All of them, without exception, require two crew in the cockpit for such an operation. That includes the SAR crews who can choose any combination of NVG and white light that gets the job done.

Sven

[TheVelvetGlove]

In the USA, the majority of night helicopter operations are VFR, and are unaided, as well...

Wen you say that VFR is not permitted at night in the UK- I assume that you mean that the aircraft and the pilot must be IFR, not that it must be an IFR operation at night, correct? Otherwise, scene work at night would be out of the question...:confused:

[Gomer Pylot]

I've done a fair amount of night offshore flying, and IMO NVGs are not the best way to do it. Enroute, it's IFR, if not IMC, and the landing is usually to a very highly-lit platform, where the goggles are not necessary or don't work well. If you can't fly in IMC, then you shouldn't be flying offshore at night, NVG or not, because it will be IMC, sooner or later.

[TheVelvetGlove]

It is interesting that this has not been regulated but the FAA.

The Nov 1991 "Rotorcraft Night Vision Goggle Evaluation" paper that Hawley, Anoll and Green had prepared for the FAA before the implementation of NVG's in the civilian sector did not have much to say about the use of NVG's in off-shore operations, other than they considered off-shore to be an "extremely difficult operating environment".

They did, however, "recommended that the FAA investigate offshore use of NVG's as part of their continuing efforts".

Here is the link to this ancient, but interesting read: http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA278777&Location=U2&doc=GetTRDoc.pdf

I suspect the FAA had no interest in evaluating the use of NVG's off-shore, and so they just dropped the ball right there...

I have been researching this for months, but I have been unable to find any tangible performance criteria that has been published regarding the use of NVG's off-shore.

Most training criteria that I have been able to get my hands on, is either silent on the issue of overwater use, or merely states that water is "not a high contrast" surface.

I know that military and SAR have been going out there for years under these conditions, but I have not come across any of their findings....perhaps they do not wish to share?

[[email protected]]

So is civilian use of NVG permitted in the US? If so why don't HEMS use it?

The lack of detail regarding location and employer give me reason to think you know that what you are doing is either wrong or foolish - what about a duty of care for your passengers.

As for sharing, I have already told you how we operate in that environment and what equipment we have - it is exactly as Gomer Pylot says, because you will end up IMC at some point we are equipped and trained to cope with it rather than having a plan B of 'turn around'.

[mfriskel]

There are a lot of HEMS operations flying NVH in the US. I have done over 100 hours this year. The new changes to Part 61and 91 actually make is a normal operation now, asof 20 Oct 2009. There are qualification requirements, currency requirements, equipment requirements ect... It also does not discriminate fixed vs rotor nor by type of flying. If you have a Cessna 152 and or an R22 and get an authorized NVG modification done, and aquire the proper TSO NVG, you can fly NVG here with the proper training.

[TheVelvetGlove]

Crab,

My comment regarding 'sharing' was not directed at you- it was directed at those agencies/municipalities/organizations/military/etc.. who have conducted technical performance testing of NVG's off-shore and who have documented their testing, but have not made their findings available to the civilian sector, which I believe is in great need of some education as to the limitations of these devices, and how they should not be utilized.

I very much appreciate your comments regarding how NVG's are utilized by you on the job.

Most reputable HEMS operators in the US are now using the the latest generation- Anvis 9 NVG's. It really isn't all that long ago that most HEMS operators did not even require an instrument rating to fly HEMS at night! Now, HEMS pilots all have instrument ratings, but they fly VFR aircraft and only get to practice IIMC procedures and instrument flight once every year when they do their annual recurrent training.

I would say that presently, close to 90% of all HEMS in the US is probably conducted single pilot in VFR helicopters, with no autopilots, and plenty of them still do not have NVG's or TAWS- so they are conducting off-airport operations at night, sometimes in very dark places, completely unaided. Do they like it? No. But that is the job.

My inquiry here was initiated in response to what is being asked of the pilots; the FAA approved the use of these night vision devices with little or no restrictions or limitations.... nothing concrete in the Part 135 Operations Specifications that would limit their use off-shore, which happens to be my primary operating environment.

[[email protected]]

Velvet - sorry if I appeared too critical but I am honestly shocked that the FAA have allowed this to happen, it seems utterly irresponsible not to impose some regulations or limits to prevent people frightening or killing themselves.

The Met Office in UK produce a light level prediction programme which might be useful but I suspect such a thing already exists within the US. Unfortunatley, although it makes allowances for differing levels of cloud cover, it can't make a go/nogo decision based on weather, it purely deals with starlight and moonlight.

[TheVelvetGlove]

Crab,

I could not agree more- a lack of FAA regulation has left civilian operators a loophole where they can go much too far with the goggles.

Civilians have begun to use NVG's to go places aided, where they cannot go unaided- instead of using them as they were intended, to enhance safety by providing better visual cues during VFR operations. I think that maybe some operators are beginning to lean on NVG's too heavily to get the job done. It is inevitable, of course....

A simple revision could cure that- maybe something like, "aided flight is not permitted in a VFR aircraft when meteorological conditions exist that would prevent a pilot from proceeding unaided..."

I have not seen a pre-flight tool that can assist a pilot in predicting light levels- I know that I would find it very useful in preliminary preflight planning- as a first step to consider before further contemplating and planning an offshore NVG flight.

[Phrogman]

Velvet. You are most correct about the gap in FAA regulation on this. But trust me when I say, and as others have said, if you are flying single pilot in a bird that is anything less than 4 axis over night to an unlighted area over the ocean, goggles or not, man I hope it is important because you are playing with fire.

When it comes to the regs, overwater FAR's talk about having floats on helos:ugh:

However, look at this way( hypothetical): the weather forecast says 6 miles in haze and overcast layers at 2K, 5K, and 10K. No wind and the moon isn't up for 3 more hours. After 5 minutes pointed at 90 degrees outbound to whatever coastline you are flying from it is freaking dark. Goggles will have nothing to enhance and it is an instrument game from there on out. Visit the US Naval Observatory and hit "data services" then select sun and moon data for the day. PM me if you have questions.

The FAA DOES say that if you don't have a visual surface reference, or at night, a visual surface light reference to safely control the helo...you are in the wrong, and you aren't allowed to operate IFR outside controlled airspace below 1200' above the surface (unless your operation has been looked at by the administrator for exception).

I have made a career flying over the water in two maritime, military services, and we aren't keeping any secrets about the issue. There are plenty of fatal accidents on file (non-combat related) where spatial disorientation claimed the lives of fine aviators in the sexiest of machines.

If you have no visible horizon, goggles or not, then you need something to orient, like an attitude indicator, and there you are... ON INSTRUMENTS. Best lesson I can pass on to you is: don't look at the regs to justify your overwater operations, they will be found lacking. It sounds like you have already seen some dark events, now use that hindsight and recall if you had a horizon...if you didn't, then you probably got lucky (regardless if the regs don't prohibit you from doing it)

Official sunset to sunrise over any significant body of water...play it as if you were IMC. If you are not instrument rated...the risk is not worth the gain.

[JimL]

Phrogman,

Well said - whatever happened to risk assessment.

The safety of this operation is the responsibility of the Operator not the Regulator. Look at the FAA guidance on Operational Control and then let us know if compliance is being shown:

N 8000.347 Operational Control: Revised Operations Specificaitons A008 and A002 (http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgOrders.nsf/0/2CB5EF03329AF90F862572600078650E?OpenDocument)

Cut to the chase, go direct to and read from Page 23.

Jim

[TheVelvetGlove]

Before operational control can be made an issue, the following phrase needs to be clearly defined:

"visual surface reference, or, at night, visual surface light reference, sufficient to safely control the helicopter." (excerpt from FAA Part 135.207)

Visual surface light reference

I know that everyone will have an opinion as to the definition of the above-referenced term, but what is the actual definition that will be utilized during enforcement of this rule?

Please understand that I am not in disagreement with you- I am merely playing the devil's advocate here in an attempt to get to the bottom of this issue.

There is common sense, and then there is the law- I'm looking for the law in this instance.

[JimL]

TheVelvetGlove,

You are looking for a subjective answer to a rule which is essentially objective. It might be better if you highlighted the more important part of FAR 135.207:

"visual surface reference, or, at night, visual surface light reference, sufficient to safely control the helicopter."

Clearly a prescriptive rule would not work in this case because it depends upon a number of issues - not the least of which is the handling qualities of the helicopter. The external references required for 'safely controlling a helicopter' with an autopilot is not the same as those for a basic Robinson R22.

The rule calls for an exercise of judgement; clearly you know the issues but are you exercising good judgement?

Jim

[TheVelvetGlove]

Jim,

If I am following you correctly, then what you are saying is that the handling properties of the particular helicopter are to be taken into consideration when making a determination as to whether or not an offshore VFR NVG operation is being conducted legally? That sounds like a subjective approach to answering the question at hand.

To state that it is NOT legal to fly offshore at night in a VFR aircraft with no autopilot, with NVG's employed as the sole means of visually orienting the helicopter (meaning that to proceed unaided would be impossible)...... and then turn around and say that it WOULD be legal to do so if the aircraft had an autopilot, seems very subjective to me. Perhaps I am not following you though...

There is VFR and there is IFR- each has it's set of rules and required equipment. I am only addressing VFR operations in a VFR helicopter.

As far as risk assessment goes, what if the pilot has been left to his own devices and the operator has not provided him with any means of performing a risk assessment (meaning: the company has no risk matrix forms, so special software, or any type of enhanced operational control)?

The pilot is then left with whatever weather reporting & forecasting is available in his region, the FAA Area & Terminal Forecasts, sun and moon rise/set tables and moon phase tables. He then sits down and performs a guesstimation as to whether or not conditions will prevail that will allow him to make the VFR NVG flight legally.

Before he can determine whether or not he is legal, he must know what "legal" means. If it is not legal to orient a helicopter solely by a solid horizon line that is produced by NVG light amplification- then that would be very important for him to know.

Please allow me to present a hypothetical scenario; then tell me whether you think the operation is illegal, and why it is illegal (under FAA Part 135).

Hypothetical:

Aircraft: light twin engine, non-stabilized, basic VFR instrumentation with attitude indicator, standby attitude indicator, radar, radio altimeter, dual Garmin 430's with ILS operational, HSI, turn & bank indicator, no autopilot, single pilot, Anvis 9 NVG equipped.

Program: FAA Part 135, VFR and NVG only- no IFR operations.

Pilot: FAA ATP or FAA commercial helicopter with instrument helicopter.

Operating Enviroment: Primarily offshore- departing from land and landing on land, but offshore for the entire route, with no offshore structures enroute, but some uninhabited or sparsely populated land masses within 30 miles of the route of flight.

Flight info-

Enroute flight time- 1:20

Weather: Area Forecast shows scattered to broken clouds with bases from 4000-6000 and tops 7000-8000. Temp 21 C, Dewpoint 16 C. No visibility given. No PIREPS below FL250. Radar is clear. We'll be flying at about 2500 MSL.

Time: 0200

Moon phase and angle: 28% disc, 45 degrees above the horizon and sinking.

I am airborne and maintaining aircraft attitude visually by means of the solid horizon line that is produced by the NVG's, and I am cross-checking my attitude with the attitude indicator and other instruments. If I flip up the NVG goggles, I see absolutely nothing. I've got another hour to go before I arrive, and so far the weather is as forecast and there are no rain showers ahead of me.

Am I legal? If not- why? I'd like to first establish whether or not it is legal- then determine whether or not it is safe or prudent.

All responses are appreciated.

[Phrogman]

Velvet, of course you are legal at take off, the weather forecast allows for that and the hypothetical operation sounds well equipped (although I like the dual pilot option). Now if I were to investigate a mishap involving this operation and had the opportunity to talk with the surviving pilot, I would have to ask if the weather at the time of the crash was VMC or IMC, how can you tell? You mentioned the moon was sinking and only 28%...can you see it or is it obscured? The overcasts will likely diminish the ability to see the oceans surface at that altitude.
Dewpoint spread isn't much in this hypothetical situation of yours, so let me throw in another variable (just for fun). Since there is no reported visibility for the entire route, then there will likely be no mention of the marine layer 15 miles off shore where some warmer water meets a loving airmass, how long do you think you would be flying above or even in the clouds before you realized you were in IMC conditions? If you have no way of determining the vis or the on scene cloud conditions with the naked eye I might ask how you would call it operating VFR if you can't see the weather for what it is and without the knowledge of what it will be at your destination. Legally, the horizon "angle" doesn't play in the definition of VMC, just clouds and vis. And then your NVG battery light flashes and you suddenly remember you forgot to change out the other one the last time you saw that light...and there are no spare AA's to be had:} Blink Blink Blink Blink...are you going to be legal when the NVG's go out? As you said, you can see absolutely nothing.
Good discussion points you bring up, but enforcing the legality of this stuff is impossible unless you run into the cloud police up there, it always seems to come to light after the crash for some reason. :E

[TheVelvetGlove]

Phrog,

You hit the nail on the head-

What will be the probable findings of an NTSB investigation conducted after an inadvertent IMC event that resulted in a crash? The NTSB will eat the pilot and the operator for lunch. But what will be the prosecutor's argument? Which rules will he point to, and what thoughts will he conjure, to bury those who are responsible for the tragedy?

Your additional variable to the hypothetical begs an important question for which I have never heard a satisfactory answer- how in the world do you determine flight visibility under NVG's when you are under low illumination levels offshore, and there are no points of reference? A difficult thing to do, especially when there is a little moisture in the air.... and I agree that if I am to maintain VFR, then I must be able to determine visibility at all times.

In answer to your question regarding when I would know when I was in a cloud- probably shortly after flipping on the landing light.

As far as seeing the "surface" - we know that at certain moon angles and illumination levels, that you will not see the surface of the ocean at all at night- just that far-away horizon line formed by contrast in the goggles.

As far as enforcement goes- I realize that will be a difficult task...but I am not looking to skirt the rules here- I just want to know what I can and cannot legally do with NVG's in a VFR helicopter.

[[email protected]]

VG - I sympathise with your position in that your operator clearly doesn't have any qualms about sending you off to do the job and if you say no they will just employ another pilot who will say yes.

But, do your customers appreciate the risks involved or are they just happy since no-one can prove it is illegal?

The rules do seem very wishy-washy and the FAA should be ashamed - when there is a spate of accidents caused by IIMC on goggles maybe they will think again.

My humble opinion is that in order to operate on NVG, the pilot must have an IR and the aircraft must be IFR fitted including an autopilot as an absolute minimum.

The thought of people doing a quick NVG course and then going flying in an R22 or similar fills me with horror.

Is it legal? it would appear not to be illegal as far as the rules are concerned.

Is is right? No way Jose

[helmet fire]

Wow, my head hurts!

What we are really getting down to is not simply "legal" v "risk", it is the continual evolution of aviation and aviators pushing the regulatory system to catch up. Everytime the law needs calrification to prescriptive and exacting standards it is because of some percieved loophole exploited beyond the reasonable. Then, we must go through another exhaustive draft of the legislation, have thousands of arguements, then write yet another prescriptive and tiny detailed rule with which people will try and misinterpret.

And I mean try. And they will complain "gee these rules are complicated...":mad:

As Jim L quite clearly pointed out, and I think we all agree, that the rules state a NVFR operations must operate IAW FAR 135.207:
"visual surface reference, or, at night, visual surface light reference, sufficient to safely control the helicopter."

Whilst that is clear, interpretations of the rule have been far less so, and if any further substantiation of that statement were required, look through this thread!! This rule and its loose inerpretations have been at the root systemic cause of many NVFR accidents in the US. But we need to look at what the INTENT of that rule was. Stop trying to play lawyer by interpreting a way around it, look at what it was trying to keep you safe from.

It was trying to avoid a scenario where a non instrument rated pilot found themselves without a visible horizon. 178 seconds ring a bell?:uhoh:

Nothing to do with autopilots - if it did then instrument skills and individual helicopter stabilities would count. They dont, it is about whether or not you have, or have the risk of, getting into a no horizon situation. Nothing to do with moon angles - if it did, then pilot age and visual acuity and humidity and dust and smoke and haze and cloud type and cloud level and even windscreen cleanliness would matter. They dont, it is about whether or not you have, or have the risk of, getting into a no horizon situation.

What it did do was allow all of those guys who did not have an instrument rating and autopilot go flying when it was perfectly safe to do so - like over LA on a clear full moonlit night - without the expense of the rating and autopilot. What do we do??? We bend it and twist it and ring it to the max so that we have to have more rules clarifying a great freedom just to keep ourselves safe. And then we complain about how many complicated rules there are!:ugh:

On to NVG. According to all the FAA literature (and that of SC-196) NVG is not to be used to alter or reduce the requirements of NVFR. FAR 135.27 WAS NOT WRITTEN FOR NVG. THERE WAS NO INTENT FOR IT TO COVER NVG. ALL EXPERT ADVICE AND FAA DOCUMETS TO DATE FAIL TO GIVE YOU A LEGAL AUTHORISATION TO ALTER FAR 135.27 BY USING NVG.

All Subject Matter Expertise (SME) so far on this thread have said that NVFR over water at night using NVG in the cirumstances mentioned represent an unacceptable practice. Clearly, the operation proposed does not meet the intent of FAR 135.27, nor in my opinion, the literature supporting NVG operations and you would be both technically in breach of the law, and, probably more importantly when you go to bed at night after the accident, disregarding and ignoring SME written advice and guidance.

It is not reasonable to look to the FAA to continue to control every possible interpretation of the rules and regs particularly in the face of rapidly developing technology. At some point to protect yourself from the law, you have to act "as a reasonable person" would have acted in the same circumstance, armed with the same knowledge (or knowledge that a reasonable person would have actively obtained).

That is the line we have to get to when introducing new technology like NVG. Would a subject matter expert think that is a reasonable thing to do?

[Phrogman]

Helmet Fire...Concur. Nicely put. VG, if you are trying to make the case to your bosses, select all from this thread and print. What will a lawyer for the prosecution do? He will muster in a hoard of SME's and then call them one by one until the judge's ears are bleeding. The answer is there in the regs, how one interprets it in this business should be all about risk vs gain, if you do that right, not a lawyer in the world is going to have a chance at making their case.

[TheVelvetGlove]

Thank you all for your opinions, information and concern.

[[email protected]]

An eloquent post Helmet Fire - the problem is that when it comes down to a courtroom battle between the intent of a law and the letter of a law, the letter usually wins.

Smart lawyers make a living out of twisting interpretations of laws to their clients advantage and, while there are aviation operators trying to make money in a competetive market, there will always be those looking to push the boundaries of legal interpretation.

A recent example (non-aviation) from the UK is comedian Jimmy Carr who was clearly using his mobile phone to write a text whilst driving - in clear contravention of the law regarding hand-held communications devices - BUT his lawyer claimed JC was dictating a joke instead - dictating machines are not covered by the same law and JC got off!

Here the intent of the law is quite clear - to prevent people crashing while they use their phones at the wheel - unfortunately a loophole in the letter of the law allowed the lawyer to sidestep the legislation.

So my point is that the FAA do need to legislate properly to prevent the unscrupulous from exploiting interpretations of inadequate laws even though to any reasonable observer that interpretation flies in the face of the intent of the law.

[helmet fire]

Too true Crab. Why dont they spell out intent rather than all the leagalese that actually helps make interpretation too complex for any normal human? How about "The intent of the law on hand held devices is that the driver should be concentrating soley on the road and vehicle operation and not be distracted. Thus the use of any ancillary device requiring division of cognitive space from the primary task of driving is covered here..."

I know. Dream on....

The reasonable person arguement will not win the FAA V Silly Pilot case, for the same reasons as the Jimmy Carr failure. They are not the cases pilots/operators fear. Post accident, when you are being sued for CFIT, any sensible lawyer will invoke intent and reasonable person...and I suggest you'd be smoked. That is the case to fear and plan for.

I'd say that strictly speaking, FAR 135.207 means if you completely cover your instrument panel (unaided because it pre dates NVG) can you still safely fly the aircraft?
That clearly excludes over water at night.
Good luck VG.