Night Vision Goggles (NVG discussions merged)

[[email protected]]

Yes I think it is one of those hard decisions you might have to take and delay the approach until the conditions are safe enough - it was taken seriously enough on the SH force that in some theatres there was no tasking 30 mins either side of ECT. If you really, really have to go in then take it very slow and steady.

Phrogman - I think that the East coast operation you mention will frighten themselves if they are not very careful - of course it depends on the size of the boat, the sea and weather conditions and the light levels but night decks are hard work whichever way you cut it and single-pilot ops over the water at night doing letdowns and winching really doesn't sound that clever to me.

[Phrogman]

No arguments there Crab, I think the whole notion is absolutely absurd to do letdowns and hoisting to civilians (small boats, untrained folks on board, etc..). Luckily there are many voices of reason in the operation, however the push comes from above and I imagine they will ultimately get some nugget willing to reinvent the wheel...once. I understand how some operations require SPIFR, however, I don't think any of them should expect those pilots to descend in IMC to try to hover in IMC and then extend a wire with something that is far from snag proof to something with snags. Let's hope they don't go there.

[sunnywa]

Crab, Helmet Fire and Phrog,

Thanks for the informed discussion about NVG ops. It was especially interesting to hear about the eye relief, so as I was on exercise in the boonies for a week in mountain terrain last week, I wound my goggles fully forward and tried them there.

Found out (as Crab suggested) that the field of view shrinks a little bit (a smaller toilet toll) but the view around the goggles is great for winching, and for general peripheral vision as well (especially over the city in my primary role as a Police chopper). I was, I admit, a bit sceptical about Crab's claim of more accurate hovering on white light but I found that to be the case when the adjustable searchlight (450W) was able to get enough light on the ground/terrain to be viewable. The other benefit was that by having the NVG there as well (just look out the front), it made any runaway scenario seem much easier as I didn't have to move my head, just my eyes.

With regards to lighting on our BK, we do not use the nite sun SX16 in the hover as it is too bright below 1000ft. We have a pilot steerable light in pitch and roll (450W), a pitch controlled light (450W), a taxi light (fixed out the front), a winch vertical down light, a rear facing light and a light on the tail boom angled down and fwd (for unloading the rear doors on the ground). The crewies winch with their NVG down and use either them or don't depending on the moment. They still have them down in case of power/light failure and can transition immediately to NVG. Wrt the lighting, the crewies find that the tail light (fwd and down) is best as it throws a nice light on the winch and gives the position of the hook/survivor much better.

Haven't done winching on NVG over the water yet, but done a bit of unaided in a Sea King. Definitely having two crew over the water and SOP's to approach the target would be the safe way to go.

Again, thanks for the comments and we all continue to learn.

[helmet fire]

Rivnut: earlier I asked you if you could detail the experiences that stopped you from degoggling or goggling up below LSALT, and what your rules were in regards to this. Any chance of filling us in?
We are intrested because we are increasingly finding circumstances where a change of status would be desireable, but it is not permitted in Australian rules. This contrasts with the Swiss who change status as required and have been doing so successfully for 25 years, including changing whilst in the hover.

Crab: have you measured your eye relief yet?

sunnywa: when increased your eye relief you mention that you noticed a smaller FOV. Do you mean smaller retinal image size of the NVG as opposed to changing eye relief also reducing the FOV of the NVG?
As I mentioned earlier, we do all our winching on white light, but goggled up. We use the white light references as our primary hover references because it is far more accurate than when using the aided references. Indeed, the closer you are to the references, the better.

[[email protected]]

Helmet fire - funnily enough almost identical to yours, 38mm - hopefully it's a case of 'great minds think alike' and not 'fools seldom differ'

Sunnywa - I get the impression that you are talking about using the searchlight for high hovering references which is not something we do (partly because we don't have a powerful enough landing lamp or a nitesun). Normally our white light references for winching would need to be within 100' or so and the closer the better.

[If all else fails]

Helmet Fire. I noted from your post - "We have removed the SX16 from our 109 due too much illum for NVG and rely on a single 450W white seachlight and landing light." Am I right in assuming you did not have an IR filter on the SX16? In my experience the NVG (IR filter) is workable to low level and with the additional stand-off capability is the deluxe solution for night searching. However I have not yet flown the A109 with NVG/SX16.

[sunnywa]

Helmet Fire,

What I mean is that the circle of green light is reduced in diameter (by a couple of mills), but this is easily overcome by the head scan. In the hover on white light, I have found it is much easier to keep the goggles looking out the front and just move my eyes to look down to the right at the reference.

Crab,

Yep, the nitesun ref was for heights above 100ft. Our 450W light does not seem to be able to give a strong enough beam for heights above that. We then found the nitesun on wide focus pointed to the 3 o'clock (and up a bit) provided both enough white light to hover unaided and not enough to wash out the NVG if we needed them. That said, this was us doing a trial and have not had to winch that high in real life yet.

If all else fails,

The IR filter on the SX16 does indeed wash out the light to be a bit more usable but we have found that the winchman then gets no benefit of white light for winching without NVG. The other problem with the nitesun is that it takes about 2 mins to cool down if you call dust (or snow I suppose in your case), so not good for that circumstance. It will be interesting to see how the Trakka light works with its LED. I wonder if you can dim the light by turning off (say) half the LED's to make it more NVG friendly at low level.

Cheers

[helmet fire]

If all else fails: you are right, we did not have the IR filter. The 22kg and reduction in VNE to 140 outweighed any benefit the IR filter would give us, and the backscatter from the white light (it is mounted side of the nose in front of the pilot as opposed to underneath) was enough to disrupt the NVG image - so off it comes!

We use side mounted white lights to light up the confined area nd a downlight. These really assist the crewman for his winching. We attempt to get very close to references for night winching and use a lot of look-around view, but for high winching like sunny is talking about, we would be using more NVG image. Like him, we are yet to have to do an NVG winch where we cannot find good close references.

[Phrogman]

Distance from eye

Gentleman, as luck would have it I just got off the phone with an aviation physiologist who does work with NVG's. I asked him about the distance between the mechanical lense (goggle tube) and that of the human lense. He said the closer the better as your eye will strain to monitor the image produced by the tubes, something about the cornea swelling...lots of medical speak...headaches etc. Still not committing to one way is better or worse, and
I understand there is a comprise between optimal performance and what you need to reference outside with white light hovering. I still need to measure how the tubes sit with respect to my eyes based on my helmet, will try and get that to you.
But it would interesting to determine what the difference in fatigue levels would be if you wired up two different crews that spend 5 hours searching on NVG's (put aside that it would be in the middle of the night and they will be crapped out anyways, but I wonder).

[helmet fire]

Phrogman:
I am not a medically qualified person...but.....
I wonder if your friend might point to the study that indicated swelling corneas?

I thought that eyes do not strain dependant upon the image size, they strain dependant upon the focus issues (and even then do not produce swelling of the cornea).

The reason we are talking about increased eye relief is beacause of the enormous amount of information a civvy cockpit and white light provides to the NVG pilot. The increase in info means less reliance on the NVG image as the "only" source However, military operations do not have such luxuries as white light, and thus the NVG image IS sometimes the only info. Accordingly, the eye relief for mil ops is close.

I recently logged 50 hours of NVG in a month with an eye relief of 39mm. I have not noticed any vision defficiencies yet. What are the symptoms of a swollen cornea?

[Phrogman]

Too funny, I wasn't suggesting there was some medical issue that would arise, just that the focal aspects of the tubes being closer or farther did something I could barely regurgitate after speaking with a doctor who works for NASA. Concur on the military aspect and why one might keep it closer than in the civvy SAR aspect. I thought it interesting there was any thought from the aviation physiology side. I will be happy to send you to the man I spoke with via email, hit me with a PM if you like. So glad your eyes aren't bleeding after 50 goog hours last month.

[[email protected]]

Our goggles have a focussing ring at the front and a dioptre adjustment at the rear (eyepiece end) and as long as they are set up properly - ie do the focussing with the front ring as best as you can get it and then fine tune it with the dioptre adjustment - there should be no eyestrain at all. I know that my right eye is about -0.5 and my left eye -1.5 from my prescription for reading glasses and a quick glance at the dioptre adjusters after focussing tells me I have got them set up right.

If you have access to a Hoffman box it is worth while spending time experimenting with different settings and it is also a very good way of monitoring the performance of your goggles.

[If all else fails]

Thanks Helmet fire and sunnywa. Good gen. Agree totally with the crewman requirement for some level of lighting (direct or flood) and that the SX16 will not be ideal for winching - but as a search tool to get to the 'survivor' - unbeatable. I guess the dichotomy is that if sustained hover heights with limited references above 100' are an issue on the A109 45OW search light, that task becomes more complex. Currently acquiring fleet of A109's and have not been able to spec SX16 (as not primary SAR asset). Will just have to be happy with the 4th axis and auto hover functions.

Have any of you chaps used or thought about using, helmet mounted eye protection (visor or specs) for NVG ops. Recall doing trials back in the 90's with clip-on arrangements but they tended to fog up and imposed a longer than perferred eye relief distance......they didn't pass the trial. To date I understand only one major helmet manufacturer offers a visor able to be used with NVG.

Clearly a tension between the balance of occupational safety and health and operator preference exists. I've always wondered at what point the longer eye relief distance would contribute to the sub-optimal outcome that required the protection in the first place?

[helmet fire]

Sorry Phrog, what were you saying? Perhaps email the guy with this link to our discussion and he can contribute directly?

IAEF: Have you got a 109 with autohover? Can you give me the details, autopilot type, stc holder, and 109 model number?

Secondly, I am not sure of the application of hoisting 100ft above references over land. We have yet to experience such a requirement, though some winches into dust environments (as opposed to landing in the dust) have come closer to what you are describing.

Thirdly, In relation to eye relief, increasing it will not then cause you to have to have eye protection. The eye protection is independant of eye relief. You would only want eye protection for very specialised operations such as crewman in rear during dust operations or when carrying armed tear gas for law enforcement. There are several models of eye protection in service, and the Australian Army regularly uses it under NVG. These eye protection devices do much more than a visor, and one wonders what a extra good a visor would be other than possibly face protection in a crash.

Only the Gentex allows practical use of the visors with NVG fitted (but de-goggled). In the goggled-up (goggles in operational position and being used) I dont know of any helmet that enables visor down as well.
The Alpha Eagle also enables visor use with NVG, but this often results in scratched visors unless very careful with fitment and maintenance.

[If all else fails]

hf - It's the A109LUH. The autopilot is a Thales 4 axis dual channel digital. Allows full range of AP functionality (incl auto app to hover) and usual Flt Director functions.

- yes - hoisting in dust is the sort of scenario envisaged, and potentially over water (higher sea states) or in steep mountainous terrain.

- only concerned with the facial protection in a crash issue (not the extreme end of 'law enforcemnet' or Mil NBC ops). I may be mistaken, but I understood that someone was manufacturing helmets with visors that allowed use of NVG (in down position)....could be wrong?

Cheers Iaef

[sunnywa]

IAEF,

We use Gallet LH250 helmets and the crewies operate with the clear (inner) visor down when winching so it protects their eyes a bit from wind. The NVG sits comfortably outside the visor. As a pilot, I normally don't have a visor down but spasmodically do when I think about something coming through the front and hitting me. That said, personally don't like it.

[If all else fails]

sunnywa << Gallet LH250 >> Thanks muchly.

[JimEli]

FYI: FAR Part 61 & 91 NVG Regulations

To the best of my ability, I extracted these changes from the Federal Register Vol. 74, No. 161 (effective 10/20/2009):

§ 61.1 Applicability and definitions.
* * * * *
(12) Night vision goggles means an appliance worn by a pilot that enhances the pilot’s ability to maintain visual surface reference at night.
(13) Night vision goggle operation means the portion of a flight that occurs during the time period from 1 hour after sunset to 1 hour before sunrise where the pilot maintains visual surface reference using night vision goggles in an aircraft that is approved for such an operation.
* * * * *

§ 61.31 Type rating requirements, additional training, and authorization requirements.
* * * * *
(k) Additional training required for night vision goggle operations.
(1) Except as provided under paragraph (k)(3) of this section, a person may act as pilot in command of an aircraft using night vision goggles only if that person receives and logs ground training from an authorized instructor and obtains a logbook or training record endorsement from an authorized instructor who certifies the person completed the ground training. The ground training must include the following subjects:
(i) Applicable portions of this chapter that relate to night vision goggle limitations and flight operations;
(ii) Aeromedical factors related to the use of night vision goggles, including how to protect night vision, how the eyes adapt to night, self-imposed stresses that affect night vision, effects of lighting on night vision, cues used to estimate distance and depth perception at night, and visual illusions;
(iii) Normal, abnormal, and emergency operations of night vision goggle equipment;
(iv) Night vision goggle performance and scene interpretation; and
(v) Night vision goggle operation flight planning, including night terrain interpretation and factors affecting terrain interpretation.
(2) Except as provided under paragraph (k)(3) of this section, a person may act as pilot in command of an aircraft using night vision goggles only if that person receives and logs flight training from an authorized instructor and obtains a logbook or training record endorsement from an authorized instructor who found the person proficient in the use of night vision goggles. The flight training must include the following tasks:
(i) Preflight and use of internal and external aircraft lighting systems for night vision goggle operations;
(ii) Preflight preparation of night vision goggles for night vision goggle operations;
(iii) Proper piloting techniques when using night vision goggles during the takeoff, climb, enroute, descent, and landing phases of flight; and
(iv) Normal, abnormal, and emergency flight operations using night vision goggles.
(3) The requirements under paragraphs (k)(1) and (2) of this section do not apply if a person can document satisfactory completion of any of the following pilot proficiency checks using night vision goggles in an aircraft:
(i) A pilot proficiency check on night vision goggle operations conducted by the U.S. Armed Forces.
(ii) A pilot proficiency check on night vision goggle operations under part 135 of this chapter conducted by an Examiner or Check Airman.
(iii) A pilot proficiency check on night vision goggle operations conducted by a night vision goggle manufacturer or authorized instructor, when the pilot—
(A) Is employed by a Federal, State, county, or municipal law enforcement agency; and
(B) Has logged at least 20 hours as pilot in command in night vision goggle operations.
* * * * *

§ 61.51 Pilot logbooks.
* * * * *
(3) * * *
(iii) Simulated instrument conditions in flight, a flight simulator, flight training device, or aviation training device.
(iv) Use of night vision goggles in an aircraft in flight, in a flight simulator, or in a flight training device.
* * * * *
(j) Aircraft requirements for logging flight time. For a person to log flight time, the time must be acquired in an aircraft that is identified as an aircraft under § 61.5(b), and is—
(1) An aircraft of U.S. registry with either a standard or special airworthiness certificate;
(2) An aircraft of foreign registry with an airworthiness certificate that is approved by the aviation authority of a foreign country that is a Member State to the Convention on International Civil Aviation Organization;
(3) A military aircraft under the direct operational control of the U.S. Armed Forces; or
(4) A public aircraft under the direct operational control of a Federal, State, county, or municipal law enforcement agency, if the flight time was acquired by the pilot while engaged on an official law enforcement flight for a Federal,
State, County, or Municipal law enforcement agency.
(k) Logging night vision goggle time.
(1) A person may log night vision goggle time only for the time the person uses night vision goggles as the primary visual reference of the surface and operates:
(i) An aircraft during a night vision goggle operation; or
(ii) A flight simulator or flight training device with the lighting system adjusted to represent the period beginning 1 hour after sunset and ending 1 hour before sunrise.
(2) An authorized instructor may log night vision goggle time when that person conducts training using night vision goggles as the primary visual reference of the surface and operates:
(i) An aircraft during a night goggle operation; or
(ii) A flight simulator or flight training device with the lighting system adjusted to represent the period beginning 1 hour after sunset and ending 1 hour before sunrise.
(3) To log night vision goggle time to meet the recent night vision goggle experience requirements under
§ 61.57(f), a person must log the information required under § 61.51(b).
* * * * *

§ 61.57 Recent flight experience: Pilot in command.
* * * * *
(f) Night vision goggle operating experience.
(1) A person may act as pilot in command in a night vision goggle operation with passengers on board only if, within 2 calendar months preceding the month of the flight, that person performs and logs the following tasks as the sole manipulator of the controls on a flight during a night vision goggle operation—
(i) Three takeoffs and three landings, with each takeoff and landing including a climbout, cruise, descent, and approach phase of flight (only required if the pilot wants to use night vision goggles during the takeoff and landing phases of the flight).
(ii) Three hovering tasks (only required if the pilot wants to use night vision goggles when operating helicopters or powered-lifts during the hovering phase of flight).
(iii) Three area departure and area arrival tasks.
(iv) Three tasks of transitioning from aided night flight (aided night flight means that the pilot uses night vision goggles to maintain visual surface reference) to unaided night flight (unaided night flight means that the pilot does not use night vision goggles) and back to aided night flight.
(v) Three night vision goggle operations, or when operating helicopters or powered-lifts, six night vision goggle operations.
(2) A person may act as pilot in command using night vision goggles only if, within the 4 calendar months preceding the month of the flight, that person performs and logs the tasks listed in paragraph (f)(1)(i) through (v) of this section as the sole manipulator of the controls during a night vision goggle operation.
(g) Night vision goggle proficiency check. A person must either meet the night vision goggle experience requirements of paragraphs (f)(1) or
(f)(2) of this section or pass a night vision goggle proficiency check to act as pilot in command using night vision goggles. The proficiency check must be performed in the category of aircraft that is appropriate to the night vision goggle operation for which the person is seeking the night vision goggle privilege or in a flight simulator or flight training device that is representative of that category of aircraft. The check must consist of the tasks listed in § 61.31(k), and the check must be performed by:
(1) An Examiner who is qualified to perform night vision goggle operations in that same aircraft category and class;
(2) A person who is authorized by the U.S. Armed Forces to perform night vision goggle proficiency checks, provided the person being administered the check is also a member of the U.S. Armed Forces;
(3) A company check pilot who is authorized to perform night vision goggle proficiency checks under parts 121, 125, or 135 of this chapter, provided that both the check pilot and the pilot being tested are employees of that operator;
(4) An authorized flight instructor who is qualified to perform night vision goggle operations in that same aircraft category and class;
(5) A person who is qualified as pilot in command for night vision goggle operations in accordance with paragraph (f) of this section; or
(6) A person approved by the FAA to perform night vision goggle proficiency checks.
* * * * *

§ 61.195 Flight instructor limitations and qualifications.
* * * * *
(k) Training for night vision goggle operations. A flight instructor may not conduct training for night vision goggle operations unless the flight instructor:
(1) Has a pilot and flight instructor certificate with the applicable category and class rating for the training;
(2) If appropriate, has a type rating on his or her pilot certificate for the aircraft;
(3) Is pilot in command qualified for night vision goggle operations, in accordance with § 61.31(k);
(4) Has logged 100 night vision goggle operations as the sole manipulator of the controls;
(5) Has logged 20 night vision goggle operations as the sole manipulator of the controls in the category and class, and type of aircraft, if aircraft class and type is appropriate, that the training will be given in;
(6) Is qualified to act as pilot in command in night vision goggle operations under § 61.57(f) or (g); and
(7) Has a logbook endorsement from an FAA Aviation Safety Inspector or a person who is authorized by the FAA to provide that logbook endorsement that states the flight instructor is authorized to perform the night vision goggle pilot in command qualification and recent flight experience requirements under § 61.31(k) and § 61.57(f) and (g).
* * * * *

§ 91.205 Powered civil aircraft with standard category U.S. airworthiness certificates; Instrument and equipment requirements.
* * * * *
(h) Night vision goggle operations. For night vision goggle operations, the following instruments and equipment must be installed in the aircraft, functioning in a normal manner, and approved for use by the FAA:
(1) Instruments and equipment specified in paragraph (b) of this section, instruments and equipment specified in paragraph (c) of this section;
(2) Night vision goggles;
(3) Interior and exterior aircraft lighting system required for night vision goggle operations;
(4) Two-way radio communications system;
(5) Gyroscopic pitch and bank indicator (artificial horizon);
(6) Generator or alternator of adequate capacity for the required instruments and equipment; and
(7) Radar altimeter.
* * * * *

[that chinese fella]

NVG filter material?

Hi all,

I couldn't find anything thru the search function, so can anyone point me in the direction of the easiest way to purchase the filter material that can be attached to radio displays etc as part of the cockpit requirements for NVG approval.

The major NVG specialists seem only interested in doing the complete mod themselves and are not really interested in supplying the material only.

Any leads appreciated..

TCF

[ARRAKIS]

The major NVG specialists seem only interested in doing the complete mod themselves and are not really interested in supplying the material only.

Maybe, because this is not a DIY job

I couldn't find anything thru the search function, so can anyone point me in the direction of the easiest way to purchase the filter material that can be attached to radio displays etc as part of the cockpit requirements for NVG approval.

Interesting to know, how you would choose the correct filters, as there are 100s of them

Arrakis