Helicopter pilots flying with EVS´system...

[tulinieto]

I am interested to know if somebody has experience fying EVS (head down display) in helicopters. I would like to do some questions about this such as cost, maintenance, better place to put display, etc.
Thanks for advance.
Tuli

[SASless]

Erlanger Hospital in Chattanooga used to have that system on their 412's....with the change to a vendor vice a hospital run operation I don't know if they still have that setup.

I knew one of the pilots there in those days....and he was quite happy with the system as an aid somewhat short of the capability of Helmet mounted NVG's.

[tulinieto]

I know it´s a usefull equipment specially at nigth or in ligth fog. When I speak EVS system I mean Max-Viz (1000). I´m flying A109A/K2 and 20% of total time that we fly by year are at nigth. I know PHI Company has installed this equipment in their helicopter´s fleet.

Regards

Tuli

[Avnx EO]

You have to be careful. Not all EVS systems are created equal. Some are very restricted in IR bandwidth due to the technology they use. For example, I was surprised to find out that fog actually ages and the frequency of IR light that will penetrate fog is affected. So you can have one guy take his narrow bandwidth EVS go through fog singing its praises, and then 15 minutes later the same type EVS equipment got through the same fog (now aged) and can't see squat. Of course the systems with more capability are more expensive.

The other issue we've run into is that most EVS are mounted at a fixed angle. This is fine for fixed wing with a consistent approach angle, but the attitude changes and changing angle of interest during approach with airspeed changes gives EVS very limited benefit in rotary wing. By the time you get a decent one and put it on something with a tilting capability, you'd be better off with a low cost FLIR. (Actually if you could slave a low cost FLIR to flight path angle that would be optimal)

The other issue is that of credit. For fixed wing, they are playing the game that you are CAT-I on an ILS if you have the runway in sight at 200 feet. EVS can put the runway in sight, therefore you can legally go into places you might not otherwise be able to if you were relying on your eye balls. Not many helicopters are trying to beat Cat I minimums on an ILS.

But EVS does provide some degree of benefit. Not sure it's really worth the dollars in its present form. It, like so many other things, is equipment built for another application that helicopters try to coble into duty it was not intended for. Wouldn't it be great if avionics companies actually designed stuff with helicopter use in mind.

[TheVelvetGlove]

I know of no EVS systems in any aircraft operated by PHI- they do have a lot of Anvis-9 NVG installations, though.

[Corax]

NVG have been around quite a while but they have drawbacks for civil use. They are controlled items, expensive to acquire and maintain properly. You require training of course but they also extol a cost in fatigue on pilots. While they are great for a military application where you need to constantly assess threats all around you, do we really need them for civil use?

Can we not move on and allow civil helos to use systems like Enhanced Vision Systems like this;

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and Max-Viz (http://www.max-viz.com)

Let's hear it lads, fire at will.

[fly911]

We considered the L3 version of this infrared system for our helicopter, but decided to stay with the NVGs because they are helmet mounted. In case of engine failure at night in the helicopter, I want to see where my eyes are looking and not straight ahead like the fixed mounted IR systems. I would give them a second look if they did make a helmet version. We probably will buy the L3 IRIS for our King Air because it is already certified on that aircraft and the price is right.

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[Corax]

Good point fly911, could we say then that it could used instead of NVG but only on twin-engine helis for that reason?

[fly911]

Corax, I could let you know better after I actually fly with one. I want to know how wide of an angle you can actually see. I noticed on your video that the camera almost lost sight of the landing pad. Any more of a flare and the ground might be out of sight. I guess it would depend on the type of operation that you are occupied with. I would like to see what a cellphone tower looks like coming at you at 90 kts. I wonder if they would record that for me?

.

[Corax]

Those are some of the concerns, the field of view laterally and how to cope with a flare. More data needed to really where this can go and I am working on getting that done.

What I am interested in from PPrune mbrs is what they think of the concept if these issues are managed. Could we not go this way instead of heavy helmet mounted snogs?

[fly911]

Corax, The vertical field of view might have to be enlarged as well (to address the flair isssue). In fact, if you put the lateral and vertical field of view together, it might be easier to incorporate a zoom lenz, or as an alternative, equip the camera with a wide angle lenz and zoom the cockpit display image on the MFD (Multi Function Display).
An evaluation or transition period might be called for with two pilot programs. One pilot would use the IR display while the other remain on the goggles.

An eight-way cone shaped hat switch might be incorporated on the cyclic or collective pitch stick it adjust the camera angle of view. (or similarly the tilt/pan function of MFD).

[JimL]

It might be a good idea, at this stage, to take a reality check and reassess the function of (night) flying aids.

For flying in any type of rule, the aim is to be able to: (a) control the aircraft; and (b) avoid obstacles.

For flight in instrument conditions; there is the added requirement that the helicopter be certificated in accordance with Appendix B of Part 27/29 (this certification is mainly concerned with stability and handling qualities and ensures that the helicopter can be flown by the average pilot, on instruments, without exceptional abilities). Certification for flight by a single pilot (SPIFR) also takes into consideration the necessity to perform tasks other than flying the helicopter. The instrument rules consist of a number of elements one of which is the minimum height above obstacles (a number of acronyms are used to describe this height). The two elements of visually flying - in IFR - occur in the departure and the visual segment of the arrival. The use of EVS (at least in fixed wing) is to improve the acquisition of the required visual references in order to complete the landing following an IFR flight - this improved acquisition can be used to obtain approval for a lower minima.

For flight in visual conditions; control of the aircraft is maintained by reference (only) to external visual cues, and avoidance of obstacles is achieved by flying at a minimum height (mandated by some States) using see and avoid.

Flying VFR at night; requires sufficient visual cues to be able to maintain control using external references. There are no specified (additional) certification elements for VFR flight at night (although a number of us feel that there should be a link between usable visual cue environment and handling qualities as a certification issue). In some States (and in ICAO Annex 2 - Rules of the Air), VFR is predicated upon minimum visibility and distance from cloud and not a visual cueing environment. Some States - like the USA - specify a level of visual light cues for night VFR; some States - like the UK - use terminology to imply that adequate visual cues must exist. The use of NVIS (NVG systems) is intended to: improve the cueing environment so that that control can be achieved by using the enhanced visual cues seen through the goggles; and improve obstacle avoidance (in conjunction with some formal procedural elements).

In summary:

EVS is intended to be used to improve instrument flying efficiency - specifically in the visual approach phase; NVG to enable visual flight at night where there are insufficient visual cues to maintain control (unaided) with external references.

Flying at night under VFR and keeping your head in the cockpit is a recipe for disaster. There is no halfway house; it is VFR or IFR and applying the full set of rules.

Jim

[rivnut]

JimL....couldn't of said it better...exactly. I use both (civil emergency service helo operator) and I can categorily say that EVS will not replace NVGs and visa versa. In fact I use NVGs more so....

[[email protected]]

And the big problem on relying on IR sensors is that the picture is massively degraded in mist, fog or heavy rain and can also be poor in periods of thermal crossover where everything is emitting radiation of the same frequency - so without contrast there is no picture.

You would also need all your flight symbology to be displayed on the EVS screen if you were to stand any chance of controlling the helicopter by flying a TV screen picture.

[Matthew Parsons]

Once the system is mature, I can see regulation catching up to technology and allowing such systems in VFR operations.

I think the field of vision is a concern that is most easily managed through helmet mounted, head tracking displays. It's been tried before and computing power was one of the limitations, probably not so anymore.

In my opinion, the bigger concern with the cockpit mounted system is the stability of the aircraft. If you try to fly with sufficient precision to land in a tight confined area with just a small TV screen providing you with approach & hover cues, at the very least you will require an advanced symbology set to give you the information you require (which will require a very precise navigation system, etc). I say at the very least, because you may also require higher order flight control systems. I participated in a symbology study to see if this level of precision is possible in a helicopter with only SAS. It was a challenge.

The other consideration is the weight of the entire system. Yes, I'm safer and more comfortable flying a helicopter without NVG than with, but if the weight of the EVS system is significantly greater then performance comes into question. That's just a maybe, for all I know this whole system weighs less than goggles.

In the end, EVS requires regulatory change and a large increase in the onboard avionics in order to replace NVG. There are benefits to EVS, so I do expect it will become commercially viable at some point, but not immediately.

Just my opinion,
Matthew.

[fly911]

Matthew Parsons: Yes, I'm safer and more comfortable flying a helicopter without NVG than with...
I guess everyone adapts differently to the use of NVGs.
I, for one, flying at night at 250 feet Above Ground Level in a tower environment, would not even consider the mission without NVGs. That is totally suicide. It's not a matter of comfort. However a well balanced helmet goes a long way towards reducing fatigue. As far as 'safer' goes, more training may be necessary or beneficial. NVG is just another tool. Just like mirrors, bubble doors, cargo hooks and winches, Night Vision Goggles just allow a pilot to do more with a helicopter. Not good. Not bad. Just is.

[heloguy412]

I'd be very interested in knowing how much less the system weighs compared to Standard Anvis 9 setup. If the fidelity is as good as anvis 9 then this would be a great option to save my neck from continuing deterioration. A far as being safer without an aid to see in the dark, i'd say you are way off base. I was one who didn't want to convert to goggles but I wouldn't want to go back now.

Cheers

[Matthew Parsons]

fly911,

Completely agree. The safety part I referred to was during a crash. The comfort part was just physical comfort.

I always use NVG for night flying (absolutely essential for about 70% of the flying, desired for the rest), but would be more comfortable without that weight on my head, and would have improved chances in a crash without it. Of course, NVG greatly reduce the likelihood of a crash.

Matthew.

[fly911]

Some counties in Florida are requiring new construction of towers to have reflective tape installed. I say great idea since an aztec lost a wing spraying for mosquitoes on an unlit tower. See video.
http://fmcpa.org/files/Tower_Tape.WMV (http://fmcpa.org/files/Tower_Tape.WMV)