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tribal
26th Mar 2007, 09:08
I see the Bell 412 manual from FSI states that nightsun cannot be installed for IFR, a read of my HP manual confirms this. Does anyone know why this is? How do operators in countries with no Night VFR use the unit? and is there a way around this by waiver, or the like
Thanks in Advance

forget
26th Mar 2007, 10:33
Try here http://www.meekeraviation.com/whatsnew.htm

They'e got Nightsun STCs for the complete Huey line. Whether or they affect 412 IFR - they'll tell you.

Flying Bull
26th Mar 2007, 11:59
Hi Tribal,

I don't know excactly, but when we started with SX16 on Bo105s, they weren't allowed to go IFR with the kit installed.
The reason was, that without proper testing and certifing, you weren't sure, wheather the SX16 would affect airspeedindication and Nav-instruments.
So when we changed over to fly BK117 with SX16 and FLIR, the helicopters went through flighttesting with the gear and certifing was done with some amendments to the flight manual.
That's a quite expensive move - and if nobody has done it before with the Bell - you're just not allowed to go IFR with the kit.

Greetings Flying Bull

SASless
26th Mar 2007, 12:21
Air Methods, a very large EMS operator,in the USA routinely flys IFR in cloud while having SX-16's installed on Bell 412's.....I wonder how they got around the prohibition as mentioned earlier?

800
26th Mar 2007, 13:06
As mentioned before;
"OPERATING LIMITATIONS
IFR operation is prohibited with Nightsun
Searchlight installed."
and another one that sliped through the hoops
"FLIGHT CREW LIMITATIONS
Operation of the Nightsun Searchlight is
restricted to the copilot or operator position."
So much for single pilot ops!:ugh:

Twiddle
26th Mar 2007, 13:24
Same problem if you fit a Nightsun onto an R22, sucks doesn't it.....

RVDT
26th Mar 2007, 13:37
..............to be correct you would probably fit the R22 to the Nightsun!!:ouch:

widgeon
26th Mar 2007, 14:55
I recall reading something about the light reflecting off the clouds possibly causing pilot disorientation .

chopperdr
26th Mar 2007, 15:15
sirs: with regards to the nightsun on ifr ships, we are working with AEC on the stc for the ec-145 ifr (as seen at HAI) for suffolk county.
flying bull is correct, the flight testing is much more extensive for IFR operations, not just for effect on instruments but also basic handling charactersitics, neutral stability etc (sx-16 turned sideways is a flying garbage can)
with all of our stc for nightsun mounts, this is our first for an IFR cert airframe. in addition, the nightsun should remain off during IFR operations, at least until visual contact is made with the ground. in addition, at that point the sx-16 is nothing more than a very high powered landing light
p.m. us, should have rfm available later this month for ec-145
cal meeker

800
26th Mar 2007, 22:00
I suppose there is a point to testing the extended envelope of the IFR configuration.
It must be remembered though that many of the 412 aircraft (and others) leave their night suns on permantely thus flying all airpspeeds and profiles by day and night.
Detrement in climb gradients would be the same, the aircraft and night sun don't know if its dark or not.
There are aircraft configurations out there that have Climb Detrements attributed to the aircraft because of external equipment fitted without the extended flight testing.
At the end of the day it comes down to the wording; "IFR operation is prohibited with Nightsun
Searchlight installed."
The bigger factor to this is the following scenerio;
Crew receive callout which is an IFR flight, they install Night Sun to aircraft planning to fly enroute IFR and then when visual use the night sun for the landing phase. Pretty normal, would you say.
Q: What would happen if there was an incident? - Would the insurance company still pay up?:=
Food for thought!

chopperdr
26th Mar 2007, 22:20
800, suggest to change the wording, " IFR flight prohibited while sx-16 energized"

Arm out the window
26th Mar 2007, 23:02
I'm sure that Queensland Rescue have operated their nightsun-equipped 412s IFR for years, ie plan and fly to an area of operations IFR, then if conditions allow, descend visually using the nightsun.
It would seem improbable that they would have simply decided to ignore a prohibition to fly IFR with the equipment installed, so I assume they have some kind of approval to do it.

As far as the effects of the nightsun on IFR operations, the thing that springs to mind that might affect other systems is the big current draw for such a powerful light - ie big current through nightsun circuits creating induced currents in other instrument systems that affect their accuracy, obviously not a player when the light's off.

800
26th Mar 2007, 23:21
Chopperdr,
It would be great if it was so easy as to just change the wording, but unfortunately that quote comes straight from the BHT flight manual supplement.
If any other operators are using a different supplement in ther flight manuals that say otherwise, could you comment please, (and does this overide the original flight manual?).
With any equipment installed on the aircraft, especially IFR, there is (or at least should be ) a load test done after the installation which would confirm normal /emergency operating capacity. The main current draw with the night sun is during the starting process.
800

Matthew Parsons
27th Mar 2007, 03:01
We've discussed this kind of thing before. Not certified does not mean not capable, not safe, or not possible. It just means that the equipment hasn't met a set of performance, handling, ergonomics, etc. specifications that the airworthiness authorities have said must be met. We have airworthiness to make things safe...its not a bad thing.

With aviation, the markets are small and the testing can be expensive. I'm not sure why the Bell 412 with nightsun isn't IFR certified, but I wouldn't be surprised to hear that cost is a big factor.

I'm not surprised that some are flying that configuration. I don't know what the outcome would be if there was an incident, but I imagine the insurance companies would consider everything. Even more importantly, if you can trust that the specifications have some sort of validity, then assume that any configuration not tested has the potential of failing, it is possible that the configuration is truly unsafe.

For the Bell 412 with the nightsun there may be some handling problems following an AFCS failure, OEI performance issues (ie not being able to meet IFR climb gradients), electromagnetic interference issues, etc. Just because some are flying with it, doesn't mean that they've seen all the conditions required for certification.

SASless
27th Mar 2007, 13:49
If one is flying IMC.....there is scant need for the nightsun to be operating.

The 412 has to have overhead curtains for IMC flight due to a concern about "Flicker Vertigo" thus it would appear there are many aspects to Instrument Flight that have to be considered.

From a personal perspective....the nightsun is a great improvement for night scene landings and if combined with an IR lens and NVG's.....really makes night scene landings a whole lot easier and much safer.

chopperdr
27th Mar 2007, 14:46
800, is the BHT flight manual you refer to specific to the install of an stc?
if so that could well be for a BHT installation, therefore another stc could allow for IFR flight with sx-16 installed. keep in mind there are a number of stc'd installs of the light, many locally approved versions and one time stc's.
dr

Avnx EO
27th Mar 2007, 19:13
There are really two issues to deal with... one, The "E3" issues as already mentioned (radio frequency interference.) The night sun uses a carbon arc light and generates a boat-load of RF interference if not adequately shielded and filtered. The second issue is flight dynamics. IFR has very specific stability requirements (discussed in AC 29-1C.) These need to be validated for the specific installation and its potential effects. The basic 412EP with 3-axis SCAS - even with the flight director kit - has no yaw damper. The yaw damping comes in with the 4th axis kit. So when you hang stuff out of the side of basic EP, you could potentially introduce yaw forces inducing tail wag and other undesirable effects that may be minor - but are beyond the stability performance that was the basis of certification. Each installation (STC) would have to be considered individually.

800
27th Mar 2007, 22:09
chopperdr
The reference came straight from the BHT POH that I saw. There are other STC's available from different Companies for quick fit installations, ie fit bracket (base plate) mounted permanantly so the night sun is easily removable.
Does any STC for this installation over ride anything originaly stated by BHT?
The installations vary from fitment of the Night Sun on the Starboard or Port side of the ship (causeing a potential lateral effect) OR on the centre butt line and installed anywhere from just forward of the forward cross tube to right up under the radar dome at FS 8.58in.
Interestingly, the B206L flight manual has exactly the same wording in its supplement.
What do aircraft such as the 230, 430 or 429 have?


So much paperwork, so little time!

chopperdr
30th Mar 2007, 18:08
sirs: currently at edwards and associates this afternoon. checked on the latest serial no. 412 BHT FMS, the nightsun limitations is for a particular bell kit and does not apply to the aircraft in general.
the flight manual supplement only applies if that particular kit no. is installed on the airframe, therefore another stc is not "over riding" the BHT manual
with regards to placement of nightsun, it would be the same for flir / winch / floats etc, they would all have to be tested to determine the effects on stability.
dr

pjohnson
1st Apr 2007, 05:23
The original FAA approved Rotorcraft Flight Manual Supplement for the Spectrolab Nightsun SX-16 Searchlight does not allow for IFR operations with the Nightsun fitted.

In 1987, Capt. Keith Inglesman, a qualified Test Pilot, conducted a review of operations with the Nightsun fitted on the Bell 412. After extensive flight testing, Capt. Inglesman was able to justify the issue of an amended “Flight Manual Supplement for Operation with SX-16 Nightsun Searchlight Installation” by the then Department of Aviation for the 412. This amended Supplement was issued on 27 July 1987.

This amended Supplement does not prohibit IFR operations with the Nightsun fitted and has been used by most Australian operators of the SX-16 Nightsun since.

In “Section 5: Performance” of this amended Supplement it does require operators to add 140 kg to the aircraft weight when calculating single engine climb performance. As all IFR operations require the pilot in command to calculate the aircraft’s single engine climb performance, this Section requires IFR operations with the Nightsun fitted to add 140 kg to the aircraft weight when entering the single engine climb performance graph.

Cheers.

800
1st Apr 2007, 08:51
pjohnson
Thanks for the info regarding the 412 supplement.
Very interesting as the details seem resonable, re SE performance.
Do you know where a copy of this supplement is to be found.
I must admit, I have never heard of or seen this one. I would have remembered the 140kg bit.
If one is available it would answer (all the legal questions) asked in this forum topic.
800:D

Driptray
1st Apr 2007, 12:01
I believe there is a flight manual supplement for the SX16 and an auto stow kit, through Aeronautical Accessories, and with the auto stow there was no IFR restriction, however I am willing to be proven wrong. I do not have access to this FMS, someone at QR or Hunter Rescue may be able to shed some light on this.