Night Limitations On Ifr????

[BeerMan]

Hoping I can get some advice and points of view.

About a year ago, I went straight in and did my MECIR. I didn't do a Night VFR.

Aside from having to keep myself IFR current, I am trying to confirm what limitations that might put on me when flying at night?

I am planning to head to the bush next year to get my first commercial job, and wondering if this will put me at a disadvantage? Should I get a Night VFR upgrade before I go? Or does it not make any difference?

Would appreciate any thoughts / points of view / advice?

Thanks,

BeerMan....

[maxgrad]

When I did the MECIR I flew 5 hours of night circuits as part of the couse. This allowed me to fly IFR/VFR at night. From memory my instructor had to apply to CASA for this but it was no big thing.
I've have had no restrictions.

[Tinstaafl]

I used the search (http://www.pprune.org/forums/search.php?s=) function available on this site to find the following threads that pretty much cover your question:


http://www.pprune.org/forums/showthread.php?s=&threadid=81028&highlight=nvfr

http://www.pprune.org/forums/showthread.php?s=&threadid=52879&highlight=nvfr

http://www.pprune.org/forums/showthread.php?s=&threadid=79207&highlight=nvfr


The precis version:

* A NVFR is permanent. NVFR privileges using your CIR lapse when your CIR lapses.

* There are times when NVFR procedures can be advantageous eg IFR isn't authorised at night into the aerodrome, or a NVFR LSALT allows a lower altitude. Unless you have completed the additional NVFR experience requirements specified under the CIR regs then you are not allowed to use NVFR procedures.


NOTE: A NVFR rating cannot be used for CHTR ops. It is only valid for PVT & AWK ops.

[Vetical Limit]

or a NVFR LSALT allows a lower altitude

G'day Tinsta, just curious as to what sort of scenario this would occur in?

Cheers

[swh]

When your visually past the obsticle....

:eek:

[Counter-rotation]

Other considerations:

A/C may only have VFR maintenance release, or may have IFR maintenance release and carrying defect (eg pitot heat inop) which disqualifies IFR flight.

No charter may be conducted with a NVFR rating - PVT and Airwork only. You must be INSTRUMENT RATED to conduct ANY charter at night - IFR or VFR; Pax or Freight only.

Recency for NVFR charter is in last para of 40.2.1 - along with an Aeronautical Experience component which must be satisfied.

Recency for IFR operations is not specific to day or night ops. Take offs and landings apply only if other persons are on board, in any category of operation (from the CAR's), or for charter at night conducted under the VFR (from the CAO's).

Clear as mud?! :ok:

CR.

[Vetical Limit]

Thanks swh, but how is getting a visual fix on an obstacle any different to having a navaid position fix confirm that you are past it?

If it was required to have a lower LSALT for a route segment, the same criteria apply at night in fixing yourself past the known obstacle whether that be VFR, IFR, visually or from a navaid.

Maybe i've misinterpreted something but to adopt a new LSALT for a route segment you are required to fix yourself past the obstacle, there is no difference between a visual or a navaid fix.

In terms of visual approaches you are still not allowed below the appropriate lowest by night until in most cases within 5nm of the aerodrome.

Hence i can't see how NVFR can have a lower LSALT?

I may have missed something so if someone wants to correct me feel free... :ok:

Cheers

[swh]

Unless something has changed, GEN 3.8 was only applicable to NVFR. IFR position fixing is in ENR 19.5.

So that means you can use a radio position for for IFR/VFR/NVFR, but a visual position fix can only be used when flying NVFR for the recalculation of LSALT.

:ok:

[OzExpat]

how is getting a visual fix on an obstacle any different to having a navaid position fix confirm that you are past it?
Using a navaid fix, it's always a good idea to allow some sort of buffer for the accuracy of the navaid/s used - and for the horizontal error applicable to the topo chart you're using. Another buffer for "the wife and kids" might also be a really good idea, in case you're in cloud at the time.

Using a buffering for any or all of the above factors, you could actually end up being a fair distance past the obstacle before descending. Obviously, a visual fix removes the need for all of that.

[Arm out the window]

Also, IFR LSALTS are calculated using splays from and to navaids etc. going out to a maximum of 50 nm from memory (less for satellite nav); NVFR is a simple 10 miles either side of track ending in a circle around the destination, then the 3 nm circling area to descend to once you're in it, so the lowest safes could well be different for a given leg.

[Tinstaafl]

V.L., IFR (more correctly, navaid...) position fixing requires a buffer behind the aircraft to allow for navaid error. NVFR allows the use of a visual fix. Under NVFR LSALT rules, an aircraft may descend immediately it is **visually** past the critical obstacle. That's not the case for IFR which must wait for the buffer to be cleared.

Also the area to be considered is different between the two categories. IFR uses splays + a 5 nm buffer. NVFR uses a 'simple' 10 nm buffer either side of track + 10 nm before & after. The different methods means they'll often result in different LSALTs.

[Vetical Limit]

Thanks, has all cleared a few things up for me.:)

[swh]

Arm out the window & Tinstaafl...

Sorry I don’t agree with you...

The 10 nm buffer (GEN 3.8 b) only applies if you do not use nav aids, normal IFR LSALT area an splays applies if using nav aids (GEN 3.8 a).

"NVFR is a simple 10 miles either side of track ending in a circle around the destination" and "'simple' 10 nm buffer either side of track + 10 nm before & after." is incorrect.

Its 10 nm from any point on the nominal track, so a 10 nm radius at the departure and destination with a tangent to 10 nm either side parallel to the track, GEN 3.8b.

If your using the IFR LSALT rules, and a TSO GPS, this can be reduced to 7 nm instead of 10 nm, so the premise that NVFR rules will give you less than IFR is flawed, you can actually have a smaller obstacle clearance area with IFR.

:ok:

[Arm out the window]

swh,

You said "Its 10 nm from any point on the nominal track, so a 10 nm radius at the departure and destination with a tangent to 10 nm either side parallel to the track, GEN 3.8b."

- not sure how that's different from what I said, apart from not specifying a 10 nm circle around the departure point, which isn't really an issue anyway because if the critical obstacle is on the side of the aerodrome away from your initial track and you depart visually on track from the circling area, you've visually fixed yourself 'past' that obstacle and can discount it for the rest of the leg.

True, if you have a TSO gps you can use 7 nm, and if you want to use IFR LSALTS using navaids as per IFR rules the lowest safes may be different to the 10 nm 'sausage' around planned track.
I'm not suggesting that NVFR LSALTS will always be lower than IFR, just that they can be different.

[swh]

Arm out the window,

GEN 3.8 does not allow that, you may descend to a lower altitude, it does not say you can climb to a lower altitude.

It was a gotya question on NVFR flight tests, and an important one as buildings in capital cities, and mountain ranges in the vicinity of coastal airports did raise the LSALT that may have been in the opposite direction to the intended track.

As with most of the rules like this, they have been written very carefully, LSALTs should not been seen as a hindrance, they are there to stop aircraft from running into the ground.

:ok:

[Arm out the window]

swh,

Say I was departing an aerodrome with a critical obstacle on the opposite side of the AD to my intended track. For the sake of argument, let's say the NVFR LSALT including that obstacle was 3000', and without considering it was 2000'.
Going by the rules as you interpret them, are you saying that I couldn't climb in the circling area to 2000' and then depart from overhead the AD on track at that height, but would have to climb to 3000?
If that's the case, what then would be the difference if I was overflying that AD rather than departing - I could presumably arrive overhead at 3000, fix myself visually as past the obstacle (because I had visually passed to the other side of the aerodrome from it), descend to 2000 and go merrily on my way?
I would then be flying exactly the same track under the same circumstances as for the departure case, but you're saying I'd have to be 1000 ft higher?
If that's how the rules are intended to work, then there's something wrong with them in my view.
As always, I stand to be corrected if I'm wrong, but how do you explain this apparent paradox?
I'm well aware of the possibility of buildings, coastal ranges and so on being an issue, but if I'm established at a safe height and fixed tracking away from them, what's the problem?

[swh]

Arm out the window,

Why dont you ask the numerous people who depart VFR and end up doing a VCA because they didnt rememeber to align the DG to compass, or mis identify a visual feature...despite seeing the opra house infiont of them etc....

Its not uncommon..thats why ASA has a Avoiding VCA's (http://www.airservicesaustralia.com/pilotcentre/training/flyingaround/avoidingavca.asp) website..from memory there were a couple a hundred a year spatially challenged pilots about.

BTW its not an interperation..unlesss you can see the word climb in GEN 3.8...

:ok:

[Arm out the window]

swh, many VCAs or other blunders have no doubt happened for various reasons at various times; I'm asking you why it would be against the spirit of the regs for me to fly the departure as described above.
I find it difficult to believe that the authors of said regs would deliberately set out to create an anti-common sense situation.
How about if I climbed in the circuit to 3000, positioned myself within the circling area so that I was tracking overhead the airfield to depart on track; then by your logic I could then descend to 2000 (avoiding the need to do the dreaded climb to 2000) and then headed off?
I would have still done all the manoueuvering that you imply might lead to a VCA, plus an extra climb and descent, but would now be descending after a visual fix to a new lowest safe, as per the order.

[swh]

Arm out the window,

I guess the problem is that if your using the 10nm paragraph, you are tracking visually, establishing yourself on track visually, you would be hard pressed to convince me that you can be on track when passing overhead your departure aerodrome.

If you said a few miles out and have a pin point on track, then I will buy it.

Anyways...I believe the intent is for using that paragraph is for when you are established on track, not in the circuit area, GEN 3.11 makes it clear to climb in the circuit area to the calculated LSALT.

:ok:

[Arm out the window]

hmmm....if I was directly overhead the departure aerodrome and on the correct heading, I would certainly be on track, seeing as track by definition starts at the ARP (unless it's a navaid I'm tracking from)!
3.11 just says that you can be lower than LSALT during takeoff and climb etc.
My problem with the issue is that it seems ridiculous that I could overfly the airfield enroute and descend to a lower height than I would have to maintain if departing - just doesn't make sense.
Anyhow I guess we will have to agree to disagree on the point.

;)

[swh]

if I was directly overhead the departure aerodrome and on the correct heading, I would certainly be on track

Are you talking compass heading, magnetic heading, or true heading ?

Set heading over a departure point is dead reckoning along the track made good.

Yes you are correct, you would be on the track made good but not necessarily the required track

The only time that will work is when forecast winds are exactly the same actual, and you have taken into account all acceleration, turning, and installation errors in the compass and DG.

Thats why I said "If you said a few miles out and have a pin point on track, then I will buy it." as then you would be on the required track.

:ok:

[Arm out the window]

Magnetic heading as calculated for planned track and forecast wind, which ought to be good enough I'd suggest.

Consider our hypothetical mate overflying the airfield on his enroute nav; he has been flying a heading which has been working for the winds along the previous section of the leg; shortly after crossing the coastal range he fixes himself over the airfield (and so past the critical obstruction) and lets down to the new lowest safe. But wait - the wind's different over the water and at the lower level...suddenly he's in the same boat, figuratively speaking, as me who has just departed - neither of us know what the wind's doing. Should he, or would he, go straight back up to the old LSALT? I think not!
:)

[swh]

"How do you legislate against stupidity?"

:rolleyes: :eek: :ouch:

[Arm out the window]

swh, if you think my ideas are stupid, come right out and say it. I have put forward and (I think) convincingly argued a point of view; if you don't like it, don't insult me.

[Arm out the window]

Just to clarify this point, could I ask for opinions on the following situation, for example;

Departing Townsville for Palm Island NVFR, a northerly heading.
(I'm just looking at the VTC for the terrain heights here for a quick example, I am aware that VTCs are not to be used for calculation of safe heights due to the disclaimer regarding use of elevations with caution).

Magnetic Island to the NNE is the highest obstacle to the north at 1683' (a tower). If that was the only thing around, it would be logical to use 2700 as the LSALT.
However, Mt Stuart to the south of the airfield is within 10 nm and higher at 2422' (also a tower), which would require 3500 as the LSALT.

I see no problem with climbing in the circuit to 2700, confirming compass function by the orientation of the airstrip, city lights, and any other visible features, and heading off on track.

How many of you would, on departure, climb to 3500? What if there was a significant deck of stratocu at 3000?

[swh]

Use the VOR or NDB, 10.3 degrees and 5 nm buffer.

You have not provided enough information on the towers..
[list=1]
What are the spot heights ?
What is the height at the top of the hypsometric tint for the terrain that the towers are on ?
What is the height at the top of the hypsometric tint for the highest terrain to the north and south ?
[/list=1]

Does the the Townsville for Palm Island tack have a published LSALT ?

Hint the

YBTL 25 nm MSA is 3000 to the NW, 10nm MSA is 3600
YPAM 25 nm MSA is 4900, 10 nm is 3000

Are you going to get radar vectors ?

[BeerMan]

Hi All,

Thanks for all the feedback. It's been very interesting.

Based on the regs and information that people have provided, I have gone and done a bit of study myself.

A couple of things I am still not crystal clear on:

1) With my MECIR, am I able to fly an aircraft under the NVFR, from take off to landing, with no IFR in between? (assuming that I have the NVFR Aeronautical Experience)

2) If a MECIR is OK and covers me to fly NVF, do I have to be IFR current (i.e. 3 hours PIC or 1 hour dual in IMC in past 90 days)? Or do I just have to have my annual renewal?

3) If flying NVFR, at what distance from the AD are you able to descend below LSA? Is it 5NM?


Apologies if these are straight forward. I just want to be crystal clear?

Thanks a lot.

BeerMan....

[swh]

Beerman,

[list=1]
Yes, but only during the validity of the instrument rating and providing the pilot meets aeronautical and recency experience requirements for NVFR - CAO 40.2.1 paragraph 14.1
At least three night take-offs and landings in the previous 90 days and at least one hour of night flying within the previous 12 months - CAO 40.2.2 paragraph 5.1 (a) and CAR 5.109 (b) – relates to carriage of passengers
3 nm generally, or being radar vectored. However if you have a lower LSALT once a positive fix is obtained having passed a higher critical obstruction AIP GEN 3.11 and AIP GEN 3.8
[/list=1]

:ok:

[Arm out the window]

swh, re the Townsville example; as I said, the heights given were read off the VTC for a quick illustration of the question, and don't reflect the level of planning required for the real trip.
No vectors, not tracking the navaid, just a visual NVFR departure where the highest obstacle to the north of the aerodrome was 1683' and to the south 2422'.
Just after opinions of who would or would not discount the higher obstacle that was on the opposite side of the airfield to the departure track, without clouding the issue.

[swh]

I don’t believe you can discount the terrain to the south to meet the requirements of CAR 174B(1).

The reason I asked about the map features, I believe your calculation of LSALT was out by at least 360ft to the NW, should have been at least 3000ft.

I don’t have a WAC with me, I would have thought the top of the hypsometric tint + 360 + 1000 will be higher than 2683'.

As spot height information shown on charts may not necessarily indicate the highest terrain in that area, it is necessary to examine the contour information to ensure that no higher terrain exists that would control the LSALT. Further, whenever contour intervals are used to determine the highest terrain, then the highest terrain must be assumed to be at the level of the next higher contour.

Obstacles shown on Australian produced WACs are generally limited to those having a height of 360 ft (110 m) or more. Therefore, whenever these charts are used for the determination of LSALTs an obstacle allowance of 360 ft must be made. Further, due to this allowance, caution must be exercised when a published tower/mast appears at first to be the critical obstacle. With the addition of the 360 ft obstacle allowance it is possible that the corrected highest terrain within the navigation tolerance area may be higher than the tower/mast first identified as the critical obstacle.

Where the corrected highest terrain or obstacle in the navigation tolerance area for a particular route or route segment is above 500 ft, the LSALT must be 1,000 ft higher than the corrected terrain or obstacle.

The altitude calculated in accordance with the above must be rounded up to the next highest 100 ft increment.

The 10 nm MSA at YPAM is 3000, that is the lowest LSALT you could have, you could not guarantee you would remain clear of cloud.

Your alternate I assume would be YBTL for YPAM, cloud base is below the 10 nm YBTL MSA, not to mention being 1000' below or above cloud in CTA.

Is there a published LSALT for YBTL-YPAM ?

IMHO you couldn’t go at night VFR.

The S in LSALT is for Safe, dont skimp on safety.

:ok:

[Arm out the window]

Yes swh, I'm not disputing any of the information you mention with regard to hypsometric tinting and the rest, and as previously stated and reiterated the example is a quick scan of the VTC to come up with some representative heights for a question as to whether some people would discount high obstacles 'behind' the departure airfield, or not, so kindly stop clouding the issue.
Please forget all the other operational considerations, I'm just after a simple consensus on this quite straightforwardly expressed point.