DR Navigation

[JSeward]

Hello,

The AIP states that a VFR flight may use the IFR techniques (Navaids, GPS etc) if the pilot is rated to use them, for navigation, as well as the map reading techniques. However there is no mention of use of dead reckoning here which is what I am currently using during my night VFR rating. What are the position fixing requirements for this? Is this a permitted navigation technique at night when I have no reference to the ground?

[Arm out the window]

For night VFR you can either navigate visually or by navaids you're rated on.

If you choose navaids and have the equipment / training to use them(which may include an approved GPS) you need positive fixes as per the AIP IFR requirements for navigation.

Otherwise you're back to the VFR position fixing requirements, ie a positive fix every 30 minutes by identifying something on the ground. You said you have no reference to the ground, but that's not correct - if the weather's clear, as it should be if you're punching off on a NVFR nav, you will be able to use DR techniques combined with identification of ground lights to get positive fixes.

If it's a DR nav to the back of nowhere on a really dark night without the possibility of identifying townships or whatever on the way, you should probably rethink your route!

On a nice moonlit night you'll be able to see clouds, horizon, ground features etc and have that nice feeling of knowing where you are, but of course that's not going to happen all the time.

NVFR will always be fraught on a super black night because you won't know you're about to go into cloud until you're in it, but that's where a (hopefully) good forecast and go / no go decision come into it.

It comes back to the whole idea of NVFR - as I understand it, it exists in the regs to allow you to have a bit more flex regarding getting somewhere after last light, or launching before first light. In reality though, there's no restrictions on moon state or anything like that, so nothing to preclude you launching off into complete darkness with all the issues that come with that (illusions, possibility of CFIT, possibility of inadvertent IMC, etc etc).

[Old Akro]

Sorry to be a pedant, but its DED reckoning, not DEAD reckoning. Short for deductive.

[Howard Hughes]

Always thought it stood for Dead Eyed Dick myself! ;)

[Old Akro]

Sorry, I stand corrected:E

[Arm out the window]

I've only ever seen it as dead reckoning. It's in the dictionary that way too!

[Old Akro]

Ok, now it gets interesting. My dictionary lists dead reckoning, but acknowledges DED reckoning. There seem to be naval references to Dead Reckoning dating to the 1600's, although there is no explanation of the source for Dead. It acknowledges that DED reckoning has stronger rationale.

I am sure I have read something by someone serious saying it should be DED reckoning. This may have been something like one of Max Conrad's books, or something of that stature.

So, I now have no idea. So for the moment you say potato..........

[Captain Dart]

Nope, it's 'deduced' or 'deductive' reckoning. 'Dead' reckoning would be relevant to doing the accounts in a funeral parlour.

[Oktas8]

I think the origins of "D" in D.R. are lost in the mists of time. I've seen it written & argued both ways, with good reasons given for each. It certainly does pre-date aviation though.

[Arm out the window]

"Iceberg! DED Ahead!"

[Shagpile]

ded reckoning is DEAD !

[aroa]

Iceberg !! Dead (meaning straight) ahead..cried the Captain.:eek:

By my Ded.reckoning, we shouldnt be here !..cried the Navigator.:ok:

Alas, precise ship's position doubtful.:suspect:

Iceberg ?, well it was just in the way.:ooh:

And the rest is history.:{:{

[jas24zzk]

JSeward,
the requirements for this stuff should be spelled out to you during your training as part of gaining the rating.
If not, then I would be highly questionable of the training you are recieving...the fact you asked here highlighted a flag for me.

An N-VFR rating is easy to obtain, difficult to maintain, let alone master.I often find I have an instructor along for the ride due currency.

NVFR is possibly harder than IFR, definatley one of the more challenging ratings that MUST be respected!

Enjoy
Jas

[JSeward]

Thanks jas,

I have done only 1 short Nav so far which was less than 30 minutes to the destination so I suppose DR navigation was suitable then, and my instructor was also reading the Garmin 430 so I suppose if he is doing that then on our Navs we are legal. I was just wondering if using DR alone was a suitable method but it appears not to be.

Or maybe it is if you have a "full time flight navigator"?

[Old Akro]

A sensible answer...

NVFR ranges from being as easy as day VFR to harder than IFR. NVFR gets harder than IFR because IFR is pretty much a binary state. You see out or you don't. NVMC can be less clear with some optical illusion effects thrown in for good measure. IFR trains you to fly the instruments at the exclusion of all else, NVFR is a shandy.

A NVFR rating teaches many good things, some instrument skills and a better understanding of NAVAIDS. When I used the NVFR rating it was almost exclusively for coming home 30 min - 1 hour after dark. Flying back into a familiar city area that is well lit falls (in my opinion) at the low risk end. But if you are going to use it a lot or for flights predominantly at night, you should get an instrument rating.

My view would be that you focus in DR during training so you show yourself how accurate you can be, but when you fly it for real, have every aid possible working & helping you. I recall that during my training (pre GPS) I successfully navigated to a one horse town whose only light was a single street light and about 2 houses. Its good to know you can do this.

NVFR is that, VFR at night. The minimum instruments are less than you might think. Your instructor was using the 430 because they all cheat. Like day VFR, most of your night navigation will be by reference to the GPS. You should be fluent with its operation.

A lot of emphasis is placed on engine failures in training, but the truth is you are many times more likely to have an alternator, vacuum pump or landing light failure. If you have an alternator failure, you'll shut everything down and fly with only the 430 & txp working, there should be enough battery to get you to where you want to go.

I won't fly at night in a single anymore, although I used to a lot. I'd be very cautious about flying NVFR or IFR in a single without an auxillary vacuum pump or back up electric AH

[QSK?]

Maybe this link will help:

The Straight Dope: Is "dead reckoning" short for "deduced reckoning"? (http://www.straightdope.com/columns/read/2053/is-dead-reckoning-short-for-deduced-reckoning)

[roundsounds]

If you've started night navs and you don't know the answer to that question, I'd be looking for a new instructor / school. If you go delving into the AIP you'll find the answer - in short your primary means of navigating is always DR, supported by various aids. eg map reading, ground based nav aids and GPS. From memory Night VFR requires the destination to be equipped with a serviceable navaid you're trained on and the aircraft equipped with or if it hasn't then you need an alternate so equipped within a specified distance or flight time.... I think it says something like that? Good luck!

[MakeItHappenCaptain]

AIP GEN 3.3
4.10 For Aircraft Flown at Night Under the VFR: the area to be considered must be:
a. the area specified in para 4.8 or 4.9 for aircraft navigated by means of a radio navigation system; or
b. within a radius of 10NM from any point along the aircraft’s nominal track.
However, the pilot of an aircraft who has positively determined by visual fix that a critical obstruction has been passed may nevertheless descend immediately to a lower altitude, provided that the required obstacle clearance above significant obstructions ahead of the aircraft is maintained.

Note that whilst you are permitted to use navaids, position fixing for enroute descent as per the quoted paragraph must still be visually confirmed.

Ps, for other position fixes as per ENR 1.1 Paras 19.4 & 19.5, the AIP do not specify IFR only.:cool:

[Arm out the window]

The alternate requirement unless there's a ground based NDB or VOR at destination has now been changed so you don't need one if you have an approved GNSS receiver and are trained to use it.

[Tinstaafl]

MakeItHappen..., are you implying that NVFR requires a visual fix to descend once a lower LSALT applies to a route segment? I read your comment that way the first time but now I'm not sure. Anyway, if you are, that's not quite correct. You may use IFR radio navigation techniques to descend to a new altitude without ever sighting the ground. You could choose to use IFR LSALTs directly from a chart, or calculate x-bearings, or use a bearing/DME fix etc. However, if you wish to descend *immediately* you pass a limiting obstacle, then the fix must be visual.

The difference is that radio nav position fixes must include a buffer. A visual fix does not.

[smiling monkey]

NVFR is possibly harder than IFR

It's been a while since I've flown NVFR but it's definitely not harder than IFR. Flying at night, you can see the lights of cities and towns 50 miles or more away, just follow them lights! The main difference between NVFR and day is the arrival and departure if you're not IFR rated. It will usually involve climbing and descending from the MSA in the circling area of the aerodrome. It's also much nicer to fly VFR at night as the air is cooler and smoother and there is less traffic.

[JSeward]

Does anyone know the definition of "full time licensed flight navigator"?

En route 1.1 - 19.1.1 part a (in the AIP)

[ForkTailedDrKiller]

Quote:
NVFR is possibly harder than IFR
It's been a while since I've flown NVFR but it's definitely not harder than IFR.

Well I am gonna disagree - sought of!

IFR for a current and experienced IR pilot is WAY easier in similar benign conditions that are a requirement for NVFR!

But then again, NVFR is pretty easy for a current and experienced IR pilot also! :confused:

Dr :8

[Old Akro]

That quote may have come from one of my posts. The point I would make is that NVFR in good conditions is not much harder than VFR. In that regard smiling monkey is correct. But NVFR in adverse conditions can be harder than IFR. With IFR you are on the gauges. Full stop. NVFR is a shandy and visual illusions from black nights, sunsets, and partial cloud make it a lot harder without full IF training to support it. Unless the NVFR flight is sightseeing around the "patch" you can't be sure when you'll be unexpectedly in a tough situation. You can only see towns 50 mile away if there is no cloud and its hard to identify cloud at night

[Lasiorhinus]

Does anyone know the definition of "full time licensed flight navigator"?

That would be a person holding a Flight Navigator's license.

[ForkTailedDrKiller]

Quote:
Does anyone know the definition of "full time licensed flight navigator"?
That would be a person holding a Flight Navigator's license

.........and working full time! :E

[Ultralights]

so nothing to preclude you launching off into complete darkness with all the issues that come with that (illusions, possibility of CFIT, possibility of inadvertent IMC, etc etc).

all this should be covered during the NVFR rating, well at a good school anyway. circuits at black hole airports. cloud covered nights cloud at levels well above LSALT, and moonless nights. its the stuff that will kill you if you dont have previous experience with an instructor onboard.

[deadcut]

What about flying over the outback. It ain't the same as buzzing around brissy at night and sure as hell harder than IFR.

[JSeward]

On the CASA website I can't find anything about a Flight Navigators license?

[dubbleyew eight]

why would you want a flight navigator's licence??

I would not be surprised if the rating vanished after WW2, and if not then, then about the time that flight engineers vanished.

navigation is the skill area developed between the restricted licence and the unrestricted licence when learning to become a private pilot in australia.

the restricted licence was the point that just about everyone ran out of money and had to pause in the flying to save up some more. the GFPT that is issued now instead of the restricted PPL isnt nearly as nice as the old Restricted licence because it doesnt allow the daily inspection to be signed off.

for the life of me I cant understand why you would want that licence.

[JSeward]

I don't want the license, I'm just curious as to why it is in the AIP under navigation of an IFR flight despite nothing being mentioned on the CASA site. I also assume that if the flight is navigated by a full time licensed flight navigator that deduced reckoning can then be used as a navigation technique?

[Capt Casper]

"Rules are for the guidance of wise men and the obedience of fools.’ Douglas Bader.
I have been flying for a long time now – Student Pilot License issued Nov 1963. My Night VMC test was undertaken in Dec 1967.
The requirements then are a bit obscure now, but at that time there were very few GA pilots with an instrument rating. The training required was, I think, some limited panel IF instruction and some instruction on intercepting and tracking to and from a navaid. Having met a standard satisfactory to your CFI you undertook a Nav exercise at night which had to include a dog leg route over a nominated visual fix in visual conditions. If you did that successfully you were given the rating. In those days most instructors had very little more experience at the task than the student. Anyone with experience had probably achieved it illegally any way. I may be wrong but I think the rating was brought in because modern American light aircraft were being imported in large numbers and they could be used legally at night in the USA. As well, it was legal to conduct charter flights at night in a twin engine aeroplane if you held a class four instrument rating and a night VMC rating. The class four instrument rating was a qualification to navigate solely with reference to a navaid – that meant, the ability to intercept and track to or from a VOR or NDB, it didn’t confer any rights to do it in IMC but you could fly over cloud without the requirement for 30 minute visual fixes. The Dead/Ded Reckoning was the only method available to fly over featureless terrain at night, often at low level to stay clear of cloud; Cobar to Parkes for instance below 5000 feet. You calculated the course and flew the heading. The destination might occur on your left or right!!
There were none-the-less, other checks and balances which have been dispensed with today. Flight plans were compulsory. Operational approval lay with the Department of Civil Aviation so they assessed the weather as well as the pilot. There were eight classifications of cloud cover instead of today’s five and they were more conservative. Departmental presence took the form of established Flight Service Units and mobile Examiners of Airmen, who actually flew themselves in Departmental Aeroplanes and who did know what was going on. As well, they were generally well respected. Thorough endorsements were required for each type of aircraft you flew. Rules were published on paper in the form of the Act, the Regulations and the Civil Aviation Orders, none of which changed much or often and were provided without cost. Compliance was with the spirit, rather than the letter of the law. Accidents were seen as such and generally scalps weren’t sought. Aero Clubs were vibrant and the young were fostered and counseled by their peers. Safety Digests were treasured, widely read and discussed. Access to workshops, hangars and airports and schools was virtually unrestricted.
Sadly, nowadays, there is little left of the industry of old; little experience in the schools; little camaraderie socially; no respect for the regulator; a mix of old rules and new, bewildering in their complexity and changing day to day.
I feel very sorry for people like Jseward who is obviously keen to learn and understand what is behind the plethora of regulations he/she has to deal with in their training and need to resort to the anonymous “experts” of the internet for guidance. The genesis of most rules lies in hard learnt experience. The rules continue to exist often past their use-by-date whilst the reasons for them are lost in time.

[Tee Emm]

In navigation (http://en.wikipedia.org/wiki/Navigation), dead reckoning (also ded (for deduced) reckoning or DR) is the process of calculating one's current position by using a previously determined position, or fix (http://en.wikipedia.org/wiki/Fix_(position)), and advancing that position based upon known or estimated speeds over elapsed time, and course.

Not "deductive":E

[dubbleyew eight]

one correction Casper.
back in the day there was schedule 67. what this schedule was about was identifying all the similar handling single engine aircraft.
if you were endorsed to fly one of the schedule 67 aircraft then , after studying the Pilot's Operating Handbook for the aircraft, you could fly any of the other aircraft in the schedule.
It worked because all the aircraft were designed to FAR 23 and as part of FAR23 certification the designs were adjusted until they met the handling characteristics required by the FAR. ( FAR = American Federal Aviation Regulation. FAR23 dealt with design standards.)
which meant that they handled almost the same.

why it has all descended to the current level of over prescriptive crap I dont know.

[dubbleyew eight]

To answer JSeward's question about using DR...

you can use any navigation technique that does the job. you can swap between techniques whenever you want.

by legislation a Day VFR aircraft is setup with the tools for visual navigation.
you have a magnetic compass, an air speed indicator, you must carry an accurate time piece, and the current maps for the area.
with these tools, an E6B and a pencil and ruler you can actually navigate.

however lets face reality. those navigational tools arent all that accurate.
these days our american friends have made publicly available their network of Global Positioning Satellites. A garmin gps receiver is probably the best investment you can make. ( I still use a garmin gps 2 plus :ok: )
A GPS Ipad running OzRunways software is what many favour as well.
My son in law uses ozrunways on his iPhone to keep track of the local area frequency in the high speed stuff he flies.

Dont shy away from learning to use an E6B. The battery life is infinite and they dont get hard to see in bright sunlight, but try all the techniques and use whatever you find does the job for you.

I knew a 29,000 hour airline pilot who wasnt too proud to fly IFR ( I follow railways ) when he wanted to go somewhere.

my gps has meant that I have never done a one in 60 calculation in all my flying life. if I divert miles out of the way to skirt around weather I use the goto function to point the way to the next waypoint. easy squeezie.