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glenb
10th Oct 2009, 06:15
Writing an article for our training notes on Low Level Navigation. would be very keen for any inputs or suggestions. cheers .

Low level navigation, often referred to as scud running, is a procedure that can be fraught with hazards. It must me pointed out that low level navigation is a technique used in marginal VMC. By marginal VMC, I stress that it is still VMC. The pilot should never allow himself to fly into non VMC conditions. This could well lead to disorientation or failure to see and avoid obstacles Low level navigation should only be conducted after careful consideration to ensure that the legal requirements can be met. The purpose of the chapter is not to encourage you to undertake low level flying but rather to practice it in the training environment with your instructor, in the event that you do ever need to do it.

Let’s use this opportunity to cover what is meant by VMC in each of the airspace categories.

In Class C airspace- Visibility of 5000 metres.
1500 metres horizontal separation from cloud.
1000 foot vertical separation from cloud.

In Class D airspace- As with Class C airspace.

In Class E airspace- As with Class C airspace.

In a GAAP- Visibility of 5000 metres.
Clear of cloud.

In Class G airspace- generally the same as class C Airspace

The exception being if we are below 3000 ft AMSL or 1000feet AGL ( whichever is the higher ) when the visibility remains unchanged at 5000 feet but we can operate clear of cloud and must remain in sight of ground or water.


Pilots are also reminded of CAR 157 with regard to low flying which basically limits flight over populated areas to 1000ft agl and 500 ft agl over non populated areas.

The reason that pilots get themselves into flight in non VMC conditions is generall an overestimation of their ability and an overly optimistic assessment of the weather conditions ahead.

Generally a turn back through 180 degrees will be the best option. Why don’t pilots do this? One reason could be the illusion that the conditions behind you are deteriorating quicker than they really are. This is because at the speeds that aircraft fly at, reference points disappear behind you in the restricted visibility. Ahead of you, as more terrain comes into view there can be the illusion of improving conditions. The faster the aircraft, the stronger this illusion. Conditions don’t usually deteriorate that quickly. If the weather conditions behind you were acceptable 3 minutes ago then the chances are that they are still acceptable

Features such as highways and roads make good features to follow. Keep these features on your left hand side wherever possible. This will make your operation substantially safer. This is where your field of view will be greatest sitting in the left hand seat. Also bear in mind that as the cloud base is lower than normal all traffic will be compressed down into the area that you are flying in, and generally not flying at the standard cruising levels. Hopefully on coming aircraft will also be keeping these features on their left hand side and therefore reducing the risk of a head on collision.

Prior to conducting low level navigation the aircraft needs to be configured.

Another aid in reducing the risk of a head on collision is to maximize the aircraft lighting. Turn on all aircraft exterior lighting.

VHF communications will be reduced at low level and you should expect a reduced range of any navaids. Consider notifying ATC of your intentions.

Ensure that the fuel tank is selected to the fullest tank in the Piper aircraft and selected to both if flying the Cessna aircraft. Ensure you are maintaining a fuel log.

Check all switches and maximize use of any exterior aircraft lighting. With a low cloud base and low flight the risk of a mid air collision is potentially increased as any traffic is condensed down into a lower vertical spread of available airspace with aircraft not being able to fly at the correct cruising levels.

Trim the aircraft for a slight nose up attitude. This is to help protect against a lapse in concentration having the aircraft have fly down towards the terrain.

It is important to keep your eyes outside the cockpit as much as possible. Have your maps correctly folded for the applicable area and keep the map between your thumb and control column to minimize the need to look down at a map on your lap.

Visually separate yourself from terrain rather than relying on the altimeter. Have a good appreciation of what 500 feet agl looks like.

If flying through a valley wherever practical keep to the downwind side of the valley. If a turn through 180 degrees does become necessary the turn into wind will reduce the radius. Bear in mind that a turn at slow speed with a steeper bank angle will offer the best turn performance. Not forgetting of course that your stall speed will however be increasing. Limit bank angle to no more than 30 degrees and increase power during the turns to increase the margin above the stall speed. Flying downwind will also help to reduce the effects of mechanical turbulence.

Flap slow the aircraft and improve forward visibility. At 120 knots 5000 metres visibility is less than 1 and a half minutes ahead. By slowing the aircraft down to 80 knots you will be able to see slightly over two minutes ahead. Still not great but substantially better.

With regard to the navigation technique there are a number of factors that must be considered.

Vertical features will become more important for navigation. Features such as buildings towers, low level hills etc will become easier to pick up than at higher levels but will move quickly past your field of view.

You will have a greater impression of speed at low level so you may think you are going faster than you really are. Aim for slow enough to avoid obstacles but keep a safe margin above the stall speed

Engine failures although unlikely must be considered. Maintain a good situational awareness and treat an engine failure as an engine failure after takeoff. Know the wind direction and have a plan for an engine failure.

Don’t pass up the opportunity to pull into an airport or conduct a prec search and landing over a suitable field. Much better to be on the ground wishing you were in the air than in the air wishing you were on the ground.

Whilst the VFR pilot should not be in IMC conditions if it really does become unavoidable consider a gentle climbing turn in the area to at least have better terrain avoidance. Don’t be afraid to ask for help. Although you as the pilot in command are responsible for your flight I have heard ATC provide wonderful guidance and assistance to a pilot under a stressful situation. A problem shared is a problem halved.

goldypilot
10th Oct 2009, 06:31
yer mate just dont forget to tell em to look out the pointy end

tmpffisch
10th Oct 2009, 07:25
Maybe a comment on uncharted obstacle heights, transmission line heights etc.

Warbo
10th Oct 2009, 07:51
Maybe a comment on uncharted obstacle heights, transmission line heights etc.

Yep, both of those will git ya! The few companies that own wind turbines like to erect wind finding towers in areas of interest to record wind data before commiting to building the turbines. They do publish this stuff (somewhere, I get them by email) but the thing is the towers are VERY hard to see and seem to be usually around 200' high. One that comes to mind was put on a peak, but certainly not the highest peak within 5 miles. Another pilot told me about it, then ferrying past it on the way to a job I still forgot about it and luckily I was about a 1/2 mile abeam of it when I remebered it. You simply cannot see them in certain lighting conditions.

Powerlines across valleys should be illegal. They are out there and they are potential killers. I remember a bloke in WA telling me that the greenies won the case to get the poles painted green on some of the long spannig wires East of Perth, so the only clue is hidden from any poor barstard in a spot of trouble due weather.

I'll bet there is a million stories of dangerous powerlines crossing valleys around peoples local domains, but you have to be a local to know them!

There's a huge difference between scud running at 800' agl and 150' agl. If your at 150' with your tail in the cloud, you really need to be in a pub somewhere waiting for the weather to clear! Proceeding in ****ty weather is the VFR pilots number 1 enemy in my opinion.

SM227
10th Oct 2009, 07:59
And if you do end up in that situation, dont keep zooming along at +120kts! chuck out some flap and slow right down, so if you do end up in a hill, you might have some chance at surviving the impact.

havick
10th Oct 2009, 08:34
for fecks sake... just look out the front.....

this is day to day flying for helicopters...

Warbo
10th Oct 2009, 08:38
for fecks sake... just look out the front.....

this is day to day flying for helicopters...


Yeah that's helpful. Care to discuss helicopters flying into wires or has that never happened?

EDIT - Let me add a bit Havick to not sound so abrupt: I think the point here is the poster is referring to low level cross country. I would think the dangers involved in low level cross country in unfamiliar areas & terrain mixed in with crappy weather would be EXACTLY the same for the helicopter pilot/hang glider pilot/Ag pilot/F-18 pilot/VFR fixed wing weekend warrior pilot/cosmonaut, etc, etc.

havick
10th Oct 2009, 08:54
warbo... maybe taken out of context... what I'm getting at is I see all to many times people getting too busy with stuff inside the cockpit as opposed to what's in front of them.

the reason I say it's more pertinent to slab drivers as most transits are done at higher levels, and once down at the lower levels, still tend to have the same habit patterns as cruising at the higher levels..

agreed, many helicopters have hit wires (probably on of the biggest killers)..
I'm not trying to debate rotary vs plank as I drive both... it's just what I've noticed..

Warbo
10th Oct 2009, 09:17
Agree, helicopter flying (in my 0.5 hours T.I.F. experience) is very visual, alot like ag flying. There is no time in heli-ops to be f'ing around with charts at 100' agl.

Back to the original topic, I believe the saying: 'It's better to be on the ground wishing you up there than to be up there wishing you were on the ground' is still the best thing I have heard as a VFR pilot.

VH-XXX
10th Oct 2009, 10:04
Trim the aircraft for a slight nose up attitude. This is to help protect against a lapse in concentration having the aircraft have fly down towards the terrain.

I would add that you should not fly too high or too close to the cloud due to inadvertant entry. If you have 500ft cloud base, don't fly at 450ft. (oh and the stress of weather clause)

training wheels
10th Oct 2009, 10:20
I actually just finished reading CASA's Flight Instructor Manual on Low Level Flying and it looks like you've got it well covered in your article. I've copied and pasted a minor point mentioned in the FIM, though, .. don't know whether you'd like to include it under the "flying technique" part of your article?

At low level, log keeping is restricted to fewer entries because of aeroplane handling considerations, and at times it may not be possible with safety to make log entries.

MakeItHappenCaptain
10th Oct 2009, 10:24
IF YOU ARE GOING TO FLY CLEAR OF CLOUD IN CLASS G AIRSPACE IT IS A LEGAL REQUIREMENT THAT YOU HAVE A VHF RADIO AND BROADCAST THAT THIS IS HOW YOU ARE OPERATING.

Nobody reads the full regulation!

If an IFR flight is descending in your area or another aircraft is doing the same thing around the other side of the cloud they have to know you are there. The 1500' and 1000m is there to provide adequete reaction time in the event of a sudden appearance of another aircraft.

Eg. On the centre frequency "All Stations Maleny, 172 ABC is tracking north over the navaid at 2800' OPERATING CLEAR OF CLOUD, Maleny"

That way anyone on frequency knows and Centre can also advise any IFR traffic in the area as well.:ok:

The requirement to remain in sight of ground or water applies to visual navigation below 2000' and is not specific to operating clear of cloud.

snoop doggy dog
11th Oct 2009, 04:34
Keep looking everywhere and Keep a good look out for the Poles. They usually have the wires attached to them :ok:

Good to know the aircraft's limitation, however, know your own as well. Every day is different and so is the weather as you would know. Some days you can fly lower than others. Considerations are the wind, sun and visibilty to name a few. :) Like you say, always look for a good landing spot along the way.

Not sure how low your low flying is? Had a station manager that used to like flying high, 300 feet. :p They were fun days.

My two cents worth ;)

FL170
11th Oct 2009, 04:46
:ok::ok:IF YOU ARE GOING TO FLY CLEAR OF CLOUD IN CLASS G AIRSPACE IT IS A LEGAL REQUIREMENT THAT YOU HAVE A VHF RADIO AND BROADCAST THAT THIS IS HOW YOU ARE OPERATING.


Eg. On the centre frequency "All Stations Maleny, 172 ABC is tracking north over the navaid at 2800' OPERATING CLEAR OF CLOUD, Maleny

Best piece of advice I've heard all week :ok:

Chimbu chuckles
11th Oct 2009, 04:48
Scud Running and Drugs.

Just say NO!

Its been a VERY long time since low level VFR nav could be considered a reasonable alternative. Not since before they started shoving all manner of man made structures up all over the country - 1000' high microwave link towers/ high tension power lines etc.

About the only thing that is safe to follow low level these days is a beach/coastline if you stay over water.

Roads (they usually put the tall, thin microwave towers next to roads - the guy wires have a large footprint) valleys and rivers, imho, are very dangerous.

poteroo
11th Oct 2009, 05:03
Glenb

You've covered most of it, but it occurs to me that much of what you've included is covered in the low level training course covered by CAO 29.10 which is itself pretty much the first 5 hrs of the Ag Rating.

For your student to even think about the 'scud-running' below 500agl option to maintaining VFR, it would seem they need some proper low level training first. Can't see how your course can be used before doing low level.

happy days,

4Greens
11th Oct 2009, 06:48
Orientate the map.