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IFR departure question (for flight sim)


Gribble

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Hey all. I play flight sim, alot. Probably too much. Even when my missus asks me what I do on the computer until late at night and I answer "looking at porn" she says "bull, your playing flight sim again".

 

So lately ive been getting into IFR stuff, downloading departure procedures and approach procedures and whatnot and trying to do things as good as I can with what little I know about IFR flight.

 

My question is lets say your at a smallish airport with no published departure procedure. Lets take Narromine for instance;

 

http://www.airservicesaustralia.com/aip/pending/dap/AeroProcChartsTOC.htm#N

 

So, my questions are to the people in the know...

 

1. How bad does the weather have to be before your not allowed to take off, not when you think its unsafe but when the particular air law requires you to stay on the ground. Visibility and cloud base for instance.

 

2. If you do take off into cloud, what is the common procedure once you leave the runway? Climb to 500ft and then turn to the heading of your first leg? In the game you would usually switch to the area freq and ATC just tells you turn to x deg or continue your own navigation.

 

3. If you take off from an airport thats NOT on an intersection for low altitude airways (temora for exampe) whats the method to get on track quick?

 

4. Not so much a departure question, but if your flying along using the enroute charts is it normal to just tune into a nearby navaid thats as close to perpendicular to the flightpath as possible, measure the bearing from said navaid to your current airway and plot that into the map to get a fix? Obviously if your heading to or from a navaid that has DME then you can just measure the distance to/from that the dme is telling you. Or you could just cheat and use the gps but where is the fun in that.

 

I know this thread should probably be in the Flight Sim threads but im unsure of just how many people read it. It may also seem confusing but thats because im going on what little I have read about IFR flight on the net and no actual bum in seat training in an aircraft with someone who is crazy enough to trust little mechanical dials with their lives. Im just trying to make my Flight simming as close to real as possible.

 

Thanks!

 

 

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If you are IFR you will have to have entered a flight plan if the conditions don't allow VFR flight. Take off and contact ATC and they will give you a clearance, which as you are a simmer, you will have to have devised yourself. It is a bit hard departing from an uncontrolled strip in less than VFR conditions.

 

 

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Guest extralite

You can normally take off using an obstacle clear take off gradient from the end of each runway. Been a while but should be in the ERSA. Will give a splay and climb gradient required, and provided you remain in that and climbing at the required rate, will stay clear of obstacles. Then when at 10 mile safe (assuming within 10 miles) can turn back and circle up within 10 mile safe to enroute safe and you are on your way. As i said, its been a while so id have to check that the info was in the pubs suggested, but its there somewhere.

 

 

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1. More dependant on aircraft capabilities than any legislation reuirement. That's why your ifr.

 

2. As someone has said you will have entered a flight plan. If in class D you will exit ad area using local instructions. If in G you will exit however you please and let ATC know (request tfc, Time of departure etc). Then we know you are there and can pass traffic and other information.

 

3. See 2.

 

4. I'll leave to an IFR pilot to answer.

 

Hope this helps. I think the most important thing here is that you have to have a flight plan lodged to fly IFR. That should clear up most of your questions.

 

 

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Guest Howard Hughes

Hi Gribble,

 

1. For multi crew aircraft (or single pilot aircraft with autofeather capability) 800M visibilty and 0 feet cloud base, if runway lighting is less than 90m spacing and there are centreline markings, this can be reduced to 550M and 0. Climb performance and lowest approach minima for a return are more of a factor in departure decisions.

 

2. OCTA, turn to an intercept heading which will have you established on track within 5NM, once again taking into consideration performance requirements and climb to LSALT. In CTA as directed by the controller.

 

3. As per above point.

 

4. I would normally use on track aids, or GPS to fix position, I can't remeber the last time I tuned up an off track aid for a position fix. But if you are going to use them they need to be within rated coverage and intersect by at least 45 degrees.

 

Cheers, Mark (aka HH).

 

 

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Howard Huges is correct.

 

The min vis/cloud base required for an IFR departure depends on the aircraft. Unfortunately the DAPs don't seem to have the requirements on the charts. They are published on the aerodrome chart in Jeppessen.

 

One thing that you need to be careful of is terrain. You may very well depart but then smack into a hill. You need to make a plan on how to depart the aerodrome in IMC safely. Each chart shows the MSA (Minimum Safe Altitude) within 10nm/25nm. You need to get above this ASAP. With no SID, the only way to do it is to stay above any DME steps, climb in the circling area or stay visual.

 

We need to be on track within 5nm of the departure aerodrome. This is done by using an intercept heading that will put you on track. Then use either NDB, VOR GPS or DR to stay on track. If in CTA, the controllers will vector you around and then send you on your way.

 

As far as tuning aids along the flight. You are right, basically tune to stations that will be of use to you. Use VORs and NDBs to cross check your position when you can. DME is easier as you will know the radial and distance :)

 

 

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If you take off into IFR conditions, you need to get a clearance ASAP. That means prior notice to ATC. It is not acceptable to fly IFR without a clearance, for the simple reason that I may be doing exactly the same thing and we don't want to meet up in the clag.

 

Of course this is all for flight simming, but the question was all about doing it legally.

 

 

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Guest extralite

Hmm. Think there is a bit of incorrect info here. Each step from rotation to en route safe needs to be above safety heights which is where the obstacle clear take off gradient comes in. Regardless of whether OCTA or CTA. In CTA, controllers have a radar safe altitude which is a bit lower than 10 mile safe, but you still need to get up above that there radar lowest safe before getting vectors . Procedure i described is the way to take off even if cloud base is 100 feet as long as visibility down runway is above that required for take off, and also there are alternate requirements too.

 

 

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Guest Howard Hughes
2. OCTA, turn to an intercept heading which will have you established on track within 5NM, once again taking into consideration performance requirements and climb to LSALT. In CTA as directed by the controller.

Hi again Gribble,

Sorry I misread your question initially and gave you tracking requirements, as opposed to obstacle requirements.

 

If I were doing a minimum visibilty departure from Narromine, my preference for departure would be runway 29, the reason being that the displaced threshold for 29 indicates a reasonable sized obstacle fairly close in to the runway and if you are doing a minimum visibilty departure, you don't want to be 'stooging' around in that area, in particular on one engine.

 

How would I go about the departure?

 

Firstly I would climb at Vx (max angle) off runway 29 (assuming all engines operating), I would conduct a normal circuit and establish on track once I reach 3100 feet (ten mile MSA). There I would accelerate to enroute climb speed and ensure reaching at least 3700 feet (25 mile MSA) by 10 miles.

 

In the event of an engine failure, there would be two possible plans. The easiest is to reverse the runway 11 RNAV and climb straight ahead to 15 miles (assuming you can reach 2000 feet by 5nm), once reaching the MSA (3700) you could set course to an alternate (assuming you departed with a 0 foot cloud base and 800M visibilty). If the weather was suitable you could conduct a reversal in the holding pattern and return to land via the runway 11 RNAV.

 

The second option if not RNAV equipped would be to reverse the NDB procedure. If an engine failure occured (at rotation) you could track 296 degrees and after two minutes turn right and track back towards the aid, once at the aid if not at MSA you could enter the holding pattern and continue climbing. Keep in mind climb performance is degraded in turns and turns should be limited to below 15 degrees angle of bank.

 

I hope that clears it up a little, 'clear as mud' probably.022_wink.gif.2137519eeebfc3acb3315da062b6b1c1.gif

 

Cheers, HH.012_thumb_up.gif.cb3bc51429685855e5e23c55d661406e.gif

 

 

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Reversing the GPS/DME arrival is also an option for a turn back. Thats what we brief prior to departure in the event on an engine failure in IMC.

 

Just be careful relying on the obstacle clear gradients for the runway, they only go out to a certain distance then you are on your own. Flying in a straight line wont guarentee terrain clearance beyond the surveyed area.

 

CAAP 89W-1(0) explains some of it. http://casa.gov.au/wcmswr/_assets/main/download/caaps/drome/89w_1.pdf

 

 

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