IMC - letting down
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Like "Pull What" I am also wondering why people are talking about minima when the task is to get through a layer in order to continue VFR to your destination - there must be more than a thousand feet of VMC under the layer or you would already have switched to plan B.
It's a few years since I did my IMC, but do they really teach such different stuff nowadays? All you do is go to the last VOR on your trip, draw a line that heads towards low ground, and as you cross through the overhead of the beacon start a descent in that direction. If you're still IMC at 1000 feet AGL, it isn't going to work so you climb back up and divert to a "proper" airfield with an approach.
It's a few years since I did my IMC, but do they really teach such different stuff nowadays? All you do is go to the last VOR on your trip, draw a line that heads towards low ground, and as you cross through the overhead of the beacon start a descent in that direction. If you're still IMC at 1000 feet AGL, it isn't going to work so you climb back up and divert to a "proper" airfield with an approach.
Fly Conventional Gear
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If you have a clearly defined route that you know that you can maintain compliance with the IFR on down to a certain altitude and know that you are on it; for example starting from a VOR and saying..."at so many miles from the airfield I can descend until atitude x, at which point I must accept that visual recovery will not be possible if still in IMC and divert" then I don't see any reason to do an IAP provided you maintain the IFR during descent.
However one might not have always worked a route out or due to ATC or whatever you may have ended up away from the waypoint you were going to use. Rather than scour the VFR chart for obstancles to work one out it might just be easier and safer to do an IAP to another airport and then if possible fly visually if you are unprepared or unsure.
However one might not have always worked a route out or due to ATC or whatever you may have ended up away from the waypoint you were going to use. Rather than scour the VFR chart for obstancles to work one out it might just be easier and safer to do an IAP to another airport and then if possible fly visually if you are unprepared or unsure.
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Rather than scour the VFR chart for obstancles to work one out it might just be easier and safer to do an IAP to another airport and then if possible fly visually if you are unprepared or unsure.
Tim
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There are cloudbreaks and cloudbreaks? The big danger are CFIT accidents or OCAS running into other aircraft that you are not aware of how do you securely cover both aspects flying OCAS?
If you are on your own ie no reliable radar coverage you have to have a plan to minimise the risks as much as possible.
To blindly follow any navaid information whether it be ILS, VOR, NDB GPS etc is asking for trouble unless you confirm those navaids are telling you what you think they are?
Always confirm the navaid info by some backup.
Descent OCAS and you want to make sure you dont fly into cumulus Granitus clouds!!!
The only way to do that is to respect the sector safety altitudes using the regional QNH.
descending below the sector safety altitude and everything becomes more precise.
Spot altitudes? Mast heights etc? How far do you descend above those points before calling it a day?
That depends on how much risk you are taking!
Are you really where you think you are? If not you could be in for a disaster.
I know of one pilot who flew dead ILS needles down the wrong valley in the Alps lucky for him ATC alerted him as he broke out in the wrong valley!!! It does happen!
Hitting other aircraft? most (not all) have transponders so should show up if your lucky enough to have TICAS!
Radar can help if you have radar coverage!!!
If not listening out on local frequences? Otherwise its relying on the big sky theory!
If you have to take an approach into a nearby airport to break off for a visual landing at your own field/ landing strip seriously consider landing off that approach as the cloudbase is likely to be be so low as to make flying VFR questionable?
Pace
If you are on your own ie no reliable radar coverage you have to have a plan to minimise the risks as much as possible.
To blindly follow any navaid information whether it be ILS, VOR, NDB GPS etc is asking for trouble unless you confirm those navaids are telling you what you think they are?
Always confirm the navaid info by some backup.
Descent OCAS and you want to make sure you dont fly into cumulus Granitus clouds!!!
The only way to do that is to respect the sector safety altitudes using the regional QNH.
descending below the sector safety altitude and everything becomes more precise.
Spot altitudes? Mast heights etc? How far do you descend above those points before calling it a day?
That depends on how much risk you are taking!
Are you really where you think you are? If not you could be in for a disaster.
I know of one pilot who flew dead ILS needles down the wrong valley in the Alps lucky for him ATC alerted him as he broke out in the wrong valley!!! It does happen!
Hitting other aircraft? most (not all) have transponders so should show up if your lucky enough to have TICAS!
Radar can help if you have radar coverage!!!
If not listening out on local frequences? Otherwise its relying on the big sky theory!
If you have to take an approach into a nearby airport to break off for a visual landing at your own field/ landing strip seriously consider landing off that approach as the cloudbase is likely to be be so low as to make flying VFR questionable?
Pace
Fly Conventional Gear
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Spot altitudes? Mast heights etc? How far do you descend above those points before calling it a day?
If you have to take an approach into a nearby airport to break off for a visual landing at your own field/ landing strip seriously consider landing off that approach as the cloudbase is likely to be be so low as to make flying VFR questionable?
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ContactTower
Totally agree 1000 feet is a good margin to use.
Being a realist pilot will use smaller margins sometimes much smaller and there lies the danger.
Normally if you fly an approved approach for a cloudbreak to a VFR field then that usually means a normal cloudbreak is not possible!
Transitioning from IFR IMC to VFR minimal VMC is always confusinng meaning getting your mindset into a VFR gear.
If when you break out the pilot is not secure I would recommend a landing request or a predeclared intention to land if VFR not acceptable to the pilot!
Obviously familiarity with the area plays a large part in that decision
Pace
Totally agree 1000 feet is a good margin to use.
Being a realist pilot will use smaller margins sometimes much smaller and there lies the danger.
Normally if you fly an approved approach for a cloudbreak to a VFR field then that usually means a normal cloudbreak is not possible!
Transitioning from IFR IMC to VFR minimal VMC is always confusinng meaning getting your mindset into a VFR gear.
If when you break out the pilot is not secure I would recommend a landing request or a predeclared intention to land if VFR not acceptable to the pilot!
Obviously familiarity with the area plays a large part in that decision
Pace
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I'm sorry guys, but once again I am going to drag the thread back to practical reality. The original question was a simple one - for a freshly rated, but not yet really used it, IMC pilot, on a perfectly fine VFR day BELOW the clouds, when the said pilot is at (say) FL055 and is ABOVE the clouds, how do you get home?
And the answer is nothing to do with instrument approaches, and dangerous ducking-under manouevres, or SRA let-downs, or any of that stuff that implies doom and gloom and that this would be an unusually scary thing that you are about to do.
The answer is - fly to an easily identified waypoint, such as a nearby VOR. (Which you will have identified using the morse code ident, and checked the flags on the indicator, and all that good stuff, because you are a well trained and recently qualified pilot). Starting from that unimpeachable position fix, point the aircraft in the direction of low ground (which includes looking at obstacles, hills, and so on - see previous comment about well-trained pilot). And then simply descend through the clouds whilst maintaining the chosen outbound track.
The only thing you need to make a mental (or perhaps written) note of before you start down is the obstacle height - to which you will have added 1,000 feet.
If the weather is as expected, you will pop out into VMC, and fly home. If the weather is worse than expected, you will still be in the clouds when you reach the previously noted altitude. DO NOT DESCEND BELOW THIS ALTITUDE. Instead, climb back up to MSA, and revert to plan B (which probably involves diverting to an airport with an instrument approach).
But in the scenario originally described, where you are flying "on top" and there is good VMC underneath, this is the time-honoured and well proven way of getting from "up there" to "down there", and is pretty much foolproof. It must be, because I've managed it hundreds of times.
And the answer is nothing to do with instrument approaches, and dangerous ducking-under manouevres, or SRA let-downs, or any of that stuff that implies doom and gloom and that this would be an unusually scary thing that you are about to do.
The answer is - fly to an easily identified waypoint, such as a nearby VOR. (Which you will have identified using the morse code ident, and checked the flags on the indicator, and all that good stuff, because you are a well trained and recently qualified pilot). Starting from that unimpeachable position fix, point the aircraft in the direction of low ground (which includes looking at obstacles, hills, and so on - see previous comment about well-trained pilot). And then simply descend through the clouds whilst maintaining the chosen outbound track.
The only thing you need to make a mental (or perhaps written) note of before you start down is the obstacle height - to which you will have added 1,000 feet.
If the weather is as expected, you will pop out into VMC, and fly home. If the weather is worse than expected, you will still be in the clouds when you reach the previously noted altitude. DO NOT DESCEND BELOW THIS ALTITUDE. Instead, climb back up to MSA, and revert to plan B (which probably involves diverting to an airport with an instrument approach).
But in the scenario originally described, where you are flying "on top" and there is good VMC underneath, this is the time-honoured and well proven way of getting from "up there" to "down there", and is pretty much foolproof. It must be, because I've managed it hundreds of times.
Thread Starter
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Thanks for the replies and in particular CJ and Pace.
Yes, I had planned on using a radial from Otringham with DME and also using the fields NDB to descent into an "area" of know altitude / obstructions on a heading inbound and if not visual by 1400ft on the QNH then diverting at my local base and this model can be used anywhere with prior planning. And should I be transiting Doncaster for example on my route back, it made only too much sense to me to ask the question - can I shoot the ILS til visual as it's almost en-route and then fly the rest of the way VFR should the cloudbase permit. This gave the added bonus of being under a radar service and descending into a safe and known area with the added bonus of, if reaching the MSA and not visual, shooting and landing at the airport and this can be applied on any trip.
At least I have in my mind my options - just need to get myself a subscription now to Jeppesen and keep practicing approaches to keep current.
Thanks all
Yes, I had planned on using a radial from Otringham with DME and also using the fields NDB to descent into an "area" of know altitude / obstructions on a heading inbound and if not visual by 1400ft on the QNH then diverting at my local base and this model can be used anywhere with prior planning. And should I be transiting Doncaster for example on my route back, it made only too much sense to me to ask the question - can I shoot the ILS til visual as it's almost en-route and then fly the rest of the way VFR should the cloudbase permit. This gave the added bonus of being under a radar service and descending into a safe and known area with the added bonus of, if reaching the MSA and not visual, shooting and landing at the airport and this can be applied on any trip.
At least I have in my mind my options - just need to get myself a subscription now to Jeppesen and keep practicing approaches to keep current.
Thanks all
