THANKS IN ADVANCE!
CP
Time to see/ Time to go
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canpilot
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Time to see/ Time to go
Anyone know how to calculate this assuming a category " B" aircraft groundspeed. I can't find any solid resources out there on how to do this.
THANKS IN ADVANCE!
CP
THANKS IN ADVANCE!
CP
Are you refering to the MAP - Missed Approach Point ?
If so .... break out the CAP and CAP Gen and have a read through
The MAP can vary pending on what type of approach you're doing .....
Most NDB Approaches have timing, which I beleive is the one that you're trying to refer to. Timing is in the bottom right box provided for you so you don't have to calculate it .... for a category B airplane, you're maneuvering between 91-120 kts. so use the 110 speed.
On the off chance that you what to figure it out, better break out out your triginometry and vectorial skills ..... have fun with that
On VOR approaches with the VOR on the field, once the flag switch and your at your MDA, you look up ... don't see the field? Overshoot
As for ILS, same idea, keep following the crosshairs till the DA/DH, no dice, up you go! Timing is provided as a prompt to look up.
Hope it helps, if I'm not even close and way off base; let me know
If so .... break out the CAP and CAP Gen and have a read through
The MAP can vary pending on what type of approach you're doing .....
Most NDB Approaches have timing, which I beleive is the one that you're trying to refer to. Timing is in the bottom right box provided for you so you don't have to calculate it .... for a category B airplane, you're maneuvering between 91-120 kts. so use the 110 speed.
On the off chance that you what to figure it out, better break out out your triginometry and vectorial skills ..... have fun with that
On VOR approaches with the VOR on the field, once the flag switch and your at your MDA, you look up ... don't see the field? Overshoot
As for ILS, same idea, keep following the crosshairs till the DA/DH, no dice, up you go! Timing is provided as a prompt to look up.
Hope it helps, if I'm not even close and way off base; let me know
"A good traveller has no fixed plan and is not intent on arriving." -Lao Tzu
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tired of the ground
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The reason you can't find any calculations for time to see is because it is useless information.
Do the approach as published, if you see the runway, land. If you reach your missed approach point don't land.
One thing that you do have to think about is if the MAP is the runway and you see it then, is the runway long enough for you to descend and land?
You have enough to think about without doing more mental gymnastics.
Do the approach as published, if you see the runway, land. If you reach your missed approach point don't land.
One thing that you do have to think about is if the MAP is the runway and you see it then, is the runway long enough for you to descend and land?
You have enough to think about without doing more mental gymnastics.
If I understand what you are asking; there is no specific time for anything Cat B. Just use your approach speed and calculate the timing based on the G/Ss in the bottom corner.
As for "time to go". When the MAP or time expires you go.
Circumstances this might be helpful. Night NDB approaches into a reserve with little or no GPS guidance. You see a runway light or a small portion of the runway but can't yet orient yourself relative to it. If you are way past your "Vis time" but still under your "Missed time" you may want to consider the missed. That could be one hell of a steep angle to try to land.
Sorry for the messy response.
BTD
As for "time to go". When the MAP or time expires you go.
I would argue in certain circumstances this information is useful. Just take the Recommended vis in the Cap and factor your groundspeed. (rough mental DR works) Eg. Cap vis 2 miles, App speed 120 kts. Should see it roughly 1 min less than your missed time.The reason you can't find any calculations for time to see is because it is useless information.
Circumstances this might be helpful. Night NDB approaches into a reserve with little or no GPS guidance. You see a runway light or a small portion of the runway but can't yet orient yourself relative to it. If you are way past your "Vis time" but still under your "Missed time" you may want to consider the missed. That could be one hell of a steep angle to try to land.
Sorry for the messy response.
BTD
Here's something I found in my notes, don't recall where I got it or how long I've had it...
VDP-visual descent point
MAP time minus H.A.T. / 10 = time back from threshold (or rather, MAP).
eg.
HAT = 358 / 10
= 35
time at '110' = 3:04
VDP = 3:04 - 35 = 2:29 for visual
Easier way to remember it is to just drop the last digit from the HAT and take that off the MAP time.
VDP-visual descent point
MAP time minus H.A.T. / 10 = time back from threshold (or rather, MAP).
eg.
HAT = 358 / 10
= 35
time at '110' = 3:04
VDP = 3:04 - 35 = 2:29 for visual
Easier way to remember it is to just drop the last digit from the HAT and take that off the MAP time.
I don't know if I'd do that flying into many places if I was planning 120 for the approach. The whole timing thing is fuzzy enough for accuracy without you not taking the time to split the difference between the 110/130 timings. It's a pretty easy piece of math and hanging your ass over the hills when you shoulda been outta there to save 2 seconds of planning just ain't worth it.91-120 kts. so use the 110 speed.
Anyway having a time to see isn't useless or a bad idea at all. Nice to have an idea where you can expect to be able to make the straight in still vs. circle. In practice I don't use a calculation - just keep it in mind on the approach if I'm expecting to be left high.
Let me share some wisdom from an old guy who has done more than his share of non precision approaches.
This "time to see....first came to my attention when I was checking out a new hire a few years ago . Apparently is was taught by a school on the west coast. Poor kid was so busy calculating everything he was having trouble aviating....
My advice is KISS. I have a hard time wondering why you would calculate time to see in real life. Never have, and it seems like one of those flight school mutation things. As to the time to go , it is not a bad idea to look on your chart. If your time does not fall exactly in, do some quick calculations so that when the cockpit sounds like it is going to come apart from rain., you are getting bounced around and near the ground, you are not thinking.ah....now what is the time I need.
but then I am from the school where for the most part we simply turned on runway heading over the beacon then went 1/2 the time on that heading (simple)., then double the error in the direction of the needle for the balance of the time......... then, if you didnt have runway envirorment,............... you had to go lower.
This "time to see....first came to my attention when I was checking out a new hire a few years ago . Apparently is was taught by a school on the west coast. Poor kid was so busy calculating everything he was having trouble aviating....
My advice is KISS. I have a hard time wondering why you would calculate time to see in real life. Never have, and it seems like one of those flight school mutation things. As to the time to go , it is not a bad idea to look on your chart. If your time does not fall exactly in, do some quick calculations so that when the cockpit sounds like it is going to come apart from rain., you are getting bounced around and near the ground, you are not thinking.ah....now what is the time I need.
but then I am from the school where for the most part we simply turned on runway heading over the beacon then went 1/2 the time on that heading (simple)., then double the error in the direction of the needle for the balance of the time......... then, if you didnt have runway envirorment,............... you had to go lower.
Last edited by trey kule on Tue Nov 20, 2007 1:43 pm, edited 1 time in total.
Accident speculation:
Those that post don’t know. Those that know don’t post
Those that post don’t know. Those that know don’t post
Low-timers do like to make things complex ....
If you are interested, a really simple way to figure out your VDP
is to knock a minute off your MAP time.
Most MDA's are 500 or 600 feet. Most pilots are going to want to
descend at 500 or 600 fpm. So, unless you're willing to accept
a near-vertical descent, you really would like to be visual one
minute before your MAP time, so that you have time to initiate
and complete a normal straight-in descent to landing from the
VDP.
The purpose of the VDP is so that you know that if you see
the runway threshold after the VDP, you cannot get there
from here, at least not without a parachute - you're just
marking time until the MAP point, at which time you want
to commence the missed approach procedure.
If you're comfortable with using beta in the air, well, just
ignore all the above
If you are interested, a really simple way to figure out your VDP
is to knock a minute off your MAP time.
Most MDA's are 500 or 600 feet. Most pilots are going to want to
descend at 500 or 600 fpm. So, unless you're willing to accept
a near-vertical descent, you really would like to be visual one
minute before your MAP time, so that you have time to initiate
and complete a normal straight-in descent to landing from the
VDP.
The purpose of the VDP is so that you know that if you see
the runway threshold after the VDP, you cannot get there
from here, at least not without a parachute - you're just
marking time until the MAP point, at which time you want
to commence the missed approach procedure.
If you're comfortable with using beta in the air, well, just
ignore all the above
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Big Pistons Forever
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How about get down to the MDA ASAP then drive on untill you see the runway. At that point ask yourself can I safely descend for a normal landing at a reasonable rate based on the visual clues I have, my experience, the current condition, and the type of aircraft I am flying.
If the answer is "HELL YES'', you are at or before the "time to see"
If the answer is anywhere between "This approach is a no hoper" to
"I think maybe I can....." then you have passed your "time to see" and should start the missed approach.
If the answer is "HELL YES'', you are at or before the "time to see"
If the answer is anywhere between "This approach is a no hoper" to
"I think maybe I can....." then you have passed your "time to see" and should start the missed approach.
