Minimums?

Opps, sent a blank message.

Someone may have already pointed this out, if so, sorry for the
duplication, Brian, if one is flying a precision instrument approach,
like an ILS, that has a glideslope, when one arrives at 'minimums' the
runway environement must be is sight if the landing is to be
continued. It would not be uncommon for ILS minimum altitude to be
200 feet above ground, so there aren't too many seconds left to decend
that last 200 feet. See the runway or fly the missed approach.


There are other kinds of approaches, called non precision approaches.
These take you you to the vicinity of the airport for circling
approaches, or near the approach end of the runway, but do not give
altitude information. What happens with these is the airplane passes
over a final approach fix, which is some form of radio derived point,
and then the approach documentation permits the airplane to decend to
a fixed altitude. At that point it will have reached minimiums, but
the pilot in general will depend on a clock and airspeed estimates to
tell when (s)he should be over the airport. (S)he does NOT have fly
the missed approach when the airplane reaches the minimum altitude
permitted by the approach, but when the estimated position is close to
the airport. Think of a small airport in a flat region near the coast.
If the approach is from the water siide it might be reasonable for the
airplane to go down to 500 feet two NM from the airport, then continue
flying toward it for another minute (if speed over the bottom is120
kts), before flying the miss.

Sorry if this is all redundant.


While watching a lot of landing videos and whatnot, I hear "minimums"
called out as an aircraft approaches its landing field.

From what I've been told, "minimums" indicates the decision as to
whether or not the field is in sight, correct?

so if minimums are not met, go around? Am I right in assuming this?

Airbus wrote in
:

In article
,
says...


Opps, sent a blank message.

Someone may have already pointed this out, if so, sorry for the
duplication, Brian, if one is flying a precision instrument approach,
like an ILS, that has a glideslope, when one arrives at 'minimums' the
runway environement must be is sight if the landing is to be
continued. It would not be uncommon for ILS minimum altitude to be
200 feet above ground, so there aren't too many seconds left to decend
that last 200 feet. See the runway or fly the missed approach.


There are other kinds of approaches, called non precision approaches.
These take you you to the vicinity of the airport for circling
approaches, or near the approach end of the runway, but do not give
altitude information. What happens with these is the airplane passes
over a final approach fix, which is some form of radio derived point,
and then the approach documentation permits the airplane to decend to
a fixed altitude. At that point it will have reached minimiums, but
the pilot in general will depend on a clock and airspeed estimates to
tell when (s)he should be over the airport. (S)he does NOT have fly
the missed approach when the airplane reaches the minimum altitude
permitted by the approach, but when the estimated position is close to
the airport. Think of a small airport in a flat region near the coast.
If the approach is from the water siide it might be reasonable for the
airplane to go down to 500 feet two NM from the airport, then continue
flying toward it for another minute (if speed over the bottom is120
kts), before flying the miss.

Sorry if this is all redundant.


Not necessarily redundant, but somewhat incorrect.
No obligation that the MDA and the MAP be close to each other, as you
suggest. Some pilots do try to descend progressively to arrive at the
MDA at or near the MAP, but others "dive and drive" losing altitude
first, then driving forward to the MAP. At the MAP, if one of the
visual items on the list is not in continuous view, (s)he MUST
initiate the missed approach. The missed approach may be initiated in
advance by climbing straight ahead, but no turns may be initiated
until reaching the MAP.




Yes, but not everywhere. The Brits regard MDA as a decision altitude.
They also don't allow a dive and drive type approach.

Bertie

I think you my have been just a little misleading. We surely agree
the missed approach may not be flown until at the MAP, but of course
the pilot is under no obligation to descend to the minimum allowable
altitude. The slightly misleading point is a miss may not include an
initial turn. Should the pilot choose to abort the landing early (s)he
can climb. I am not sure, but would expect the pilot owns the airspace
up to the altitiude of his/her final approach fix until the missed
approach point is reached (unless cleared higher, of course), and then
owns the altitudes published on the approach plate for the miss.

Finally, and it might be interest to the intial poster, good pilots
who are flying an instrument approach
are thinking about flying the miss -- initial heading, gear up, adjust
flaps, climb to altitude, all of that-- rather than landing the
airplane. Finding the runway, which happens nearly all of the time, is
treated as a happy accident. The alternative, thinking about the
landing and not the miss, could leave someone low and slow in clouds
trying to figure out what to do next. That can lead to unhappy
accidents.

Please feel free to correct errors or other misleading statements I've
made.


turnOn Jan 11, 11:07*pm, Airbus wrote:
In article
,
says...







Opps, sent a blank message.

Someone may have already pointed this out, if so, sorry for the
duplication, Brian, if one is flying a precision instrument approach,
like an ILS, that has a glideslope, when one arrives at 'minimums' the
runway environement must be is sight if the landing is to be
continued. It would not be uncommon for ILS minimum altitude *to be
200 feet above ground, so there aren't too many seconds left to decend
that last 200 feet. See the runway or fly the missed approach.

There are other kinds of approaches, called non precision *approaches.
These take you you to the vicinity of the airport for circling
approaches, or near the approach end of the runway, but do not give
altitude information. What happens with these is the airplane passes
over a final approach fix, which is some form of radio derived point,
and then the approach documentation permits the airplane to decend to
a fixed altitude. At that point it will have reached minimiums, but
the pilot in general will depend on a clock and airspeed estimates to
tell when (s)he should be over the airport. (S)he does NOT have fly
the missed approach when the airplane reaches the minimum altitude
permitted by the approach, but when the estimated position is close to
the airport. Think of a small airport in a flat region near the coast.
If the approach is from the water siide it might be reasonable for the
airplane to go down to 500 feet two NM from the airport, then continue
flying toward it for another minute (if speed over the bottom is120
kts), before flying the miss.

Sorry if this is all redundant.

Not necessarily redundant, but somewhat incorrect.
No obligation that the MDA and the MAP be close to each other, as you
suggest. Some pilots do try to descend progressively to arrive at the MDA
at or near the MAP, but others "dive and drive" losing altitude first,
then driving forward to the MAP. At the MAP, if one of the visual items
on the list is not in continuous view, (s)he MUST initiate the missed
approach. The missed approach may be initiated in advance by climbing
straight ahead, but no turns may be initiated until reaching the MAP.- Hide quoted text -

- Show quoted text -

On Jan 11, 9:12*pm, Airbus wrote:

so if minimums are not met, go around? Am I right in assuming this?

For part 91 ops, you only need to have the required inflight
visibility.

Hmmm - I'm wondering if maybe that didn't come out they way you meant it.
The only thing special about Part 91 is that you can initiate the
approach without being sure of having minimum requirements at the end of
it. But when you do get down to DA or DH, you need more than in-flight
visibility - you must continuously see one of the items on that list and
be in a position to land normally - otherwise you go missed.- Hide quoted text -

Hmmmm- Thats exactly the way I meant it. There are plenty of
differences between 91 and 121 and in the context of the original
post, this is what I was trying to point out.
Frank

It's interesting that you find most pilots expect to land. The guy I
fly with (aka husband) briefs himself and me on the miss before
reaching the final approach fix every time -- it's part of his
checklist, I think just before extending the gear at the outer marker.
Lots of redundancy on that check list, too -- how many times can you
extend the gear on an approach anyway? (yeah, yeah, I know.)




On Jan 12, 1:15*am, Airbus wrote:
In article ,
says...







I think you my have been just a little misleading. We surely agree
the *missed approach may not be flown until at the MAP, but of course
the pilot is under no obligation to descend to the minimum allowable
altitude. The slightly misleading point is a miss may not include an
initial turn. Should the pilot choose to abort the landing early (s)he
can climb. I am not sure, but would expect the pilot owns the airspace
up to the altitiude of his/her final approach fix until the missed
approach point is reached (unless cleared higher, of course), and then
owns the altitudes published on the approach plate for the miss.

Finally, and it might be interest to the intial poster, good pilots
who are flying an instrument approach
are thinking about flying the miss -- initial heading, gear up, adjust
flaps, climb to altitude, all of that-- rather than landing the
airplane. Finding the runway, which happens nearly all of the time, is
treated as a happy accident. The alternative, thinking about the
landing and not the miss, could leave someone low and slow in clouds
trying to figure out what to do next. That can lead to unhappy
accidents.

That's an excellent point - oft taught, oft forgot! It just goes against our
nature. All pilots I know - good or otherwise - are expecting to land. The
controllers are expecting it too. But at least - even if you're expecting to
land, at least prepare for the missed - know it, brief it, set up frequencies
for it *- *otherwise going missed can coincide with going missing (sometimes
for years!!)- Hide quoted text -

- Show quoted text -

On Fri, 11 Jan 2008 15:03:39 -0800 (PST), Tina
wrote:

It's interesting that you find most pilots expect to land. The guy I
fly with (aka husband) briefs himself and me on the miss before
reaching the final approach fix every time

So do we, but we still expect to land.

If it's obvious that I'm not landing, I'm already off to the
alternate.

We make a weather induced miss about every 400 hours flying in the
north east and south east, most often on non precision approaches at
uncontrolled airports. These are mostly business related flights
scheduled some time in advance (about 10% of those planned flights are
cancelled because of weather and at least a third include IMC). I
can't remember the last time it happened on an ILS. Your statement
makes it sound like a more common occurance for you. What is your
experience?


On Jan 11, 6:05*pm, B A R R Y wrote:
On Fri, 11 Jan 2008 15:03:39 -0800 (PST), Tina
wrote:

It's interesting that you find most pilots expect to land. The guy I
fly with (aka husband) briefs himself and me on the miss before
reaching the final approach fix every time

So do we, but we still expect to land.

If it's obvious that I'm not landing, I'm already off to the
alternate.

A weather induced miss every 400 hours is a very low fraction. It
usually means the weather forecast for an uncontrolled airport was
better than actual. On a non precision approach, unless there were
strong hints -- peeks of the of ground during the day or lights at
night near the MAP, or (can I say this?) an approach not flown well,
not to his personal minimums, husband goes elsewhere. He may have
flown a second approach once in the past 4 years (he logs about 200
hours of complex sel (a Mooney) a year.

He had to search his memory to remember that level of detail --
remember, the airplane doesn't leave on about 10% of his planned
trips, so he avoids weather induced misses because if it looks like
it'll be below minimums he doesn't take off, or while on the way if
the controlled airport is reporting conditions worse than minimums he
won't take a peek even if as a part 91 operation he could.

I don't think he's doing anything a prudent pilot wouldn't do. Well,
IMC at night might be pushing that, I guess. He does say -- and this
might be something many do not agree with -- workload with a single
pilot just is not a big deal, especially if IFR. He says that, but if
I'm in the right seat the only thing he wants to hear me say when he's
flying an approach in IMC is "You are visual".



On Jan 12, 5:02 am, Airbus wrote:
In article
,
says...



We make a weather induced miss about every 400 hours flying in the
north east and south east, most often on non precision approaches at
uncontrolled airports.

That's a very intriguing number.
At first glance, it looks like a high percentage. But normalized to the
type of equipment, mission and approach you are typically flying it may
not be. From accident reports, we all know that missed approaches are in
the high-alert category for risk, however this again probably deserves to
be normalized against they type of operation - go-arounds being possibly
more common and better integrated in corporate 91 and 135 flights than in
part 121 ops.

The experience level you describe indicates you may have quite a few
missed approaches in your log. For many of us, it's a fairly rare
occurrence. Out of curiosity, what do you do, typically, in these cases?
Do you go around to try again? Once? Twice? Try a different approach with
lower minima? Go elsewhere? How do you handle the missed?

Tina wrote in
:

I think you my have been just a little misleading. We surely agree
the missed approach may not be flown until at the MAP, but of course
the pilot is under no obligation to descend to the minimum allowable
altitude. The slightly misleading point is a miss may not include an
initial turn. Should the pilot choose to abort the landing early (s)he
can climb. I am not sure, but would expect the pilot owns the airspace
up to the altitiude of his/her final approach fix until the missed
approach point is reached (unless cleared higher, of course), and then
owns the altitudes published on the approach plate for the miss.

Finally, and it might be interest to the intial poster, good pilots
who are flying an instrument approach
are thinking about flying the miss -- initial heading, gear up, adjust
flaps, climb to altitude, all of that-- rather than landing the
airplane. Finding the runway, which happens nearly all of the time, is
treated as a happy accident. The alternative, thinking about the
landing and not the miss, could leave someone low and slow in clouds
trying to figure out what to do next. That can lead to unhappy
accidents.

Please feel free to correct errors or other misleading statements I've
made.


Nope, very good and absolutlely correct, especially the part about
preparing for the go-around.

Bertie

In article
,
says...


Opps, sent a blank message.

Someone may have already pointed this out, if so, sorry for the
duplication, Brian, if one is flying a precision instrument approach,
like an ILS, that has a glideslope, when one arrives at 'minimums' the
runway environement must be is sight if the landing is to be
continued. It would not be uncommon for ILS minimum altitude to be
200 feet above ground, so there aren't too many seconds left to decend
that last 200 feet. See the runway or fly the missed approach.


There are other kinds of approaches, called non precision approaches.
These take you you to the vicinity of the airport for circling
approaches, or near the approach end of the runway, but do not give
altitude information. What happens with these is the airplane passes
over a final approach fix, which is some form of radio derived point,
and then the approach documentation permits the airplane to decend to
a fixed altitude. At that point it will have reached minimiums, but
the pilot in general will depend on a clock and airspeed estimates to
tell when (s)he should be over the airport. (S)he does NOT have fly
the missed approach when the airplane reaches the minimum altitude
permitted by the approach, but when the estimated position is close to
the airport. Think of a small airport in a flat region near the coast.
If the approach is from the water siide it might be reasonable for the
airplane to go down to 500 feet two NM from the airport, then continue
flying toward it for another minute (if speed over the bottom is120
kts), before flying the miss.

Sorry if this is all redundant.


Not necessarily redundant, but somewhat incorrect.
No obligation that the MDA and the MAP be close to each other, as you
suggest. Some pilots do try to descend progressively to arrive at the MDA
at or near the MAP, but others "dive and drive" losing altitude first,
then driving forward to the MAP. At the MAP, if one of the visual items
on the list is not in continuous view, (s)he MUST initiate the missed
approach. The missed approach may be initiated in advance by climbing
straight ahead, but no turns may be initiated until reaching the MAP.