Winds on approach

[kevmor]

I flew yesterday and did some practice approaches, and the winds were
about 20 knots gusting to 26-28. I've flown almost all approaches so
far in a different 172 that had a 180hp conversion. Because of the
winds, I kept almost full cruising power on the descents to try and
maintain my normal 90 kts ground speed for timing and roughly 500fpm
for the ILS.

This plane did have an IFR GPS indicating ground speed, but the one
I've been using for all other approaches didn't, neither DME. The CFI
informed me I should have used known power settings. What are your
thoughts? I'm not sure how I would've known the right power setting,
unless I used what I normally do, and accept the lower ground speed,
then adjust my descent for the ILS to a much lower fpm descent?

[Mark Hansen]

On 03/29/07 12:59, kevmor wrote:
> I flew yesterday and did some practice approaches, and the winds were
> about 20 knots gusting to 26-28. I've flown almost all approaches so
> far in a different 172 that had a 180hp conversion. Because of the
> winds, I kept almost full cruising power on the descents to try and
> maintain my normal 90 kts ground speed for timing and roughly 500fpm
> for the ILS.
>
> This plane did have an IFR GPS indicating ground speed, but the one
> I've been using for all other approaches didn't, neither DME. The CFI
> informed me I should have used known power settings. What are your
> thoughts? I'm not sure how I would've known the right power setting,
> unless I used what I normally do, and accept the lower ground speed,
> then adjust my descent for the ILS to a much lower fpm descent?
>


I was taught that you should use the proper power settings during the
approach. I would not change these due to my expectation of ground
speed. However, with a higher than standard ground speed, you will
have to adjust your descent rate to maintain the proper glide path.

Here's a question for you to think about. If you have a tail wind which
results in a ground speed of 95 knots, do you need to use the category 'B'
approach minimums?


--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

[Brad[_1_]]

On Mar 29, 3:59 pm, "kevmor" > wrote:
> I flew yesterday and did some practice approaches, and the winds were
> about 20 knots gusting to 26-28. I've flown almost all approaches so
> far in a different 172 that had a 180hp conversion. Because of the
> winds, I kept almost full cruising power on the descents to try and
> maintain my normal 90 kts ground speed for timing and roughly 500fpm
> for the ILS.

Why does ground speed matter? Why does the 500fpm matter?

> This plane did have an IFR GPS indicating ground speed, but the one
> I've been using for all other approaches didn't, neither DME. The CFI
> informed me I should have used known power settings.

I agree.

> What are your
> thoughts? I'm not sure how I would've known the right power setting,
> unless I used what I normally do, and accept the lower ground speed,
> then adjust my descent for the ILS to a much lower fpm descent?

What's wrong with a much lower descent rate? All that matters is that
you keep your needles centered. Did you have faster traffic behind
you and you increased speed as a courtesy? I presume you wanted to
maintain 90 kts so that you could time the approach, but aside from it
being an ILS where it doesn't matter, your GPS could tell you where to
go missed if your glide slope goes TU.

[Tim]

It's probably a good idea to know the power settings for some high speed
descent/approach. Like if you are asked to do maximum speed on approach
or something like that. As long as you can handle it and can get the
time right then no problem.

kevmor wrote:
> I flew yesterday and did some practice approaches, and the winds were
> about 20 knots gusting to 26-28. I've flown almost all approaches so
> far in a different 172 that had a 180hp conversion. Because of the
> winds, I kept almost full cruising power on the descents to try and
> maintain my normal 90 kts ground speed for timing and roughly 500fpm
> for the ILS.
>
> This plane did have an IFR GPS indicating ground speed, but the one
> I've been using for all other approaches didn't, neither DME. The CFI
> informed me I should have used known power settings. What are your
> thoughts? I'm not sure how I would've known the right power setting,
> unless I used what I normally do, and accept the lower ground speed,
> then adjust my descent for the ILS to a much lower fpm descent?
>

[Jose]

> What are your
> thoughts? I'm not sure how I would've known the right power setting,
> unless I used what I normally do, and accept the lower ground speed,
> then adjust my descent for the ILS to a much lower fpm descent?

Exactly. Airspeed is what's crucial for aircraft control. Ground speed
is just used for timing. Adjust the timing. If it's gusty, you might
want a slightly higher airspeed, just like for VFR landings in gusty winds.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[Bob Gardner]

You are timing your ILS approaches? Any reason for this? I can't find
anything in my 172P book that suggests 90 kts as an approach speed, even in
gusty winds. Seems fast to me.

Bob Gardner

"kevmor" > wrote in message
ups.com...
>I flew yesterday and did some practice approaches, and the winds were
> about 20 knots gusting to 26-28. I've flown almost all approaches so
> far in a different 172 that had a 180hp conversion. Because of the
> winds, I kept almost full cruising power on the descents to try and
> maintain my normal 90 kts ground speed for timing and roughly 500fpm
> for the ILS.
>
> This plane did have an IFR GPS indicating ground speed, but the one
> I've been using for all other approaches didn't, neither DME. The CFI
> informed me I should have used known power settings. What are your
> thoughts? I'm not sure how I would've known the right power setting,
> unless I used what I normally do, and accept the lower ground speed,
> then adjust my descent for the ILS to a much lower fpm descent?
>

[Jose]

> You are timing your ILS approaches? Any reason for this? I can't find
> anything in my 172P book that suggests 90 kts as an approach speed, even in
> gusty winds. Seems fast to me.

IF one times their ILS, and loses the glideslope, one can often convert
to a localizer approach easily. And approach plates give canned timings
for various speeds, 90 knots is probably the best of the bunch for a
172. Of course that's ground speed, not airspeed.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[Mark Hansen]

On 03/29/07 14:34, Bob Gardner wrote:
> You are timing your ILS approaches? Any reason for this? I can't find
> anything in my 172P book that suggests 90 kts as an approach speed, even in
> gusty winds. Seems fast to me.

Well ... 90 knots was the speed I was taught to use when flying precision
and non-precision approaches (in the C-172 airplane in which I trained).

>
> Bob Gardner
>
> "kevmor" > wrote in message
> ups.com...
>>I flew yesterday and did some practice approaches, and the winds were
>> about 20 knots gusting to 26-28. I've flown almost all approaches so
>> far in a different 172 that had a 180hp conversion. Because of the
>> winds, I kept almost full cruising power on the descents to try and
>> maintain my normal 90 kts ground speed for timing and roughly 500fpm
>> for the ILS.
>>
>> This plane did have an IFR GPS indicating ground speed, but the one
>> I've been using for all other approaches didn't, neither DME. The CFI
>> informed me I should have used known power settings. What are your
>> thoughts? I'm not sure how I would've known the right power setting,
>> unless I used what I normally do, and accept the lower ground speed,
>> then adjust my descent for the ILS to a much lower fpm descent?
>>
>
>



--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

[Bob Gardner]

Conventional wisdom (as I see it) is to execute a miss if you lose the
glideslope, go around, prepare and brief the localizer approach, then do
it. Changing horses in midstream is not wise policy, especially in the
clouds and close to the ground. YMMV, but I'll never teach or advocate the
switch.

Bob Gardner


"Jose" > wrote in message
...
>> You are timing your ILS approaches? Any reason for this? I can't find
>> anything in my 172P book that suggests 90 kts as an approach speed, even
>> in gusty winds. Seems fast to me.
>
> IF one times their ILS, and loses the glideslope, one can often convert to
> a localizer approach easily. And approach plates give canned timings for
> various speeds, 90 knots is probably the best of the bunch for a 172. Of
> course that's ground speed, not airspeed.
>
> Jose
> --
> Get high on gasoline: fly an airplane.
> for Email, make the obvious change in the address.

[kevmor]

I think I should clarify a couple things from the original post, it
was a headwind on the approach, and I also did a VOR, LOC, and GPS.

If I used the normal power settings, then on the ILS I could just
reduce my descent rate. After reading what you guys said, this should
be fine unless I'm told to fly it faster. But either way, on the ILS
if the needles are centered, you're good.

On the others though, if I kept power at the normal settings with the
headwind, I would've descended to the MDA further out... to me this
seems like an added risk... For timing these, if I didn't have an IFR
GPS or DME (they're new to me), how should I figure the ground speed
for timing?

On Mar 29, 1:16 pm, Mark Hansen > wrote:
> I was taught that you should use the proper power settings during the
> approach. I would not change these due to my expectation of ground
> speed. However, with a higher than standard ground speed, you will
> have to adjust your descent rate to maintain the proper glide path.
>
> Here's a question for you to think about. If you have a tail wind which
> results in a ground speed of 95 knots, do you need to use the category 'B'
> approach minimums?

[Jose]

> Conventional wisdom (as I see it) is to execute a miss if you lose the
> glideslope, go around, prepare and brief the localizer approach, then do
> it.

That might be smart for some approaches, but if the only change between
an ILS and a localizer is the minima and the timing, being in the habit
of timing the ILS will save your bacon if you are low on fuel, racing a
storm, or otherwise in a tight spot when the GS goes TU.

IT also keeps you in the habit of timing other approaches, especially if
you don't fly many.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[Jose]

> On the others though, if I kept power at the normal settings with the
> headwind, I would've descended to the MDA further out... to me this
> seems like an added risk... For timing these, if I didn't have an IFR
> GPS or DME (they're new to me), how should I figure the ground speed
> for timing?

As long as you are above the minima, and past any stepdown fixes, you're
ok. (This is one reason localizer minima are higher.) And being down
early gives you a better chance to break out to visual, and maybe fly
around the one cloud that would otherwise be in the way.

To figure ground speed, subtract the headwind from the airspeed. It
will be close enough.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[Bob Moore]

Bob Gardner wrote

> Conventional wisdom (as I see it) is to execute a miss if you lose the
> glideslope, go around, prepare and brief the localizer approach, then
> do it. Changing horses in midstream is not wise policy, especially in
> the clouds and close to the ground. YMMV, but I'll never teach or
> advocate the switch.

Nor do Part 121 Aircarriers permit their aircrews to change-over.

Bob Moore

[Tim]

One should always time the approach. In some senses it is easier. if
the GS goes bad, just go to the minimum altitude - one less needle to
keep track of.

Always time it. The wx could go worse or low on fuel - why abandon the
approach if you have it set up already?

What you advocate makes no sense to me. What is the rationale?

Bob Gardner wrote:
> Conventional wisdom (as I see it) is to execute a miss if you lose the
> glideslope, go around, prepare and brief the localizer approach, then do
> it. Changing horses in midstream is not wise policy, especially in the
> clouds and close to the ground. YMMV, but I'll never teach or advocate the
> switch.
>
> Bob Gardner
>
>
> "Jose" > wrote in message
> ...
>
>>>You are timing your ILS approaches? Any reason for this? I can't find
>>>anything in my 172P book that suggests 90 kts as an approach speed, even
>>>in gusty winds. Seems fast to me.
>>
>>IF one times their ILS, and loses the glideslope, one can often convert to
>>a localizer approach easily. And approach plates give canned timings for
>>various speeds, 90 knots is probably the best of the bunch for a 172. Of
>>course that's ground speed, not airspeed.
>>
>>Jose
>>--
>>Get high on gasoline: fly an airplane.
>>for Email, make the obvious change in the address.
>
>
>

[Tim]

Is that FAA or air carrier rule?

That does not mean it is a bad thing.
It seems to me that abandoning an approach with the risk of fuel and
worse weather is worse.

Bob Moore wrote:
> Bob Gardner wrote
>
>
>>Conventional wisdom (as I see it) is to execute a miss if you lose the
>>glideslope, go around, prepare and brief the localizer approach, then
>>do it. Changing horses in midstream is not wise policy, especially in
>>the clouds and close to the ground. YMMV, but I'll never teach or
>>advocate the switch.
>
>
> Nor do Part 121 Aircarriers permit their aircrews to change-over.
>
> Bob Moore

[Mortimer Schnerd, RN[_2_]]

Bob Gardner wrote:
> You are timing your ILS approaches? Any reason for this? I can't find
> anything in my 172P book that suggests 90 kts as an approach speed, even in
> gusty winds. Seems fast to me.


You're thinking in terms of landing; he's thinking of getting along with a
controller and then landing. When I was a student on my long solo cross
country, I dragged into RDU after a loooong final at 60 knots in VFR conditions.
For some reason, I seemed to have trouble getting permission to leave after I
got my logbook signed. Suddenly they had trouble hearing me.

Years later as a courier pilot, I regularly flew ILSs into that same airport at
120-140 knots... well above what the Lance called for, but it sure made for
happy controllers. With 2 miles of runway in front, I still managed to get the
beast slowed down in time after I broke out. Never had problems with the
controllers hearing me when I called either....



--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

[Paul kgyy]

Consistency is valuable when you're still getting the hang of IFR
approaches. However, once past the initial phase, you need to
practice approaches at different speeds because eventually you will
need to move the airplane along with traffic behind you. Also, I find
that in windy conditions, a faster approach is easier to control so
often add an inch of MP to my customary power setting.

[Dave S]

Tim wrote:

>
> What you advocate makes no sense to me. What is the rationale?
>
>

Preventing accidents from shifting gears in a high stress, relatively
risky portion of the flight.

If you are flying an ILS, you should brief the ILS and fly what you
brief. Your choices should be one of two: Land or go missed. Trying to
make the most of a bad situation usually results in a worse situation.


If its a bad idea for a professional, 2 person ATP rated or eligible
crew, flying into places they are used to going on a daily basis, why is
it a good idea for a single pilot op?

As for bad weather getting worse, with diminishing fuel reserves.. does
anybody remember something about enough fuel to make your destination,
plus filed alternate, plus 45 more minutes. I dont think it was a
suggestion. And something about weather minimums at alternates?

If you are getting in this kind of a pinch, might want a refresher on
flight planning and rule requirements.

Dave

[Jose]

> As for bad weather getting worse, with diminishing fuel reserves.. does anybody remember something about enough fuel to make your destination, plus filed alternate, plus 45 more minutes. I dont think it was a suggestion. And something about weather minimums at alternates?
>
> If you are getting in this kind of a pinch, might want a refresher on flight planning and rule requirements.

and the ability to control the weather while in flight.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[M[_1_]]

You should fly your normal approach *indicated airspeed*, not ground
speed.

This is particularly important if it's windy and bumpy. If you fly
that approach at cruise power to keep the groundspeed at 90 knots
you're likely above your Va, which can overstress the airframe.

On Mar 29, 12:59 pm, "kevmor" > wrote:
> I flew yesterday and did some practice approaches, and the winds were
> about 20 knots gusting to 26-28. I've flown almost all approaches so
> far in a different 172 that had a 180hp conversion. Because of the
> winds, I kept almost full cruising power on the descents to try and
> maintain my normal 90 kts ground speed for timing and roughly 500fpm
> for the ILS.
>
> This plane did have an IFR GPS indicating ground speed, but the one
> I've been using for all other approaches didn't, neither DME. The CFI
> informed me I should have used known power settings. What are your
> thoughts? I'm not sure how I would've known the right power setting,
> unless I used what I normally do, and accept the lower ground speed,
> then adjust my descent for the ILS to a much lower fpm descent?

[Tim]

Dave S wrote:
> Tim wrote:
>
>>
>> What you advocate makes no sense to me. What is the rationale?
>>
>>
>
> Preventing accidents from shifting gears in a high stress, relatively
> risky portion of the flight.
>
> If you are flying an ILS, you should brief the ILS and fly what you
> brief. Your choices should be one of two: Land or go missed. Trying to
> make the most of a bad situation usually results in a worse situation.
>
>
> If its a bad idea for a professional, 2 person ATP rated or eligible
> crew, flying into places they are used to going on a daily basis, why is
> it a good idea for a single pilot op?
>
> As for bad weather getting worse, with diminishing fuel reserves.. does
> anybody remember something about enough fuel to make your destination,
> plus filed alternate, plus 45 more minutes. I dont think it was a
> suggestion. And something about weather minimums at alternates?
>
> If you are getting in this kind of a pinch, might want a refresher on
> flight planning and rule requirements.
>
> Dave


Actually, if you are in the kind of pinch where you can;t start a timer
at the appropriate time and transition to a localizer approach from an
ILS you might want a refresher. Obviously we have different views on
this. I do not see a transition from a GS to Localizer as risky. There
is only one difference - that is how one gets to the DH/MDA. - either
on a GS or descending at some rate after a certain point. I can;t agree
that that is risky.

[Tim]

Dave S wrote:

>
<SNIP>
> As for bad weather getting worse, with diminishing fuel reserves.. does
> anybody remember something about enough fuel to make your destination,
> plus filed alternate, plus 45 more minutes. I dont think it was a
> suggestion. And something about weather minimums at alternates?
>

So what if you are already at your alternate with low fuel and this
happens? Or what if winds are not as forecast, or what if you had to
hold at/before the primary airport? Perhaps there was a fuel problem in
flight? If the GS goes out and you haven't seen the runway already -
what makes you think going for a second try will make the approach
better? This is a sure way of wasting fuel so that I get into a risky
situation. Again, if you can't handle it then fine, but don;t tell
others it is risky and please don't suggest I need refresher on
regulations or flight planning.


> If you are getting in this kind of a pinch, might want a refresher on
> flight planning and rule requirements.
>
> Dave

[Bob Noel]

In article et>,
Dave S > wrote:

> > What you advocate makes no sense to me. What is the rationale?
>
> Preventing accidents from shifting gears in a high stress, relatively
> risky portion of the flight.

How many accidents have been caused by transitioning from an ILS
to a LOC?

>
> If you are flying an ILS, you should brief the ILS and fly what you
> brief. Your choices should be one of two: Land or go missed. Trying to
> make the most of a bad situation usually results in a worse situation.

Train as you fly, fly as you train. If you've always trained this way, and
you include the one extra step (if above MDA, then fly continue to MDA)
you are still in the Land or Go Missed mode.

Also, if the weather is above LOC minimums, then this isn't a particularly
high stress approach.

>
> If its a bad idea for a professional, 2 person ATP rated or eligible
> crew, flying into places they are used to going on a daily basis, why is
> it a good idea for a single pilot op?

The small aircraft generally flies slower than an airliner. The pilot has
a lot more time to react and think on the 90 knot approach than the
160 knot approach.

--
Bob Noel
(gave up looking for a particular sig the lawyer will hate)

[Ron Natalie]

Jose wrote:

> As long as you are above the minima, and past any stepdown fixes, you're
> ok. (This is one reason localizer minima are higher.) And being down
> early gives you a better chance to break out to visual, and maybe fly
> around the one cloud that would otherwise be in the way.
>
I agree. Don't change the power settings. The descent on a
non-precision approach for step downs is fairly rapid in all
circumstances. A headwind is usually less of a problem.
A tailwind may mean that you don't get to the MDA or stepdown
altitude in time.

The bigger is adjusting your times for things like the
distance from passing a fix before starting the PT and
the times flown in the PT's. With a tail wind you
can end up doing the PT uncomfortably close in if you
don't extend the time. Then add to that you are
being pushed down the final course rapidly, things
might happen too fast.

Admittedly the moving map is a big crutch not just
because it gives you the distances but it also gives
you the ground speed read out which lets you pick
the times more easily.

[David Cartwright]

"kevmor" > wrote in message
ups.com...
> I'm not sure how I would've known the right power setting,
> unless I used what I normally do, and accept the lower ground speed,
> then adjust my descent for the ILS to a much lower fpm descent?

That's what I'd do. The key is that you're doing the things you do in the
right places, not at any specific speed. So as long as the places and
altitudes that you turn and/or descend correspond to what it says on the
approach plate, that's just peachy - it'll stop you banging into mountains
and whatnot. Yes, you'll end up with a lower rate of descent in order to
keep the glideslope needle centred, but that's perfectly normal.
Additionally, the POH says that you should approach at such-and-such a
speed, so do so - the wing doesn't care how fast the sky is moving over the
ground, only how fast it's moving over the aerofoil.

If you want to keep the power up for a bit longer than normal just so you
don't grow old waiting for the glideslope to come down to meet you, then
that's up to you. But by the time you're established on your approach, you
ought to be at your proper approach airspeed - once established it's a
non-trivial task to adjust your speed markedly, then fix the rate of descent
to compensate for all that thrust you just took off, all the while ensuring
you're still on the glideslope.

Assuming you're into a headwind, the groundspeed is largely irrelevant -
except that you'll wear the tyres out a little bit less than usual, and
you'll have further to taxi once you've landed, as the landing roll will be
shorter than usual.

D.

[David Cartwright]

"paul kgyy" > wrote in message
ps.com...
> Consistency is valuable when you're still getting the hang of IFR
> approaches. However, once past the initial phase, you need to
> practice approaches at different speeds because eventually you will
> need to move the airplane along with traffic behind you. Also, I find
> that in windy conditions, a faster approach is easier to control so
> often add an inch of MP to my customary power setting.

When it's gusty, yes - you'd always add a squirt of power above the normal
approach speed just to cater for Sod's law which states that you'll get a
lull half a second before you flare, and the concrete will happen rather
more noticeably than you hoped.

I'd attach a caveat concerning the aircraft behind you, though. Yes, it's
good to be nice to him/her if it's convenient and safe to do so, but
remember that (a) you're primarily responsibility for the safety of your
aircraft, not the convenience of his/hers; and (b) the manufacturer of your
aircraft wrote the POH, not the ATC guy or the bloke behind you :-)

D.

[John R. Copeland]

"M" > wrote in message oups.com...
>
>
> This is particularly important if it's windy and bumpy. If you fly
> that approach at cruise power to keep the groundspeed at 90 knots
> you're likely above your Va, which can overstress the airframe.
>
A touch of hyperbole, maybe?
Va is the G-safe speed for *abrupt full deflection* of any control.
Most of my ILS approaches thankfully don't require that. :-)

[Bob Gardner]

Let's see, Tim...you do carry IFR reserves, right? So you should have enough
for the approach plus what it takes to get to an alternate plus 45 minutes?
Where does the risk of fuel come in?

Bob Gardner

"Tim" > wrote in message
...
> Is that FAA or air carrier rule?
>
> That does not mean it is a bad thing.
> It seems to me that abandoning an approach with the risk of fuel and worse
> weather is worse.
>
> Bob Moore wrote:
>> Bob Gardner wrote
>>
>>
>>>Conventional wisdom (as I see it) is to execute a miss if you lose the
>>>glideslope, go around, prepare and brief the localizer approach, then
>>>do it. Changing horses in midstream is not wise policy, especially in
>>>the clouds and close to the ground. YMMV, but I'll never teach or
>>>advocate the switch.
>>
>>
>> Nor do Part 121 Aircarriers permit their aircrews to change-over.
>>
>> Bob Moore

[Mark Hansen]

On 03/30/07 09:31, Bob Gardner wrote:
> Let's see, Tim...you do carry IFR reserves, right? So you should have enough
> for the approach plus what it takes to get to an alternate plus 45 minutes?
> Where does the risk of fuel come in?

To imagine that low fuel will never be a consideration is simply ridiculous.
How about when you get to your alternate, and can't get in due to weather,
and you're forced to go to another airport? How about unexpected holding?
How about a fuel leak (as someone else pointed out)?

Are you really saying that a pilot need not consider the possibility?
That would be very bad advice, in my opinion.

>
> Bob Gardner
>

--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

[Tim]

Bob Gardner wrote:
> Let's see, Tim...you do carry IFR reserves, right? So you should have enough
> for the approach plus what it takes to get to an alternate plus 45 minutes?
> Where does the risk of fuel come in?
>
> Bob Gardner
>

Well, Bob, let's see here. Maybe I can come up with a possible scenario
for low fuel situation...

Winds not as forecast
holds and delays
I already went missed once and now at my alternate
I am sure you can think of others, but those are quite likely -
especially in conditions where instrument approach procedures are
necessary.

Now, are you still going to claim that the only time low fuel is an
issue is when the pilot did not plan correctly? That is absurd.

My point was that going missed, getting another approach clearance,
eating into the reserves is a bad idea when you are already established
on the approach.

tim

> "Tim" > wrote in message
> ...
>
>>Is that FAA or air carrier rule?
>>
>>That does not mean it is a bad thing.
>>It seems to me that abandoning an approach with the risk of fuel and worse
>>weather is worse.
>>
>>Bob Moore wrote:
>>
>>>Bob Gardner wrote
>>>
>>>
>>>
>>>>Conventional wisdom (as I see it) is to execute a miss if you lose the
>>>>glideslope, go around, prepare and brief the localizer approach, then
>>>>do it. Changing horses in midstream is not wise policy, especially in
>>>>the clouds and close to the ground. YMMV, but I'll never teach or
>>>>advocate the switch.
>>>
>>>
>>>Nor do Part 121 Aircarriers permit their aircrews to change-over.
>>>
>>>Bob Moore
>
>
>

[Bob Gardner]

Well, Mark and Tim, if I had been keeping up with weather conditions at the
destination while enroute, which is a common-sense precaution, and learned
that the weather was really going downhill, I would have landed short or
turned around and gone home. I have done this on Part 135 trips,
discomfiting but not killing my passengers. There is nothing so urgent that
you have to do what you had planned to do.

When I chose my alternate, I had to meet the 1-2-3 rule. If the wx at the
alternate has gone to hell in a handbasket, I have done a lousy job of
planning. The best alternate has good and improving VFR weather.

I've never had a fuel leak to deal with, but I would hope that sinking fuel
gauges would have caught my eye before I was on the approach. No platitudes
about fuel gauges, please.

Unexpected holding? The word is "unable due to low fuel state."

Bob Gardner

"Mark Hansen" > wrote in message
...
> On 03/30/07 09:31, Bob Gardner wrote:
>> Let's see, Tim...you do carry IFR reserves, right? So you should have
>> enough
>> for the approach plus what it takes to get to an alternate plus 45
>> minutes?
>> Where does the risk of fuel come in?
>
> To imagine that low fuel will never be a consideration is simply
> ridiculous.
> How about when you get to your alternate, and can't get in due to weather,
> and you're forced to go to another airport? How about unexpected holding?
> How about a fuel leak (as someone else pointed out)?
>
> Are you really saying that a pilot need not consider the possibility?
> That would be very bad advice, in my opinion.
>
>>
>> Bob Gardner
>>
>
> --
> Mark Hansen, PP-ASEL, Instrument Airplane
> Cal Aggie Flying Farmers
> Sacramento, CA

[Tim]

I understand.

Weather and fuel are never a concern for you. I will flight plan
accordingly from now on.

However, I will continue to TIME my ILS approaches and if the GS ever
fails while I am on an ILS I will continue with the localizer approach -
but not because of fuel or weather concerns.

I see no FAR prohibiting this and still cannot find a single good reason
to discontinue its practice. No one has offered one that satisfies me.
There is nothing inherently dangerous about it.

tim


Bob Gardner wrote:
> Well, Mark and Tim, if I had been keeping up with weather conditions at the
> destination while enroute, which is a common-sense precaution, and learned
> that the weather was really going downhill, I would have landed short or
> turned around and gone home. I have done this on Part 135 trips,
> discomfiting but not killing my passengers. There is nothing so urgent that
> you have to do what you had planned to do.
>
> When I chose my alternate, I had to meet the 1-2-3 rule. If the wx at the
> alternate has gone to hell in a handbasket, I have done a lousy job of
> planning. The best alternate has good and improving VFR weather.
>
> I've never had a fuel leak to deal with, but I would hope that sinking fuel
> gauges would have caught my eye before I was on the approach. No platitudes
> about fuel gauges, please.
>
> Unexpected holding? The word is "unable due to low fuel state."
>
> Bob Gardner
>
> "Mark Hansen" > wrote in message
> ...
>
>>On 03/30/07 09:31, Bob Gardner wrote:
>>
>>>Let's see, Tim...you do carry IFR reserves, right? So you should have
>>>enough
>>>for the approach plus what it takes to get to an alternate plus 45
>>>minutes?
>>>Where does the risk of fuel come in?
>>
>>To imagine that low fuel will never be a consideration is simply
>>ridiculous.
>>How about when you get to your alternate, and can't get in due to weather,
>>and you're forced to go to another airport? How about unexpected holding?
>>How about a fuel leak (as someone else pointed out)?
>>
>>Are you really saying that a pilot need not consider the possibility?
>>That would be very bad advice, in my opinion.
>>
>>
>>>Bob Gardner
>>>
>>
>>--
>>Mark Hansen, PP-ASEL, Instrument Airplane
>>Cal Aggie Flying Farmers
>>Sacramento, CA
>
>
>

[M[_1_]]

On Mar 30, 8:42 am, "John R. Copeland" >
wrote:
> "M" > wrote in ooglegroups.com...
>
> > This is particularly important if it's windy and bumpy. If you fly
> > that approach at cruise power to keep the groundspeed at 90 knots
> > you're likely above your Va, which can overstress the airframe.
>
> A touch of hyperbole, maybe?
> Va is the G-safe speed for *abrupt full deflection* of any control.
> Most of my ILS approaches thankfully don't require that. :-)

A big gust of wind with vertical components can put a lot of stress on
airframe. Va doesn't completely protect you against bent airframe
in turbulence but it provides a lot more protection than a typical
criuse IAS.

[Bob Gardner]

If weather is not a concern for me, why do I keep checking on destination
weather? Fuel is definitely not a concern because I plan conservatively and
always have more than enough. This philosophy got me through over 7000 hours
of piston and jet time, almost all of it for hire.

Bob Gardner

"Tim" > wrote in message
...
>I understand.
>
> Weather and fuel are never a concern for you. I will flight plan
> accordingly from now on.
>
> However, I will continue to TIME my ILS approaches and if the GS ever
> fails while I am on an ILS I will continue with the localizer approach -
> but not because of fuel or weather concerns.
>
> I see no FAR prohibiting this and still cannot find a single good reason
> to discontinue its practice. No one has offered one that satisfies me.
> There is nothing inherently dangerous about it.
>
> tim
>
>
> Bob Gardner wrote:
>> Well, Mark and Tim, if I had been keeping up with weather conditions at
>> the destination while enroute, which is a common-sense precaution, and
>> learned that the weather was really going downhill, I would have landed
>> short or turned around and gone home. I have done this on Part 135 trips,
>> discomfiting but not killing my passengers. There is nothing so urgent
>> that you have to do what you had planned to do.
>>
>> When I chose my alternate, I had to meet the 1-2-3 rule. If the wx at the
>> alternate has gone to hell in a handbasket, I have done a lousy job of
>> planning. The best alternate has good and improving VFR weather.
>>
>> I've never had a fuel leak to deal with, but I would hope that sinking
>> fuel gauges would have caught my eye before I was on the approach. No
>> platitudes about fuel gauges, please.
>>
>> Unexpected holding? The word is "unable due to low fuel state."
>>
>> Bob Gardner
>>
>> "Mark Hansen" > wrote in message
>> ...
>>
>>>On 03/30/07 09:31, Bob Gardner wrote:
>>>
>>>>Let's see, Tim...you do carry IFR reserves, right? So you should have
>>>>enough
>>>>for the approach plus what it takes to get to an alternate plus 45
>>>>minutes?
>>>>Where does the risk of fuel come in?
>>>
>>>To imagine that low fuel will never be a consideration is simply
>>>ridiculous.
>>>How about when you get to your alternate, and can't get in due to
>>>weather,
>>>and you're forced to go to another airport? How about unexpected holding?
>>>How about a fuel leak (as someone else pointed out)?
>>>
>>>Are you really saying that a pilot need not consider the possibility?
>>>That would be very bad advice, in my opinion.
>>>
>>>
>>>>Bob Gardner
>>>>
>>>
>>>--
>>>Mark Hansen, PP-ASEL, Instrument Airplane
>>>Cal Aggie Flying Farmers
>>>Sacramento, CA
>>
>>

[Roger[_4_]]

On 29 Mar 2007 12:59:55 -0700, "kevmor" > wrote:

There have been a lot of answerers to this and I've not read the who
thread. but there are some very important things to take into account.
>I flew yesterday and did some practice approaches, and the winds were
>about 20 knots gusting to 26-28. I've flown almost all approaches so
>far in a different 172 that had a 180hp conversion. Because of the
>winds, I kept almost full cruising power on the descents to try and
>maintain my normal 90 kts ground speed for timing and roughly 500fpm
>for the ILS.
>
You are flying an airplane, you are not driving a car. You fly the
proper airspeed! If an ILS you adjust the power to maintain the GS.
Remember you fly the airplane, CALCULATE the ground speed
and from that derive the time. Your time will change with the winds.

Think of it this way. If you had a 30 knot tail wind would you slow up
by 30 knots from your regular approach speed? More than likely that
would put your below stall speed.

>This plane did have an IFR GPS indicating ground speed, but the one
>I've been using for all other approaches didn't, neither DME. The CFI
>informed me I should have used known power settings. What are your

Yup! IOW you need to maintain the proper airspeed and rate of descent
where necessary.

>thoughts? I'm not sure how I would've known the right power setting,

You will eventually learn to set the power to get the speed or rate of
descent at the speed you want. Although the power settings between the
two planes may be different there is going to be little difference in
the approach speeds.

>unless I used what I normally do, and accept the lower ground speed,

Yes

>then adjust my descent for the ILS to a much lower fpm descent?

Yes

As I said, you are flying an airplane in the air, not driving a car on
the ground. You fly the airplane at the proper speed and take what
ever ground speed you get. From that you calculate or derive your
times. You should try flying an ILS in a high performance plane with
a 30 knot tail wind, followed by a circle to land<:-)) I normally
fly approaches at 120 be they step down or precision. I land VFR at 80
MPH minus 1 MPH for each 100 # under gross. That means I have a lot
of slowing up to do. Now add a 30 knot tail wind and I'm coming down
the ILS with 150 for ground speed. I have to circle at low altitude
and lose 70 MPH in the process. Actually that is for the over the
fence speed so I will need to lose about 80 to 90 MPH before I can get
the wheels on the runway.

BTW I rarely look at the power settings coming down the ILS. When I
adjust the power (MP in this case) to stabilize at 120. When I
intercept the GS I drop the gear while holding a level attitude. This
alone should put me right on the GS at the proper rate of descent. I
do know that 1" +/- MP will change the rate of descent 100 FPM. I do
look at the MP gage to get the one inch, but I really don't pay much
attention to the actual reading. Nor do I look out the window at the
scenery for visual clues as to GS as I don't care what the ground
speed turns out to be. I'm only concerned about air speed.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

[Bob Gardner]

http://www.warmkessel.com/jr/flying/td/jd/5.jsp

"The exceptional pilot uses his exceptional judgment to avoid having to use
his exceptional skill" --Anonymous

Bob Gardner

"Tim" > wrote in message
...
>I understand.
>
> Weather and fuel are never a concern for you. I will flight plan
> accordingly from now on.
>
> However, I will continue to TIME my ILS approaches and if the GS ever
> fails while I am on an ILS I will continue with the localizer approach -
> but not because of fuel or weather concerns.
>
> I see no FAR prohibiting this and still cannot find a single good reason
> to discontinue its practice. No one has offered one that satisfies me.
> There is nothing inherently dangerous about it.
>
> tim
>
>
> Bob Gardner wrote:
>> Well, Mark and Tim, if I had been keeping up with weather conditions at
>> the destination while enroute, which is a common-sense precaution, and
>> learned that the weather was really going downhill, I would have landed
>> short or turned around and gone home. I have done this on Part 135 trips,
>> discomfiting but not killing my passengers. There is nothing so urgent
>> that you have to do what you had planned to do.
>>
>> When I chose my alternate, I had to meet the 1-2-3 rule. If the wx at the
>> alternate has gone to hell in a handbasket, I have done a lousy job of
>> planning. The best alternate has good and improving VFR weather.
>>
>> I've never had a fuel leak to deal with, but I would hope that sinking
>> fuel gauges would have caught my eye before I was on the approach. No
>> platitudes about fuel gauges, please.
>>
>> Unexpected holding? The word is "unable due to low fuel state."
>>
>> Bob Gardner
>>
>> "Mark Hansen" > wrote in message
>> ...
>>
>>>On 03/30/07 09:31, Bob Gardner wrote:
>>>
>>>>Let's see, Tim...you do carry IFR reserves, right? So you should have
>>>>enough
>>>>for the approach plus what it takes to get to an alternate plus 45
>>>>minutes?
>>>>Where does the risk of fuel come in?
>>>
>>>To imagine that low fuel will never be a consideration is simply
>>>ridiculous.
>>>How about when you get to your alternate, and can't get in due to
>>>weather,
>>>and you're forced to go to another airport? How about unexpected holding?
>>>How about a fuel leak (as someone else pointed out)?
>>>
>>>Are you really saying that a pilot need not consider the possibility?
>>>That would be very bad advice, in my opinion.
>>>
>>>
>>>>Bob Gardner
>>>>
>>>
>>>--
>>>Mark Hansen, PP-ASEL, Instrument Airplane
>>>Cal Aggie Flying Farmers
>>>Sacramento, CA
>>
>>

[Steve Schneider]

For what it is worth, during my IFR training I was taught to time the
approach so that I'd have the option of continuing localizer only if
the GS failed. Both the ground instructor for the IFR written and
later my CFII during the flight instruction made this point -- and
there was no connection between the two instructors.

Short of reading this thread, I would have thought that this was
a common point of instruction for IFR students.

Steve


Tim wrote:
> One should always time the approach. In some senses it is easier. if
> the GS goes bad, just go to the minimum altitude - one less needle to
> keep track of.
>
> Always time it. The wx could go worse or low on fuel - why abandon the
> approach if you have it set up already?
>