PDA

View Full Version : Personal Minimums SEL?


Paul kgyy
January 17th 07, 03:11 PM
I'm curious what Instrument Rated members of this group use for
personal minimums for takeoff and landing for single engine aircraft.

The question is prompted by a recent flight where the takeoff
conditions were 200 ft + 1 mile. That's lower than I've ever done
before, and it occurred to me that if I had any significant engine
problems, it was all over unless I was extremly lucky.

Nathan Young
January 17th 07, 04:18 PM
On 17 Jan 2007 07:11:47 -0800, "paul kgyy" >
wrote:

>I'm curious what Instrument Rated members of this group use for
>personal minimums for takeoff and landing for single engine aircraft.
>
>The question is prompted by a recent flight where the takeoff
>conditions were 200 ft + 1 mile. That's lower than I've ever done
>before, and it occurred to me that if I had any significant engine
>problems, it was all over unless I was extremly lucky.

I fly a single. I will land in minimums, but will not launch into
them. 500ft on takeoff is more comforting in the event of an engine
failure. I am also cautious about flying over extended areas of low
ceilings/vis, the so-called low-IFR.

Had to put this into practice about 1 week ago, as we had fog in the
morning. The fog was thick, at times less than 1/4 mile vis.
However, looking straight up, you could occasionally see the blue sky,
and it was obvious the fog layer was less than 500 feet thick.

My homefield is ~3400ft, without precision approaches, and surrounded
by homes and gravel pits. Not a good engine out/IMC scenario, so I
waited for the fog to clear and departed VFR.

-Nathan

Robert M. Gary
January 17th 07, 04:29 PM
paul kgyy wrote:
> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.
>
> The question is prompted by a recent flight where the takeoff
> conditions were 200 ft + 1 mile. That's lower than I've ever done
> before, and it occurred to me that if I had any significant engine
> problems, it was all over unless I was extremly lucky.

Flying IFR over low ceilings is like flying at night. There will often
be phases of your flight that an engine failure outcome may be very,
very bad. Its like driving through an intersection on a green light.
There is always the chance someone will run the red light and kill you.
You just have to decide your own personal risk management levels.
Personally, I have launched in that and less. I also chose to buy a
factory new engine rather than overhaul my last one, I do oil analysis
every oil change and do a boroscope inspection inside the engine at
least every 6 months. I could still lose an engine but that's where
I've choosen to set my level.
We live in the fog belt and I often take students up to do multiple
approaches when its 200 ft 1/2 mile or even less. Sometimes we don't
even see the approach lights at minimums (we have an alternate airport
nearby above the fog). I think its important that students see what it
really looks like to break out so low and to understand the difference
in intensity level between breaking out (or taking off) with a 500 ft
ceiling vs a 100ft ceiling (at 001VV you usually have an 80% chance of
seeing the rabbit). I've seen otherwise great students almost lose it
when entering the close right after take off. I'd rather have them
experience that with me that just to trust me that its different.

-Robert, CFII

Kusi (us-ppl, sep, d.-ir)
January 17th 07, 04:43 PM
> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.
>
> The question is prompted by a recent flight where the takeoff
> conditions were 200 ft + 1 mile. That's lower than I've ever done
> before, and it occurred to me that if I had any significant engine
> problems, it was all over unless I was extremly lucky.

Aim at worst case without using your luck.

What counts are the "way-out" options: What to do with an inflight
problem (anything better as an engine failure) after take-off? Can you
do the go-around-procedure? What are the minimums now for a landing at
your "new destination-welcome-home" airport?

What do you do enroute with an engine failure? Hopefully your are high
enough to navigate, decide and communicate. You better have some VFR
below, to avoid trees and cumulus grantitus during your perfect
500ft/min one-way descend.

At the destination you want to see the runway early enough to fit your
personal experience and capability.
The legal CAT I conditions (200 ft, 550 m) are something special!

Personally I got my IFR Ticket last year, so I set my personal minimus
rather high for the beginning. I seek for a "way out" under all
conditions: Such as suitable VFR below and 1000 ft at the destination.
Maybe at a later stage I would reduce the 1000ft to NON-PREC.
conditions.

I did not dare to deal with the legal CATI options (PREC. APR.) but
tried losy weather in a simulator. Try to see the approach lights in
550m yourself with a 200ft ceiling! MS Flight simulator is absolutely
sufficient for this impression.

Michael[_1_]
January 17th 07, 05:27 PM
paul kgyy wrote:
> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.
>
> The question is prompted by a recent flight where the takeoff
> conditions were 200 ft + 1 mile. That's lower than I've ever done
> before, and it occurred to me that if I had any significant engine
> problems, it was all over unless I was extremly lucky.

One of the risks you take in flying single engine night/IFR is engine
failure without the option of seeing your landing spot until you are
comitted. I know several people who have had this happen. Most of
them are still alive. One is not. The reality of engine failure
fatalities is this - most of them do not occur due to unsurvivable
terrain. Most of them occur due to failure to attain/maintain flying
speed.

In my opinion, there really isn't much difference (in a single engine
airplane) between taking off into 500 ft ceilings and 50 ft ceilings.
Either way, you don't have the altitude to do anything but land pretty
much straight ahead. Either way, the chance of engine failure low
enough for it to matter is tiny. Look at it this way - you just ran up
your engine, and all indications were perfectly normal (I trust you
would not launch into IMC otherwise). The engine was fine on the
entire last flight (I trust you would not launch into IMC on your first
flight after maintenance). What are the odds the engine is going to
fail in the first two minutes of flight?

I would be a lot more concerned about extended flight over an area of
low IMC - that pushes up the exposure.

Most of my IFR and night flying is in a twin these days, because I'm
just not that comfortable with the exposure of flying a fast single
night/IFR. Doesn't mean I won't do it - I will do it when my plane is
down and I borrow one, and I will do it to train someone. I just
figure the more you do it, the better the odds that it will eventually
catch up with you.

Michael

Mortimer Schnerd, RN[_2_]
January 17th 07, 05:30 PM
paul kgyy wrote:
> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.
>
> The question is prompted by a recent flight where the takeoff
> conditions were 200 ft + 1 mile. That's lower than I've ever done
> before, and it occurred to me that if I had any significant engine
> problems, it was all over unless I was extremly lucky.


I'll take off in that if there's improved weather nearby. I will never take off
with that if that describes the entire route of flight.... I prefer about 600
feet and 3/4 miles. Otherwise it's a sucker's bet.

Frankly, around here you're pretty much screwed anyway if you have problems
immediately after takeoff as there's really no where to land but on someone's
house. But WTH; you can't live your life in fear.

I used to fly in and out of KCLT Monday through Friday in the early AM flying
either a Lance or a Geronimo conversion Apache. Some days I sat on the ground
waiting for the visibility to improve to legal minimums. Pretty much the second
it did I took off, knowing the weather at KRDU was going to be improved by the
time I got there. Sometimes it was a bit dicey but I always got in.



--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

Jose
January 17th 07, 06:11 PM
> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.

Each case is different, so I don't set personal minimums. That's too
broad a stroke. While in theory this leaves me vulnerable to pushing
the limits because "I gotta get there", in reality I do not do that
(evidenced by tempting flights I've turned down) so I'm not concerned
about not being conservative enough.

I'd launch into fog where I could see blue, and I'd be on top in thirty
seconds. No problem. The chance of an engine failure at =just= the
wrong time is low enough that I accept it the way I accept other
inherent risks of flying. I'd be more concerned about widespread low
conditions at my destination - if the weather goes any lower and I can't
get in anywhere, that's a problem. So I want real alternates thoughout
the flight.

I'd do approaches to minimums. That's what my rating is for. However,
I'd want an alternative that is not to minimum within my gas range.

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

Nathan Young
January 17th 07, 08:09 PM
On 17 Jan 2007 09:27:26 -0800, "Michael"
> wrote:

>
>In my opinion, there really isn't much difference (in a single engine
>airplane) between taking off into 500 ft ceilings and 50 ft ceilings.
>Either way, you don't have the altitude to do anything but land pretty
>much straight ahead.

Depending on where you fly, I say there is a big difference.

In the Midwest, 500 ft offers a lot of options in selecting a landing
site. Sure, you aren't going to make the runway, but landing in any
open area is better than hitting a tree or a house.

50 ft is 99% luck. Pitch for lowest speed above stall, and pray
whatever is in front of you is soft. Hell, if you have really bad
luck, you might hit a tree while still in the clouds.

-Nathan

Bob Noel
January 18th 07, 12:13 AM
In article . com>,
"paul kgyy" > wrote:

> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.

I use landing minimums for takeoff, especially with tops easily
in reach.

>
> The question is prompted by a recent flight where the takeoff
> conditions were 200 ft + 1 mile. That's lower than I've ever done
> before, and it occurred to me that if I had any significant engine
> problems, it was all over unless I was extremly lucky.

Given the probability of an engine failure, I don't sweat the
engine-out hazard that much.

--
Bob Noel
Looking for a sig the
lawyers will hate

vincent p. norris
January 18th 07, 12:34 AM
My first several years of flying were in the military, when all we had
were Adcock range approaches and NDB (we called them ADF) approaches.
We did them to 200' and 1/4 mile. Sounds hard to believe today, but
we took it for granted.

So ILS mins of 200 and 1/2 seem quite reasonable.

vince norris

Jim Carter[_1_]
January 18th 07, 12:55 AM
> -----Original Message-----
> From: paul kgyy ]
> Posted At: Wednesday, January 17, 2007 9:12 AM
> Posted To: rec.aviation.ifr
> Conversation: Personal Minimums SEL?
> Subject: Personal Minimums SEL?
>
> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.
>
> The question is prompted by a recent flight where the takeoff
> conditions were 200 ft + 1 mile. That's lower than I've ever done
> before, and it occurred to me that if I had any significant engine
> problems, it was all over unless I was extremly lucky.

Since I fly to please myself now instead of some employer, and since
I've got a LOT greyer on the roof my personal minimums have definitely
changed. 35 years ago, I resented having to depart zero/zero because I
needed the job and there were too many unemployed pilots willing to take
it. I also only did that about a dozen times before I found a new
career. (That's why I can afford to fly now.)

Today, I like options. Published minimums make me sweat too much
(remember I'm older now) so I don't even like them for departures any
more. I personally don't care how many fans are turning because if
anything happens unexpectedly I don't want to have to work that hard to
save my butt.

I think I like published alternate minimums for departures with no
cumulo-granite in the vicinity. Of course departure and approach
minimums might have to get higher after an extended period of time away
from the clocks.

I'm sure others who fly every day and have a great personal intimacy
with their aircraft will depart in conditions in which I would prefer to
sit and drink coffee, but then I don't fly every day and I know from
experience that no matter how much of a first name basis you're on with
that fan up front - it will quit on you some day.

John R. Copeland
January 18th 07, 01:52 AM
"vincent p. norris" > wrote in message ...
> My first several years of flying were in the military, when all we had
> were Adcock range approaches and NDB (we called them ADF) approaches.
> We did them to 200' and 1/4 mile. Sounds hard to believe today, but
> we took it for granted.
>
> So ILS mins of 200 and 1/2 seem quite reasonable.
>
> vince norris

You had ADF? You lucky guy!
We had to find the cone of silence, turn to the appropriate heading,
and make a timed descent to visual contact with the airport.
I don't remember the minima, but I think they were higher than 200+1/4.

A Lieberma
January 18th 07, 02:26 AM
"paul kgyy" > wrote in news:1169046707.212374.112150
@m58g2000cwm.googlegroups.com:

> I'm curious what Instrument Rated members of this group use for
> personal minimums for takeoff and landing for single engine aircraft.

ILS minimums for me.

Only thing is if I go out seeking ILS minimums, I must be prepared to not
come back to my airport, as GPS minimums apply.

Allen

Robert M. Gary
January 18th 07, 05:36 AM
vincent p. norris wrote:
> My first several years of flying were in the military, when all we had
> were Adcock range approaches and NDB (we called them ADF) approaches.
> We did them to 200' and 1/4 mile. Sounds hard to believe today, but
> we took it for granted.
>
> So ILS mins of 200 and 1/2 seem quite reasonable.

When students ask me what my personal mins are here in the fog, I used
to just tell them "2 dots". If at any point I get more than 2 dots off
the loc, I'll go missed, otherwise I'll follow it all the way to mins.
As a CFII I'm not really suppose to say that though ;)

-Robert

Robert M. Gary
January 18th 07, 05:37 AM
vincent p. norris wrote:
> My first several years of flying were in the military, when all we had
> were Adcock range approaches and NDB (we called them ADF) approaches.
> We did them to 200' and 1/4 mile. Sounds hard to believe today, but
> we took it for granted.

Probably one of the differences back then vs now is that you probably
had at least one guy on the field that just went around and tuned up
ADF receivers. If you've been tuned in the last 30 days you could
probably get a good approach. Most ADF planes on the field now would be
lucky to get w/i 3 miles of the airport on the ADF today.

-Robert

Roger[_4_]
January 18th 07, 08:15 AM
On Thu, 18 Jan 2007 02:26:33 GMT, A Lieberma >
wrote:

>"paul kgyy" > wrote in news:1169046707.212374.112150
:
>
>> I'm curious what Instrument Rated members of this group use for
>> personal minimums for takeoff and landing for single engine aircraft.
>
>ILS minimums for me.

The same here if I'm proficient.

>
>Only thing is if I go out seeking ILS minimums, I must be prepared to not
>come back to my airport, as GPS minimums apply.

My instructor put me through so much actual right down to and below
minimums that my first flight after getting the rating was comfortable
at minimums. I'm currently not that proficient.


>
>Allen
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Dane Spearing
January 18th 07, 05:00 PM
In article >,
Nathan Young > wrote:
>50 ft is 99% luck. Pitch for lowest speed above stall, and pray
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>whatever is in front of you is soft. Hell, if you have really bad
>luck, you might hit a tree while still in the clouds.
>
>-Nathan

"Pitch for lowest speed above stall"?!? While this may provide for the lowest
possible forward airspeed/groundspeed, you're going to have one helluva sink
rate. In addition, your ability to manuver and flare with be severely
degrated. Everything I've ever read and been taught says to push the nose
over to maintain best glide speed (which is usually very close to Vy for
most light singles). There was even an article in last month's issue of
AOPA pilot about this which mentioned how much you really do need to push
the nose over to attain best glide speed upon engine failure after take off.

I'd be curious as to your rationale for pitching to lowest speed above
stall....

-- Dane

Marco Leon
January 18th 07, 09:17 PM
Dane Spearing wrote:
>
> "Pitch for lowest speed above stall"?!? While this may provide for the lowest
> possible forward airspeed/groundspeed, you're going to have one helluva sink
> rate. In addition, your ability to manuver and flare with be severely
> degrated. Everything I've ever read and been taught says to push the nose
> over to maintain best glide speed (which is usually very close to Vy for
> most light singles). There was even an article in last month's issue of
> AOPA pilot about this which mentioned how much you really do need to push
> the nose over to attain best glide speed upon engine failure after take off.
>
> I'd be curious as to your rationale for pitching to lowest speed above
> stall....

I don't want to speak for the other poster but the rationale seems
obvious. If you can't see anything and/or you don't know what's in
front of you, then how long you stay aloft isn't going to matter. Of
course, one does not want to have TOO much of a vertical speed if they
value their spine but most likely the thing that's to the aircraft's
nose will be the killer item.

Marco

Nathan Young
January 19th 07, 12:55 AM
On Thu, 18 Jan 2007 17:00:16 +0000 (UTC),
(Dane Spearing) wrote:

>In article >,
>Nathan Young > wrote:
>>50 ft is 99% luck. Pitch for lowest speed above stall, and pray
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>whatever is in front of you is soft. Hell, if you have really bad
>>luck, you might hit a tree while still in the clouds.
>>
>>-Nathan
>
>"Pitch for lowest speed above stall"?!? While this may provide for the lowest
>possible forward airspeed/groundspeed, you're going to have one helluva sink
>rate. In addition, your ability to manuver and flare with be severely
>degrated.

Good question. First off, just to make crystal clear, I am not
advocating the low speed descent in a normal engine out scenario. In
that case, standard practice of best glide and then once visual
maneuver as required, culminating in a flare just above stall speed.

However, this scenario is quite a bit different. IMC to 50ft is
crappy weather. Unless you departed off a runway in the middle of a
flat bean field, there is a high likelyhood of the plane hitting
something (like a tree) on the way down, and if that occurs, I want
the plane's energy to be at it's minimum. Hence, my comment about
keeping the airspeed just above a stall.

I also want to mention that if the weather is IMC to 50 ft, there is a
good chance that a few clouds will go to the surface. In which case,
even in the beanfield scenario, you may hit the ground without ever
going visual.

Your point(s) about controllability at stall point and sink rate are
great ones. You probably don't want VS0 + 1mph. Maybe VS0 + 5 or 10
mph. Just enough extra speed to allow a reasonable flare (assuming
you go visual at some point before impact).

But adding speed is a big trade off, because if you hit something
before going visual, that's a lot of extra energy to dissipate on a
crash.

In my plane, best glide is 80mph. Stall is 50mph. What I was trying
to avoid was impacting something at 80mph. That's 2.5x the energy to
dissipate in the crash.

Vertical speed & forward speed vs crash survivability data would be
interesting to see. At best glide & idle throttle my Cherokee
descends at about 950fpm, which is about 11mph or the equivalent of a
free-fall from 4 feet.. I haven't checked the engine out descent rate
at VS0 + 1mph, so I have no idea what the fpm would be. That will
be a fun test next time I go flying. Previously, I did test out
70mph and 90 mph, and found minimal increase (<<100fpm) on the VSI.

-Nathan

vincent p. norris
January 19th 07, 03:11 AM
>You had ADF? You lucky guy!
>We had to find the cone of silence, turn to the appropriate heading,
>and make a timed descent to visual contact with the airport.

IIRC, our ADF was useless when shooting an Adcock range approach,
which is what you seem to be talking about. We flew to the high cone,
did a procedure turn, descended and flew to the low cone, than, as you
say, took a heading to the airport.

ADF approaches had no "cones." As I recall, we often shot them using
commercial AM radio stations. Perhaps those were just practice
approaches, not actual approaches in IMC. It was half a century ago,
and I don't recall all the details perfectly.

>I don't remember the minima, but I think they were higher than 200+1/4.

Ours were, of course, if the terrain required, but could be as low as
200 and a quarter.

vince norris

vincent p. norris
January 19th 07, 03:12 AM
>When students ask me what my personal mins are here in the fog, I used
>to just tell them "2 dots". If at any point I get more than 2 dots off
>the loc, I'll go missed...

Sounds like prudent policy.

vince norris

Google