Backup gyros - which do you trust?

Sidney

On Mon, 14 Jul 2003 05:10:26 GMT, Sydney Hoeltzli
wrote:

Big John wrote:

NDB approach is a non precision approach. Takes less Partial Panel
proficiency.

I'm quite aware of what is and isn't a precision approach.

You ask and I gave a straight forward answer. Why did you parse my
answer and get snippy???? If you didn't want to know, why ask?

Are you trying to tell me it's not easier to fly a PP NDB approach
than a PP ILS?

What I don't understand is why you feel it's easier to fly an
NDB approach than an ILS approach partial-panel.

How many times have you flown a hard IFR partial panel NDB or ILS
approach? Are you making your statements from reading a book or from
bar talk? If you don't want to take advice from someone who has been
there and done that then use your own procedure. There are many ways
to fly an airplane, some better and more safe than others but only the
individual can make the decision of what is right for him/her within
the rules and their experience level.

It's too bad we are not closer and I could jump in and let you
demonstrate to me how easy it is to fly PP without killing us.

It seems to me that the NDB approach most strongly requires
accurate heading information. The course to be flown can not
be determined from the position of the ADF needle alone, it
can only be determined by comparing the ADF bearing to heading.
If your only source of heading info is a compass dancing wildly
as you bounce around, this gets "too interesting"

A NDB can be flown with very sloppy heading control. Use whisky
compass outbound in pattern and just point the needle at 360 degrees
(top of dial) in bound. After needle swing you can use time and
distance and compass heading to field letting down to minimums.

On an ILS or GPS approach, OTOH, it seems to me that the
course to be flown can be determined from the CDI position
alone. Needle left, turn left etc.

I'd like to see you PP trying to use GPS to make an approach. It's
hard enough to keep the airplane flying PP without using the benefits
of GPS. Not saying it can not be done but I'd bet against anyone doing
it successfully and win a bundle. Could throw an Irish Wake with
dancing and drink galore.

Another post pointed out an individual practicing using his back up AI
across the panel and got vertigo. He probably was moving his head back
and forth which gives you vertigo when on instruments, Your scan is
only with your eye balls or you will probably get vertigo.

You can flop around on a NDB approach with it's higher minimums easier
on partial panel than you can on a precision ILS.

I don't understand this at all. Yes, the ILS becomes increasingly
sensitive as one descends closer to DH. But, if the wx is such
that the 800 ft minimums (or 600, or whatever they are) on an
NDB approach will get one in, one need not fly the ILS minimums
but can "flop around" on the less sensitive portion.

True. If you have NDB minimums and only an ILS then you can probably
get down using the ILS assuming you are proficient enough to fly the
two needles and all the PP instruments required to just keep the bird
airborne.

OTOH, if the wx is really crappy, all the flopping around on an
NDB you might care to do won't help you.

Again. Want to see you make a IFR PP ILS. Doubt if I could when I was
able to fly the box the bird came in. It's very hard and very
dangerous.

On instruments, it is hard enough with full panel to fly precision IFR
especially if the ILS beams have splits in them and the needles bounce
from stop to stop at minimums. We used to practice at Scramento and
never felt comfortable making the ILS approach there due to erratic
needle movements on final.

I've never experienced anything like this. Is this a Cat II or III
ILS?
Don't know. It was the initial type that was used for years. Each one
had different beams causing different display in cockpit from the
installation at each field. Some fields were so bad that they could
not install an ILS and meet FAA standards. That was one of the reasons
(to learn the ILS quirks) an Airline Pilot had to make several flights
into an airport before he was checked out to fly as captain to that
field.

Does that explain my feelings enough?

Not really I'm afraid. I must say the view that partial panel
NDB approachs are the most difficult seems to be held by many
of the local DEs, who will require a partial-panel NDB if there
is an ADF installed in the plane.

Don't know where you are reading this in my posts. A PP ADF is the
easiest PP approach to fly IFR. Still not easy, but the easiest.

It's been so many years since I made a real partial panel approach.
It was a Radio Range (A/N) approach as I recall. Hit cone of silence,
turned to heading to field, let down to minimum altitude and flew the
time (minutes and seconds) to field. All the pilots wore those fancy
chronometers to time from cone of silence to field for instrument
approaches in those days )

Whew...is this the sort of approach being described in "Fate is
the Hunter"? How would you handle adjusting groundspeed vs. time?
Would you guesstimate your groundspeed from time between waypoints
before initiating descent, would someone on the ground give you
winds from which you'd calculate groundspeed? Would you adjust
power to always fly the same groundspeed, or adjust time? Sorry
for all the naive questions, but pilots who actually flew radio
range approaches are few and far between.

Sidney. All of the above G The approach plate gave the time to field
in minutes and seconds listing several speeds to accommodate all the
aircraft in inventory. Normally max time would only be 3-4 minutes and
normally just 1-2 minutes after crossing cone of silence. You rarely
landed straight in and many of the headings to field were not lined up
with a runway. After sighting the field you would circle and land on
the active runway. If you were in radio contact with the field/tower
you could get surface wind and compute a ground speed from cone of
silence to field, other wise you made a WAG from forecast and what you
encountered en route. As you only were flying a couple of minutes and
the wind would only make the difference of a few seconds to field it
was not a super big problem in most cases.. Remember a ceiling of
6-800 feet (above obstructions) was the norm in those days. None of
the 200 & 1 (or less) like today.. Hope this gives you a feel for how
crude things were in those days. Norm was when WX was bad we sat until
it improved and then continued cross country. As an aside, in all my
years of flying, I only made one zero zero landing.

These days, if I time an approach where I could use DME to define
the MAP my instructor beats me with a board "timing is the least
accurate way to determine the MAP! Never depend upon time if
there's another way!" And he's not a young whippersnapper
either.

If all the instruments and nav aids are working then he is correct but
when the bottom falls out then timing is a very good fall back. Tape
the DME for him and fly time and then uncover the DME and see how far
you are off. If done properly is pretty accurate for short distances.
Doing on occasion gives you confidence in timing, if required.

Appreciate your comment re practice instrument approaches.

I instructed for so many years in heavy iron I tend to push the
routines I developed to give maximum safety and yet perform the
mission. As I've said, there may be other ways to fly but what I push
has stood the test of time and is a good place to start until one gets
lots of experience.

As I have also said prior, these postings have taken the place of what
we called hanger flying in the old days where lots of tips and tricks
were passed on to the younger pilots by the old gray beards.

For example, I can loop a T-6 starting at zero indicated airspeed. Two
people and normal load of fuel. No tricks, just super technique.

Can also do a double immelman (sp) in a T-33. Only a couple of us I
know who did that. Max use of energy. One good friend of mine who did,
died a few years ago (probably drank himself to death). At reunion in
San Antonio we stayed in the hotel room and knocked off a couple of
quarts of vodka to get ready for evenings activities while the gals
went 'out' to do what women do G. He was the one that was shot down
in Europe and stole a FW-190 and flew it back to England. Got gear up
but didn't know how to unlock and get the gear down so had to belly in
G His exploit has been published a few times in the War Stories
magazines.

Enough rambling.

I'm going to back out of most of these threads and let yu'all have at
it. I'll just read and enjoy. Might even look at a sport bird since I
can't get a third class anymore. At least with out several years and a
lot of time and money to fight the system. Have you heard of any one
getting by OK City with a pacemaker? I pass a monthly check ok.

Have enjoyed many of your posts. Keep it up. You are not afraid to ask
questions which is good.

Erin go bragh

Big John

Best instruments you can buy and also radio's. Practice instruments
and fly at least 10 hours a month (100 hours a year minimum).

Air Force ran an expensive study that showed 17 hours a month gave
minimum accident rate in heavy iron. Less than 17 hours, proficiency
suffered. More than 17 hours you were exposed to flying hazards more
and more accidents. The 17 hours a month is close to 200 hours a year
which is a very good figure if you have the money and time to fly that
much.