ThirtyEcho
Topic Author
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Needle, Ball, Airspeed

Wed Sep 13, 2006 2:22 pm

Having noticed the Garmin glass cockpit in a C182, I wonder about a few things.

Fine that you have a backup AI, airspeed and altimeter but how about a turn coordinator with ball and a Heading Indicator? Are you REALLY going to use that whiskey compass for your heading reference when the TV fais?

I have flown a lot of needle, ball, airspeed in my training and I fail to see how you'd keep the blue side up when the TV fails.
 
Ralgha
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RE: Needle, Ball, Airspeed

Wed Sep 13, 2006 2:41 pm

All you need to keep the blue side up is an AI. Why not use the compass? Lead it and lag it and all that fun stuff. If they stick a backup turn coordinator and DG in there, they may as well ditch the PFD and go back to the classic sixpack. If you're in radar and radio contact so much the better. ATC can tell you when to start and stop your turn.

The backup AI is electric and independently powered, just as reliable as a turn coordinator. Of course it has the potential to tumble, but if you manage to do that, you probably wouldn't recover with a turn coordinator either.

Really it's just a paradigm shift. The old partial panel was airspeed, altimeter, VS, and TC. The new partial panel is airspeed, altimeter and AI. Different, but not worse. Instead of turning at standard rate, you'll turn at a set bank angle and speed to give you an appropriate rate of turn (figure this out before you have to do it for real).
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KELPkid
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RE: Needle, Ball, Airspeed

Wed Sep 13, 2006 2:45 pm

If you examine the backup attitude indicator, I think you'll notice that 1) it's electric and 2) it has an inclinometer (the "ball" portion of the turn indicator). That said, I'd think you'd still need a turn coordinator, because it is the only instrument that can measure the rate of turn (which is really what you'd need if you were Needle, Ball, Airspeed-I shudder to think about doing compass turns considering how iffy and lattitude-dependent compass turns are.
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
milski
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RE: Needle, Ball, Airspeed

Wed Sep 13, 2006 3:36 pm

If you really cannot hack it without the TC, there is one behind the MFD, it's used by the auto-pilot for roll control. Of course, pulling out the MFD might be a rather tricky business in flight.  Wink
 
ThirtyEcho
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RE: Needle, Ball, Airspeed

Wed Sep 13, 2006 7:23 pm

Start turn-Stop Turn...hmmm...ever tried that, Ralgha? Especially, have you ever done it without a turn coordinator?

Baxk in my teen years. a regional SAC base offered civvy pilots the chance to fly GCA approaches, for controller practice, in VMC flight. My insructor was a real Devil who offered the spicy option that the approach was to be "no gyro." Start turn-stop turn does not use an attitude instrument (the AI) but relies on a rate instrument known as the turm coordinator.

The thought of using the whiskey compass and a clock as rate instruments makes my head hurt.
 
Ralgha
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RE: Needle, Ball, Airspeed

Thu Sep 14, 2006 1:11 am

Quoting ThirtyEcho (Reply 4):
Start turn-Stop Turn...hmmm...ever tried that, Ralgha? Especially, have you ever done it without a turn coordinator?

Yes, I've actually done it quite a lot. The controllers at Eugene were more than happy to do this for us as it was good practice for them too. I've also done it without a TC.

You can get by just fine without a TC if you spend a few minutes before losing everything determinine what bank angle works for a few different airspeeds. At a given airspeed, a standard rate turn is a given bank angle (coordinated of course). That doesn't change. All you have to do to make a timed turn, is establish an airspeed (which would be done when you discovered you were partial panel), establish the known bank angle, and start the clock. It works like a charm, I've done it, many a time.

Like I said, AI instead of TC is simply a different paradigm. It requires a change in thinking, but it is not a worse solution.

The airplane I fly now doesn't even have a TC when full panel. Bank is our turn standard.

[Edited 2006-09-13 18:13:41]
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meister808
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RE: Needle, Ball, Airspeed

Thu Sep 14, 2006 2:11 pm

Standard rate is generally going to work out to about 1.5(Airspeed/10).

So... if you are going 120 kts, you bank 18 degrees or so. It's not perfect, but it works out, and like Ralgha said, mess around with it a little bit in the model of aircraft you are flying and you should get a really good feel for what the exact relationship is going to be.

-Meister
Twin Cessna 812 Victor, Minneapolis Center, we observe your operation in the immediate vicinity of extreme precipitation
 
113312
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RE: Needle, Ball, Airspeed

Thu Sep 14, 2006 8:52 pm

Just be happy that you don't have to demonstrate use of turn and bank plus wet compass on your checkrides like we did in the old days! Considering the wonderful glass cockpits we have today, consider having to revert to wet compass plus standby airspeed, heading and altimeter.
 
113312
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RE: Needle, Ball, Airspeed

Thu Sep 14, 2006 8:54 pm

I used to tell students that flying needle ball and airspeed flying the Cat and Duck method.
 
SlamClick
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RE: Needle, Ball, Airspeed

Thu Sep 14, 2006 11:20 pm

Quoting 113312 (Reply 8):
flying the Cat and Duck method.

The 'cat and duck' method is not quite complete. For directon seeking you need a tree. We all know that moss grows on the north side of trees in the northern hemisphere.

And when you splatter your self against a tree you have just completed a:

cat - duck - gory tree approach
Happiness is not seeing another trite Ste. Maarten photo all week long.
 
meister808
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RE: Needle, Ball, Airspeed

Thu Sep 14, 2006 11:35 pm

Whats the Cat and Duck method?

Do tell

-Meister
Twin Cessna 812 Victor, Minneapolis Center, we observe your operation in the immediate vicinity of extreme precipitation
 
KELPkid
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RE: Needle, Ball, Airspeed

Thu Sep 14, 2006 11:47 pm

Quoting Meister808 (Reply 10):
Whats the Cat and Duck method?

Sounds a little like "peeking from under the hood without getting caught" to me  Wink

Hey, at least when you're partial-panel, you have an excuse-you have to include the compass (up on the panel) in the scan Big grin
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
3DPlanes
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RE: Needle, Ball, Airspeed

Fri Sep 15, 2006 12:16 pm

Oh man, this goes back a ways... I've got an old (as in first generation Xerox type) copy of this...

The Cat and Duck Method of IFR Flying

1. Get a wide-awake cat. Most cats do not want to stand up at all, at any time. It may be necessary to get a large fierce dog in the cockpit to keep the cat at attention.
2. Make sure your cat is clean. Dirty cats will spend all their time washing. Trying to follow a cat licking itself usually results in a tight snap roll, followed by an inverted (or flat) spin. You can see this is very unsanitary.
3. Old cats are best. Young cats have nine lives, but an old used-up cat with only one life left has just as much to lose an you do and will therefore be more dependable.
4. Beware of cowardly ducks. If the duck discovers that you are using the cat to stay upright - or straight and level- she will refuse to leave without the cat. Ducks are no better on instruments than you are.
5. Be sure the duck has good eyesight. Nearsighted ducks sometimes will go flogging off into the nearest hill. Very short-sighted ducks will not realize they have been thrown out and will descend to the ground in a sitting position. This maneuver is quite difficult to follow in an airplane.
6. Use land-loving ducks. It is very discouraging to break out and find yourself on final approach for some farm pound in Iowa. Also, the farmers there suffer from temporary insanity when chasing crows off their corn fields and will shoot anything that flies.
7. Choose your duck carefully. It is easy to confuse ducks with geese because many water birds look alike. While they are very competent instrument flyers , geese seldom want to go in the same direction you do. If your duck heads off for the Okefenokee Swamp, you may be sure you have been given the goose.
"Simplicate and add lightness." - Ed Heinemann
 
pilotpip
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RE: Needle, Ball, Airspeed

Fri Sep 15, 2006 12:20 pm

The standby attitude indicator in Cessna aircraft is Vacuum powered. There is an emergency power system that is designed to power the PFD for 30 minutes so you still have a radio and engine instruments. However, in some other applications, like the DA-40, the standby AI is powered by a ELT-like battery that is supposedly good for at least 90 minutes. There is no inclinometer at the bottom of the Attitude indicator on the Cessna or Diamond aircraft. I believe that Beech has one though.

The turn coordinator is behind the panel for the autopilot. This will dissapear if the Garmin AP gets certified in most aircraft as is the plan.
DMI
 
3DPlanes
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RE: Needle, Ball, Airspeed

Sat Sep 16, 2006 7:14 am

Quoting 3DPlanes (Reply 12):
The Cat and Duck Method of IFR Flying

Oops. It would make more sense if I had actually posted the method... Here it is:


Place a live cat on the cockpit floor. Because a cat always remains upright , he or she can be used in lieu of a needle and ball. Merely watch to see which way the cat leans to determine if a wing is low and , if so , which one.

The duck is used for the instrument approach and landing. Because any sensible duck will refuse to fly under instrument conditions, it is only necessary to hurl your duck out of the plane and follow her to the ground.


The first post covers some of the important tips and/or restrictions for this method of IFR flying...
"Simplicate and add lightness." - Ed Heinemann
 
atct
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RE: Needle, Ball, Airspeed

Sun Sep 17, 2006 12:02 am

It all comes to stick and rudder skills....not much taught nowadays to 99% of part 141 pilots and like 60% or 61 pilots. If you cant fly on an altimeter, ASI, art. horz., and a wet compass, you're screwed. I dont want you flying my airplane.


ATCT
Trikes are for kids!
 
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Jetlagged
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RE: Needle, Ball, Airspeed

Mon Sep 18, 2006 6:41 am

Using a cat is a nice idea, but a glass of whisky would be more reliable. Just make sure the precious liquid surface remains parallel with the base of the glass and you will be perfectly co-ordinated (just as long as you don't drink any of the contents).

Not too many airliners have turn rate indications these days, so the glass C-182 display is not unusual. Not having rate of turn information is hardly the worst thing which could happen. If I'm not mistaken needle, ball and airspeed gives you heading, sideslip and, well, airspeed. Not turn rate, though it could be computed if you had the time.

My only knowledge of the so-called turn co-ordinator instrument is from the MSFS default Cessna. The UK equivalent was the turn and slip indicator which had a pointer to indicate rate of turn, much more useful than a wing shape which looks like it should be indicating bank angle, but isn't.
The glass isn't half empty, or half full, it's twice as big as it needs to be.

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