Single most important instrument?

If your instruments failed and you could have only one:

Day VFR?

In IMC?

I know my answer for the first. The second I'm conflicted a little bit. What say you?

VMC: not real critical. I'll take the ASI just because the Mooney is unforgiving of landing speed.

IMC: AI

Added question: In IMC, pick two!

For two, I'd pick DG/HSI and altimiter. I think you'd have a chance of surviving on those two.
 
VMC= nothing (unless you count the yoke)
IMC = Attitude (Indicator that is)


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VMC: HSI

IMC: HSI

Why HSI instead of attitude indicator?

Well, I'm assuming that everything goes to crap at once while I am already in IMC and in cruise. So, I'm already trimmed out for pitch. I'm also already leaned to just this side of rough. So I don't really have to worry about my altitude getting lower. If I come down too much my engine will get rough from being too lean. So, I just climb a little bit. As I burn off fuel I'm going to get lighter, so I am going to naturally climb anyway. Altitude is our friend. So that takes care of my vertical part of the AI.

The HSI will show me if I'm turning more accurately than the AI will. And with an HSI I know where I'm going. And no, I'm not using the VOR/GPS navigation on it. If the HSI isn't showing a turn, I'm not in a bank. If I'm not in a bank, I don't have to worry about going into a spin.

Them be my answers.
 
VMC: HSI

IMC: HSI

Why HSI instead of attitude indicator?

Well, I'm assuming that everything goes to crap at once while I am already in IMC and in cruise. So, I'm already trimmed out for pitch. I'm also already leaned to just this side of rough. So I don't really have to worry about my altitude getting lower. If I come down too much my engine will get rough from being too lean. So, I just climb a little bit. As I burn off fuel I'm going to get lighter, so I am going to naturally climb anyway. Altitude is our friend. So that takes care of my vertical part of the AI.

The HSI will show me if I'm turning more accurately than the AI will. And with an HSI I know where I'm going. And no, I'm not using the VOR/GPS navigation on it. If the HSI isn't showing a turn, I'm not in a bank. If I'm not in a bank, I don't have to worry about going into a spin.

Them be my answers.

Nice explanation, I like the thought behind it.
 
Nice explanation, I like the thought behind it.

I like to look at things not so straight forward. Like how to fly a VOR radial with a broken needle on the CDI and no other form of navigation.
 
I was going to say Cylinder Head Temperature (reacts faster than Oil, but Oil would be #2)
While I agree the response might be a little faster CHT gauging isn't even required by CFR so it can't be all that important in the universal sense.

Actually I think the question is absurd or unanswerable, kinda like asking which organ is the single most important in an animal body. There might be a few one could live without but there are plenty that are needed.
 
Personally, I could live with nothing in VMC but I'll take an ASI if I could have it. A close second would be an altimeter.

In IMC, as a practical matter, you probably aren't going to have a AI as your only functional instrument unless it's a standalone AHRS unit. But yes that would be my choice if I could have it. Really, all that's going to do for me is keep me upright until I can either climb or decend to visual conditions. Very doable if you're over flat ground with at least a few hundred feet of ceiling.

Also your gyro instruments can tumble if you exceed their allowable bank, except for the TC. So I'd probably take that in my plane if I couldn't have a functional AI.
 
While I agree the response might be a little faster CHT gauging isn't even required by CFR so it can't be all that important in the universal sense.

Actually I think the question is absurd or unanswerable, kinda like asking which organ is the single most important in an animal body. There might be a few one could live without but there are plenty that are needed.

Is it? Some feel no instruments are necessary for VMC, and I think most people could agree that only one is needed to survive IMC if the conditions permitted.

Plus I'm allowed one absurd question a year.
 
............................
Also your gyro instruments can tumble if you exceed their allowable bank, except for the TC. So I'd probably take that in my plane if I couldn't have a functional AI.
That's the reason I'd prefer the T&B (or TC) in favor of the Attitude Indicator. The AI's you'll find in most if not all light GA airplanes will tumble if certain attitude limits are exceeded leaving you with nothing, the T&B (or TC) won't tumble. The AI operates on the principle of gyroscopic rigidity in space while the T&B operates on the principle of gyroscopic precession.
 
Is it? Some feel no instruments are necessary for VMC, and I think most people could agree that only one is needed to survive IMC if the conditions permitted.

Depending on what's below and whether or not your airplane has a parachute you can survive IMC with no instruments. A "common" IMC escape plan in days past was to deliberately spin the airplane and hold pro-spin controls until you came out of the clouds. I'd hate to try that in a twin given their propensity to resist spin recovery but it should be very survivable in most singles as long as there's room below the clouds to regain straight and level.

And if you're range is limited to a flying within an area of low IMC, no single instrument is going to save your bacon. Your AI might allow you to remain upright but it won't help avoid crashing into the ground when you eventually return to earth for lack of fuel.

Plus I'm allowed one absurd question a year.
Heck, this is the internet. There is no limit on absurd questions here.:D
 
As I recall in the 1938 "A" model Taylorcraft the instrument panel was dominated by a HUGE tachometer, so I must assume that C G Taylor considered the tach the most important instrument for VFR flying, either that or he got a really good deal on a truckload of 10" tachometers?
OTOH if I'm limited to just one instrument in IMC I'm gonna' invent a new instrument...........unveil my NEW combined "turnandbankairspeedindicator" (needle, ball & airspeed all rolled into one).
 
VMC: HSI

IMC: HSI

Why HSI instead of attitude indicator?

Well, I'm assuming that everything goes to crap at once while I am already in IMC and in cruise. So, I'm already trimmed out for pitch. I'm also already leaned to just this side of rough. So I don't really have to worry about my altitude getting lower. If I come down too much my engine will get rough from being too lean. So, I just climb a little bit. As I burn off fuel I'm going to get lighter, so I am going to naturally climb anyway. Altitude is our friend. So that takes care of my vertical part of the AI.

The HSI will show me if I'm turning more accurately than the AI will. And with an HSI I know where I'm going. And no, I'm not using the VOR/GPS navigation on it. If the HSI isn't showing a turn, I'm not in a bank. If I'm not in a bank, I don't have to worry about going into a spin.

Them be my answers.

Nice explanation, I like the thought behind it.


I like it too, but it was SCREAMING in my head that Ed can't lean his engine:rofl:
 
So why are so many of you saying oil temp indicator for day vfr? I would say ASI.
 
So why are so many of you saying oil temp indicator for day vfr? I would say ASI.

They are either joking, or noting that in day VFR engine performance is more important than situational instrumentation. I mean I agree with that, it wasn't my intent to include navigational or engine instrumentation but the point is well taken.
 
They are either joking, or noting that in day VFR engine performance is more important than situational instrumentation. I mean I agree with that, it wasn't my intent to include navigational or engine instrumentation but the point is well taken.

That's what I thought; I just wanted to make sure they didn't know something I don't!
 
If your instruments failed and you could have only one:

Day VFR?

In IMC?

I know my answer for the first. The second I'm conflicted a little bit. What say you?

In both cases: My iPad mini/Garmin Pilot App/GDL39 3D [that's all one instrument btw :rofl:.

Gene
 
VFR: fuel guages

IFR: turn and bank or a tuba



Because if I'm going to graveyard spiral in, I just think it would be cool to be playing a tuba. You could blow on it like BLAAAAAAAAAAAAAAAAAAAA! at the world as you meet the ground. Later, when they find you, someone would say, "looks like he was playing a ****ing tuba!!!" wtf? :happydance:
 
Yeah and iPhone will kick its ass. Certainly we have options these days we didn't ten years ago.
 
Reality for IMC, with one instrument you are likely dead.

Best bet in IMC with only one allowed instrument would be the attitude indicator. Set a pitch and guess at power that should give me a slow descent. Then I'd just hope I break out before I hit the ground.

In my neck of the woods, in light aircraft, you'd survive the vast majority of the time with that strategy.
 
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