Flying in the Yellow Arc

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Martymccasland

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M.McCasland
Do any of you regularly fly smooth air in the yellow arc?

I recently bought an A36 and gently manage my descent to stay in the green arc -- at the very top of the green arc, admittedly, but still in it.

I realize the yellow is there for smooth air only, but up to the A36, I haven't owned a plane that could very easily get there -- so it was more of a theoretical limit than a real limit to me for normal (with the family) flight attitudes. Now with just a couple degrees nose-down, the plane will race deep into the yellow arc unless power is carefully managed.

I've decided to just keep the plane completely out of the yellow arc all the time. There seems to always be a bump or two, even on very calm mornings or late nights, that come out of nowhere then never reappear for the rest of the flight. Occasionally, a larger magnitude surprise bump or two comes out of nowhere on an otherwise calm night -- large enough to potentially become an issue if I was 20 knots deep into the yellow.

'Leaves me thinking if there's ever a good time to be the yellow -- since I have no idea when those rogue bumps are coming and don't feel like it's a good gamble just to shave 10 mins off a flight by screaming down on the descent.

Do some of you veteran pilots intentionally put it in the yellow? Any deeper judgement tools use other than "it's a pretty smooth night out" before going there? Or do you always just avoid it?

Thanks in advance for the responses & teaching...
 
I'm with you. The top of the haze layer or clouds are good indicators of the altitude at which the bumps start, but not guarantees. It's usually bumpier lower, so I just manage the power accordingly. Time difference can't be more than a minute or two. Not that it matters to you, but when the A-36 is converted to turbine the yellow line turns red.

Martymccasland said:
Do any of you regularly fly smooth air in the yellow arc?

I recently bought an A36 and gently manage my descent to stay in the green arc -- at the very top of the green arc, admittedly, but still in it.

I realize the yellow is there for smooth air only, but up to the A36, I haven't owned a plane that could very easily get there -- so it was more of a theoretical limit than a real limit to me for normal (with the family) flight attitudes. Now with just a couple degrees nose-down, the plane will race deep into the yellow arc unless power is carefully managed.

I've decided to just keep the plane completely out of the yellow arc all the time. There seems to always be a bump or two, even on very calm mornings or late nights, that come out of nowhere then never reappear for the rest of the flight. Occasionally, a larger magnitude surprise bump or two comes out of nowhere on an otherwise calm night -- large enough to potentially become an issue if I was 20 knots deep into the yellow.

'Leaves me thinking if there's ever a good time to be the yellow -- since I have no idea when those rogue bumps are coming and don't feel like it's a good gamble just to shave 10 mins off a flight by screaming down on the descent.

Do some of you veteran pilots intentionally put it in the yellow? Any deeper judgement tools use other than "it's a pretty smooth night out" before going there? Or do you always just avoid it?

Thanks in advance for the responses & teaching...
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My risk tolerance is lower than Henning's (probably my butt-smack tolerance, too), so I don't fly in the yellow arc except in truly smooth air. Even light turbulence slows me back to the green, and moderate turbulence gets me down to turbulence penetration speed (usually Va, i.e., maneuvering speed, in a light single). But in smooth air? Any time.
 
I've had this conversation with the professor of the applicable studies from the Daytona Beach educational establishment. His take on it - he flies in the yellow all the time and wouldn't worry about it unless he's near the mountains known for the wing-snapper shears and such

YMMV etc
 
In the 172, it's a stretch to even get there. But as soon as I finish my RV, maybe I'll just cruise at Vne all the time....

:stirpot:
 
Generally I stay green only because wind noise is quite loud when I get in the yellow (170 kts) on the Glasair. Structurally I'm not really worried flying in the yellow in smooth air.
 
Yellow arc? Coming down from 11-thousand with a wife open throttle maybe. LOL. What's a yellow arc? :)
 
Let me reiterate that my biggest reason for staying out of the yellow arc except in truly smooth air, and below Va in moderate or greater turbulence, is comfort, not safety.
 
moonshine said:
I've had this conversation with the professor of the applicable studies from the Daytona Beach educational establishment. His take on it - he flies in the yellow all the time and wouldn't worry about it unless he's near the mountains known for the wing-snapper shears and such

YMMV etc
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Yeah, professors are usually a great source of information for flying or doing anything else in the real world. Which one of the faces is for dripping sarcasm ?
 
Do the yellow in smooth air with no problem,start to get some bumps throttle back. When VFR you can usually feel the aircraft and fly accordingly.
 
Flew in the yellow arc in smooth air in a Cherokee Six (Constant speed prop)
 
frfly172 said:
Do the yellow in smooth air with no problem,start to get some bumps throttle back. When VFR you can usually feel the aircraft and fly accordingly.
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Why? Yellow arc is to warn against full deflection of flight controls. Bumps and throttle back? Why? Read the FAA's definition of turbulence. Moderate = things flying around the cabin. Severe means structural damage. :dunno:
 
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I fly in the yellow routinely in smooth air.

It never saves any time but it does help my think that those extra few knots are what I am spending this dough for...
 
For me the yellow arc usually started about three hours into a patrol, depending on how much coffee I had.......What? Oh..... Never mind.
 
Ron Levy said:
Let me reiterate that my biggest reason for staying out of the yellow arc except in truly smooth air, and below Va in moderate or greater turbulence, is comfort, not safety.
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I think the issue in my mind is (was) how I personally was defining "smooth air". Smooth air in my mind was perfect air -- no slight bubbles, bumps, or anything at all. Late at night, early in the morning, etc. i.e Maybe 5% of the time, tops.

If I am hearing the crowd right, "smooth air" can have a few minor "bubbles" every once in a while, just nothing at all like true "bumps" from clouds, a ridge pushing up air, going through a mixing layer, an big inversion, a really hot day down lower, around cumulus build-ups, etc.?
 
Geico266 said:
:redface:

Why? Yellow arc is to warn against full deflection of flight controls. Bumps and throttle back? Why? Read the FAA's definition of turbulence. Moderate = things flying around the cabin. Severe means structural damage. :dunno:
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Like that extra security,but thanks.
 
Henning said:
Sure, a "bump or two" in the yellow arc is not a big deal.
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I'm with Henning, I routinely keep cruise power set when coming down at 500fpm. This results in an airspeed right in the middle of the yellow, about 182-185kts. From everything I've read, the plane handles normal bumps well at this speed.

Note: Normally as I pass thru 5000msl on the way down I start doing 1" power reductions every minute or so and am normally down to 23" and 2400rpm by the time I'm at 3000msl.

When do I pull it back? My gut knows.
 
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I've never even gotten close in a 172. However, I have gotten well in the yellow arc on a Lance and in a Comanche 250.
 
frfly172 said:
Like that extra security,but thanks.
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I agree, security is nice, but once you understand what the yellow arc means ( not what the CFI told you) then you'll understand that slowing down because of "bumps" in the yellow is completely unnessessary.

Do you see commercial planes slowing down at altitude when they are in bumps? :no:

I've flown humpndreds of hours in the yellow in all kinds of bumps and light turbulence. :dunno:
 
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Geico266 said:
Why? Yellow arc is to warn against full deflection of flight controls. Bumps and throttle back? Why? Read the FAA's definition of turbulence. Moderate = things flying around the cabin. Severe means structural damage. :dunno:
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Maybe I'm reading your statement wrong -- but it sounds like you're talking about Va and not the yellow arc -- i.e. "full deflection of flight controls". In my last two planes, at least, there's a good bit of green arc above Va. I can do a good bit of damage without being in the yellow arc by doing "full deflection of flight controls". Maybe it's different in your plane.

One can even do damage with full deflections at Va in some planes, the A36 being one of them. See Chapter 4 in John C. Eckalbar's "Flying the Beech Bonanza"... also the Beech POH calls out to do Chandelles, Steep Turns, etc. 7 knots BELOW Va -- at least -- which is a good 35 knots below the yellow arc.
 
Geico266 said:
Do you see commercial planes slowing down at altitude when they are in bumps? :no:
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Bad argument. Those "commercial planes" have a maximum operating (i.e. redline) airspeed that is equivalent to Vno.

14 CFR 23.1505
 
dmspilot said:
Bad argument. Those "commercial planes" have a maximum operating (i.e. redline) airspeed that is equivalent to Vno.

14 CFR 23.1505
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Possibly, thanks. I don't know commercial aircraft, I know GA piston operating parameters.

There is no reason to slow down if flying in the yellow arc and you hit a few bumps. And this is in experimentals ! :eek:
 
dmspilot said:
Bad argument. Those "commercial planes" have a maximum operating (i.e. redline) airspeed that is equivalent to Vno.

14 CFR 23.1505
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I don't think you read far enough down the page.

(c) Paragraphs (a) and (b) of this section do not apply to turbine airplanes or to airplanes for which a design diving speed V D /M D is established under § 23.335(b)(4). For those airplanes, a maximum operating limit speed (V MO /M MO -airspeed or Mach number, whichever is critical at a particular altitude) must be established as a speed that may not be deliberately exceeded in any regime of flight (climb, cruise, or descent) unless a higher speed is authorized for flight test or pilot training operations.
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http://www.law.cornell.edu/cfr/text/14/23.1505

Besides, I just noticed that was Part 23 whereas transport category jets are certified under Part 25.
 
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Geico266 said:
Why? Yellow arc is to warn against full deflection of flight controls. Bumps and throttle back? Why? Read the FAA's definition of turbulence. Moderate = things flying around the cabin. Severe means structural damage. :dunno:
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You might want to go into the books to review the difference between maximum structural cruise speed (the point where the green arc turns yellow) and maneuvering speed (Va). You seem to have them backwards. Va is the speed above which sudden full deflection of any control may break the airplane, while the yellow arc is where a vertical gust of a defined magnitude may break the airplane.
 
Martymccasland said:
I think the issue in my mind is (was) how I personally was defining "smooth air". Smooth air in my mind was perfect air -- no slight bubbles, bumps, or anything at all. Late at night, early in the morning, etc. i.e Maybe 5% of the time, tops.

If I am hearing the crowd right, "smooth air" can have a few minor "bubbles" every once in a while, just nothing at all like true "bumps" from clouds, a ridge pushing up air, going through a mixing layer, an big inversion, a really hot day down lower, around cumulus build-ups, etc.?
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I think the problem there is deciding what's a "bubble" and what's a "bump." Basically, if the I'm not comfortable, I slow until I am.
 
Ron Levy said:
You might want to go into the books to review the difference between maximum structural cruise speed (the point where the green arc turns yellow) and maneuvering speed (Va). You seem to have them backwards. Va is the speed above which sudden full deflection of any control may break the airplane, while the yellow arc is where a vertical gust of a defined magnitude may break the airplane.
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I see your point Ron, but we are not talking about turbulence, the OP is talking about "bumps". Most pilots over exaggerate turbulence. This is actually a real problem for controllers when pilots give PIREPS. Once the definitions of light, moderate, and severe are understood, flying in the yellow "with bumps" is not dangerous, and well within the operating limits of most aircraft. We (as I understand it) are talking about "chop" not FAA defined "turbulence".
 
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Everskyward said:
I don't think you read far enough down the page.

(c) Paragraphs (a) and (b) of this section do not apply to turbine airplanes or to airplanes for which a design diving speed V D /M D is established under § 23.335(b)(4). For those airplanes, a maximum operating limit speed (V MO /M MO -airspeed or Mach number, whichever is critical at a particular altitude) must be established as a speed that may not be deliberately exceeded in any regime of flight (climb, cruise, or descent) unless a higher speed is authorized for flight test or pilot training operations.
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You didn't read far enough. Why did you cut off the regulation in the middle of a paragraph?

The part you quoted says what I just said: that Vne and Vno don't apply to turbine and transport category; instead, a Vmo is established.

The part you cut out stated that the Vmo may not exceed the design cruise speed (Vc).

On a piston aircraft, Vno is equal to design cruise speed (Vc) or 89% of Vne, whichever is less.

Therefore, what I stated was correct. The "redline" speed in a turbine or transport category aircraft is equivalent to Vno (top of the green arc, bottom of the yellow arc) on a piston.

Everskyward said:
Besides, I just noticed that was Part 23 whereas transport category jets are certified under Part 25.
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You are right, but 25.1505 is similar to 23.1505(c).
 
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dmspilot said:
Bad argument. Those "commercial planes" have a maximum operating (i.e. redline) airspeed that is equivalent to Vno.

14 CFR 23.1505
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Commercial aircraft (transport) have turbulence penetration speeds.

A320/319 is 250kts to FL200, 275Kts to FL300 or .76M
 
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dmspilot said:
Therefore, what I stated was correct. The "redline" speed in a turbine or transport category aircraft is equivalent to Vno on a piston.
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Actually it's closer to Vne than Vno since you are not supposed to exceed it. Also, as Ron says, there is a turbulence penetration speed which is lower but not as low as Va.
 
I actually fly a plane that is capable of cruising in the yellow arc. Now, it's only capable of doing it in the winter and at 5,000 ft, but it's capable of doing it there at 25 squared (basically max cruise/ROP). I did it when breaking in the engines, but otherwise I try to avoid being in the yellow, especially since it gets bumpier lower.

Do I think the wings are going to fall off? No, I don't. They get checked every annual and they're in very nice shape. I also don't see a point in stressing a 45 year old airplane that we're looking at keeping another several decades any harder than necessary. My landings are hard enough. :D
 
Geico266 said:
I see your point Ron, but we are not talking about turbulence, the OP is talking about "bumps".
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You want to quibble over "bumps" versus "turbulence," leave me out of it -- that's a subjective discussion. I've yet to see any official FAA definition of a "bump", but they do have definitions in the AIM of the various types and levels of turbulence, so that's the term I understand and use.
 
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