Pinnacle NTSB Update

[zonker]

I flew the CRJ for 4.5 years, and I always operated it in V/S mode and monitored the speed profile, which was 290/.74 at the time. A little faster than that doesn't hurt, either. Occasionally in turbulence I would fly it in pitch mode because it would tend to chase the V/S as well. IAS mode is almost completely useless in this airplane, IMO. The lack of power becomes apparent above FL 200 (and during a v1 cut), and Oakum Boy is correct... once you've lost your airspeed, it's not coming back except in a level off or a descent.

It may be "certified" for 410, but what is reasonable or practical in this airplane is another matter entirely.

 

[upndsky]

In the Jungle Jet, I'll fly FLC to 10,000 feet, which is a speed hold of 240 KIAS. Past 10K, I'll dial down the VSI to 1,000 fpm and let the plane accelerate to 290-300 KIAS. Then I'll crank up the VSI to 1,500-2,000 fpm (depending on weight, temp). When the speed hits .65M, I'll set the VSI to maintain that.

I don't have a whole lot of time in the ERJ, but it seems to work well.

 

[patq1]

MANY aircraft cannot be flown to altitude on FLC or IAS hold as they will oscillate so much that you look terrible nevermind practically throw-up. Most will FLC well through the early 20's but after that the use of VS and auto-throttles maxed seems to be pretty standard (for those who know where the Airspeed Indicator is)

In these I will include Global Express, Falcon 50EX, Falcon 900EX, and Galaxy. And the oldest one of the bunch I have flown is a 2001 model. (Not really OLD planes and autopilots)

If you need FLC or IAS to keep you safe in a climb you have no business flying a jet.....(or chewing gum really).

jesh...common sense folks.....

I agree completely. You can add the Hawker 800,800XP, and Challenger 600 to that list. I am appalled at some of the things I see posted here. Most of the airplanes that we fly will only go to their max altitude under very restrictive conditions of weight and temperature. You better have the numbers right or you are not going to make it. No amount of hoping or wishing is going to change the physics involved. But then again if you are trying for an altitude that is unattainable(temps higher than forecast, for instance) you don't just suddenly fall out of the sky. It becomes readily apparent well before you reach that point. It then is your responsibility to inform ATC and head back down. Or if the situation is becoming dangerous start down and then tell ATC but obviously it should never get that far.

pat

 

[Captain X]

Would this really be an issue if "regional jets" were actually powered the way a jet should be? (I say that tongue in cheek). But by that I mean a jet should be able to:

1. Takeoff
2. Accelerate to Vmo/Mmo
3. Climb at Vmo/Mmo
4. Cruise at Vmo/Mmo
5. Descend at Vmo/Mmo
6. Slow down
7. Land
8. Go have a beer

Anything slower than that should be commanded by the pilot. And any aircraft should have the available thrust to climb to its maximum service ceiling at its maximum weight, stay there and have its full operating envelope available. When I'm the boss I will fix this!

The derated engines that they hang on aircraft these days for economical purposes (JET SPEED TURBOPROP EFFECIENCY) are also a factor that hampers climb performance in modern small passenger jets.

On the 145 at least we get a couple of options:

1. Clog the departure route with a climb speed 30-40 KTS slower than most of the bigger planes and have ATC get grumpy with us.

2. Clog the departure route with a climb rate 500-1000 FPM slower than most of the bigger planes and have ATC get grumpy with us.

Of course I'm partly joking about that but I think ya'll get my point.

 

[NewBlue]

I remember a regional coming out of Denver a while back in a CR7 that put it in v/s mode and then went into the ignore mode.........until the stick shaker went off that is.

 

[Oakum_Boy]

That's why Pitch mode is the safest and sometimes most accurate mode to climb in. If for some reason its forgotten, it will just level off and maybe start descending once the wings get tired...

 

[patq1]

That's why Pitch mode is the safest and sometimes most accurate mode to climb in. If for some reason its forgotten, it will just level off and maybe start descending once the wings get tired...

Yes it will start descending once you stall. I sincerely hope you were kidding.

 

[Oakum_Boy]

Yes it will start descending once you stall. I sincerely hope you were kidding.

Keep in mind this is a theoretical exercise and never to be tried except in a simulator. Having said that; say you have a +2.0 degree deck angle set. As you climb into less dense air your V/S will decrease until the aircraft levels off and maybe descends, eventually finding equillibrium. This is considering everything else is stable, like the air and available CLB thrust is maintained. It is in my opinion an accurate way to climb, but into the higher flight levels, V/S is better for control of the profile.

Conversely, consider setting vertical speed at 500 fpm and letting it go. As air density decreases, the airplane will CONTINUE TO PITCH UP to achieve the desired climb rate. When it runs out of energy, it will stall.

HOWEVER- The CRJ autopilot will disconnect at a predetermined AOA, coincident with the stick shaker.

Of course one should never find himself in this scenario, but for the sake of pondering the attributes of this fine aircraft....

 

[enigma]

I think we answered this one. I don't think any of us are advocating using anything, just pointing out that it is not unsafe and sometimes preferable in terms of operational technique. I would think anyone who's climbed in FLC/IAS in the 30000' flight regime in chop could testify to this. The other point is certain groups of people are always looking for ways to make operations "fool-proof," which is impossible (partly because fools are so ingenious).

To answer your question, obviously one still must maintain an operationally safe airspeed within the recommended flight envelope by simply rolling down the selected vertical speed. Come on man, what's the alternative?

h25b, I'll be the first to admit that I'm a not your average bear and maybe my thought processes work differently than most, so I recognize that my quirks sometimes make my hard to follow.
Sorry.

You wrote, "obviously one still must maintain an operationally safe airspeed within the recommended flight envelope by simply rolling down the selected vertical speed."

What's the difference between you varying the rate of climb with the VS wheel, and me varying the rate of climb with airspeed? To me, you're doing the same thing that I am, except that I have airspeed protection and you don't.

enigma

 

[73belair]

h25b, I'll be the first to admit that I'm a not your average bear and maybe my thought processes work differently than most, so I recognize that my quirks sometimes make my hard to follow.
Sorry.

You wrote, "obviously one still must maintain an operationally safe airspeed within the recommended flight envelope by simply rolling down the selected vertical speed."

What's the difference between you varying the rate of climb with the VS wheel, and me varying the rate of climb with airspeed? To me, you're doing the same thing that I am, except that I have airspeed protection and you don't.

enigma

The why do you set the VS mode rather than IAS mode in the CRJ is because above about 15k or so and all the way up it pitches a lot to keep the speed. You can see the VS vary anywhere from 15000fpm to 500fpm. So we set it to VS and monitor the airspeed. It is different because we are able to keep the airplane from pitching up and down trying to keep the speed. As speed decreases we decrease the climb rate to compensate. So rather and an up and down nose we just have a slowly settling down nose. Once we get to 500fpm on the VS mode we let it climb that way until it gets to cruise. No pitching. Climb is (after 10k ft) 290/.70, and the airspeed can bleed back to 250 in the climb, but no lower.

 

[enigma]

That is, IMO, extremely poor advice. Many autopilots will get into pitch oscillations when in airspeed/mach hold. Climbing in VS mode is fine...just PAY ATTENTION to the airspeed and AOA(if installed).

THAT I agree 100% with. I've seen guys try it...and had to stop them. Those min speeds are there for a reason. Many people say "but there's a safety factor built in, so we can go a little below it". Bullsh!t. I'm not a test pilot. I'm not going to test the limits of any jet at high altitude unless I'm trained to do so.

And that makes for a very sloppy ride for the pax.

FracCapt, I may have been slightly too adamant by using NEVER, but I do believe that my advice is acceptable in the context in which it was given. This advice was directed toward new jet pilots, especially toward guys who are flying heavily loaded, poor performing airline aircraft.



I don’t disagree that there is nothing unsafe about utilizing VS for a long climb, but it is not the safest way, especially when you are approaching the edge of the envelope. I’ve used VS and or pitch hold myself, but that was in a Lear with performance to spare. In DC9’s and Super80’s the oscillations you refer to are of small amplitude. I doubt that the pax ever even notice if the climb rate varies between 500 and 1500fpm.

Let me approach the subject this way. The laws of physics apply to the airplane regardless of the method used to control the climb. Assuming that we all climb at maximum climb power, and recognizing that aircraft climb ability changes due to atmospheric variations during the climb, the aircraft is not capable of a consant rate of climb. You can either manually use verticle speed mode and vary the verticle speed in response to the changing conditions, or you can use speed hold. Either way, the rate of climb will not remain constant, but the pilot climbing in speed hold will have airspeed protection.

enigma

 

[enigma]

The why do you set the VS mode rather than IAS mode in the CRJ is because above about 15k or so and all the way up it pitches a lot to keep the speed. You can see the VS vary anywhere from 15000fpm to 500fpm. So we set it to VS and monitor the airspeed. It is different because we are able to keep the airplane from pitching up and down trying to keep the speed. As speed decreases we decrease the climb rate to compensate. So rather and an up and down nose we just have a slowly settling down nose. Once we get to 500fpm on the VS mode we let it climb that way until it gets to cruise. No pitching. Climb is (after 10k ft) 290/.70, and the airspeed can bleed back to 250 in the climb, but no lower.

What do you do if the speed decays after you reach 500fpm?

I fear that I've given you guys the wrong impression. I completey understand why you climb in VS. I just don't agree that doing so is as safe, or as efficient as climbing in a speed hold mode.

enigma

 

[Hugh Johnson]

Climb in VFLC

We program our 900EX to climb at 300/.80. Climb in VFLC and that protects you. FMS will descend to maintain if it has too.

Having said that, we never try to outclimb the gross weight either. The 900 and 50 seem to be very sensitive to ISA plus anything. If we're close to a published climb weight and its not minus 10, we'll wait till the next weight. We've also noticed on the 50 that if the trim is less than 2 degrees nose down you can usually climb to the next FL.

We used to have a C650 that was certified to 510, but at a weight less than our BOW. Made it to 46700 once, but the wing started rumbling so we descended.

When I flew for Eagle, it was standard to fly in VS but it was also standard to forget and open the paper and get the shaker. It was pretty funny the second time and always funny when it happend to someone else.

 

[73belair]

What do you do if the speed decays after you reach 500fpm?

I fear that I've given you guys the wrong impression. I completey understand why you climb in VS. I just don't agree that doing so is as safe, or as efficient as climbing in a speed hold mode.

enigma

That is where being a pilot with training comes in handy. If you can't do at least 250kts and 500fpm then you arn't going to get to your cruise altitude and you need to pick a lower one. Simple as that. I don't know about other places, but this is hammered into us at ASA. You can look at the charts in the airplane, but usually there are so many other outside things that you just need to only do what the airplane is telling you it can do.

 

[h25b]

Enigma,

Sorry if I came off as a butthead (happens often... ). Anyway, I think you will find that using VS gives you a much more stable climb. Like I have said, when you get in to chop or start having large ISA variations you'll start to see the autopilot "chase" for the selected airspeed. The result WILL BE that the pitch oscillates up and down. Just not the result people expect from a professional pilot. Likewise as I stated earlier, in some instances that I have personally witnessed when you're getting larger temp. variation during turbulent conditions the autopilot simply cannot manage it and you'll end up with airspeed variations as well. So in that case you just lost the airspeed protection. So, in my opinion climbing in FLC/IAS is not the more safe way to go and it is certainly not better in terms of aircraft control and passenger comfort.

By the way, like the other guy said... If you cannot maintain 500'/min and the min climb airspeed that just simply means that the aircraft is not capable of climbing to that altitude under those conditions...