E170/190 Angle of Attack

[Check Airman]

Hi all,

The E170/E190 series doesn't have angle of attack vanes. How does it sense AoA?

[Chesty Morgan]

Smart probes.
http://utcaerospacesystems.com/cap/systems/sisdocuments/Air%20Data%20Products%20and%20Systems/SmartProbe(R)%20Air%20Data%20Systems.pdf

[Amadis of Gaul]

PFM principle.

[Piltdown Man]

And now for the real killer. These aircraft use the "Smart" data to drive the flight path vector. The flight path vector cannot be removed from the PFD. After a few hundred hours you forget the actual pitch associated with any aspect of your flight. You and the autopilot merely drive the FPV onto the flight path target. What could possibly go wrong? Erm... birdstrike (bee strike), pitot heat, writing, leak, system failure etc. followed by one EICAS message and a double ding you now are flying with invalid FPV data. You have three systems and one or two of them are telling lies. You can't get rid of the FPV and possibly both sides have different FPV values (or both are wrong, both are right or No. 3 is invalid, but it's not displayed) and the pitch you need is... Oh, and you need to kill the auto throttle before it kills you as a well.

I notice they don't crow about how simple it is to deal with system failures.

[gearlever]

I had a look on smart probes website, but it still puzzles me how they derive AOA from a probe what looks like a pitot probe.

[Check Airman]

Smart probes.
http://utcaerospacesystems.com/cap/systems/sisdocuments/Air%20Data%20Products%20and%20Systems/SmartProbe(R)%20Air%20Data%20Systems.pdf

Thanks for the link. I think it sent me in the right direction.

[Check Airman]

I had a look on smart probes website, but it still puzzles me how they derive AOA from a probe what looks like a pitot probe.

Apparently there's another hole underneath the dynamic pressure port that is used to drive AoA data.

[Check Airman]

And now for the real killer. These aircraft use the "Smart" data to drive the flight path vector. The flight path vector cannot be removed from the PFD. After a few hundred hours you forget the actual pitch associated with any aspect of your flight. You and the autopilot merely drive the FPV onto the flight path target. What could possibly go wrong? Erm... birdstrike (bee strike), pitot heat, writing, leak, system failure etc. followed by one EICAS message and a double ding you now are flying with invalid FPV data. You have three systems and one or two of them are telling lies. You can't get rid of the FPV and possibly both sides have different FPV values (or both are wrong, both are right or No. 3 is invalid, but it's not displayed) and the pitch you need is... Oh, and you need to kill the auto throttle before it kills you as a well.

I notice they don't crow about how simple it is to deal with system failures.

What's worse is that the FPV is in front of the crntre dot of the miniature airplane, and thus partially obscures the attitude indication. A truly horrible design.

[FE Hoppy]

It's a flight path angle on the EJet PFD. Not a Vector.

And the pitch attitudes are in the QRH

[Amadis of Gaul]

Those who need the QRH to know their pitch attitudes have bigger problems than an FPA indication.

[Check Airman]

On the 190, the design philosophy seems to have been that attitude is a secondary parameter, as the FD only shows the flight path you need, and not the pitch. It's a most asinine system.

[simmple]

On the 190, the design philosophy seems to have been that attitude is a secondary parameter

Have things changed in the magenta following world that pilots or should they now be called aircraft operators no longer fly pitch and power= performance, they just blindly follow a vector!

[Check Airman]

Perhaps at the Embraer factory. Thankfully Boeing and Airbus still know what they're doing.

[Chesty Morgan]

Those who need the QRH to know their pitch attitudes have bigger problems than an FPA indication.

Where else are you going to get them?

[Amadis of Gaul]

Experience, my brother, experience.

[Amadis of Gaul]

Have things changed in the magenta following world that or should they now be called operators no longer fly pitch and power= performance, they just blindly follow a vector!

And that's not even the worst of it, I fear...

[Chesty Morgan]

So you can remember ALL combinations of pitch and power for every airspeed, weight, altitude, aircraft configuration, climb, cruise, descent and holding?

Because at the last count there are 115 different combinations in my QRH with plenty of interpolation available.

[FE Hoppy]

And for those banging on, the CSeries has FPV as primary too.
Like the Ejet, the pitch indication is always in view and the same style pitch tables are available in the QRH.

Welcome to the 21st century ;-) no bits of string tied to the windscreen required.

[Amadis of Gaul]

So you can remember ALL combinations of pitch and power for every airspeed, weight, altitude, aircraft configuration, climb, cruise, descent and holding?

Because at the last count there are 115 different combinations in my QRH with plenty of interpolation available.

I don't need to remember all of them, TLAR principle does wonders. Airmanship is an amazing thing.

[Chesty Morgan]

No you don't because some clever chap has published then for you.

The correct use of airmanship is an amazing thing. The incorrect use of ego isn't.

[Amadis of Gaul]

What ego, O Chesty of My Soul? Airplanes flew long before the 170/190 and will long after. Physics haven't changed, aerodynamics haven't changed.

Outta curiosity, what do you plan on doing one fine day when the QRH is not available (for whatever reason)? Are you up the proverbial small river without the similarly proverbial rowing device or what?

[Piltdown Man]

It's not too difficult to fly once you have realised what is going on. The difficult bit is working out which system/s are correct and which are wrong.

[Chesty Morgan]

The ego part of thinking what you think looks about right is better than flying the actual pitch and attitude you need to achieve the performance you need.

The chances of not having either of the two electronic QRHs or the two paper QRHs available when we need them is minute but I guess that's why we also have a broad stroke memory item. That would also be the time to employ airmanship.

[Vessbot]

The ego part of thinking what you think looks about right is better than flying the actual pitch and attitude you need to achieve the performance you need.


Surely you're not suggesting that one look up the pitch from a 115 cell table every time time he changes the attitude. Then what other option is there but to TLAR it first, and then fine-tune based on the performance instruments?

[Chesty Morgan]

No.........

[Amadis of Gaul]

Surely you're not suggesting that one look up the pitch from a 115 cell table every time time he changes the attitude. Then what other option is there but to TLAR it first, and then fine-tune based on the performance instrument?

That's exactly what he's suggesting.

[Vessbot]

No.........

Then what?

That's exactly what he's suggesting.

I refuse to believe such an absurdity unless he says it explicitly. Principle of charity, and all that.

[Amadis of Gaul]

I refuse to believe such an absurdity unless he says it explicitly. Principle of charity, and all that.

He HAS said it explicitly. In fact, he labeled anything else "excessive ego".

[Chesty Morgan]

No I haven't.

[Vessbot]

So what is it?

[Chesty Morgan]

What is what?

[Vessbot]

What are you suggesting regarding the proper setting of pitch attitude?

[Chesty Morgan]

I'm suggesting that to achieve the performance you require then you fly the correct pitch and power settings.

It might help you to understand that, in normal circumstances, we don't fly pitch and power.

[Vessbot]

I'm suggesting that to achieve the performance you require then you fly the correct pitch and power settings.



That sounds reasonable. But the discussion was already at a point beyond that. So how do you know the correct pitch and power settings to fly?

[Chesty Morgan]

No, the discussion was at the 'I know better so I'll make it up' point.

I don't. No, I can't know them all. That's why the same nice man who Amadis is going to ignore has provided them for me.

[Vessbot]

I don't. No, I can't know them all. That's why the same nice man who Amadis is going to ignore has provided them for me.

I guess I wasn't as clear as I thought. I didn't mean knowing them as in being able to recite them to me on the forum, but rather knowing them as in applying them in the cockpit. (Flight director aside, of course.) So, while flying, how do you set the correct pitch and power?

[Chesty Morgan]

Like I said, they're all in the QRH.

[Vessbot]

Like I said, they're all in the QRH.

I don't understand. What do you do with this information? When I said "Surely you're not suggesting that one look up the pitch from a 115 cell table every time time he changes the attitude" you flatly said "no." So you don't look it up when you're flying, you don't memorize them all (as you've said a few times, it's impossible), then what do you do?

[Chesty Morgan]

I use it when I need it.

We don't fly pitch or power (no airliner I've ever flown requires it), in normal circumstances, so there's no need to refer to any table, in normal circumstances.

[Vessbot]

You've said what you don't do (many times over), but my question is, what do you do?

[Chesty Morgan]

Many times I've also said I will refer to it when I need it. It's in the QRH, feel free to go and have a look why.

[Amadis of Gaul]

We don't fly pitch or power (no airliner I've ever flown requires it), in normal circumstances, so there's no need to refer to any table, in normal circumstances.

Help us, Osiris, in your mercy.

[Vessbot]

Many times I've also said I will refer to it when I need it. It's in the QRH, feel free to go and have a look why.

When do you need it and when do you not? It would help me to understand your position if you gave some examples of what to do. Let's say (it's the US) you're climbing at 250 knots as you climb through 10,000 feet, and you have to accelerate to 300 knots as per the SID. It's a bog-standard day in your operation, can you walk me through what happens next?

[Chesty Morgan]

Sure, the autopilot pitches down and accelerates towards the target speed. Once there it pitches up to maintain that speed. Thrust stays at climb power. Similar in fashion to, I suggest, most other airliners in operation today. Maybe you fly something different?

You and Amadis can, I hopefully assume, read. It's all there in your QRH. I'm not going to do your leg work for you.

[Vessbot]

I guess I shot myself in the foot when I said "bog standard operation" and opened up to this type of irrelevant response that completely fails to engage with the issue already under discussion. Let me rephrase, what do you do in that situation when *you* (not the autopilot) are flying?

You and Amadis can, I hopefully assume, read. It's all there in your QRH. I'm not going to do your leg work for you.

What exactly is this a response to? What question did I ask that would be answered in a QRH? I'm lost.

[Chesty Morgan]

Yep, the response you got was entirely relevant to your question. When I am flying I would follow the flight director, pitch is irrelevant providing you maintain the minimum climb rate and thrust stays at climb power.

You asked when I need it (the only other question in your post). It tells you in the QRH when you need it.

[Amadis of Gaul]

Flight director failed. Moreover, one ASI is at 310kts while the other is at 205. Your next move, please.

[Vessbot]

Hey we don't even need that, how about simply flight director failed, and accelerate from 250 to 300?!

[Amadis of Gaul]

The chances of not having either of the two electronic QRHs or the two paper QRHs available when we need them is minute but I guess that's why we also have a broad stroke memory item. That would also be the time to employ airmanship.

BTW, what broad stroke memory item are you referring to in this case? Granted, I only flew the 170/175 for about 15 months, but I distinctly remember there being only eight memory items (four of them exactly the same) and none had to do with pitch settings.

[simmple]

When I am flying I would follow the flight director, pitch is irrelevant

Sums up todays pilots, sorry aircraft operators completely

[Chesty Morgan]

Simmple, wind your neck in. In the very specific case of accelerating by 50kts is there any reason to not follow the FD?

Vessbot, pitch down to maintain 500fpm until you approach the speed you want then pitch up to maintain it. Thrust stays at climb. Is this difficult for you to understand?

Amadis, pitch and power settings are produced for all airliners. This isn't specific to the EMB. In answer to your question, and it's pretty obvious, you establish which is the accurate instrument.

[Vessbot]

You asked when I need it (the only other question in your post). It tells you in the QRH when you need it.

That doesn't make any sense. I asked when you need the QRH. (Bizarre that that would even come up when the topic is basic fight control on a normal day.) The answer to that can't be in the QRH, because you'd need to already be looking in the QRH in the first place! So what would prompt you to do that?

Simmple, wind your neck in. In the very specific case of accelerating by 50kts is there any reason to not follow the FD?

Yes. On my airplane, the FD in this case commands a pitch down to a few hundred FPM, sometimes down to completely level flight. A bit overboard to actually do that, don't you think?

Vessbot, pitch down to maintain 500fpm until you approach the speed you want then pitch up to maintain it. Thrust stays at climb. Is this difficult for you to understand?

Yes, it is difficult, because you keep changing your story; it's especially difficult to follow with your brusque one-word fob-off replies. This is the first time in 3 pages you're making what looks like an honest attempt at actually engaging.

For a long time you kept banging on about pitch tables in the QRH, but got evasive when asked when they would come into play. Now, it seems that they don't come into play after all.

Our exchange started when I said "... Then what other option is there but to TLAR it first, and then fine-tune based on the performance instruments?" To which you flatly said "no," but now it seems like is what you're also describing.

[Amadis of Gaul]

Amadis, pitch and power settings are produced for all airliners. This isn't specific to the EMB. In answer to your question, and it's pretty obvious, you establish which is the accurate instrument.



Precisely, Chesty, precisely. The question is what pitch and thrust setting do you use while you're doing that. Besides, who is to say any of them are accurate?

[Chesty Morgan]

That doesn't make any sense. I asked when you need the QRH. (Bizarre that that would even come up when the topic is basic fight control on a normal day.) The answer to that can't be in the QRH, because you'd need to already be looking in the QRH in the first place! So what would prompt you to do that?

Is it? The topic is pitch and power settings in the QRH. Don't you know when you'd refer to them?

[QUOTE]Yes. On my airplane, the FD in this case commands a pitch down to a few hundred FPM, sometimes down to completely level flight. A bit overboard to actually do that, don't you think?

Not really. I take it you disconnect the AP every time you need to accelerate to avoid it then?

Yes, it is difficult, because you keep changing your story; it's especially difficult to follow with your brusque one-word fob-off replies. This is the first time in 3 pages you're making what looks like an honest attempt at actually engaging.

I do not keep changing anything chum.

For a long time you kept banging on about pitch tables in the QRH, but got evasive when asked when they would come into play. Now, it seems that they don't come into play after all.
You can look in your own QRH to find out when you'd use them. I'm not going to spoon feed you.

Our exchange started when I said "... Then what other option is there but to TLAR it first, and then fine-tune based on the performance instruments?" To which you flatly said "no," but now it seems like is what you're also describing.
No, you said every time you need to change pitch would I refer to the QRH. The answer is still no.

[Chesty Morgan]

Precisely, Chesty, precisely. The question is what pitch and thrust setting do you use while you're doing that. Besides, who is to say any of them are accurate?

It really isn't that difficult. Thrust stays at climb thrust and I'd pitch down to whatever achieved the minimum climb rate until I got to whatever speed I wanted.

If none of them are accurate what are you going to do?

[Amadis of Gaul]

Fly pitch and power. Which is what I've been saying all along.

[Chesty Morgan]

Yeah, some made up numbers. Yeehaw.

[Amadis of Gaul]

Not made up. They come from experience. It's called knowing one's airplane rather one's QRH.

[Chesty Morgan]

And every other variable...

Anything wrong with knowing both? Or would that not be cool?
What do you suggest someone new on type should do?

[Vessbot]

Is it? The topic is pitch and power settings in the QRH. Don't you know when you'd refer to them?

I do, but that's not my question. I'm trying to figure out your conception of flying an airplane, in normal flight.

Not really. I take it you disconnect the AP every time you need to accelerate to avoid it then?

You assume it's already connected. Most of the time it's not, and when it is, I use VS mode for that phase to avoid leveling off.

You can look in your own QRH to find out when you'd use them. I'm not going to spoon feed you.

Again, you seem to be trying to help me find my way (arrogantly, at that) to an answer to a question I didn't ask.

No, you said every time you need to change pitch would I refer to the QRH. The answer is still no.

I said both things. I can only interpret the "no" to apply to both. So now that it's cleared up that you don't use the QRH every time you change pitch in normal fight, what about "TLAR and then fine tune it with the performance instruments?" First you said "no," but then you described how you accelerate to 300 in a way that's tantamount to the same thing. So which is it?

What do you suggest someone new on type should do?

Only use the autopilot, don't bother learning the attitudes, (or any other aspect of flying the airplane) and enjoy life. After all, "we're not pilots anymore, but automation managers!"(Something said to me by a line check airman, with no hint of irony; he was in support of the notion.)

[Chesty Morgan]

I do, but that's not my question. I'm trying to figure out your conception of flying an airplane, in normal flight.
Like I said we don't use pitch and power in normal flight. How many times do I need to repeat it to you?

You assume it's already connected. Most of the time it's not, and when it is, I use VS mode for that phase to avoid leveling off.
So in manual flight you use a pitch attitude to accelerate. Why?

Again, you seem to be trying to help me find my way (arrogantly, at that) to an answer to a question I didn't ask.
I must have misinterpreted this question.
I guess I wasn't as clear as I thought. I didn't mean knowing them as in being able to recite them to me on the forum, but rather knowing them as in applying them in the cockpit. (Flight director aside, of course.) So, while flying, how do you set the correct pitch and power?

I said both things. I can only interpret the "no" to apply to both. So now that it's cleared up that you don't use the QRH every time you change pitch in normal fight, what about "TLAR and then fine tune it with the performance instruments?" First you said "no," but then you described how you accelerate to 300 in a way that's tantamount to the same thing. So which is it?
No it isn't. Where have I stated I use a pitch to accelerate?

Only use the autopilot, don't bother learning the attitudes, (or any other aspect of flying the airplane) and enjoy life. After all, "we're not pilots anymore, but automation managers!"(Something said to me by a line check airman, with no hint of irony; he was in support of the notion.)
Sad answer.

[Amadis of Gaul]

Like I said we don't use pitch and power in normal flight. How many times do I need to repeat it to you?


So, as long as the FD is centered up, you don't crosscheck anything else. Do I have that about right?

[Chesty Morgan]

Nope. Nice try at a strawman. Bye now.

[Amadis of Gaul]

Buh-bye, tailwinds and clear skies to ya.