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-   -   Max 10 (https://www.airlinepilotforums.com/united/118993-max-10-a.html)

ReadOnly7 03-10-2020 06:37 AM

It’s “per se”. Just se-ing.

webecheck 03-10-2020 07:50 AM


Originally Posted by horrido27 (Post 2993205)
You then went and compared MCAS to a Stick Shaker.

Except I didn't, because a shaker is entirely different than a stick pusher system or the more robust mcas.

It's clear you just interpret words how you want because you're the aforementioned guy who just wants to argue on internet forums.

Larry in TN 03-10-2020 09:07 AM


Originally Posted by horrido27 (Post 2992866)
Yes, all the transport category aircraft I've flown have had a stall/stick pusher. But so does the Max's.

The 737 does not have a stick-pusher. Neither does the 757/767, DC8, or DC9 that I've also flown. Aircraft I've flown with stick-pushers have been the Jetstream (J32) and CRJ.


Originally Posted by horrido27 (Post 2993205)
I asked a question about the MCAS on the M10. So far, we've gotten a Yes and a No.

My understanding is that the MCAS function of the FCC software is not planned to be a part of the 737-10. The airplane has not yet begun flight testing, though, so the design is not yet finalized.


The MCAS (to my knowledge) was installed on the Max's due to a change in how the aircraft handles while going to full thrust in certain situations.
MCAS has nothing to do with thrust, full or otherwise.

The engines were moved forward and up. Moving them up moves the thrust-line closer to the airplane's longitudinal axis which REDUCED the pitch moment-arm with regard to thrust. This REDUCES the pitching-moment produced as thrust is increased or decreased.

The problem that MCAS was designed to address relates to the certification requirement that pitch forces must increase proportionally as the AoA increases. i.e. As you keep pulling the nose up, it becomes increasingly more difficult to continue to pull up. This is a normal, desirable handling characteristic of a stable airplane. As AoA increases, the nacelles produce some lift as a result of them deflecting airflow downward. The MAX's nacelles are both larger and located farther forward. Being farther forward of the lateral axis increases the moment-arm of the lift generated from the nacelle as does the increased size of the nacelle.

This increased nose-up moment from the nacelles, in very high AoAs, reduced the natural increase in nose-down tendency as AoA increases. MCAS was designed to introduce additional nose-down bias, in very high AoA situations, through the introduction of nose-down stabilizer trim.

The 737-10 is nearly six feet longer than the 737-9 and fourteen feet longer than the 737-8. That additional length increases the moment-arm of the horizontal stabilizer and elevator which reduces the effect of the increased pitch-moment from the lift generated by the engine nacelles. The design is intended to meet certification requirements without MCAS. That will be confirmed, or not, in certification flight testing.

horrido27 03-10-2020 09:46 AM

Thanks Larry..
Just trying to remember which aircraft I use to fly that had a stick pusher on top of a stick shaker.
Maybe it's a system that time has made redundant due to software limitations?

I guess I just assumed that it was also a function of thrust due to this little statement-
The Maneuvering Characteristics Augmentation System (MCAS) flight control law was implemented on the 737 MAX to mitigate the aircraft's tendency to pitch up because of the aerodynamic effect of its larger, heavier, and more powerful CFM LEAP-1B engines and nacelles

But it will be interesting to see if the M10 does away with the MCAS, as it seems that (they way you described it) the longer the aircraft, the less of an issue it is.

I also got this tidbit from AW&ST-
The Maneuvering Characteristics Augmentation System (MCAS) is a flight control law managed by the flight control computer (FCC) and introduced on the 737 MAX to help it handle like a 737 Next Generation (NG), particularly at slow speeds and high angles of attack (AOA).

Hence why I relate the MCAS to a type requirement and not so much as an anti stall system.
Then I also found this nugget (from Wiki) -
"Contrary to descriptions in news reports, however, Boeing emphasized that MCAS is not an anti-stall system"

Thanks for your insight!
What are your thoughts about the seating configuration? (which was my original question! lol)
Just trying to figure out the window shade issue and the tv monitor. Seems like a nightmare.

Motch

PS) Guess I should have typed Stall Shaker/Stick Pusher. Some have one, some have both..?!

blockplus 03-10-2020 12:54 PM

Then comes the question of why they didn’t just use the elevator feel computer to augment the feel as aoa increased?

MiLa 03-10-2020 02:56 PM


Originally Posted by blockplus (Post 2993617)
Then comes the question of why they didn’t just use the elevator feel computer to augment the feel as aoa increased?

Because it’s not just the feel. The actual maneuvering characteristics changed with the new engines. At high AOAs the engines themselves started producing lift like a wing. This caused the actual control forces to get lighter at higher AOAs. Changing how it feels wouldn’t do anything to counteract those control forces...

Larry in TN 03-10-2020 04:39 PM


Originally Posted by horrido27 (Post 2993410)
What are your thoughts about the seating configuration? (which was my original question! lol)!

My thought is that we should put the 737-10 on the route between my home of record and DEN so I can try them out when I have my next CQ!

baseball 03-10-2020 07:44 PM


Originally Posted by MiLa (Post 2993744)
Because it’s not just the feel. The actual maneuvering characteristics changed with the new engines. At high AOAs the engines themselves started producing lift like a wing. This caused the actual control forces to get lighter at higher AOAs. Changing how it feels wouldn’t do anything to counteract those control forces...

man, if that's the case, then this airplane should really be a B-7ABC.... it seems like it's no longer a 737. Maybe it would be wise to fly it as a different type rating? Would that solve the problem?

Dave Fitzgerald 03-10-2020 07:53 PM

I firmly believe that when it is recertified, Boeing will rename the plane, viola! New plane no more max!

jamesholzhauer 03-11-2020 03:38 AM


Originally Posted by baseball (Post 2993932)
man, if that's the case, then this airplane should really be a B-7ABC.... it seems like it's no longer a 737. Maybe it would be wise to fly it as a different type rating? Would that solve the problem?

No. Even if they made it another type rating, the pitch up moment in high AOA/high thrust situations isn’t certifiable under 25.203.


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