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To: TexasGator

“So based on that extensive experience you post false data?”

Pretty much, yeah.

It’s just like I said.

The longitudinal static stability of the King Air is such that it can maintain steady flight in normal conditions without input from the pilot or control systems.

The 737 Max would become a lawn dart without considerable constant input from a pilot or a control system. And that’s in good weather, no turbulence, and without any mechanical problems.

That’s the difference.


48 posted on 04/09/2019 3:55:44 PM PDT by MeganC (There is nothing feminine about feminism.)
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To: MeganC

“The longitudinal static stability of the King Air is such that it can maintain steady flight in normal conditions without input from the pilot or control systems.”

Or how long?


53 posted on 04/09/2019 4:26:20 PM PDT by TexasGator (Z1z)
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To: MeganC
The link below discusses Positive and Relaxed Longitudinal Static Stability.

The Handling Characteristics of Swept-wing Commercial Airplanes

FTA: "Since download on the tail is negative lift, effectively increasing the weight of the airplane, the location of the CG affects the cruise performance of any airplane. Flying at an aft CG will reduce the download on the tail and improve cruise performance."

"When airplanes are operated near the aft CG limit, download on the tail is minimized and angles of attack and drag are reduced. However, moving the CG aft reduces the longitudinal static stability of the airplane, something that all flight crews should be aware of"

"As airspeed varies from a trimmed condition, the column force required to maintain a new speed (without re-trimming) is a measure of static longitudinal stability. For any conventional airplane, the location of the CG has the strongest influence on static longitudinal stability. For a statically stable airplane the required column force, as speed varies from the trimmed condition, is less at an aft CG than it is at a forward CG. The minimum average gradient allowed by U.S. Federal Aviation Administration FAR Part 25 is one pound for each six knots. As the CG moves aft, it reaches a point where the stick force per knot drops to zero, then reverses. This location is called the neutral point. The difference between the actual CG location and the neutral point is called the static margin. With a CG forward of the neutral point, an airplane has a positive static margin and positive static longitudinal stability. At a CG aft of the neutral point, an airplane has a negative static margin, is statically unstable, and requires some form of augmentation to be flown with an acceptable workload."

My guess is that Boeing designed the MAX with a CG further aft than earlier versions of the 737. This was done to improve cruise performance and compete against the Airbus 320. During flight test the test pilots discovered that the aft CG causes adverse stall characteristics, necessitating the MCAS (stall prevention) system.

MeganC...kudos to you for bringing up Longitudinal Static Stability. I believe this will be a contributing factor in the accident reports. My hope is that the accident reports get published for all to read.

Also, best wishes on your upcoming solo...an event you will always remember.

63 posted on 04/09/2019 6:48:15 PM PDT by FtrPilot
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To: MeganC
The longitudinal static stability of the King Air is such that it can maintain steady flight in normal conditions without input from the pilot or control systems.

The 737 Max would become a lawn dart without considerable constant input from a pilot or a control system. And that’s in good weather, no turbulence, and without any mechanical problems.

That’s the difference.

Comparing the flight characteristics of a tiny general aviation prop plane to a modern turbofan commercial airliner is bizarre. You may as well throw in an F-16 to the discussion.

That said, it seems to me that you are implying that the 737 Max would drive itself into the ground without input from a pilot or control system, and that the previous 737 NG (and perhaps A320 Neo?) would not. Is that what you are implying? That all older 737s and A320s would fly along just fine without any inputs until they run out of fuel like your King Air?

What makes your assessment a particularly interesting statement is that from what we know so far, both 737 Max crashes were due to input from a (faulty) control system, not a result of any aerodynamic deficiencies.

76 posted on 04/09/2019 8:34:35 PM PDT by OA5599
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