mooniac15u

I've seen the comments. Pretty much just idle speculation. I don't recall any such posts by J owners.

I finished mine this weekend. I was able to source all the parts from a local electronics store so I ended up with a different SDR and wifi adaptor. $85 all in, although I'm using a battery pack that I already owned.

There seem to be a lot of F owners spending significant time and money making their F "as fast as a J" or "just like a J." I have yet to hear from a J owner trying to make their J more like an F.

There is no evidence whatsoever that the plane spontaneously broke apart while flying below Vne.

Part 23.335 (and CAR 3) formulae generally provide a minimum value. They both have a provision for demonstrating a higher dive speed that supersedes the calculation. I ran some calculations and the Vne for the early E's looks like it comes from the wing loading formula. For the later serial numbers I would guess that they demonstrated a higher dive speed.

The E and F have different max weights and different wing loading. Vne is ultimately derived from Vc which is calculated from wing loading.

It's an old CAR 3 term that is synonymous with Calibrated Airspeed. 3.46 (b ) "True indicated" or "calibrated" air speed for performance and operating purposes equal to indicator reading corrected for position and instrument errors.

That is the regulatory implication. I do not personally think that would be a good idea. If you hit a single gust or bit of turbulence you will likely exceed Vne. Then you will be a test pilot and you will not know for sure that you haven't damaged your aircraft by exceeding load limits.

There seems to be a lot of confusion here between the physical limitations of our aircraft vs the legal limitations of our aircraft. Sometimes these are the same (Vs) sometimes they are not (Vne). Vne is a legal limitation. It is designed to protect you from encountering the physical limitations of your airframe. The physical limitations are absolutely related to TAS. The legal limitations are IAS. Only the FAA gets to define legal limitations and they are very clear in defining Vne as an IAS. Think of Vne like max gross weight. Is max gross weight a physical limitation of your airframe? No, it is a legal limit below which your aircraft operates in a safe and predictable way. Vne is a legal limitation below which your plane will operate in a safe and predictable way.

For a given IAS the corresponding TAS changes with altitude. That has absolutely nothing to do with Vne in a certificated aircraft like ours. Vne is quite simply and quite clearly an IAS per the certification process.

23.335Design airspeeds. Except as provided in paragraph (a)(4) of this section, the selected design airspeeds are equivalent airspeeds (EAS). Vne is defined in Part 23 1505: (a) The never-exceed speed VNE must be established so that it is— (1) Not less than 0.9 times the minimum value of VD allowed under § 23.335; and (2) Not more than the lesser of— (i) 0.9 VD established under § 23.335; or (ii) 0.9 times the maximum speed shown under § 23.251. Vd is defined in Part 23 23.335 (see above where design airspeeds are Equivalent Airspeeds) (b)Design dive speed VD. For VD, the following apply: (1)VD/MD may not be less than 1.25 VC/MC; and (2) With VC min, the required minimum design cruising speed, VD (in knots) may not be less than— (i) 1.40 Vc min (for normal and commuter category airplanes); (ii) 1.50 VC min (for utility category airplanes); and (iii) 1.55 VC min (for acrobatic category airplanes).

Incorrect. The formula for calculating Vne is laid out in Part 23. It is derived from other IAS measurements.

23.1545 Airspeed indicator. (a) Each airspeed indicator must be marked as specified in paragraph (b ) of this section, with the marks located at the corresponding indicated airspeeds. (b ) The following markings must be made: (1) For the never-exceed speed V NE, a radial red line. (2) For the caution range, a yellow arc extending from the red line specified in paragraph (b )(1) of this section to the upper limit of the green arc specified in paragraph (b )(3) of this section. (3) For the normal operating range, a green arc with the lower limit at V S1 with maximum weight and with landing gear and wing flaps retracted, and the upper limit at the maximum structural cruising speed V NO established under § 23.1505(b ). (4) For the flap operating range, a white arc with the lower limit at V S0 at the maximum weight, and the upper limit at the flaps-extended speed V FE established under § 23.1511. (5) For reciprocating multiengine-powered airplanes of 6,000 pounds or less maximum weight, for the speed at which compliance has been shown with § 23.69(b ) relating to rate of climb at maximum weight and at sea level, a blue radial line. (6) For reciprocating multiengine-powered airplanes of 6,000 pounds or less maximum weight, for the maximum value of minimum control speed, VMC, (one-engine-inoperative) determined under § 23.149(b ), a red radial line. (c ) If V NE or V NO vary with altitude, there must be means to indicate to the pilot the appropriate limitations throughout the operating altitude range.

Sorry Peter, but you are wrong about this. There is a speed not to be exceeded that is related to TAS. However, Vne is a precisely defined term in aviation. It is defined by the FAA. The means of determining it can be found in Part 23 (and the old CAR 3). It is a marking on the airspeed indicator and as such is legally defined to be IAS per Part 23.

Do you often see women flying overhead?

I think you are finding arguments where none exist. Everyone is agreeing with you that Vne is IAS and flutter is related to TAS.

Believe what you want...

Who suggested that Vne reflected TAS?

Did you read the full narrative on the M20K break up? Mooney said they predicted the onset of flutter at ~240 knots for that airframe. I suspect that 300 mph dive is just an OWT.

The published maneuvering speed is supposed to ensure that the plane will stall and unload the wing before you over stress the airframe. The key aspect is that it is full deflection of ONE control ONE time. The FAA published some clarification of that not too long ago.

I don't think he reported being at 2900 feet. I think he just read back a clearance to descend to 2300 feet. "At 0929:35, the pilot was cleared to descend and maintain 2,300 feet. The pilot responded at 0929:40 by stating "down to two thousand three hundred one bravo yankee." No further communications were recorded from the pilot." 5 seconds earlier he reported descending through 10,200. "At 0929:30, the pilot indicated that he was descending through 10,200 feet. "

At any rate, there are probably two key takeaways from this: 1) Mooneys can and do break up in flight. 2) Mooney expects the onset of flutter to be around 240 knots in the mid body airframe.

Yes, they are different. In the full narrative both Mooney and the FAA concluded it was flutter. I think I'll go with the experts.

Perhaps that's what this pilot thought as well. It didn't work out very well for him.

You didn't read this to mean flutter? " CAUSE: The pilot's operation of the airplane at a speed well in excess of it's designed never exceed speed that resulted in elevator flutter and in-flight failure of the airplane. Turbulence and icing conditions were factors in the accident."