Wasn't there a comment that the orange suits would make them easier to find?

Yup.

Rick, that sounds logical at first glance but at higher altitudes it isn't that simple. But don't ask me to explain it either! Read that article written by the RV people.

Rick, it might not be a problem for the TN guys but more so for the tubine conversions. But not really sure about either one.

Rick in my firsts post on this thread (post #8) I made an off the cuff estimate of the TAS represented by Vne during certification testing and came up with 250 KTAS which is the TAS equivalent to Vne at 14,000 MSL. I doubt that any NA Bonanza could exceed that under normal circumstances. The real issue here is whether a TN conversion should include a reduction in Vne with altitude like the 58P has.

Lance,

There's a little thing that is done during flight testing for flutter, or at least it used to be done in the old days. (Now days testing is done on the ground with sensors and a few magic words being cast at the airplane.) At or near VNE the control sticks or yokes are given a nice slap to see if the control surfaces go into flutter. So with a only a high volume of air passing over the surfaces the energy might not be enough to start the flutter, but if initiated by another action such as a passenger reaching for something and bumping the control the high volume(TAS), but low ram pressure (IAS) might be enough to ruin somebodies day. I tend to agree that with the turbo'd planes and the turbo prop conversions flying around at really high speeds the design has been demonstrated capable and seems to prove the generous saftey buffer that Beech built in is truly adequate. With balanced control surfaces the issue should never be problem in my very small corner of the Beech world.

Best,
Bryan

Bryan

Agreed, I believe the APS class is this weekend so George probably will not be weighing in unless he's checking email. This might be a good question for the class.

I believe the A36TC and B36TC also have the reduction in VNE with altitude.

Hello Lance,

I was hoping someone more ambitious about posting would chime in.

From the TAT AFMS-550

Limitation F33A (SN CE-290 to CE-815)

...
MAX STRUCTURAL CRUISE -- 165KTS
- DECREASE 3 KNOTS PER 1000 FT ABOVE 16,000 FT
NEVER EXCEED -- 195KTS
- DECREASE 3 KNOTS PER 1000 FT ABOVE 16,000 FT

The difference between airplanes is the late model A36s have a slightly higher Vne. Same decrease methodology is applied. For aircraft with 15 degree approach flaps, same decrease methodology applies.

Ward

The A36TC has a VNE of 203 and a reduction of 4 KIAS per 1000 ft above 16000ft. See PDF attached.

Hello Lance,

I was hoping someone more ambitious about posting would chime in.

From the TAT AFMS-550

Limitation F33A (SN CE-290 to CE-815)

...
MAX STRUCTURAL CRUISE -- 165KTS
- DECREASE 3 KNOTS PER 1000 FT ABOVE 16,000 FT
NEVER EXCEED -- 195KTS
- DECREASE 3 KNOTS PER 1000 FT ABOVE 16,000 FT

The difference between airplanes is the late model A36s have a slightly higher Vne. Same decrease methodology is applied. For aircraft with 15 degree approach flaps, same decrease methodology applies.

Ward

Actually the airplane does "care" what the TAS is, especially WRT flutter because it's the speed of the air molecules flying by that determines the potential for flutter,

Alan, We're not going to leave you alone until you agree with Lance

Alan,

IMO, the author in the RV article made some broad based assumptions about other airframe designs based upon the RV designers practice. His assertion that airframe designers were not worried about Vne as it relates to whether to use TAS in lieu of IAS in a NA plane is absurd.

I make the assumption that the Beech designers would have made the IAS/TAS conversion at the service ceiling of the airplane and put the redline on "the guage that lies" in a location that if traveling at 18,000 and the pilot puts the nose down that the wings won't fall off.

Maybe a real aeronautical engineer will chime in and straighten us out.

Which would be indicated air speed.

Alan Bradley

BTW, my wife and daughter both who are student pilots have read the RV article and we have spent quite a bit of time discussing the merits. The are leaning towards the more conservative approach and of course I'm leaning towards believing the Beech designers are smarter that the RV guys.

Crossing West Texas, New Mexico, Arizona, Nevada in the summer time always get my attention. I had a trip once where I had to put the gear down 3 times to get slowed down and reasonably stablized. I threw that pair of skivies away! Ironically you could see a hundred miles. Green arc reminds me of money which is good.

I flew in the older Lear jets alot years ago the 25's and we would be up at FL410 the pilots told me that the stall speed and VNE and VMo(?) max MACH# were all with in about 10kts at that altitude. So it would seem that the Bo's would have a simmular situation at some given Alt. and speed. Yes or no?

Jay

Assuming you can climb to that altitude, I think that's true of all airplanes.

But then, science wasn't my strong suit.

(I'm still trying to find out what is.)

I have not given this careful thought as I am tied up on some other matters.
However, on a quick review, and subject to further consideration:

The RV article is horribly mis-leading. The chart in the lower right hand corner of page one is exhibit A.

It creates a baseline flutter margin limit that is equal to the Vne KTAS - - - AT SEA LEVEL - - -

But that is not how the OEMs do that. They do that at altitudes near the service ceiling.

So the original flutter margin whch is stated to be 42.7 ( 230 KIAS/KTAS @SL - 187.3 KTAS cruise = 42.7) should have really been more like 290 - 187 = ~ 103 kt flutter margin.

[ Based on 230 KIAS at a density altitude of 15,000 feet => KTAS of ~ 290]

As such, the table on page one of the RV article would show a positive flutter margin of around 48 Kts at 24,000 feet, rather than the "negative" 12 knots shown.