Overspeed Needle

[slick552 0]

Thought i'd check here to see if anyone else has a 'stuck' overspeed needle on their Airspeed Indicator. If so, then i'll contact Carenado.

[Barry1976 0]

Yep, I can comfirm this. My barber pole is not moving eigther.

[styckx 1,870]

Same here

[Guest bstolle]

???? Why should it move. The Vno doesn't change at all within the envelope.

[slick552 0]

If that's the case, then something is still wrong. I am getting sim overspeed warnings (which I believe is Vne in FSX) short of the 'barbers pole'. Vno comes before Vne, yes? Unless i'm mistaken about how FSX determines overspeed.

[Guest bstolle]

There's no Vne with the C90, only Vno.

Weird that there's a difference as the barber pole is at 226kias and the max speed in the cfg file also 226kias.

At which speed does the overspeed warning occur?

[HighFlyer310 21]

I can confirm this as well.. and it seems like it changes with altitude (as the barber pole should indicate)... I started a descent from FL270 and got an O/S warning at around 180 kias.. as I descended lower the warning disappeared, I increased KIAS to around 200 and it lit up again...

[briwith 2]

As the King Air does not have a Mach meter, the barber's pole should move down in IAS terms to show Mmo when it is limiting at the top of the flight envelope. I think HighFlyer310 is experiencing a sim overspeed warning generated by exceeding Mmo or Mne. Hope this helps.

 

Brian W

[Guest BeaverDriver]

OK, this got explained to me elsewhere and it makes sense, so I'll give Bernt a break and chime in here if you don't mind. On this version of the King Air, it can't get close enough to the speed of sound to require a mach meter. As such, the "barberpole" really is just a "redline" that you see on light aircraft IAS gauges. Thus, no matter the altitude (that this aircraft can attain), as long as you don't exceed that speed (which is fixed), you're good to go. The aircraft will not overstress. I *think* the B200 does have an actual barberpole because it can get a lot higher and go faster, but the C90 is an earlier version of the King Air. Typically you'll only find them cruising in the high teens or low twenties (probably can go higher, but it would take a long time to get there, and I'm not sure what the max cabin differential pressure is on those but it's not up to the B200 level I'm pretty sure). So you really aren't getting into any serious mach territory, thus you don't need the moving barberpole. That all is a long way of saying, "Think of the barberpole as the redline speed" and as you know, on most IAS gauges, redlines don't move (if they do, you need to get help - fast :Hypnotized: !).

[briwith 2]

Agreed. With the C90 I would not have thought Mach would play a big role. I was merely trying to explain the FSX warning that HighFlyer310 got. It might be worth looking what "max mach" is set to in the aircraft.cfg file. BTW, I believe the ASI would have a painted red line at Vno if the flight envelope did not permit Mmo to be limiting under some circumstances. Barber's pole ASIs are more expensive!

[Jack_C 1]

I posted this in another topic too.

You sure the 90's airspeed barber pole shouldn't move? It does in every other king air series. The movement represents the limitation of the Mach speed. In the king air 100 it was Mach .46. The king air 100's vne is 226 as well. I bet a buffalo nickel this just isnt simulated properly.

[Guest BeaverDriver]

Agreed. With the C90 I would not have thought Mach would play a big role. I was merely trying to explain the FSX warning that HighFlyer310 got. It might be worth looking what "max mach" is set to in the aircraft.cfg file. BTW, I believe the ASI would have a painted red line at Vno if the flight envelope did not permit Mmo to be limiting under some circumstances. Barber's pole ASIs are more expensive!

 

Oh for sure. I suspect that's where the problem lies because we shouldn't be getting overspeed alerts.

 

I know what you are saying about the barberpole being more expensive (and why have it if it doesn't move!). I went looking for pics of C90's and did find quite a few with them (example below). Couple that with Jack's comments, and one does have to wonder. However, I have no personal experience with these so I'll 'gracefully exit' and watch with interest what comes from this. I am very interested in this stuff though so hopefully the debate does continue.

[WarpD 824]

Ok... 226kts @ FL270 = (270/2)+226 = 361kts TAS. That puts the aircraft at mach 0.60... I'm pretty certain that's an overspeed condition.

[Guest bstolle]

Ok... 226kts @ FL270 = (270/2)+226 = 361kts TAS. That puts the aircraft at mach 0.60... I'm pretty certain that's an overspeed condition.

 

Perfect find Ed!!!!

 

Browsed through all FAA docs and manuals again and found the following.

 

The original Raytheon C90 manual (seems to be a rather old one) mentions a Vmo of only 208kias.

EDIT: Even in that case a Mach number limit would be necessary as 208kias at 30000ft means M0.56

 

The FAA doc mentions a Vmo of 226kias but no Mach limit.

 

The C90 manual from Flight Safety does mention a maximum Mach number of 0.46

In that case the barber pole definitely moves.

 

3 different sources, 3 different limits....

[Guest BeaverDriver]

Oops, posted just as Bernt replied, so my post isn't relevent :Peace: .

 

SO, the pole SHOULD move then?

 

We now return you to your regularly scheduled mayhem