Flying above Service Ceiling?

Jaybird180 said:
Wikipedia says the service ceiling on that is 18,100
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On what, a Travelair? Sounds about right, once Jack Riley put the turbo normalization system on though that changed and I ended up with a placard that read, " This aircraft has not been evaluated for flight above 25,000'"
 
Jaybird180 said:
91.3(a) says the PIC is the final authority as to the operation of the aircraft. In this case the limitations section says not to operate above xxx altitude and the PIC says that the aircraft continues to perform normally at xxx + yyy altitude.
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91.3a is in there to make it clear that the PIC is the one to blame no matter what goes wrong. It does not authorize the pilot to ignore other regs just because he feels like it.
 
Aerodynamic flutter may also be a concern for aircraft operating above it's maximum operating altitude due to higher TAS.

Not sure about you guys, but that's not something I want to be dealing with.
 
Turningfinal said:
Aerodynamic flutter may also be a concern for aircraft operating above it's maximum operating altitude due to higher TAS.

Not sure about you guys, but that's not something I want to be dealing with.
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The TAS for Vne stays the same, TAS is easily calculated, some airspeed indicators even have an adjustable scale built in to dial in.
 
Henning said:
The TAS for Vne stays the same, TAS is easily calculated, some airspeed indicators even have an adjustable scale built in to dial in.
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The TAS for Vne certainly does not stay the same. Since Vne is an indicated airspeed as marked on the airspeed indicator. Maintaining Vne at sea level will show a much lower TAS than maintaining Vne at the maximum operating altitude.

And herein lies my point:

The FAA requires that certified airplane must be shown to be free of flutter within its entire flight envelope at any airspeed less than Vne at any altitude less than it's maximum operating altitude (or absolute ceiling).

So if you're happily (and theoretically) cruising along at Vne at the maximum operating altitude, your TAS must, by certification standards, be below that which would cause flutter.

Exceed that maximum operating altitude and still cruising along at Vne? You've just raised your TAS, and you're in test pilot territory now. Flutter becomes a real issue since you've now exceeded Vne-TAS, even though you're still under Vne-IAS.

Of course, there are airspeed indicators that have a moving barber pole, but I haven't seen these in light aircraft like the T182T used in this example. Glider pilots will also be familiar with pressure altitude - maximum airspeed tables.
 
Turningfinal said:
The TAS for Vne certainly does not stay the same. Since Vne is an indicated airspeed as marked on the airspeed indicator. Maintaining Vne at sea level will show a much lower TAS than maintaining Vne at the maximum operating altitude.

And herein lies my point:

The FAA requires that certified airplane must be shown to be free of flutter within its entire flight envelope at any airspeed less than Vne at any altitude less than it's maximum operating altitude (or absolute ceiling).

So if you're happily (and theoretically) cruising along at Vne at the maximum operating altitude, your TAS must, by certification standards, be below that which would cause flutter.

Exceed that maximum operating altitude and still cruising along at Vne? You've just raised your TAS, and you're in test pilot territory now. Flutter becomes a real issue since you've now exceeded Vne-TAS, even though you're still under Vne-IAS.

Of course, there are airspeed indicators that have a moving barber pole, but I haven't seen these in light aircraft like the T182T used in this example. Glider pilots will also be familiar with pressure altitude - maximum airspeed tables.
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Vne is a TAS speed, as long as you know the TAS, you can stay below Vne. Most planes to get above their service ceiling will be operating near Vy IAS which will typically be below Vne TAS.

http://www.vansaircraft.com/pdf/hp_limts.pdf
 
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Henning said:
Vne is a TAS speed, as long as you know the TAS, you can stay below Vne. Most planes to get above their service ceiling will be operating near Vy IAS which will typically be below Vne TAS.

http://www.vansaircraft.com/pdf/hp_limts.pdf
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I'm very familiar with that document (building an RV myself) and i'm not arguing that Vne is based on TAS.

All i'm saying is that, above the maximum operating altitude, one could easily find themselves in flutter territory (in a descent for example) even though they are under Vne-indicated.

Of course, if you know all of this (and know what your Vne-TAS is) and you don't exceed that critical number, you won't have to worry. However, I'm willing to take a large bet and say that a majority of pilots flying small aircraft have no idea about this. It caused quite a stir on the VAF forums when that document came out.
 
Turningfinal said:
I'm very familiar with that document (building an RV myself) and i'm not arguing that Vne is based on TAS.

All i'm saying is that, above the maximum operating altitude, one could easily find themselves in flutter territory (in a descent for example) even though they are under Vne-indicated.

Of course, if you know all of this (and know what your Vne-TAS is) and you don't exceed that critical number, you won't have to worry. However, I'm willing to take a large bet and say that a majority of pilots flying small aircraft have no idea about this. It caused quite a stir on the VAF forums when that document came out.
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One could, but not everyone is incompetent and many people have panels that read them TAS.
 
Henning said:
One could, but not everyone is incompetent and many people have panels that read them TAS.
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Not disagreeing there. I was just pointing out a concern of exceeding the maximum operating altitude of an aircraft, per my first post.
 
Not to leave helicopters out of the Vne TAS discussion, they too have a reduction in Vne with altitude. The TAS Vne isn't a constant limit with them either. One is due to compressibility and one is due to retreating blade stall. Both completely different TAS based on temp and DA. Without reference to a chart you would have no idea what to indicate to keep you out of Vne. A 4 per rev vibration would be the best indicator though.
 
Turningfinal said:
The FAA requires that certified airplane must be shown to be free of flutter within its entire flight envelope at any airspeed less than Vne at any altitude less than it's maximum operating altitude (or absolute ceiling).

So if you're happily (and theoretically) cruising along at Vne at the maximum operating altitude, your TAS must, by certification standards, be below that which would cause flutter.
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So, if that's the case, you could figure out what Vne TAS is by figuring what TAS is at the maximum altitude at Vne IAS?

Let's say you have a plane certified to 18,000 feet with a marked Vne of 200 KIAS (or about 265 KTAS at standard temp). Does that mean that, for example, at 28,000 feet Vne will be 265 KTAS/168 KIAS?

I was under the impression for some reason after reading that same RV article that Vne was calculated at sea level, so even if you were below max altitude and under the marked Vne on the airspeed indicator you could be over Vne.
 
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