What do I do? What do I do?

[Doug G.]

Speak softly and carry a big stick!! :angry:

 

Didn't Teddy Ruxpin used to say that?

[Ed Cesnalis]

"If there is insufficient manufacturer's information available for the aircraft you fly — and you are uncertain about the appropriate Vne for an operating altitude — then multiply the density altitude, in thousands of feet, by a factor of 1.5 to get the percentage decrease to apply to the specified Vne to establish a safe Vne appropriate to the altitude. For example if density altitude is 8000 feet and specified Vne is 100 knots then 8[000] × 1.5 = 12%. Corrected Vne = 88% of 100 = 88 knots IAS/CAS."

 

 

If we use the above adjustment, at 14,000'DA ( service ceiling ) our 145kt Vne adjusts to 114.55kts. In the green arc.

 

If we assume 162kts as the likely flutter speed we get 127.98kts.

 

Increase altitude due to lee side wave lift to 17,500 and the values drop to 106kts and 119kts.

[mocfly]

Charlie Tango,

Why not send an email to the guys @ Flight Design and ask for some direction on actual figures? With aircraft located in close proximity to the Alps(max height 15,771) I would think they have a database full of the type of information you are looking for.

 

[GlennM]

IIRC, to certify the aircraft or any modifications to the control system, Flight Design had to bring the aircraft to 180kts IAS without flutter (for the rest of the world). For the US, I believe it is 155kts without flutter. I know my aircraft made it to 155 IAS.