Vne Testing

[ChiefPilot]

I've heard it both ways:

- There is no need to go beyond the published Vne during phase one because the RVs are such well proven designs, and
- You must go to 110% of Vne to establish that your specific aircraft meets design specifications plus a small margin of safety.

AC90-89a seems mum on the topic.

What say you? Do people commonly flight test to 10% past Vne, right to Vne, or just assume that your bird will hold together to Vne so no need to actually check?

[bkthomps]

Try it and let us know


just kidding...i'm curious to see the answers here

[Kevin Horton]

It is quite unlikely that your RV will have a flutter issue at speeds of 1.1 VNE or less, unless you have made some major construction screwup.

But, on the small chance that your aircraft has a problem, when would you rather find it:

• during dedicated flutter testing, when you are by yourself, wearing a parachute, at a safe altitude, over an uninhabited area, mentally prepared to bail out if necessary, or
• on the day when you screw up and exceed VNE, possibly with a passenger, and not wearing parachutes?

[Sig600]

Anyone that tells me I HAVE to exceed a published limit (110% of Vne) can do it themselves. I'll likely never listen to anything they have to say on anything ever again either.

To Kevin's point, I'd rather stay within the safety margins all the time. 1500+ hours riding ejection seats, I've never once felt compelled to exceed the published limitations just because I had an "out."

BTW, If you think you can bail out after strucutral failure beyond Vne, you're shooting craps with your life.

[JonJay]

Used when you hit a really bad shot that somehow works out.

It's called the "sister in law"
"Your up there laddie, but you know you shouldn't be."

[Kahuna]

You are required to make log book entries on your TESTED speeds to enter phase 2.
During the test phase you are the test pilot or who ever is flying your plane. Its not for boring holes. Its to test the flight envelope of plane.
If your not up to the task, you should pay someone who is.
The verbage to make phase 2 speeks for its self.
You should not put someone in your plane if you have not actually performed the tests that you say you did.

[sahrens]

As Sig600 stated

'I've never once felt compelled to exceed the published limitations just because I had an "out." '

The aircraft I fly do not have that same "out", but even if they did I do not exceed limits; ever. I believe the design engineers of "certified" aircraft. I will stay with what Van says.

[DanBaier]

Just another $.02. I know personally of a case where the first shot at Vne testing pegged the airspeed indicator. That's more than + 10%. The good news is that a RV7A, with a reasonable layer of paint, can evidently handle that plus a respectable margin. My advice is to approach this carefully.

An interesting video is at http://www.youtube.com/watch?v=iTFZN...eature=related

[ChiefPilot]

Originally Posted by Sig600

Anyone that tells me I HAVE to exceed a published limit (110% of Vne) can do it themselves. I'll likely never listen to anything they have to say on anything ever again either.

To Kevin's point, I'd rather stay within the safety margins all the time. 1500+ hours riding ejection seats, I've never once felt compelled to exceed the published limitations just because I had an "out."

BTW, If you think you can bail out after strucutral failure beyond Vne, you're shooting craps with your life.

I took Kevin's point to be that however unlikely it might be that my plane has a problem, why not positively prove it does not in a controlled situation when you have the preparation & equipment to deal with a bad situation? That line of reasoning is very logical to me.

Although I'm still 6+ months away from first flight, thinking about all the stuff that needs to be done during phase one and doing the project plan to accomplish those tasks makes me think I'll need more than 40 hours to get everything done.

[Kahuna]

Originally Posted by ChiefPilot

I took Kevin's point to be that however unlikely it might be that my plane has a problem, why not positively prove it does not in a controlled situation when you have the preparation & equipment to deal with a bad situation? That line of reasoning is very logical to me.

Although I'm still 6+ months away from first flight, thinking about all the stuff that needs to be done during phase one and doing the project plan to accomplish those tasks makes me think I'll need more than 40 hours to get everything done.

You have the right midset Brad.
Take all the time you need. Your given hours in your test phase is just a min.