straight down

bugsiegel

bugsiegel

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Bugsiegel
Are there any GA planes that can hold nose straight down without exceeding Vno or Vne speeds?
 
I've flown a Cessna 150 "backwards" in high winds once. Was interesting, but fortunately not too turbulent.
 
bugsiegel said:
Are there any GA planes that can hold nose straight down without exceeding Vno or Vne speeds?
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All of them, when dropped from a high enough altitude, for a limited amount of time... Far enough up, any airplane at any speed will be at zero IAS no matter how fast they're falling. ;)

I think in the sense you're probably asking about, though, where the plane would climb up under its own power and then push over to point straight down - I think the answer is "No". Gravity = acceleration, so even with no engine power an airplane would accelerate towards the earth until parasitic drag reached an equilibrium with that acceleration. I don't think any airplane would be able to fly in the first place if it had enough drag for that to happen below Vne.

Now if you want to cheat and use reverse thrust to counteract gravity as well, it might be a different story. Maybe.
 
Doubt any GA airplane has a Vne greater than its terminal velocity. C-17 in a combat descent comes close.
 
I recall a pc6 with a drogue doing something like that once for a skydive stunt, if memory serves it did have a structural failure later on in it's life though.
 
I watch acrobatic and I see planes pulling out of the nose down attitude pretty quick while airspeed rises fast. Do any of the acro planes have the capability of holding nose down for long duration? How much would decreasing pitch on the variable aid to this?
I'm guessing the only planes really built this strong are military.
 
Every plane in the sim does it.

What?
 
GoingDown.jpg
 
bugsiegel said:
I watch acrobatic and I see planes pulling out of the nose down attitude pretty quick while airspeed rises fast. Do any of the acro planes have the capability of holding nose down for long duration? How much would decreasing pitch on the variable aid to this?
I'm guessing the only planes really built this strong are military.
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If aerobatic planes hold the nose straight down to long they will hit the ground!
Not sure what you are asking?
Climb to 20,000 feet and go straight down until you are at 1,500 feet?
 
I dunno, I would think there's got to be something out there that, with flaps/spoilers fully-extended, it wouldn't be able to accelerate past Vne due to all of the drag deployed.
 
If you mean indefinitely, no. I don't know of any airplanes that will hold a 90 degree nose down and NOT accelerate. Acro planes doing vertical dives can't typically sustain it though it typically won't exceed Vne before you need to pull out to avoid hitting the groud.

That brings up a second question is whether you can pull out of a Vne vertical dive without bending the airplane.
 
A Stearman might have enough drag to do it at idle...I know the acceleration in an accidental split-S at cruise power is minimal.:yikes:

:D
 
I believe I could have done it in my CT when I was in mountain wave on the back side of the Oregon Cascades...
 
If you dove a Cessna with full flaps for even a couple seconds, you'd exceed the white arc and risk breaking one or more flaps off. Flap hits tail... :eek: :dunno:
 
Not sure of any planes that can do it, but some gliders were designed with terminal velocity drive breaks to allow a vertical dive without exceeding VNE. One example is the Schweizer 1-34.
This was originally a requirement for standard class gliders, but was later dropped.
 
Wait, I've got it...

An LTA balloon, with a gondola that will pivot 90 degrees.



ok...maybe not a "plane"...
 
petrolero said:
If you dove a Cessna with full flaps for even a couple seconds, you'd exceed the white arc and risk breaking one or more flaps off. Flap hits tail... :eek: :dunno:
Click to expand...

Actually, I doubt you'd break them off, but you'd quite possibly bend the flap brackets and tracks.
 
That was a long time dive in the video above. I would think that plane reached its maximum power off nose down speed in that dive.
 
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