Air scoop popping open at high speed

[Matt Herron Jr.]

This weekend I did a high speed run to test some new seals I had installed on the rudder for vibration. VNE is 147 Kts in the Ventus, and so I only took it up to 130 kts IAS (yes I was only at 2000 ft MSL, so altitude was not a factor). At that speed the air scoop on the sliding canopy window suddenly popped open and scared the hell out of me with the sudden noise and rush of air.

Anyone have this happen, and is there a way to fix it?

Thanks for any suggestions.

[JS]

On Monday, March 27, 2017 at 1:45:44 PM UTC-7, Matt Herron Jr. wrote:
> This weekend I did a high speed run to test some new seals I had installed on the rudder for vibration. VNE is 147 Kts in the Ventus, and so I only took it up to 130 kts IAS (yes I was only at 2000 ft MSL, so altitude was not a factor). At that speed the air scoop on the sliding canopy window suddenly popped open and scared the hell out of me with the sudden noise and rush of air.
>
> Anyone have this happen, and is there a way to fix it?
>
> Thanks for any suggestions.

Yes, both vent windows at the same time giving a ride in a DG1000.
Install a cockpit extractor vent.
Jim

[Charlie M. (UH & 002 owner/pilot)]

Agreed, the OP needs a better way to vent air out. Doing the rear seals allow the vent to pressurize the interior which blew the side vent open since it can't escape through the rudder hinge.
Or, close the front vent and don't fix the exit issue.

[Matt Herron Jr.]

On Monday, March 27, 2017 at 1:45:44 PM UTC-7, Matt Herron Jr. wrote:
> This weekend I did a high speed run to test some new seals I had installed on the rudder for vibration. VNE is 147 Kts in the Ventus, and so I only took it up to 130 kts IAS (yes I was only at 2000 ft MSL, so altitude was not a factor). At that speed the air scoop on the sliding canopy window suddenly popped open and scared the hell out of me with the sudden noise and rush of air.
>
> Anyone have this happen, and is there a way to fix it?
>
> Thanks for any suggestions.

[Karl Striedieck[_2_]]

On Monday, March 27, 2017 at 4:45:44 PM UTC-4, Matt Herron Jr. wrote:
> This weekend I did a high speed run to test some new seals I had installed on the rudder for vibration. VNE is 147 Kts in the Ventus, and so I only took it up to 130 kts IAS (yes I was only at 2000 ft MSL, so altitude was not a factor). At that speed the air scoop on the sliding canopy window suddenly popped open and scared the hell out of me with the sudden noise and rush of air.
>
> Anyone have this happen, and is there a way to fix it?
>
> Thanks for any suggestions.

Tighten the pivot bolt.

[Dan Marotta]

What KS said. There's a screw and nut about which the vent scoop
rotates. Tighten that until you're happy with the stiffness of opening
the window. Don't tighten it so much that you break the window.

On 3/27/2017 7:17 PM, Karl Striedieck wrote:
> On Monday, March 27, 2017 at 4:45:44 PM UTC-4, Matt Herron Jr. wrote:
>> This weekend I did a high speed run to test some new seals I had installed on the rudder for vibration. VNE is 147 Kts in the Ventus, and so I only took it up to 130 kts IAS (yes I was only at 2000 ft MSL, so altitude was not a factor). At that speed the air scoop on the sliding canopy window suddenly popped open and scared the hell out of me with the sudden noise and rush of air.
>>
>> Anyone have this happen, and is there a way to fix it?
>>
>> Thanks for any suggestions.
> Tighten the pivot bolt.

--
Dan, 5J

[MNLou]

I have the same issue when I fire up the sustainer engine on my LAK17at. Don't know why.

During normal flight, never an issue - at any speed. Start the motor and, boom, the side vent flies open. This is flying at 51 kts.

I'll try closing the front vent the next time and see if that helps.

Lou

[Ramy[_2_]]

You probably sealed your canopy too well...

Ramy

[[email protected]]

A small piece of tape on the exterior of the scoop is a quick/temp fix that can be done in flight and removed in flight (for the window next to a person). I do this for extended hi-speed ridge flying.

[Dan Marotta]

That's the "Auto-Vent System" designed to keep you from choking on
gas/oil fumes... :-D I'll bet that doesn't happen with Renny's LAK-17bfes.

On 3/27/2017 7:59 PM, MNLou wrote:
> I have the same issue when I fire up the sustainer engine on my LAK17at. Don't know why.
>
> During normal flight, never an issue - at any speed. Start the motor and, boom, the side vent flies open. This is flying at 51 kts.
>
> I'll try closing the front vent the next time and see if that helps.
>
> Lou

--
Dan, 5J

[MNLou]

On Tuesday, March 28, 2017 at 1:48:30 AM UTC-5, Ramy wrote:
> You probably sealed your canopy too well...
>
> Ramy

If a tightly sealed cockpit is the "problem", kudos to the folks at LAK. As far as I know, this is how it came from the factory.

Lou