AVSIG: Vortex Generators on M20J avsig.jpg (7236 bytes)

About AVSIG Membership Blog The AVSIG Store Free Guest Registration Mark All Posts "Read"


AVSIG Discussion Sections >> Mooney

Pages: 1
Tom Eckinger (CAK)
AVSIG Member


Reged: 05/18/04
Posts: 86
Loc: Ohio
Vortex Generators on M20J
      #171870 - 10/12/07 09:38 AM

I have a 1984 M 20J. I would like to solicit opinions from anyone who have the vortex generators on this model plane.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Ron Rosenfeld (EPM)
Public Guest


Reged: 04/28/04
Posts: 2772
Loc: Maine
Vortex Generators on M20J [Re: Tom Eckinger (CAK)]
      #171990 - 10/13/07 09:43 AM

I don't have that modification, although it looks very interesting.

I imagine it would improve short field landing performance, due to the
decrease in stall speed. And I suppose I would consider it if I were
routinely operating my M20E out of sub 1900' (at sea level; longer at
altitude) strips. But I don't.

--------------------
--ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom Eckinger (CAK)
AVSIG Member


Reged: 05/18/04
Posts: 86
Loc: Ohio
Re: Vortex Generators on M20J [Re: Ron Rosenfeld (EPM)]
      #172156 - 10/15/07 01:48 PM

I would be more concerned with improving the margin of safety on takeoff. Slowing up the plane and landing short is not much of a problem. Take off on a hot day and loaded near gross is an area that this plane is not strong. The vortex generators decrease the stall spead by about 4.5 knots. A little slower landing spead could help the tire wear a little but that's not my main concern. I have the vortex generators on my C 421 and they work very well.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Ron Rosenfeld (EPM)
Public Guest


Reged: 04/28/04
Posts: 2772
Loc: Maine
Re: Vortex Generators on M20J [Re: Tom Eckinger (CAK)]
      #172172 - 10/15/07 04:19 PM

Tom,

I should have just written short-field "performance". I agree with you about
landing vs takeoff. But still, as I wrote, with my -E- model, I don't have a
concern until I get under 1900' (sea level).

I don't have any experience with the -J- (or with vortex generators), but
looking at a performance chart for a -J-, it would seem your takeoff
distances are considerably longer at MGW. Of course, your weight is much
higher, also.

What does the company say will happen to the takeoff performance with the
VG's?

--------------------
--ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom Eckinger (CAK)
AVSIG Member


Reged: 05/18/04
Posts: 86
Loc: Ohio
Re: Vortex Generators on M20J [Re: Ron Rosenfeld (EPM)]
      #172249 - 10/16/07 08:32 AM

Their web site only talks about better performance in general. It does not talk about specific performance figures such as reduced takeoff roll or distance over a 50' obstacle. We primarily use this plane as our trainer as the radios are just about identical to the ones in the 421. However we do fly it to some jobsites when the closest airport has a short runway.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Ron Rosenfeld (EPM)
Public Guest


Reged: 04/28/04
Posts: 2772
Loc: Maine
Re: Vortex Generators on M20J [Re: Tom Eckinger (CAK)]
      #172261 - 10/16/07 09:49 AM

I wish I could help you with some real numbers on a -J-. Perhaps the company
can give you a referral to an owner.

--------------------
--ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed Williams [PHOG]
Top Gun


Reged: 08/31/01
Posts: 2779
Loc: Maui
Re: Vortex Generators on M20J [Re: Ron Rosenfeld (EPM)]
      #172277 - 10/16/07 11:56 AM

The vortex generators are going to improve handling at high angles of
attack. This will enable lower approach speeds and better landing
performance. It may shorten the takeoff roll, because you can lift off at a
slower speed, but I wouldn't expect much improvement in the takeoff
performance over an obstacle. The rate of climb won't improve (in fact it'll
be worse if you climb at a slower speed), so if the distance over 50
feet will improve less than the amount the takeoff roll is shortened.

On a twin, the big advantage of VGs is the improvement in engine-out
handling.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ron Rosenfeld (EPM)
Public Guest


Reged: 04/28/04
Posts: 2772
Loc: Maine
Re: Vortex Generators on M20J [Re: Ed Williams [PHOG]]
      #172322 - 10/16/07 08:24 PM

Ed,

It'd be interesting to see. I'd have guessed that there'd be some
improvement in obstacle clearance if only because by getting off the ground
sooner, you should be able to accelerate in ground effect faster and get to
the best climb speed sooner.

But, as I wrote, I don't go into fields short enough to tax my -E-.

--------------------
--ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1



Extra information
0 registered and 1 anonymous users are browsing this forum.

Moderator:  Mike Overly 

Print Topic

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Rating:
Topic views: 6811

Rate this topic

Jump to

Contact Us AVSIG

Powered by UBB.threads™ 6.5.5

Logout   Main Index    AVSIG Aviation Forum