Retractable Step Vacuum Replacement

[802flyer]

The vacuum servo for the retractable step in my F model is in need of replacement. Does anyone know if Brittain is still replacing/overhauling these, or does anyone know where one might be found for sale used? Nothing on ebay at the moment. I'm aware of the electric conversion, but still curious to know what my options would be to simply replace the existing unit. Thanks!

[carusoam]

10 minutes ago, 802flyer said:

The vacuum servo for the retractable step in my F model is in need of replacement. Does anyone know if Brittain is still replacing/overhauling these, or does anyone know where one might be found for sale used? Nothing on ebay at the moment. I'm aware of the electric conversion, but still curious to know what my options would be to simply replace the existing unit. Thanks!

about a decade ago…

Somebody came up with a modern solution to the un-available Brittain servo boot…

An STC’d electric servo… that does everything slightly better… compared to the vacuum servo…

Search on electric servo step… or just find @takair… there is a website that has the details…

Easy upgrade, hundred(s) in the field…

Best regards,

-a-

 

[Robert Hicks]

I think Ilya Sevrugin just removed one. Let’s see if I can get him to chime in here.

[lithium366]

Yeah I have one from when I replaced vacuum step with an electric. PM me

[carusoam]

 

Solid answers in under an hour…

Go MS!

Best regards,

-a-

[AdamJD]

My M20F has been in the avionics shop for the past 5 weeks for an upgrade, which included replacement of the vacuum step with an electric step from http://flightenhancements.com/auto-step.html.  I pick it up this Friday, so I'll let you know how it turns out.  My Britain system was full of leaks, including the boot for the step.  So it is a timely replacement.  The shop put in a dedicated switch for the step - Up and Down.

[DCarlton]

I would likely repair or upgrade mine if it were INOP but after seeing an Aclaim with a fixed step, I’ve wondered if it would be better to just leave it down and fabricate a fairing for the opening…. and call it good enough.  An STC for a fixed step might be a practical solution.  

[LOCOLJ]

20 hours ago, 802flyer said:

The vacuum servo for the retractable step in my F model is in need of replacement. Does anyone know if Brittain is still replacing/overhauling these, or does anyone know where one might be found for sale used? Nothing on ebay at the moment. I'm aware of the electric conversion, but still curious to know what my options would be to simply replace the existing unit. Thanks!

I have one in good shape that came out of a 67E.  PM me and  I will send you pics

[jamesm]

I installed an auto-step from  http://flightenhancements.com/auto-step.html easy peasy in a '67C a few years ago. it is really light and works great.

Rob has well  thought out and designed unit.  But if you insist on vacuum actuators variety out on the market.  Plus if you get rid of the step and later on decide to get vacuum driven instruments   (AI & DG), if you haven't already replaced them. you can get rid of the vacuum pump unless vacuum operated speed brake option installed  or wing lever, Brittian autopilot .

James '67C

[carusoam]

15 hours ago, DCarlton said:

I would likely repair or upgrade mine if it were INOP but after seeing an Aclaim with a fixed step, I’ve wondered if it would be better to just leave it down and fabricate a fairing for the opening…. and call it good enough.  An STC for a fixed step might be a practical solution.  

The LBs kind of compromised their design… for leaving it out in the wind…

If you leave the retractable step down, you get a pretty big yaw from it….

 

Many Mooniacs remove the step altogether after it has stopped operating…

 

Regarding acclaims, some get two steps… L & R…. They fly in the FLs where the drag component is lessened….

Some get 310hp to make the drag even less noticeable….

Note: the LBs use a sheet metal wrap around their round tube for improved aero…. Get a good look at it.

Best regards,

-a-

[802flyer]

My M20F has been in the avionics shop for the past 5 weeks for an upgrade, which included replacement of the vacuum step with an electric step from http://flightenhancements.com/auto-step.html.  I pick it up this Friday, so I'll let you know how it turns out.  My Britain system was full of leaks, including the boot for the step.  So it is a timely replacement.  The shop put in a dedicated switch for the step - Up and Down.

Yeah I’ll definitely look into the electric option a bit more, although would prefer just to drop in a direct swap for now.

Curious to hear the real-world losses from a deployed step based on your handy up/down switch, once you get the plane back.


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[takair]

12 minutes ago, 802flyer said:

Yeah I’ll definitely look into the electric option a bit more, although would prefer just to drop in a direct swap for now.

Curious to hear the real-world losses from a deployed step based on your handy up/down switch, once you get the plane back.


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I’ve done some testing on this and have video buried somewhere in the forum.  The old retractable step has lots of un-aerodynamic surface area as compared to a fixed step, so there is a lot more drag.  You have to be very patient to measure the speed, but I’ve measured from 2 to 4 kt reduction, depending on how hard you want to push the plane.  The greater speed loss is not entirely from the step, but because the plane is out of trim.  In fact, a good hint that the step is down is that the ball will be out of center.  Rest your foot on the rudder and you will regain about two knots.  You could of course rig the plane to compensate, but you will still lose about 2 knots.  Keep in mind that it takes multiple minutes and stable air to measure this….it is not near as dramatic as speed brakes. 
 

As a side note, that same drag puts lots of preload on the step in flight.  I would not encourage moving the step in flight, at speed, as it can prevent smooth movement and loads up the actuator and mechanism.  

[M20F-1968]

On 11/6/2022 at 3:54 PM, 802flyer said:

The vacuum servo for the retractable step in my F model is in need of replacement. Does anyone know if Brittain is still replacing/overhauling these, or does anyone know where one might be found for sale used? Nothing on ebay at the moment. I'm aware of the electric conversion, but still curious to know what my options would be to simply replace the existing unit. Thanks!

I have in my notes somewhere the name of a manufacturer in NH that makes rubber products such as this.  There may be a part being made that can suffice.  I'll try to look for the name.

John Breda

[AdamJD]

Pirep.  I love my electric step.  Installer put in an up/down switch.  The step automatically comes down when the master goes off.  But it is slooooow.  So I put "Step Down" on my clear of runway checklist.  Step switch is right by the avionics switch, so it's hard to forget to put the step up on start up.  For what it's worth, I think some of my suction issues were from the step.  The installer showed me the pneumatic boot for the step and it was all torn from wear.  I wouldn't be surprised if the steps wasn't even retracting before.  Anyway, I love the electric step and am glad I didn't just have it welded down and I'm glad I didn't remove it like some folks do.  My wife wouldn't appreciate a missing step.