1967 vs 1968 - Max Flaps Speed Increased 20 MPH - what's different?

[Mooneymite]

 

Next questions is , once you do this SB, does the reinforcement let you lower at a higher speed i wonder?

Doesnt say so in the SB so guessing not.

 

I would suspect that "limitations-wise", no there's no way to change the flap speed.  However, from a practical perspective, if the spar mod is done and one "accidentally"      over-speeds the flaps....say, up to 125 mph there would probably be no damage done.

[StinkBug]

So if 1969 is when they beefed up the spar, why is the flap speed 125 on the 1968 models?

[furledd]

Well, now you've thrown a wrench into things!  

Maybe the 1969 models were being built in 1968??

But if your serial number is 68-XXX and you can go 125 mph then i dunno

[Alhall]

Just finished installing the rear spar center splice mod on my plane. I don't think stepping on the flap will cause any damage to the rear spar. All it does pull the shaft out of the hydraulic cylinder. The problem was the rear spar center splice was too thin material and flexed each time the flaps were lowered due to the pressure applied at the hinge of the actuator.

Al

[furledd]

How much does that SB update/mod cost to do, if the spar is currently in good shape?

 

I pulled my bottom panel last night and looked up at that area, and all looks good but wondering what the added insurance of the SB might cost?

 

Parts still available/cost?

[Alhall]

The kit from Laser is about $200. I'm old and slow and it took me about 35 or 40 hours. I did a a lot of cleaning while I had it apart. I have heard figures of $1200 and $3000. If you do the mod before it cracks the rib it would not be as big of job.

[furledd]

Thanks for the info.... I will look on the LASAR web site ..

 

How hard is it to get the baggage compartment floor out - is that all riveted?  I wonder if my fast working A&P could get it done in a long day?

 

( I know the bottom panel was easy to pull in like 5 minutes - but the baggage floor not sure..)

 

Was yours cracked already? how did you find it, during an inspection? Did you get any pics of where it was cracked? Sorry for al the questions...but i frankly never heard of this issue for the whole time of owning the plane and never remembered anyone telling me about watching for it.

[Alhall]

Search for the service bulletin SB20-217 it shows some pictures of where to look. I did not remove the whole baggage floor just the side rivets. The front is riveted to an angle that is bolted in. The bolts are hard to get to. Then I propped the floor up with two wood blocks. Two of the rear side rivets hold the brackets for the Actuator springs. Might be able to leave those rivets that hold the brackets.

Yes mine was cracked and the rib was also cracked. I found it after reading some post on this forum. You also have to remove the rear seat and panels in that area to get to the back side of the spar to buck rivets.

[furledd]

FYI,

 

I found a picture of one of those original ASI's for a Mooney that was mismarked at 100 MPH instead of 105 MPH for flaps max speed.

 

Note the 2nd version picture "looks" likes it 100 MPH but it's really showing 105 MPH if you look closely at the scale.

 

The 3rd photo with the TAS adjustment windows its pretty clear its 105 MPH.

 

4th one is for the later models at 125 MPH - but all other speeds are the same..

[BigTex]

I'm surprised that this hasn't become an AD.  Seems like when you cracks in the spar, you have a potential air worthiness issue.

[JaredDavis]

The first ASI may not be from an F and therefore not an error. My 65 C has a 100MPH limit.

[furledd]

Well that begs a new question - why did they go from 100 to 105 at some point then between 1965 and 1967??

[47U]

Well that begs a new question - why did they go from 100 to 105 at some point then between 1965 and 1967??

Maybe to allow flap extension on a 90kt instrument approach? That lines up with the time on the approach plate to go missed..

[Andy95W]

I'm surprised that this hasn't become an AD.  Seems like when you cracks in the spar, you have a potential air worthiness issue.

Common misconception. It's not the actual spar, or even the stub spar (rear spar). It's a sheet metal box that has some stuff hung off it, like the flap attachment mechanism, and it has a confusing name.