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305 Rocket W&B vs 231K?


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I've been flying a 305 Rocket for about 6 months now and looking forward to taking it to an accelerated IFR training and checkride next month.

i'm just curious if you K drivers have the same wacky forward CG that the Rocket has?  I know it won't be AS significant as the big 6 cylinder engine/turbo stuff is probably another 150ish lbs...but wonder if you guys are in a situation where pretty much no matter what your load out is - you're way forward CG?

We're due to weigh the airplane, but we're looking at around 900lbs or so useful.  With 60 gallons and me (200lbs) I'm so far forward CG that even burning the fuel down doesn't get me back into the box.

As for the Rocket, and obviously knew this going into the airplane to begin with is that it's a wife and me and a few bags kinda plane.  I could also do myself and my 3 boys and a few bags or my Dad and I and golf bags.  Again, all scenario's - even with people in the back seats the W&B shows far forward CG outside the 'box'.

How do you guys talk through these kinds of scenario's with a DPE on a checkride?  Obviously way better to be forward CG than aft and as long as you know it you can 'compensate' for it.  

Edited by Austin305Rocket
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8 minutes ago, Austin305Rocket said:

I've been flying a 305 Rocket for about 6 months now and looking forward to taking it to an accelerated IFR training and checkride next month.

i'm just curious if you K drivers have the same wacky forward CG that the Rocket has?  I know it won't be AS significant as the big 6 cylinder engine/turbo stuff is probably another 150ish lbs...but wonder if you guys are in a situation where pretty much no matter what your load out is - you're way forward CG?

We're due to weigh the airplane, but we're looking at around 900lbs or so useful.  With 60 gallons and me (200lbs) I'm so far forward CG that even burning the fuel down doesn't get me back into the box.

As for the Rocket, and obviously knew this going into the airplane to begin with is that it's a wife and me and a few bags kinda plane.  I could also do myself and my 3 boys and a few bags or my Dad and I and golf bags.  Again, all scenario's - even with people in the back seats the W&B shows far forward CG outside the 'box'.

How do you guys talk through these kinds of scenario's with a DPE on a checkride?  Obviously way better to be forward CG than aft and as long as you know it you can 'compensate' for it.  

Mine was not beyond forward envelope but it was at the front end of the envelope.  But then I got a 35lb lighter prop - an MT four blade prop - that moved the CG back quite a bit and balance is no longer a major thing.

Do you have the 19b of charlie weights in the tail?  That helps a lot.

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2 minutes ago, Austin305Rocket said:

We do have the weights back there...but not the composite prop...on the list. :)

Ah - the weights are cheap.

The prop is expensive.

Meanwhile, I used to carry a 50lb bag full of gym weights in the baggage area.  It helps a bit - but not as much as the prop since the arm isn't as good.  But anyway maybe that's your solution for DPE - shows a thoughtful pilot to pro-actively understand your W&B table and to do something about it.  I also had about 20lb of lead bars that I got and put into the old battery box - which is in the tail but not far back in the tail - right behind the baggage area wall.  My battery box was still there form the original 231 system, but now empty of any battery since the batteries for the rocket are also in the far back of the tail.

Congrats on your new ride!

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A friend of mine got a mod field approved to add as much as 120 pounds of weight to the tail. I can give you his info if you are interested.

 The FAA said they would sign them off any time. He has drawings and a DER analysis of the mod.

 It totally fixes the CG issue, but doesn’t help the payload issue. It is designed so the weights can be changed in less than 1/2 hour.

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6 hours ago, N201MKTurbo said:

A friend of mine got a mod field approved to add as much as 120 pounds of weight to the tail. I can give you his info if you are interested.

 The FAA said they would sign them off any time. He has drawings and a DER analysis of the mod.

 It totally fixes the CG issue, but doesn’t help the payload issue. It is designed so the weights can be changed in less than 1/2 hour.

WOW - 120 seems like way too much!  10 or 20 more lbs back there could be helpful.  But I got the prop lightener.

I suppose if you remove the engine from the front that would also help the balance?

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7 hours ago, Austin305Rocket said:

As for the Rocket, and obviously knew this going into the airplane to begin with is that it's a wife and me and a few bags kinda plane.  I could also do myself and my 3 boys and a few bags or my Dad and I and golf bags.  Again, all scenario's - even with people in the back seats the W&B shows far forward CG outside the 'box'.

How do you guys talk through these kinds of scenario's with a DPE on a checkride?  Obviously way better to be forward CG than aft and as long as you know it you can 'compensate' for it.  

Just remember to account for actual front seat positions when figuring CG. They are on the Type Certificate. It can make a difference versus using a generic distance, especially if one front seat is slid way back like (tall, tall) Erik does.

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You are correct, we knocked it back to about 80 lbs. The design was approved for 120 lbs. 

to change the weight all you have to do is remove either of the big inspection plates in the tail, unscrew 4 bolts that are easy to get to, remove or add the lead plates as desired and put the bolts back in. You need different bolts for different stacks. It is kind of slick.

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The CG in my 231 is forward but in the envelope and I usually don’t have a problem with it.  However, I recently had the O2 bottle (steel) removed to be hydrostated and had another guy along on the trip home.  It was ugly.  The AP ran the trim way nose down.  I put 110 pounds of scuba weights in the baggage compartment until the tank comes back.  Now the plane is happy again.

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44 minutes ago, Hank said:

Just remember to account for actual front seat positions when figuring CG. They are on the Type Certificate. It can make a difference versus using a generic distance, especially if one front seat is slid way back like (tall, tall) Erik does.

I had an extra hole drilled in the seat rails so I can put the seat even further back for good leg room.  

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Something isn’t quite right if you go outside the envelope...

Yes, Rockets and Missiles went with larger hardware on the nose...

That weight does put things toward the front of the envelope...

But once you get outside the envelope... you are now in the test pilot regime...

 

Rocket engineering didn’t change the tail feathers... so their ability to keep the nose up during the landing can get outside the norm...

 

too far forward, the tail can stop flying during the landing process... this would drop the nose really hard...

 

You can probably read through the STC paperwork that comes with the plane...  Rocket engineering does a great job with documentation...

 

I’m glad you asked...

Don’t guess, there isn’t any magic... RE updated the power plant, and didn’t change the rest of the plane... All the other limitations are still in place...

 

when it comes to balance... outside the envelope at either end has some ill effects... worth avoiding...

Transition Training is worth the money...

Hmmmm is it a new requirement to be named Austin while flying a Rocket? :)

welcome aboard, other Austin with a Rocket!

PP thoughts only, not a CFI... My O has an RE engine/prop package on the front and Charlie weights in the back...

Best regards,

-a-

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14 hours ago, jlunseth said:

The CG in my 231 is forward but in the envelope and I usually don’t have a problem with it.  However, I recently had the O2 bottle (steel) removed to be hydrostated and had another guy along on the trip home.  It was ugly.  The AP ran the trim way nose down.  I put 110 pounds of scuba weights in the baggage compartment until the tank comes back.  Now the plane is happy again.

I notice this as well - our autopilot trims down a decent amount as well even with 2 adults up front and 60 gallons. I thought that was interesting given the almost severe forward CG but just figured that was a Mooney thing. 

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13 hours ago, carusoam said:

when it comes to balance... outside the envelope at either end has some ill effects... worth avoiding...

Transition Training is worth the money...

Hmmmm is it a new requirement to be named Austin while flying a Rocket? :)

welcome aboard, other Austin with a Rocket!

PP thoughts only, not a CFI... My O has an RE engine/prop package on the front and Charlie weights in the back...

Best regards,

-a-

Thanks! I did do transition training with 2 different CFI's - both are probably on here and one of them flew a M20K around the world.  So, feel pretty good about that.

I guess the big talking point is dealing with the landing configuration with a nose heavy airplane.  I know I tend to use a significant amount of trim up when landing - makes for a much smoother flare/landing vs a neutral trim and man handling the controls.  As mentioned, Rocket didn't do anything with the 'tail feathers' so perhaps there's something to that.

Again, just knowing that I'll walk into a checkride with a W&B printout that shows the airplane far forward CG for the duration of the flight makes me a bit nervous and want to be sure I'm covering all the bases - especially from those who also fly Rockets.  Thanks guys.

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Thanks! I did do transition training with 2 different CFI's - both are probably on here and one of them flew a M20K around the world.  So, feel pretty good about that.
I guess the big talking point is dealing with the landing configuration with a nose heavy airplane.  I know I tend to use a significant amount of trim up when landing - makes for a much smoother flare/landing vs a neutral trim and man handling the controls.

Have you ever practiced a go around with the trim up? Be prepared for the plane wanting to go nose up and stall when you apply full power.
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Just now, ArtVandelay said:


Have you ever practiced a go around with the trim up? Be prepared for the plane wanting to go nose up and stall when you apply full power.

Yes, I have.  With the Rocket especially, you can get yourself into big trouble pretty quickly...pull the gear up with the trim up and it wants to go vertical. 

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Plan on tying a good tool box into the baggage compartment... (Not loose)

It is a nice way to alter the WnB in a temporary fashion...

This way your WnB calcs will not only look good, but be good...

+1 On full knowledge of the go around technique with Hobbs of up trim in place...   with the Rocket, full power is not going to be needed... so balance the power until the trim can be reset...

MS has recently lost a member where it is suspected the trim and flaps were left in place after landing, leading to a stall on T/O...

Another way to add some weight to the tail, without it being useless lead... see what batteries are back there and look what else may be available... more capacity weighs a couple of pounds more...

Definitely pay close attention to the WnB... there is no room for guessing... see Hank’s post above...

Glad you got the good TTer. :)

Best regards,

-a-

 

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1 minute ago, carusoam said:

with the Rocket, full power is not going to be needed... so balance the power until the trim can be reset...

Correct!

I find that to keep the engine running smoothly all the way to touchdown I can and should just leave the mixture where it was for cruise--which was for me 30" and 2200 rpm. So a go around is just 30" initially and it climbs just fine. I have no problems managing trim.

I watched David MaGee take OFF with just 30" in my Rocket on the way back from pre-buy last April! 

But also I gotta say something I've said before:  I have a very healthy skepticism for all Rocket weights and W&B.  Your 231 Rocket probably has a UL north of 1000 lbs, while mine has barely 900#.  I seriously doubt my airplane weighs 100+ pounds more than yours especially since it just lost 80 lbs at the avionics shop.  And yet with your 1000+ UL your CG is way forward while mine is right on top of the fuel station at 47.75". Not nose heavy at all.  How can they be that different?

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Flying with David Magee... be ready to take notes!

David IS a fountain of Mooney knowledge... it comes out in a casual conversation and goes on all day...

I was truly surprised by how much more there is to know when transitioning from the short to the long body... I had taken a year off from flying in between...

The biggest differences are simply power and weight/momentum... but that Was enough to keep me busy for a couple of days...  :)

The other differences are every system has been updated, and had power added... some funny details like the tail trim moves at the same speed the flap motors operate... Lower the flaps, and remember to start the trim... hold the trim for the same period of time the flaps are moving...  (who would of thought of that?  Go Mooney!)

Best regards,

-a-

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