Rayjay Turbo STC

[Guest Spike Kavalench]

How does adding a Rayjay Turbo affect useful load on an M20B? 

[Raptor05121]

Well it has mass and weight, so negatively unless it allows a gross weight increase which I'm sure it doesnt. Its not a turbocharger, its a turbonormalizer.

[carusoam]

Spike,

Find the weight of the turbo and extra pipe and expect to put a similar weight on the other side of the center of lift..

If it weighs 25 LBs expect to lose a total of 50LBs to make the WnB work...

Overall a relatively small amount for the benefits it can provide.

PP thinking only, not a mechanic...

Best regards,

-a-

[Raptor05121]

I wouldn't be so sure. My 3 blade is 22lbs heavier than the 2 blade. I lost 22lbs and my CG went forward. I didnt need a counterweight

 

[carusoam]

If you wanted to keep the same balance, Alex.... an extra weight in the tail would work. The arm for things in the engine compartment is pretty short. So the torque calculation, weight x distance, can be pretty small...

Not sure what the rules are regarding adding hardware and having to balance it or not.... I ask my mechanic, and document the results... the LBs have a few Charley weights to help with that...

My current 3 blade prop weighs a few pound more than the old 3 blade prop.  With the long body, it takes a lot of change to run out of trim...

My C would run out of trim on short final with it's two blade.

I guess the real important question is how much does the TN actually weigh?

I’d ask Alexa, but I don't have a decade to get an answer...

In the end a new WnB calculation needs to be done.  That is personalized for each plane.  Making the answer to the OPs question.... go do a WnB on the plane with before and after data to find out how much UL is lost...  it won't be less than the weight of the new hardware...

PP thoughts only, not a mechanic...

Best regards,

-a-

[N201MKTurbo]

My turbo system added 32 lbs to the airplane.

[MIm20c]

Mine is probably in that 30-40 lb range when you add the extra hoses etc. I also have two external oil filters, one dedicated for the turbo and the other for the engine.  With two heavy people in the front, nothing in the back, and full fuel I’m getting close to the forward cg.  This gives me a lot of latitude in loading because my normal loads will fall into cg as I work towards gross. 

My plane would not be a good candidate for a heavy 3 blade or even a top prop.  But it works great now and with the battery in the back stays in balance without adding weight. 

[Jerry Pressley]

Still have the low smoh system from my 200 hp for sale if anyone interested.  Jerry   423 231 3491

[Guest Spike Kavalench]

5 hours ago, N201MKTurbo said:

My turbo system added 32 lbs to the airplane.

Ok, thanks. The reason I ask is the weight of a plane I’m buying has gone up 250 pounds since 1964 (according to a weight and balance do e two years ago) with only the turbo and a paintjob added in between. And it should have lost weight with a lightweight starter and alternator...250lbs is crazy, it only leaves about 600lbs of useful load!  

[Guest Spike Kavalench]

13 hours ago, carusoam said:

Spike,

Find the weight of the turbo and extra pipe and expect to put a similar weight on the other side of the center of lift..

If it weighs 25 LBs expect to lose a total of 50LBs to make the WnB work...

Overall a relatively small amount for the benefits it can provide.

PP thinking only, not a mechanic...

Best regards,

-a-

Looks like they moved the battery back and didn’t add any ballast. I’m going to have it reweighed, it could not have gained 250 pounds since it was born with nothing added besides a turbo and a paint job. Could it!?!

Edited January 20, 2018 by Spike Kavalench

[DonMuncy]

43 minutes ago, Spike Kavalench said:

Looks like they moved the battery back and didn’t add any ballast. I’m going to have it reweighed, it could not have gained 250 pounds since it was born with nothing added besides a turbo and a paint job. Could it!?!

I doubt it would have gained that much. I would look over all prior W&B calculations carefully. Did you weigh the plane or are you working from the W&B numbers.

[carusoam]

Spike,

When able, you may want to add some details to your avatar... specifically model of M20...

It will help people with their memory issues... 

Some planes have gained weight over the years...  fancy interiors, lots of radios and a nice rug...

But, unless somebody added a second engine or brought a mechanic along, it would be a challenge to accidently add 250 LBs...

Best regards,

-a-

 

[kortopates]

250 lb increase from weighing it does sound excessive. But is also crazy to weigh a plane and not expect it to go up in weight, which is reason enough IMO to stick to calculated W&B updates. I'd carefully go back and review every superseded W&B update looking for mistakes and if still convinced the 250 lb weight increase is not justified, I'd re-weigh it or even re-do it by re-calculating the last update based on the Turbo STC info for weights. If you know the paint job included a full strip before re-paint, then that shouldn't change W&B. And of course there is nothing wrong with weighing it to verify the CG is very close to the calculated CG and using the weighed version for informational purposes only -i.e. not using it officially.

[Raptor05121]

1 hour ago, Spike Kavalench said:

Looks like they moved the battery back and didn’t add any ballast. I’m going to have it reweighed, it could not have gained 250 pounds since it was born with nothing added besides a turbo and a paint job. Could it!?!

Sounds like someone did not follow Mooney's weighing procedure. Fuel AND oil need to be drained prior to weighing. I would put that plane on scales ASAP. My C model with a 3-blade has 1,015 useful

[ArtVandelay]

If you have it reweighed, make sure they do it correctly and empty the fuel tanks, not just read fuel weight using gauges unless your gauges read high.

[Guest Spike Kavalench]

46 minutes ago, DonMuncy said:

I doubt it would have gained that much. I would look over all prior W&B calculations carefully. Did you weigh the plane or are you working from the W&B numbers.

Somebody else weighed it a couple years ago, going to have to reweigh it myself.

[Guitarmaster]

If you have it reweighed, make sure they do it correctly and empty the fuel tanks, not just read fuel weight using gauges unless your gauges read high.

Do you drain the tanks completely, or do you just bring it down to unusable fuel?

Sent from my XT1585 using Tapatalk

[Guest]

Here is reweighing from an older manual.

 

[Raptor05121]

Which serial number range does that apply to? My service manual calls to empty all useable fuel AND oil sump.

[ragedracer1977]

45 minutes ago, Raptor05121 said:

Which serial number range does that apply to? My service manual calls to empty all useable fuel AND oil sump.

So does mine-we should have the same service manual.

[Raptor05121]

Even at the bottom it states: "Empty weight includes unusable fuel and undrainable oil"

Completely contradicts itself

[carusoam]

This line may not be correct for all planes for all reasons...  but know why they want you to follow this procedure...

1) '4. Fill oil to Capacity (8.0qts)'

2) last line... Empty weight includes unusable oil and unusable fuel....

2a) Also know Lycoming has a minimum oil for continuous use of about 2qts... (heat wise... not a good idea to fly like this)

3) For Best useful load numbers you want to compare to the numbers using the oil and fuel tanks being empty... only the unusable liquids being left in...  a legal definition at best.

4) realistically for every day use,  setting the oil to be a 6qts saves some time in your WnB calculations.... if you always use 6 qts of oil.  1.5 gallons of motor oil weighs 10.5 pounds... 7 pound / gallon...

5) WnB apps make Doing these calculations more error free, easier, faster, more accurate within reason....

6) The definition of unusable fuel is also kind of fuzzy.  Because unusable in flight is different than unusable in climb, which is different than unusable on final approach.... this is because the fuel pick-up is at the rear of the tank... better in climb than on short final... the procedure mentions leveling the plane, but may not mention the effect on actual usability of fuel...

7) Just looking at the balance aspect... they seem to be focusing on the plane's sensitivity to being nose heavy at slow speeds... Having two people up front and loading the oil to capacity is in the area of worst case scenario for falling out the front of the balance envelope...

8) Take a look a the date of the procedure.  Try to determine if a word processor was used before being sent to print.

Errors like this used to be printed all the time.  It isn't right. It isn't wrong,  but it could have been explained better...  

in the old way of doing things there was no way to identify something could be explained better, and get an update in, prior to going to print, and being held for an eternity...

PP thoughts only, not a WnB expert...

Best regards,

-a-

[kortopates]

All aircraft certified under CAR part 3, which was everything prior to Jan 1, 1958, were certified with a Basic Empty Weight that did NOT include oil. Mooney's of course were originally certified under CAR part 3 and new models after '58 were added to the amended certification. But at some time, Mooney did change to the Part 23 weighing requirements that all the mid-body's and long body's go by where full oil is included in the Basic Empty Weight plus all required equipment for flight including POH, tow bar, etc. as it left the factory. There was an original equipment list provided that checked what equipment and arm was included.  One should be able to resolve which rules their Mooney falls into by looking at your POH or equivalent guidance for calculating W&B, TCDS notes or even their existing W&B sheet.

Its not necessary though to drain the oil for earlier models, instead its perfectly acceptable fill to capacity and use the specified arm and 7.5 lb/gal to compute oil weight and arm to subtract from the weighed aircraft with full oil. The same can be done for fuel. Both old CAR part 3 and new Part 23 rules call for the Basic empty weight to include unusable fuel only.  But for accuracy (since its near impossible to be assured you have filled your Mooney tanks to the actual stated capacity) I would personally drain the tanks dry and then add in the actual unusable fuel as specified for your year & model (even on some of the same models it can change by year or serial number) - just as Mooney's weighing procedure advises. You can look up the precise unusable fuel for your model/serial number in the TCDS (I recall note 1).  Besides too many people still use 6.0 lbs/gal (which was the generic weight for leaded avgas no longer in use) when FAA approved weight for 100LL is 5.82 lb/gal (although technically it varies by temperature).