Zero Fuel Weight

[Hugo]

I downloaded a wt&balance ap for the M20R and it works great.  However, they indicate a 'zero fuel weight' number in the envelope.  I have been unable to find any reference to a 'zero fuel weight' limit in the POH.  I am accustomed to dealing with this limit with jet aircraft but have found no reference in the M20R manual.  Is there a 'zero fuel weight' limit on the M20R?

[Jerry 5TJ]

There is no zero fuel weight published for the M20R.

There is a max landing weight of 3,200 pounds.

 

[carusoam]

Which weight and balance app are you using?

I think I have WnB Pro or something like that.  It is resident on an old iPad...

Putting the data into it was a bit challenging from what I remember.

Did they mean empty weight for your plane?

the R has

- MGTOW,

- MGLW,

- empty weight

- front seats

- back seats

- fuel

- baggage compartment

- hat shelf

- seat positions, sliders...

- seat positions, recliners...

plotting a graph as fuel burns is helpful to understand how the cg changes with time and how long you need to fly to be under the MGLW.

PP thoughts only, not a CFI...

Best regards,

-a-

Edited April 6, 2017 by carusoam

[Mooney Search]

I just posted the same question over on the "modern mooney" section.  I was left confused by the exact same thing - app had a zero fuel weight, but I could not find a POH that reflected this limited. The responses I got all indicated that there is no zero fuel weight as the app would lead you to believe. 

[Rmag]

I just played around with my W&B with the Garmin Pilot App.  It shows zero fuel weight.  The zero fuel weight was the weight of the aircraft plus anything other than fuel.

Example:  2000 lbs empty aircraft, zero fuel weight = 2000 lbs

200 lb pilot loads 40 lbs of bags in the plane and he gets in.  Zero fuel weight is now 2240.

110 lb passenger climbs in, Zero fuel weight is 2350.

Maybe that's why it's not in a POH as it is variable depending on what you load in the aircraft at any given moment?

[Sean S]

Zero fuel weight is not in the POH. That number is found in the most recent weight and balance information. The number changes anytime you make a change to the installed equipment, such as removing your old transponder and installing a new ADS-B conpliant transponder. Or if you remove obsolete equipment like the nice Loran I have, then you would calculate the weight removed and be pleased with a inceased useful load!

[PTK]

Zero fuel and landing weights are calculated values off of take off weight. They're based on fuel burn. All fuel burned (zero fuel remaining) or whatever fuel the specific trip requires. All weight in excess of zero fuel weight is due to fuel only.

My J has no published zero fuel weight limit. The UL takes into account fuel, bodies and stuff interchangeably. At a full gross take off weight of 2740 with full fuel, the zero fuel weight will be 2356. (2.5 gal unusable fuel is included in zero fuel weight.)

[Marcopolo]

Zero Fuel Weight is similar to MGLW.  It is a value that keeps one from adding things other than fuel that would put you over the MGLW if you were to land with zero fuel. 

Simple math

MGTOW = 3500

MGLW (zero fuel) = 3000

Empty weight = 2300

You could add 1200# of "stuff" but no more than 700# of non-fuel "stuff" so there would not be a chance of landing over MGLW with zero fuel.  Not saying it makes aviation sense, but thats the way I understand it.

 

Ron

[RobertGary1]

I've not seen any piston with a zero fuel weight. Fuel just doesn't make up that big a percent of our weight the way it does in jets that literally use fuel hoses the diameter of a fire hose. 

-Robert

[Htwjr]

It is my understanding that on some planes the center of gravity changes with fuel burn.  I think it is helpful for a W&B app to show that even if you used all of the fuel you are still within the W&B envelope. 

[carusoam]

Mooneys WnB does change some as the fuel load burns off.  It is smart to know where you are in the envelope for the entire flight.

Other planes are significantly challenged with a lighter load of fuel making the get there-itis more serious...  a get-there-more-efficiently-itis before you fall out the back of the envelope kind of thing.

Best regrads,

-a-

[Rszent]

If Intrested I made my own weight and balance for my Ovation .. It is in Excel and all the information can be changed to fit the loaded aircraft if anyone is intrested I can email it to you....

[Hank]

This is the W&B for a recent flight in my C, with 52 gal fuel capacity. Note how little the fuel load changes CG. On the graph, fuel is the top leg, going from empty weight + people + bags to add in the fuel so you can observe the CG shift as fuel burns off. It's not much . . . Oh, the "48 usable" isn't right, that's a carryover I just noticed, it should be 51 usable [it's either 0.5 or 0.6 unusable per tank, I forget].

[TBar]

As I understand, zero fuel weight refers to certain aircraft (think larger wing spans) that must have a significant portion of the useful load as fuel.

Weight in the form of passengers & cargo, even if they are well below MGTW, place excessive stress on the wing in turbulent conditions. 

Said another way, an example aircraft may have a useful load of 1000 pounds, but 400 pounds MUST be as fuel in order for the aircraft to be safely loaded. Meaning only 600 pounds may be people & stuff. Go over that number and you exceed the zero fuel weight.

IF an aircraft has a zero fuel weight requirement, it will be listed in the POH for that aircraft.

PP studying for CFI

[jetdriven]

On 4/7/2017 at 10:51 AM, RobertGary1 said:

I've not seen any piston with a zero fuel weight. Fuel just doesn't make up that big a percent of our weight the way it does in jets that literally use fuel hoses the diameter of a fire hose. 

-Robert

Cherokee six have a zero fuel weight. 

[KLRDMD]

Just now, jetdriven said:

Cherokee six have a zero fuel weight. 

As do Senecas

[carusoam]

Welcome aboard, Tbar.

You have answered a question that came up in a WnB app that I used years ago.

I never got a full understanding of what they were asking about.  The M20s don't have this limitation.  

You just made a lot of sense by showing why other planes use it... Thanks!

Best regards,

-a-