My first question is – why do you need full fuel? The TB20 has amazing range and unless you aim to replicate one of Peter’s epic 7-hour runs, I doubt you need to top off. Especially with pax, you prop90 want to limit yourself to about 2-3 hour legs. You ‘aim’ to be overweight by about 45kgs, that’s 90 pounds or 15 USG. You really need these 15 gals?
Other than that: have you ever flown the airplane close to or at MTOW ? I’m not very familiar with the TB20, but for example the C210 I fly changes characteristics pretty drastically if you get close to max weight.
In short: I wouldn’t do it.
I haven’t flown the airplane with more than 1 passenger or close to its MTOW before. I am pretty sure @Peter ’s 7 hour flight was done with less than 4 people on board and IFR, at high altitude.
I won’t fill up the tanks fully, but the weight is still an issue, with the damn TKS system and overweight pax and baggages.
The intended flight time is about 3.5 hours long, but with the legal fuel reserve for holding time and contingency, I will need about 275 liters of fuel. This will put me almost 50 kilos north of the W&B diagram.
Probably the most sensible thing to do is to split the trip with refueling stops along the way…
172driver wrote:
I doubt you need to top off.
Good point. My last flight the wb was a factor. Planned flight time was only one hour so adjusted fuel uplift accordingly. As it was a rental plane I called the pilot flying it a day before and asked him not to fill it up.
Well, obviously, nobody recommends flying over MTOW; it is illegal, etc 
Now let’s look at what happens if you do it.
As already posted above, if you load too far forward or back, you can run out of elevator authority, etc, and crash.
The TB20 is an unusual plane in that it is virtually impossible to overload fore or aft without exceeding the MTOW. You could do it by putting a ~40kg pilot in the front, empty RHS, 250kg in the back seats (the structural limit there) and 65kg in the luggage compartment (the limit there) – from memory. Obviously this type of loading is not likely.
So it is a “relatively safe” plane to overload.
For each 1% extra weight you need 2% more runway. Vs goes up in proportion to weight, IIRC. Other things also change.
A guy “close to Socata” reported, some years ago in the Socata owners’ group IIRC, that Socata tested the TB20 at MTOW plus 30%. I am completely unsurprised by this; lots of people have ferried all kinds of GA planes at MTOW plus 20-30%. The plane will fly just fine. Need lots of runway… probably best part of 2km.
At 50kg over MTOW, this is just 3.6% over. You will not even notice that. Make sure you have loads of runway, etc. And that 50kg will get burnt off in about an hour anyway.
The full TKS system (I have it too) does add an unwelcome bit of weight but is worth having.
On the TB20 there is no significant CofG change due to fuel quantity change.
With the sizes of “modern people”, I reckon most PPL training in the C150/152 types is done at at least 10% over MTOW 
Peter wrote:
And that 50kg will get burnt off in about an hour anyway.
It’ll help wrt of the total weight, but what will be the impact on CG location? (I know nothing about TB20s, but it should move the CG aft, shouldn’t it?).
I don’t think anoyone would advise you to take off over MTOM on a public forum.
So let me just leave this here:
https://www.ainonline.com/aviation-news/business-aviation/2019-03-11/tbm-930-completes-paris-new-york-record-flight
A 3354kg MTOM plane approved by FAA to fly 940kg or 28% overweight.
wleferrand wrote:
It’ll help wrt of the total weight, but what will be the impact on CG location? (I know nothing about TB20s, but it should move the CG aft, shouldn’t it?).
I don’t think there are many SEP tourers where the CG changes significantly with fuel burn.
AlexTB20 wrote:
The intended flight time is about 3.5 hours long, but with the legal fuel reserve for holding time and contingency, I will need about 275 liters of fuel. This will put me almost 50 kilos north of the W&B diagram.Probably the most sensible thing to do is to split the trip with refueling stops along the way…
For most pax (by which I mean non-aviation people) 3.5 hours in a SEP isn’t fun. Agree with your idea to break the trip into two legs.
I haven’t flown the airplane with more than 1 passenger or close to its MTOW before.
An incremental experience would usually be my way to approach this.
If I was one of your pax, and due to be in a rear seat I would be uncomfortable.
The Robin was a good load carrier but the difference in handling between 2 up and plenty of fuel, and 4 up, full fuel plus bags to MAUW wasn’t insignificant.
The same for the 172, and the Cherokee.
If you have nice conditions and a long runway (staying inside MAUW )you should be fine, but do give it the consideration it deserves.
As mentioned by a couple of the other guys, maybe a fuel stop on the way out, and if she feels great, maybe consider your options for the return trip.
Enjoy.
AlexTB20 wrote:
I am wondering what’s the worst that can happen if I take off with 1 crew and 3 pax, full gas and about 20kg of baggage?The aircraft is equipped with a full TKS system that should weight about 40kg.
Did any of you take off with an overweight of let’s say 50 to 100kgs? Is it really dangerous, or I only need a longer runway and stay clear of turbulence?
Alex, forgive me for being absolutely brutal about this, but the question you ask here disqualifies you as pilot in command.
Your first line indicates you are willing to operate illegally.
Your second line indicates that you do not know the empty weight of your plane which prevents you from doing a proper WnB.
And anyone answering the third line in the positive would, ferry permits with overweight by the CAA excluded, openly admit he has comitted a serious violation of the rules of the air.
Flying outside weight and balance envelope is illegal and it is so for all the reasons mentioned above by many posters who appear to have a much better understanding of the issues involved than it appears you do.
As to what will happen every time you are overweight and/or out of CG:
- Your airplane will not perform as advertized in the POH. If out of CG, it will be difficult up to impossible to control.
- The moment you are as much as 1 lb overweight or 1 mm out of CG and it can be proven and written into an accident report, you loose your insurance cover. No matter why the accident happened, your insurance will not pay ONE cent or, if it is not your plane, come after you for full regress on what they have to pay the owner. Families of pax lost or hurt will sue your estate with the full risk of your family having to caugh up.
- Checking weight and balance is very easy for ramp checkers and if they suspect you, they will do it. If they find you illegal, you will get busted.
Yet it has to be said, MTOW and CG violations are propably the most commonplace of all violations in aviation and not only in GA but also in the airlines. Why? Because it is so darn easy to screw up your wnb and never even coming close to question it.
Almost all GA planes are constructed that they realistically can never carry the full pax load they have seats for and a reasonable amount of fuel. Almost none can carry full fuel and full pax load. Consequently they get overloaded every time all seats are filled, particularly if it is a holiday flight where baggage is involved. My own take is that if you want to fly with the same number as pax than you have seats for in a light 4-6 seater, you will need to bring a scale to the airplane and weigh every tiny item and add up and only then order the fuel truck. Who does this? Nobody. So consequently the only way to be sure is to leave at least 2 seats empty at all times or better rip them out of the airplane in the first place and then make sure the space won’t get used for people carrying everything and the kitchen sink.
Realistically, loading a plane with 4 adults plus baggage even if we take IATA standard weights means 4×83 kgs plus 4×23 kgs bags. That is 430 kgs folks. Most 4 seaters have 250 to 350 kgs payload including fuel.
People take empty weight of the AFM but tend to forget that they carry loads of junk in the boot to start with which never gets weighed: Chocks, tiedowns, tool boxes, oil cans, airplane covers, e.t.c. All that combined often comes up to 30-50 kgs which you loose as payload. Clearing out the junk might be a good idea and then create a flight kit which you know how heavy it is.
Passengers: Who ever weighs the people you take on board with clothes and shoes e.t.c.? People lie about their weight more than about most other things, so you can never rely on what they tell you, because a) they never step on a scale fully clothed and fed and b) most are embarrassed about their weight. So the only way to know is to add a scale to the flight kit and weigh every single item.
Those who can’t be bothered to do that should simply say, ok, my payload with the fuel I got on board is 250 kgs, so I will fly with 2 people and bags or 3 without any bags, where in the latter case you are most probably overloaded already.
Silvaire sais it correctly: Most trainers and all UL’s fly illegally 99% of the time as even the CFI and student exceed the total payload of the plane (which is in the 150 kg area). And then there are planes which should never have been certified as they can never fly legally whenever they have full fuel on board: Some Jetprops and almost all Mooneys with LR tanks can carry an infant pilot without baggage if the fuel is full. IMHO whoever certified this nonsense should be dismissed from the certifying body and those planes should be modified so that at least minimum crew with realistic flight bag can go on that plane with full fuel.
Add to that: Some planes CG changes massively when fuel has been used. So it can be within CG at take off but totally out on landing. Beech Bonanzas are notorious for this! I know at least one which got lost over the north sea because of this with 4 people I knew lost.
Airliners are a different piece of cake in this and they do fly overweight a lot as determining the real weight of them is next to impossible, so approximations are used which are quite off most of the time but which are within the regulative. The difference is, that if an airliner ends up in a smoking hole in the ground, determining the exact weight the thing had when it took off is next to impossible and therefore the weight and balance sheet compiled by the pilots or handling agent will have to do even if in many cases it is quite optimistic. Looking at reality, I would have to say EVERY airliner operating at MTOW or max RTOW is overweight in some regards as it is not possible to determine the correct weight unless they do have inbuilt weight on wheel sensors which do so. Why? They operate with standard pax weights which also include hand luggage which in theory should weigh 6 kgs per person. First of all, MANY passengers today are a lot over the standard weight including the bag allowance (83 kgs anyone??) and almost hand luggage taken on board is most of the time more in the region of 20 kgs upwards unless you have airlines who religiously check it and then ban it to the hold where it hopefully gets weighed. Airliner losses where the airplanes where massive overweight was a factor are relatively rare or at least they hardly ever get caught out, but the most prominent one where the fact that the plane was hopelessly overloaded was mentioned but played down by the investigative agency was the Air France Concorde at Gonesse, which was only counting the known factors at least 6 tons overweight for the runway and wind they took off from. In reality, it was probably closer to 10 tons.
Of course airliners will have more tolerance than small planes for the simple weight they have to start out with. But the industry is also quite complacent with this, even though particularly LCC’s like Easy, Wizzair and Ryanair are probably the best in regards of wnb simply because they make money by busting pax with overweight handluggage. Whether they actually put the overweight someplace is a different story but people are sufficiently scared that they do get proper handbags for fear of additonal costs (= fines in real world). I’ve noticed also that more and more regular airlines start to check handluggage at the gate too and will refuse them which is about bloody time this is done.
If it was for my experience, I would up the IATA standard weights to 120 kgs per pax, regardless of male, female or child and while this might mean we are going to fly a bit lighter than now, it would err on the safe side. Today, any 100 seater most likely is between 2 and 3 tons overweight at MTOW and 300-500 seaters up to 10 tons. Yet CG is never compromised in these scenarios and obviously 10 tons on a 500 ton airplane is a lot less in terms of % than 4 full adults with IATA bags on a TB20.
Anyone here on the forum even thinking about overloading without due process (e.g. getting exemptions from their CAA for ferry trips e.t.c., which means it has been properly documented, the awareness is there and so on): What I wrote to Alex is true for everyone else who contemplates that “50 kgs won’t matter”. They matter to your family if a lawsuit will come after them robbing them of all their assets after they just lost the guy providing the family income. If for nothing else, that should be enough reason to employ some thought policing onto yourself on this subject.
