Airborne:
a digital camera, or one with film? ;-)
Flyer59 wrote:
a digital camera, or one with film? ;-)
Would it matter?
Guilty as charged and by about 70kg due to an error in the w&b calculation. Absolutely no effect on performance including takeoff roll. I would not knowingly do it again though.
I recall being an innocent pax on a C172 from La Rochelle to Jersey a long time ago. 4 POB and a load of wine. As we were landing at Jersey it was only by moving boxes forward and under the front seats that we were able to maintain control. Once parked on the apron as the front passenger stepped out the tail started to come down. I learned a lot about flying from that experience.
I never knowingly flew with the weight above MTOM. However consider an old C172 with a dipstick (accuracy +/- half the tank 
) and a few hundred items left inside by other pilots (renting). You can never be sure if the weight is exactly what you calculated. I try to counteract that by adding about 3-5 kg per person (e.g. rounding the weight up) but that might as well be incorrect (see comment from Airborne_Again). So if I get a weight of 6 kg above MTOM I would still consider taking off – I’ll have used part of that fuel till takeoff plus those buffers I add should actually bring me to approximately MTOM. Probably everyone has his own limit and I think for me the number 10 kg would be a decisive one – if more than 10 kg then the buffer might not be enough, so I will replan. But for 5-6 kg, I would probably fly.
Here is a good example why MTOM is important: https://en.wikipedia.org/wiki/Air_Midwest_Flight_5481. Also there is an air crash investigations episode about that crash:
Flyer59 wrote:
2. i drank alcohol the last time in 1996
That was just another example where some pilots draw their own line.
Flyer59 wrote:
i draw an intelligent, sensible line
Difficult one. Were you involved in the design and calculations and test flying of your aeroplane? Have you any professional background that enables you to draw that “intelligent” line? (I do for example, yet lacking insight into the calculations of the aircraft manufacturer I would not know where to “intelligently” start extrapolating their figures…)
The problems that come with overweight operations are three:
1. Structural. Usually not a big issue because in normal operations one stays far away from the design load factors (part 23: -1.5g … +3.8g) anyway. Theorectically you could overload your aircraft by a factor of 2 and not inflict any structrual damage if you don’t pull more than 2g.
2. Aerodynamic. The stall speed and the stall behavior will change when you overload your plane. Especially the latter might do so in a surprising way. Also the gliding properties will change in case of an engine out landing.
3. Takeoff and landing performance: This is where a little overweight will have the greatest effect. Especially in the case of an aborted takeoff, the total distance required will be significantly influenced by the mass of the aircraft. The book figures end at MTOM, beyond that you are on your own. Simply extrapolating the figures will not always result in correct figures.
NB: In the past, especially when flying cargo, I have on some occasions flown significantly over MTOM. Sometimes knowingliy, other times it came as surprise, usually because the papers of the cargo were wrong. There was at least one occasion when we would surely have crashed into a densely populated area in case of an engine failure after takeoff (in a twin!) because of that. Totally unacceptable and not something I want to experience again. Therefore the line in the book is the only line that counts for me.
Rather than going round and posting personal views 
does anyone know the % effect of say 1% over MTOW on the takeoff roll and the Vr?
(those who do this for a living need not reply )
Firstly, thanks for posting this thread. As a new owner of a PA32 its something which interests me, and if you hadn’t asked the question, then i would have.
There isn’t a lot about it on the internet, I suspect for an obvious reason.
My take-home points, from my looking about were:
MTOM is a certification limit, and exceeding it makes you a “test pilot” but, ferry pilots often need ferry tanks which make an overweight condition of 30KG seems v small.
CofG is more of a killer than exceeding MTOM
Cirrus have a chute-well done you, I don’t have one, so I don’t worry about being a little overweight when I pull the chute (!!!!!) as I don’t have one.
It seems sensible anyway not to rely on the book performance figures, because they relate to a new plane with a fairly current pilot, and ideal surface conditions. None of these things apply to me flying the plane I fly.
Mostly, having taken off overweight, you will be within the MTOM fairly quickly, and usually well before you land again.
Given enough weight, and a long enough runway, most planes can drive to their destination, but it aint efficient, so you need to be able to get to flying speed well before you look like running out of accelerating distance.
To play devlis advocate, just a little, my MTOM is 3600 lbs, and I could well imagine up to 10% over that being illegal, but basically safe. The difficulty comes when after managing 3960lbs for a while, someone might add an extra bit, then a bit more, until it gets silly.
Put another way, we know there must be a family big design margin built in anyway (?150%), and up to 10% seems a pragmatic way of dealing with these things, even though it is illegal, Id never suggest anyone else did it, and my advice could be screaming at the moon crazy.
About 3 years ago I was in a major maintenance shop in the south of Germany to have the annual performed on my TB21. There was another German registered TB20 on jacks there and I was told it had been there for months as the owner and the insurance company were fighting the payment of a gear up landing. It doesn’t seem as clear cut as you think what an insurance company will eventually pay. There is room for interpretation, there might very well be one that pays without any question while another one will try to offload to you. As soon as the numbers involved are large they will try to come after you. The insurance company will always pay third party damage but they will come after you if they have the slightest chance.
what_next wrote:
Also the gliding properties will change in case of an engine out landing.
The best glide speed will increase, but the gliding angle will not.
