Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Flyingfemme
#1839015
The allowable weight is the weight in the book. Anything else requires a special certificate of airworthiness - generally called a "ferry permit".
As for CofG, you go back to first principles and do the calculations (for takeoff and touchdown) because the graph is only for flights within the MTOW.
Oh, and climb rates for an aircraft in ferry config can be way lower than 500 ft/min.................the difference between climb and descent is sometimes your breath on the yoke!
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By akg1486
#1839030
Our club bought a C172 in upstate New York in 2005 and we hired an experienced ferry pilot to bring it home over the Atlantic. Its MTOM is 1157 kg, and in the special ferry permit he was allowed 30% overweight. That's an extra 347 kg. When leaving Bangor, Maine, it took the pilot 25 minutes to reach 9 000 feet. That's an average of 360 fpm, but he wrote in an article for our club magazine that the climb performance was good at first and then became progressively worse.

As @Flyingfemme wrote: the fact than an aircraft is capable to fly with overweight is not a permission to do it. MTOM is exactly that: maximum take-off mass.
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By Trent772
#1839031
Having operated 3 large single pistons for skydiving in the 80's, MTOW and C of G are just suggestions !

If you did the c of g calculation for a Cessna 207 with 3 guys in and 3 guys outside the door you would feint !

If you did the take off calculation for a knackered Cherokee 6 with 5 in, from Doncaster on a hot summer day.....

No - not that Doncaster, THE Doncaster - where you pass the light poles in the train yard on departure :lol: :lol:
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By Rob L
#1839056
Long-distance ferry permits (such as cross oceanic flights with ferry tanks) are issued on the basis that most of the excess weight (fuel in ferry tanks) will be burned off during the flight, allowing for a safe landing at the other end.

In commercial airliners, it's why they often spend time dumping fuel if intending to return to their point of departure after a take-off engine failure or similar, to prevent an overweight landing (not always possible!).

I know of one Rockwell 114 transatlantic pilot (direct Boston USA to Shannon Eire with a big tank) who had a bit more tailwind that was expected and so he re-filed to East Midlands
After 17 hours he could not get out on his own.
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By aerobatic_dude
#1839074
SteveX wrote:I'm interested to know from this old discussion what others think would work in terms of overweight in a C150/152. Clearly 100kgs is unacceptable (to me at least although perhaps not with a ferry tank across the Pacific). But ignoring runway length, assuming one is ok with a climb rate of 500ft/min (rather than 1000 in a lighter aircraft), what would be a guess as to an upper limit? 50kg?

As for balance, I assume with the above that an imaginary line beyond the top of the chart that shows it 'would' clearly be within balance at that weight is ok. I'm talking about just off the published charts, not something daft eg 300kgs overweight.


I wouldn't consider anything overweight to be OK - whether i'm flying a 737, A320, 206 or my buddies microlight.

Someone far more intelligent has been paid to figure out how much weight is ok and how much isn't - then the legal team were paid far more to put the ink to paper.

Anything outside of that then you're in test pilot territory.
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By Trent772
#1839077
As airlines use notional weights for passengers, and when you are going a long way, so are close to or at the defined gross weight, consider this.

The A330 I flew didn't know how heavy it actually was to probably within 4 or 5 tonnes because of notional weights. Std person say 86kg, std luggage bag 15kg, std hand bag 5kg....

Now consider how much the average charter passenger weighs, how much they cram in their luggage and how heavy their carry on is and you get the gist !

Most older light aeroplanes operate over gross when you have two guys and fuel in.

A matter of common sense and wisdom :pirat:
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By A4 Pacific
#1839079
I agree with aerobatic_dude

There’s a well known phenomena called ‘normalisation of deviance’. It’s pretty self explanatory, but basically if you break a rule without good reason, before you know it you’ll be breaking a few more. (Because, why wouldn’t you??)

This comes from someone who has often broken the rules, and would have been happy, even expected, to subsequently stand in a court of law to explain the very considered justifications and the mitigations of every single breach.

If you’re happy to do that, then crack on!

Trent772

How many passengers does an A330 carry? A few will be overweight, a few will be under. Each individual passenger (and their luggage) being a fraction of the total. Not to mention your 4 or 5 tonnes is probably 1-2% of the gross.

Very different kettle of fish when you’ve got two beer balloons in a Piper Cub.

Either way. One’s legal. One ain’t! :roll:

Oh, and “most older light aeroplanes” may not be quite as robust as when they were first certified. I’d suggest (paraphrasing Fred Dibnah) treating them with a little respect.

Finally, when it’s discovered that an aircraft was overweight when it crashed, like the Air France Concorde. People’s hearts sink. Not because the overweight may have ‘caused’ the accident, but because it often reveals an underlying culture of deviance.
Last edited by A4 Pacific on Thu Apr 08, 2021 8:17 pm, edited 1 time in total.
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By Jonzarno
#1839082
Trent772 wrote:As airlines use notional weights for passengers, and when you are going a long way, so are close to or at the defined gross weight, consider this.

The A330 I flew didn't know how heavy it actually was to probably within 4 or 5 tonnes because of notional weights. Std person say 86kg, std luggage bag 15kg, std hand bag 5kg....

Now consider how much the average charter passenger weighs, how much they cram in their luggage and how heavy their carry on is and you get the gist !

Most older light aeroplanes operate over gross when you have two guys and fuel in.

A matter of common sense and wisdom :pirat:


Makes me think of this accident:

https://www.dailymail.co.uk/travel/article-590144/Obese-passengers-caused-plane-crash.html
By RayP
#1839084
What is overweight for a Skyranger?
If you look at the spec on Wikipedia it says mtow of 560kg but I'm only legally allowed 450kg (this month anyway)
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By Trent772
#1839085
Jonzarno wrote:
Makes me think of this accident:

https://www.dailymail.co.uk/travel/article-590144/Obese-passengers-caused-plane-crash.html



The Beech 1900 is not a great aeroplane - all fairings and fins and strakes. Makes you wonder what issues they had in certification. Positioned in one around the Caribbean once or twice - not a fan.
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By Trent772
#1839088
MikeE wrote:Just saw this...

https://www.dailymail.co.uk/news/articl ... litch.html

regards

Mike



4 departures from Las Vegas in 2001 around 7 tonnes overweight because one of the idiot savan people who did our performance didn't apply the aerodrome elevation correction (2,200') into the calculations.

Thought it felt a bit woolly at the time but it flew OK. Thanks Mr Aeeerrboooos :pirat:
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By A4 Pacific
#1839091
Thought it felt a bit woolly at the time but it flew OK. Thanks Mr Aeeerrboooos :pirat:


It’s an Airbus. Are you saying there were times it didn’t feel woolly? :lol:
By Gasbag
#1839105
Totally agree with @Trent 772.
374 pax all who’ve been stuffing themselves for 2 weeks. Handling agent gave us ACTUAL bag weights which took us 5 tonnes over max. Recalc with notional weights and we were several tonnes under max. Paperwork looked legal and we calculated performance on a far more realistic weight. Could still flex way down for take off as 330 is stunning!
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