Pirho wrote:
For passenger weights, we use 88kg for male, 70kg for female and 35kg for children. This includes hand carry on baggage.
Mooney_Driver wrote:
Wow. These are pretty close to the old “Iata” weights I last saw when I started in 1986….
That is actually exactly what part-CAT says for aircraft with more than 19 pax seats. (Lower weights are allowed in some circumstances and airlines are allowed to devise their own standard masses based on statistical analysis.)
Mooney_Driver wrote:
De-fuelling is almost never an option.
If there is little traffic, you can always say you need to use the runway for 5 mins, line up, perform a high power engine run, then you’ll find yourself one ton lighter after 5 mins and call rdy for t/o…much cheaper than defuelling
Airborne_Again wrote:
That is actually exactly what part-CAT says for aircraft with more than 19 pax seats. (Lower weights are allowed in some circumstances and airlines are allowed to devise their own standard masses based on statistical analysis.)
Amazing. My load control days were in the years 1986-98 with intermissions, in those days we had massively different weights. It started out with 75/65/30/10 (M/F/C/I)and evolved to 88/38/10 (Adults/kids/babies) over the years. It’s been too long to remember all the different weights used by airlines (I did loadsheets for loads of different ones including some very interesting ones) but mostly weights went up over the years.
(These weights are standard pax weights. Add 20 kgs baggage to get planning weights. Most airlines used 100 kg for ease of calcs though. )
Antonio wrote:
f there is little traffic, you can always say you need to use the runway for 5 mins, line up, perform a high power engine run, then you’ll find yourself one ton lighter after 5 mins and call rdy for t/o…much cheaper than defuelling
5 mins with high power will cause most pax to have nervous breakdowns by the time you are ready to go. Not to speak of noise. Also no idea how long you need for a 737 to burn a ton, but I’d think it’s more than 5 mins. Have to try in the sim once. On the Tupolev or widebodies you’d probably have it out in no time though. Apart, one ton won’t do much I reckon.
But back to the flight in question: I don’t have IRT’s for an A320 handy but I did manage to find some for a A310-300. They are years and years out of date, but they will give a bit of an idea. The runway has not changed as far as I know.
Conditions: OAT 30°C, 0 Wind, STD QNH.
RWY22/2400 m: Flaps 20/20: Runway limited weight 155.8 tons. Obstacle not limited. RTOW is 155.8 tons
RWY04/2150 m: Flaps 20/20: Runway limited weight 147.2 tons, Obstacle limited 135.7 t. RTOW is 135.7 tons.
So not only is the declared runway lenght on runway 04 smaller (there is a displaced THR the runway before it was not usable at the time) but the obstacle is brutal. A full 20 tons.
Now that A310 has an MTOW of 164 tons. So it’s roughly twice the MTOW of a A320. So if the performance penalty for 04 vs 22 is roughly 20 tons on the A310, I’d give a wild guess and estimate 10-12 tons on the A320.
That is not something you burn off quickly.
I will try to find out if I can source some IRT’s for an A320 but I guess you can get the gist of the problem.
Mooney_Driver wrote:
Amazing. My load control days were in the years 1986-98 with intermissions, in those days we had massively different weights. It started out with 75/65/30/10 (M/F/C/I)and evolved to 88/38/10 (Adults/kids/babies) over the years. It’s been too long to remember all the different weights used by airlines (I did loadsheets for loads of different ones including some very interesting ones) but mostly weights went up over the years.
In Swedish national regs. the standard weights were increased in 1989 after a fatal accident with a domestic scheduled flight caused by heavier than normal pax. The actual CG was well behind the aft limit and as full flaps were extended for landing, the nose-up moment caused the aircraft to stall before the pilot could react. (There were, of course, as always, other contributing circumstances.) The crash attracted particular attention as there were several MPs and other well-known politicians aboard.
Problem is that averaging is no good for the safety of a specific flight. On a recent flight EGKK-LGKO, A320 or some such, it was obvious that the average passenger weight was well above 88kg 
Well, the women might have been 88kg. The men… more like 100kg.
On top of that there is a tendency to stuff maximum carry-on luggage into the overhead lockers, and that stuff is not weighed.
Peter wrote:
On a recent flight EGKK-LGKO, A320 or some such, it was obvious that the average passenger weight was well above 88kg Well, the women might have been 88kg. The men… more like 100kg.
Average is often very difficult to determine by the naked eye… And weighing every single pax is simply not feasible: First you’d get a revolution and folks who would strictly refuse and 2nd you’d end up with even eariler reporting times to accomplish this. Rather pax weights generally should be increased and quite a few airlines have done that too.
Handluggage is quite often weighed at check in, if the maximum weight is in doubt. Some LCC’s make a business out of weighing and cashing in on overweight too.
Surely it isn’t beyond the capabilities of the engineers at Boeing and Airbus to put sensors on each wheel to determine the exact weight of the aircraft and cargo after loading?
Peter wrote:
averaging is no good for the safety
I don’t understand why actual weights of pax, hand-luggage, luggage, cargo, etc, are not taken on the spot, and then used. With today’s tech no problem at all.
Or use, as we had on the MD-11, wheel axle sensors giving the actual weight of the aircraft.
Aviation is all about safety, but greed was, is, and will be the real winner here.
Surely it isn’t beyond the capabilities of the engineers at Boeing and Airbus to put sensors on each wheel to determine the exact weight of the aircraft and cargo after loading?
Yes; this was done decades ago. I designed such a system for trucks c. 1980.
I don’t understand why actual weights of pax, hand-luggage, luggage, cargo, etc, are not taken on the spot, and then used. With today’s tech no problem at all.
For passengers, it is largely customer-acceptance-political, but once passenger weighing starts it will likely become universal very fast, due to the financial benefits. One airline has already started it; I saw the article a few months ago and cannot remember it now. IIRC it was not a European airline.
Peter wrote:
once passenger weighing starts it will likely become universal very fast, due to the financial benefits. One airline has already started it; I saw the article a few months ago and cannot remember it now. IIRC it was not a European airline.
As I remember things, it was something like a local Hawaii or (American/Western) Samoa airline, if I’m not confusing the latter with another island territory where fried spam (the meat product) is popular? Some territory where severe obesity prevalence is very high even by USA standards.
