If you want to see weight limits, think offshore helicopters. My minimum safety gear and personal stuff in 2 bags (10kgs max per bag) weighs 18Kgs… sounds alot, right, 18Kgs… but that’s with EVERYTHING being weighed. My safety gear alone is 9-10Kgs, that I must take to each job to work outside accomodation units. So 8kgs left for personal electronics/clothes/toiletries etc. Some companies impose a 15kg limit and you must designate a priority bag if you go over that limit…. And yes, it does happen that you pitch up to a location but can’t work without your safety gear… 
Cue much giggling (or not) as a multi million operation grinds to a halt based on a bag policy…
Regards, SD..
Ultranomad wrote:
Maybe the airlines will eventually start pricing passenger tickets like cargo, per kilogram of weight.
Seeing that most regulation comes from the US and is led by US airlines, I strongly doubt that any of this anti-fat stuff will ever happen. I bet there would be plenty of lawyers shouting discrimination and stop it or do a couple of lawsuits against airlines on discrimination charges and that would be the last thing heard about it.
It’s always “funny” to see how people who are not suffering from a particular vice want it outlawed our outpriced so those lazy fat idiots can be once pointed fingers at or exploited for more money. The system has worked really well over decades but there are always people who can find discriminatory ways of twisting it to follow their own religions…
Weight on wheel sensors were quite common for a while. No idea why the concept did not survive operational experiences. Maybe @Dan can tell us a bit how accurate they really were. The only airplane I recall which had something like that was a DC8 which constantly showed quite a lot less weight off the sensors than the actual loadsheet. So nobody really believed them.
Attaching strain gauges is nontrivial, especially for harsh environments and wide temperature swings. +30C to -60C in not many minutes.
It’s also a major failure rate in King autopilot servos, in the pitch trim torque sensor assembly. The gauges only cost a few quid, four of them, $1k from King The glue is basically epoxy, except King use crap epoxy. But there isn’t a great solution; one has to trade off signal level against the strain, by mounting the gauges on a spot which moves very little (another mistake many make, including King).
Let’s not stir the old “anti fat” pot again. This is a technical/safety issue. If you were flying a GA plane, doing some Wingly (or other “blind date” kind of job) and a couple of 150kg people turned up, would you do the politically correct thing and load them and crash and burn when you come off the far end of the runway (like so many have done)?
Airliners have more leeway because they mostly have huge runways and tons of power (especially twins, for the OEI case), so they know that regardless of what is actually loaded, provided they comply with company regs, they will get airborne, and won’t get fired which is what really matters. Now I better find the famous Tupolev takeoff video
Peter wrote:
This is a technical/safety issue. If you were flying a GA plane, doing some Wingly (or other “blind date” kind of job) and a couple of 150kg people turned up, would you do the politically correct thing and load them and crash and burn when you come off the far end of the runway
Cherokee 140 some 400 lbs / 200kg overweight. If you’ve ever flown a Cherokee 140 (they are a real ground-gripper with a poor climb rate) I’m surprised he even got off the ground. He was later sent to prison for this crash.
Documentary footage, photgraphs and old movies of Croydon airport when it was the London Airport shows every passenger and their luggage being weighed before boarding.
But that’s when to fly you had to be rich.
The G-BAKH pilot had a reputation which preceeded him as they say in the James Bond films
Mooney_Driver wrote:
Maybe @Dan can tell us a bit how accurate they really were
Good luck on testing my fading memory, we’re talking last century and a few more type ratings in between @Mooney_Driver
AFAIR we used them just as an informal indication since the system was installed, but not certified for operation. As to judge the precision of the system, that would have been difficult if the PAX were not weighed in the first place, so no valid comparison data.
Same for the CG indication on the ECAM, I sure don’t recall how this one worked either (by the way I gave away all my MD-11 manuals (made out of real paper) to some airplane fanatic a dozen or more years ago…), but I remember the display and the changing value as fuel was transferred to the horizontal stabiliser during climb (was it out of FL190 or close?).
Peter wrote:
Airliners have more leeway because they mostly have huge runways and tons of power (especially twins, for the OEI case), so they know that regardless of what is actually loaded, provided they comply with company regs, they will get airborne, and won’t get fired which is what really matters.
Airliner pax weights have been under scrutiny for as far as I can think back and it has always been concluded by IATA and most airlines, that the averages used in the end ARE representative. Some airlines have adjusted them upwards in order to reflect their reality, others keep to the standard IATA tables. So far, I can’t recall that a single accident or even incident in airline traffic has been attributed to overweight passengers. It also has to be mentioned that airliners have huge reserves as all their take off and landing performance is based on one engine out at V1. Hence, in normal ops, they will take their MTOW out every time.
On the other hand there have been several which have blown their limits by simply disregarding them, such as the famous Concorde crash at Gonesse. The problem there however was fuel and tailwind which resulted in an overweight of 6 tons, which even for Concorde is not trivial. Loose 2 engines and bang.
Dan wrote:
As to judge the precision of the system, that would have been difficult if the PAX were not weighed in the first place, so no valid comparison data.
I recall somehow that Swissair ran statistics on the figures taken from the weight sensors and compared them with the on the loadsheet, and almost always came to the conclusion that the weight sensors recorded LESS weight than on the load sheet, even though the figures usually were within 2-3 tons. I also recall the CG sensor, which was used for trim fuel. I can look them up, I have the red books on the MD11. If you recall that Zebra DC8 operating out of BSL; that thing also had a CG and weight sensor (it was ex KLM) and they constantly complained about CG but never about weight. It turned out that once they were very right as a full hold of baggage was left behind by error which nearly caused massive control forces on take off… so I reckon those things were quite accurate.
Peter wrote:
Now I better find the famous Tupolev takeoff video
That was an IL76 freighter…. and I would really have liked to know what happened there.
Standard practice in the USSR – only real hairy men with hairy balls fly these
Right up to the line every time. Or they assume 20% of the cargo has been stolen, but this time it – exceptionally – wasn’t.
