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W & B even the big boys can get it wrong...


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Mistakenly wrongly classifying pax If likely, has to be ruled out by some process of error management. Having a large number of them in one area makes the error more serious. Incorporating some method of weight reading into the tug, which I believe lifts the nosewheel could detect large errors. Nev

 

 

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Mistakenly wrongly classifying pax If likely, has to be ruled out by some process of error management. Having a large number of them in one area makes the error more serious. Incorporating some method of weight reading into the tug, which I believe lifts the nosewheel could detect large errors. Nev

Every towbar I've seen just connects to the steerable wheel of the aircraft (tail wheel or nose wheel) nothing is lifted. The exception is debogging kits which sometimes use a chain or cable directly to the main gear.

 

 

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It was obviously a jockey who determined what a "standard" weight should be. Which is why, if I was able to fly again, I would require an RPL at least, so I could fly a four seater (PA28, C172) with one pax.

 

 

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It was obviously a jockey who determined what a "standard" weight should be. Which is why, if I was able to fly again, I would require an RPL at least, so I could fly a four seater (PA28, C172) with one pax.

Keep at it! Aim for that RPL!

 

 

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Mike Valentine ( he worked for RAAus till he died ) nearly died much younger when the delivery flight he was doing to an oil-field in the middle-east took off loaded too far aft.

 

They had told the loaders to put the crates of lettuce at the back. Well one day the lettuce was green cucumbers, but the loaders thought it was the same on account of being green. Mike thought he was going to lose control but managed to survive. And yes he checked the loaders more carefully after this.

 

 

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Well Jetstar were being pretty careful a few days ago when we flew Hobart - Melbourne at 9:40pm on a very lightly loaded A321. There must've only been about 30 or 40 passengers on the flight, evenly distributed around the cabin. However the cabin attendant wouldn't let me put one of the kids in the row ahead so I didn't have to hold the 2yo until we were well in the air - I knew and she knew that moving 25kg about 400mm would make precisely f-all difference to the W&B of a large passenger aircraft, but she stuck to the rules.

 

 

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Surely a six seater charter works on actual weights, seat by seat!

I believe that is correct - can't remember the specific reg, but it was something I had read when studying for the PPL written. I believe 7 PAX and below requires actual weights, can't use standard.

 

 

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Here it is - CAA 235-1, paragraph 11:

 

Standard weights should not be used in aircraft with less than seven seats

 

11. Because the probability of overloading a small aircraft is high if standard weights

 

are used, the use of standard weights in aircraft with less than seven seats is

 

inadvisable. Load calculations for these aircraft should be made using actual weights

 

arrived at by weighing all occupants and baggage.

 

235_1.pdf

 

235_1.pdf

 

235_1.pdf

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Well Jetstar were being pretty careful a few days ago when we flew Hobart - Melbourne at 9:40pm on a very lightly loaded A321. There must've only been about 30 or 40 passengers on the flight, evenly distributed around the cabin. However the cabin attendant wouldn't let me put one of the kids in the row ahead so I didn't have to hold the 2yo until we were well in the air - I knew and she knew that moving 25kg about 400mm would make precisely f-all difference to the W&B of a large passenger aircraft, but she stuck to the rules.

Yeah the problem arises when we start allowing the flight attendants to interpret the rules and do their own mental arithmetic or use their own judgement for airworthiness matters. It opens a can of worms. Trust me! What will happen is that one day, an F/A, when asked why she took the liberty of allowing 20 pax to move from B zone to E zone, will say "well I remember when we moved a baby to a row in front and it made no difference at all!" Before you ask: while not all are that stupid, some certainly are!

 

 

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Interesting comment DR. Having carried out decades of mass distribution calculations on thousands of vehicles the over-riding thing that strikes me is that you cannot determine balance by eyesight or guessing. I've lost count of the times I've pulled out a calculator, measuring tape or computer to be met with a derisive "I thought YOU would be able to tell just by looking".

 

A classic case in trucks is when a hydraulic crane is fitted to the rear of the chassis, and people extend the wheelbase of the truck and fit the crane right up behind the rear wheels "to take the weight of the crane" when in fact the heaviest of these cranes (which take up the length of a pallet on the chassis) is lighter than two heavy pallets of freight.

 

Most errors are in not getting the distance from the datum point correct, which throws out the imposed loads, and magnifies any weight input error.

 

In an aircraft it can cost you airspeed, and excess fuel burn due to the drag from flying trimmed out of the optimum, apart from any falling out of the sky.

 

Each trip needs its own calculation.

 

 

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