View Full Version : C.G. Changes
lymanm
12th Dec 2000, 08:04
My dad, who always likes to humour me and talk about his airplane trips told me about his latest trip. He wanted to move forward one seat during the flight (he thinks it was an A320), but was told by an FA that it would dangerously disrupt the centre of gravity. While I'm quite sure this would be the case in my 172, I am not so sure about an Airbus.
On a short flight (ie relatively little fuel burn) how much of an effect would a passenger changing seats have on the centre of gravity ? Do some carriers have policies that prohibit this? Would it ever really make the difference between being within the CG envelope or not? Or was this just a particularly difficult FA in this case?
Thank you for any response!
Cheers
It would make no difference whatsoever. Due to the moment arm, a pilot carrying a laptop computer with him into the cockpit would probably have more effect than a passenger in the middle of the a/c moving one seat.
There are some VERY general guidelines for passenger loading. For example, perhaps 20 pax between rows 20-30, and 20 pax between 31-40. If he moved from row 29 to 30, it would be OK, but if he moved from row 30 to 31 it might exceed what's allowed on the paperwork. Perhaps that's what happened.
I'd hate to think that if a passenger got up in flight and went to the loo that I'd tip over! What a way to go! ;)
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lymanm
13th Dec 2000, 09:47
Perhaps this is just an old, tall tale that's been endlessly recycled, but is it true that once upon a time a hijacker forced all the pax into the back of the a/c during the approach and caused the aircraft to crash? That's the extreme of an aft C.G., I suppose...I seem to remember that it was an old VC-10...
Anybody? Or am I on crack?
Squawk 8888
14th Dec 2000, 18:57
A few years back the Canada 3000 were red-faced after a loading error at CYYZ. The A320 was to pick up 70 pax at YYZ and another group at YUL. Someone in passenger service decided that it would speed things up if all the YYZ pax were loaded into the back of the plane. Can you say, "Tail strike on takeoff"?
Capt Pit Bull
14th Dec 2000, 22:51
The trouble with this kind of thing is that its the thin end of the wedge. Once one person moves, others assume its ok for them to.
Or the person whose seat it was finds it occupied and decides to sit at the other end, taking their party with them.
Serious incidents (and fatal accidents) due to misloading occur depressingly often.
CPB
strobes_on
17th Dec 2000, 04:02
Speaking of A320's, how many have noticed a fully extended nose oleo during a transit stop walk around as things get a little light in the front end?
FE Hoppy
18th Dec 2000, 08:36
In a past life used to fly modified comet4s.
With new FOs in the cruise it was a jolly jape to get all the back end crew to come to the front and then when sweaty FO had it trimmed to send them to the back.
we had one guy who could move the C o G by himself but no names no pact drill.