LMC
Joined: Sep 1999
Posts: 58
Likes: 0
From: Geneva, Switzerland
The above exchange is really scary!!! <img src="eek.gif" border="0">
Do we really have people out there with responsability for the final load sheet who need to ask this type of question...
Whatever happened to training, supervision and probation periods? <img src="frown.gif" border="0">
Do we really have people out there with responsability for the final load sheet who need to ask this type of question...
Whatever happened to training, supervision and probation periods? <img src="frown.gif" border="0">
Thread Starter
Joined: Jan 2001
Posts: 154
Likes: 0
Assumptions are not always correct, if someone has an answer to a question that might benefit others then he would be appreciated. We all learn from each other, but there are at times the unnecessary negative comments
Joined: Apr 2000
Posts: 50
Likes: 0
From: somewhere south-east of here
ok then, if your talking about the max weight changes that are permitted to be made for our company a/c are (doing this from memory)
a/ weight change less 500kg just amend LMC box
b/ 500kg to 1500kg need to do a new trim sheet to get new MACTOW
c/ more than 1500kg..complete new loadsheet please
Hope this helps..but check your own company manual you may have your own company regs.
Bondy
[ 05 January 2002: Message edited by: Bondman ]</p>
a/ weight change less 500kg just amend LMC box
b/ 500kg to 1500kg need to do a new trim sheet to get new MACTOW
c/ more than 1500kg..complete new loadsheet please
Hope this helps..but check your own company manual you may have your own company regs.
Bondy
[ 05 January 2002: Message edited by: Bondman ]</p>
Thread Starter
Joined: Jan 2001
Posts: 154
Likes: 0
For every airplane there is an approved LMC wt. on the Boeing a/c it is easy to locate in the loading Manual. On Airbus I don't know where they have it, even though I know the figures now, I just need the reference.
Fleet Manager
Joined: Apr 2001
Aviation Qualifications: ATPL
Posts: 7,447
Likes: 310
From: various places .....
Not quite as simple as that, good people.
The trim sheet (or whatever loading system is used) designer makes a number of assumptions which will differ between designers and between trim sheets devised by the one designer.
If the published trim sheet CG envelope replicates the AFM data (which is just about never the case) then the effect of LMCs can be judged by a simple correction working of the sheet.
However, the more general case is that the sheet envelope will be compressed for a variety of reasons and the extent of the compression will not be evident to the user.
Therefore, presuming that the sheet has been executed in the prescribed manner, it is not at all a straightforward matter to assess the effect of LMCs on the CG unless you know what considerations went into the design.
The following rules (however enshrined in your paperwork and manuals) must be adopted without any flexibility -
(a) complete the sheet in accordance with the prescribed instructions
(b) process LMC assessments strictly in accordance with the prescribed instructions.
(c) the specific numbers etc associated with one sheet have no relationship with those associated with a different sheet. This is sacrosanct. I have seen many and significant errors over the years which have arisen from the "but that is the way we do it on the other aircraft" mentality.
(d) if your particular airline has generated a sheet different to the manufacturer's data, then the recommendations and directions for use of the manufacturer's loading system contained within the manufacturer's manual may not be relevant to your company's data. That is ... use the instructions relevant to the particular system being used ...
[ 09 January 2002: Message edited by: john_tullamarine ]</p>
The trim sheet (or whatever loading system is used) designer makes a number of assumptions which will differ between designers and between trim sheets devised by the one designer.
If the published trim sheet CG envelope replicates the AFM data (which is just about never the case) then the effect of LMCs can be judged by a simple correction working of the sheet.
However, the more general case is that the sheet envelope will be compressed for a variety of reasons and the extent of the compression will not be evident to the user.
Therefore, presuming that the sheet has been executed in the prescribed manner, it is not at all a straightforward matter to assess the effect of LMCs on the CG unless you know what considerations went into the design.
The following rules (however enshrined in your paperwork and manuals) must be adopted without any flexibility -
(a) complete the sheet in accordance with the prescribed instructions
(b) process LMC assessments strictly in accordance with the prescribed instructions.
(c) the specific numbers etc associated with one sheet have no relationship with those associated with a different sheet. This is sacrosanct. I have seen many and significant errors over the years which have arisen from the "but that is the way we do it on the other aircraft" mentality.
(d) if your particular airline has generated a sheet different to the manufacturer's data, then the recommendations and directions for use of the manufacturer's loading system contained within the manufacturer's manual may not be relevant to your company's data. That is ... use the instructions relevant to the particular system being used ...
[ 09 January 2002: Message edited by: john_tullamarine ]</p>
