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Hello,

Wondering if someone would be able to answer my question -

Why do helicopter cargo baskets have maximum weight capacities (i.e. is it for maneuverability, emergency landings...)? To illustrate, the Bell 206L4 helicopter has a max gross weight (external load) of 4,550 lbs but most standard cargo baskets can only hold 200-300 lbs. Why can't cargo baskets hold more weight?

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Hey Lindsay, 

That is a good question to ask if you are not familiar with these types of modifications. 

The main reason is due to "Lateral C of G" limitations pertaining to the helicopter.  Simply put, if one were to put too much weight on the side of the helicopter you could lose control of the helicopter relating to the sideways (or lateral) movement/control.

Another very important reason pertains to the structural limitations of the airframe where the cargo basket is attached.  Some helicopters have fittings (aka "Hard Points") where equipment may be secured to, and some attach it to existing areas originally meant for other parts of the helicopter such as the Crosstubes (landing gear component) which due to structural analysis would have  their own limits.  The restrictions or limits assigned to the basket would be taking this into account as well.

Hopefully this helps you understand a little bit better.

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1 hour ago, wcobra said:

Hey Lindsay, 

That is a good question to ask if you are not familiar with these types of modifications. 

The main reason is due to "Lateral C of G" limitations pertaining to the helicopter.  Simply put, if one were to put too much weight on the side of the helicopter you could lose control of the helicopter relating to the sideways (or lateral) movement/control.

Another very important reason pertains to the structural limitations of the airframe where the cargo basket is attached.  Some helicopters have fittings (aka "Hard Points") where equipment may be secured to, and some attach it to existing areas originally meant for other parts of the helicopter such as the Crosstubes (landing gear component) which due to structural analysis would have  their own limits.  The restrictions or limits assigned to the basket would be taking this into account as well.

Hopefully this helps you understand a little bit better.

That was an excellent response! Well done! This is a great environment to learn. Let’s ieep it that way...

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What simpleton said and good reply WC...people that make this stuff go thru a process that would boggle your mind to get an stc for certification and maybe read your flight manual.They don't just dream up numbers! I have used both types of baskets on L4 and 407...there is a bit of weight difference in the two as the mast height is greater on the L than the 407 which changes the lateral c of g quite a bit. The quick disconnect basket is the way to go as it really sucks to try and longline with the basket on the side.

IMG_20180528_082350.jpg

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19 hours ago, Lindsay said:

Hello,

Wondering if someone would be able to answer my question -

Why do helicopter cargo baskets have maximum weight capacities (i.e. is it for maneuverability, emergency landings...)? To illustrate, the Bell 206L4 helicopter has a max gross weight (external load) of 4,550 lbs but most standard cargo baskets can only hold 200-300 lbs. Why can't cargo baskets hold more weight?

Wasn’t a stupid question Lindsay. It could be C of G, could be structural, could be aerodynamic or whatever. Ignore the egos here, no question is a stupid question. Alll aircraft have limitations for different reasons, that includes supplements. 

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Hi Lindsay,

The max load in a basket is due to the structural limitations of the aircraft and the basket.  As said above, the centre of gravity is very important in a helicopter and the further you get from the centre, the more effect the weight has on the aircraft.  The maximum external hook load is still roughly 2000lbs but is located close to the centre.  The 4550 lbs. Max (external) You quoted is for the entire helicopter, including people, equipment, fuel and a cargo hook external load.  The 206l4 can operate to a maximum gross weight of 4450 lbs. internal (no hook load) and this would include the weight of the basket and goods.

The baskets can handle a heavier load structurally but when operated beyond the working limits, will start to resonate more and will eventually fail due to metal fatigue.

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All great responses. Nice and clean.

I think also worth mention that the external load limit is referring to a load that does not put more weight on the skids.

As an example the Bell 407 has a internal limit of 5250 (suck it b3) but an external of 6000. The limiting factor is the skid gear. The powertrain and engine can do 6000 but if you are going down the skid gear wont save your back. as you would be falling faster than a manhole cover..

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4 hours ago, Bell-powered said:

 

As an example the Bell 407 has a internal limit of 5250

......& if it had a flat floor like a B3 you might even be able to use some of that capacity!

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