I'm doing helo loadouts and I can't figure out how much various sonobuoys weigh.

 

Any help is appreciated.

I can see the sonobuoy range of weights on Annex K-2 of America's Aircraft.  However the range for a Size A sonobuoy (7-17.7kg) is kind of broad.  Any specificity available?  I'm assuming passive sonobuoys weigh less than active ones but I'm not sure.

Are you trying to determine the weight for purposes of aircraft loading?  My guess is that sonobuoy weights (and quantity) is not enough to make an aircraft more than lightly loaded.

1 hour ago, kmart494 said:

Are you trying to determine the weight for purposes of aircraft loading?  My guess is that sonobuoy weights (and quantity) is not enough to make an aircraft more than lightly loaded.

That's exactly what I'm trying to do.  The sonobuoy weight does make a big difference.

 

For example - I'm loading a 1990 S-3A for an ASW Patrol.  It has 2 external fuel tanks and 4 Mk46 Mod 5 torpedoes.  Total load is 61% with a range of 3200nm.  If I also include a load of 60 sonobuoys at an average weight of 27kg/sonobuoy then my load goes to 94% and range to 2400nm.  Maybe I'm reading the 'America's Aircraft' entry for the S-3A incorrectly and it can have a loadout of 4 torps OR sonobuoys (but not both).  If I'm reading it correctly and the S-3A can carry torps and sonobuoys then the sonobuoy weight does make a difference.

Any help is greatly appreciated.

I will forward the question to Chris Carlson for his input.

Hey Onkle Karl,

For the vast majority of situations, a maritime patrol aircraft on an ASW mission would not be fully Loaded - ≥80% load. This is why we didn't include actual sonobuoy weights. 

Not sure why you were using 27 kg/sonobuoy - that's way to big for standard A-size sonobuoys and is more representative of a B-size.

For a S-3A with a typical ASW load, you are looking at:

1. 40 SSQ-41A/B x 7.5 kg = 300 kg
2. 16 SSQ-53A/B x 10.5 kg = 168 kg
3. 4 SSQ-62A/B x 18 kg = 72 kg
4. 4 Mk 46 Mod 2 x 231 kg = 924 kg
5. 2 300 gal drop tank x 920 kg = 1,840 kg

Total payload: 3,304 kg (about 73% of full load)

R/

Chris 

 

Thanks.  My screw up.  The Size A sonobuoys I used as an average of 27kg (the simple average of the range in the book).  On rereading the 'America's Aircraft' table I used 27kg as an average and I should have used 27lbs. as the average.  My screw up.  Sorry about that.