Aerial Spraying From B737
 

Have any of you techies been involved in the flying or conversion of B737 (probably the QC model) in an airborne spraying fit? I gather there is a STC out there somewhere and would very much like to get my hands on the details?
:confused:

There was a program started in Canada to fit a 737-200 with a belly mounted retardent tank for aerial forest fire suppression but I would be very surprised if a spray rig would work. Spray systems consist of a series of nozzles below and behind the wing. The flow rate is fairly low and a lot of work is put into palcing the nozzles so that they exhuast into smooth air. The underwing mounted engines of a 737 would put so much heat and turbulance into the pattern I would guess you could only put nozzles at mid span and outboard which would put a big gap into the middle of the pattern. Also I cannot think how you would mount the nozzles and still allow full flap operation.

ExCreamie
 

Plenty of information here. :ok:

ExC, PM for you..

Spray adaptations
 

I don't think the actual spray modification would be difficult although as a correspendent says it would require cutting into the pressure hull - need to get some good clas though! The interesting bit is the in-aircraft dispersant aspects (tankage needs to be vented externally thus pressure vessel, fluid has SG approx 1 so high denstity: both Cof G locations and floor strength need to be considered.

Who cares how hard it is to acheive what a job im in if you need a driver!!!!:D

What am I missing here? I keep seeing mention of 'pressure vessel'. As pressurisation only applies to ferry/positioning flights why is it an issue? There must be dozens of temporary ways to take pipework from inside to outside.

Sounds fun - if you need a jockey gimme a call ;)
Just have to raise my life insurance before...

Assuming this is not a windup, and assuming it is about spraying Gulf-sized areas rather than poppy fields, I fear that you are way off track in envisaging Pawnee-style kit - 'spray arms' - being strapped to a 737. Furthermore, the prospect of flying a 737 at crop-spraying height over an oil-smoothed surface is not one which would appeal to me - or to cirr737's insurers! - it is inappropriate, and unnecessary.

The essential challenge (apart from keeping the CofG about right) is in securing a spray discharge with the right droplet size range. (Bear in mind that droplet formation is governed by the free surface energy characteristic of the liquid, and that that of a dispersant may differ from those of agri-fluids).

Overcome that, and Stokes' Law is your friend. You may achieve good and wide surface distribution from a sensible and safe height without spray arms, and indeed without any new penetrations of the pressure hull. ( If you are serious and need more 'gen feel free to PM me ).