scraping the bottom o the barrel.
T28D
To save precious cumulative payload weight for your 'croppie' why not ;
(1) use a pilot who weighs less than the others,
(2) put the existing pilot on a diet,
(3) fly nude,
(4) remove the ELT,
(5) only fly with the absolute minimum of fuel required for a job,
(6) only fly when the air-density is favourable,
(7) make the pilot take a dump before flight. (there's at least a kilo saved)
(8) don't let the pilot drink a can of something before flight. (nearly 0.4kg there!)
(9) remove all the exterior paint,
(10) drill more holes in non-structural panels,
arggggghhh..... that has got to be the lamest excuse for not fitting ADSB to an aircraft that I have ever heard.
If the extra weight was to be 20 kg or more I would then actually start to have some concerns and/or sympathy., but for < 5kg ?
(with present-day electronics the replacement transponder could even turn out to be lighter in weight than the old mode-C unit)