On 17.2.2015 Robinson R44 Raven II helicopter ZS-RNF crashed crashed and burnt out after attempting to lift a presumed 100 kg animal attached to the right skid. The accident report # 9411 is
here.
The commercial pilot had over 20,000 HRS flying experience (6,500 HRS on type). A weight & balance calculation for the mishap flight was not done, as it was an ad-hoc decision to take the animal. In this case too, the rear pax was placed, same as the pilot and the animal, on the right-hand side. Luckily nobody go hurt, as the pax got out before the R44 (fitted with bladder tanks, which ruptured during the accident sequence) burst into flames. (The animal was dead before take-off, and was burnt beyond recognition after take-off, so its weight could only be estimated.)
The accident investigator from the South African CAA determined that the lateral CoG for this operation couldn't be calculated, as - according to him or her - "the right skid has an unknown arm datum". Therefore the official accident report didn't calculate the actual lateral CoG for this flight. The report ventures however to find that
3.1.5 The helicopter was unduly heavy on the right-hand side skid and the CG was out of the regimen over the skid.
I must wonder how John R81 or I were able to do our calculations then
. Maybe taking the skid position from the airframe dimensions graph in the POH is an entirely unscientific approach?