The Bo105 certainly did have a fuel dump capability. It was the only way it could get a practical Group A Certification. Engine fails dump fuel and restore OEI performance to something passable ie. you stopped going down.
In 1990 MBB issued a service letter explaining that a review of the certification data had shown an overestimation of performance by 175kg and all graphs relating to performance should be altered accordingly. The following week MBB issued another service letter explaining that due to an improvement in the main gearbox life 175 kg can be added to all graphs with immediate effect provided the MGB was lubricated by (here it gave the spec no. for an Esso oil that I can no longer remember. Read into this what you will but I cannot imagine that the 175 kg performance 'error' truly represented the otherwise meticulous German precision in all things technical. Methinks there was touch of the Neslon's eye about that particular nonsense.
We also had fuel dump fitted to our (BCAL (H) ) Sikorsky S61Ns for the same reasons - we needed to have Group A performance when we crossed the coast outbound but could operate Group B until then. It gave us enough extra fuel to make a difference.
G.
Last edited by Geoffersincornwall; 7th Nov 2018 at 22:20.
Reason: corrected the 15 to 175 - typing error