Post the Ventral fin mod for the J170C where is the fore ballast attached?
Is it fibreglassed into the forward engine cowlings ? upper or lower , fore or aft ? What is the limit of weight that can be accommodated ?
Is it attached to the front of the engine ? (which could affect G loading because extra weight on the front of the engine would put more force of the engine mount during a G shock event
I have looked at a few J170C. The field upgraded ones did not have the ballast fitted at all , and the factory unit with the ventral fin factory fitted does have the fore ballast on the weight sheet (and thus more favourable CoG)
with thanks, GLEN.
Hello Glen,
Depending on what was required to maintain the CoG in a favourable position the aircraft can have ballast in the ventral fin or in the engine cowl or no ballast at all.
When the ballast is fitted to the cowl it is in the form of lead sheet fibreglassed inside the cowl. Depending on the amount required this can be on one top cowl only or divided between the top and bottom cowls. I think 6kg is about the limit.
Thanks very much for the information.
OK, lead sheet. That simplifies housing compared to lead shot.
Approx what is the weight of the added ventral fin components ? (someone at the factory would know, approximately).
with thanks, glen.
The extra weight for the enlarged ventral fin that was fitted to J170-C's is only a few hundred grams.
OK thanks. right, not much !
350 grams added at 3600mm arm will only increase %MAC by 0.2 to 0.3%.... about the same as 2kg on the baggage arm
with thanks,
glen.
