Robinson just released updates to the R22 and R44 POH, main points of interest being changes to the clutch light emergency procedure (now 10 seconds and land as soon as practical unless other indications) and the section on use of carburetor heat/assist.
I am trying to fully understand the implications of the new Safety Notice SN-25 on carburetor ice, where it talks about an additional 1.5 in. Hg of MAP. Read the SN here:
http://www.robinsonheli.com/srvclib/rchsn25.pdf
The final paragraph reads (I added emphasis):
Carburetor heat reduces engine power output for a given manifold pressure. Approximately 1.5 in. Hg additional MAP is required to generate maximum continuous power (MCP) or takeoff power (TOP) with full heat applied. The additional MAP with carb heat does not overstress the engine or helicopter because power limits are still being observed. Since the engine is derated, it will produce TOP at lower altitudes even with full heat. However, avoid using more heat than required at high altitudes as the engine may reach full throttle at less than MCP or TOP.
Does that mean that the pilot can pull an additional 1.5 MAP over the determined MAP limits when operating with full carb heat? Or is it saying that the additional 1.5 in. Hg will be applied even though the manifold pressure gauge shows you are at normal MAP limit for the day?
Any thoughts?
Many thanks in advance.
Jay (R22/R44 pilot)