Vref in Navajo

[apcooper]

If you are flying the Navajo for example and you have a lot of ice while on the approach how many kts should you increase your Vref by? What flap setting is recommended as well?

 

[wings421]

Lot of factors go into an answer for that question. Are you assuming that you don't have boots or that you are iced up past the capacity of the boots?

Anyways, if you have "a lot of ice", I would recommend only going to the first detent of flaps, if that. The PA31's will land all day with no flaps. Also would depend on how much runway you have available and its condition. If you have a long runway and are really iced up, I wouldn't use any flaps at all. Come over the fence with some power at maybe 120-130 knots (I'd rather find out the stall speed iced up in ground effect rather than to get to slow on the approach). Slowly reduce the power and when the props hit the stops you will slow down really fast. Try this on a clear day and see how it works out. The ice will create some drag for you too, so you'll touchdown pretty comfortably.

Just remember, with a lot of ice, there's probably a lot more on the tail than on your wings. The more flaps you go with, the more likely you are to stall the tailplane and on approach in IMC isn't where you want to recover from that. You might not have time.