Performance class two enhanced (offshore)

[JimL]

Firstly to the take-off masses:

Some mass figures which relate to the observations in the post above (addressing Pure PC2 and PC2e).

Using the manufacturer's data for, the AW139, the EC225 (included for HC's benefit), the EC155 and the S76C++.

Taking ISA SL conditions the following masses are provided by the graphs:

For the AW139:

PC2e - there is no drop-down with a mass of 6,400kg in nil wind up to ISA + 20

For the EC225:

The Pure PC2 mass is 10,875kg

The PC2e mass with an unfactored wind of 20kts is:

10,500kg for a 50ft drop down; and

11,000kg for a 100ft drop down (limited by the deck-edge mass of 10,875kg)

Zero drop down is achieved with an unfactored wind of about 35kts (extrapolated)

For the EC155:

The Pure PC2 mass is 4,750kg

The PC2e mass with an unfactored wind of 20kts is:

4,920kg for a 30 ft drop down (limited to 4,750kg)

Zero drop down is achieved with an unfactored wind of 27kts

For the S-92:

The Pure PC2 mass is 26,250lbs

The PC2e mass with an unfactored wind of 20kts is:

26,500lbs for a 50ft drop down

Zero drop down is achieved with an unfactored wind of 30kts

For the S=76C++:

The Pure PC2 mass is 11,500lbs (wind up to 10kts)

The PC2e mass with an unfactored wind of 20kts is:

11,700lbs with a drop down of 15ft

Zero drop down is achieved at 11,700lbs with 23kts of wind (extrapolated)

NB 'Zero drop down' is no drop down below deck level.

Jim