Tactics

"For preflight planning, a ten percent safety margin between HOGE power required (computed) and power available (100% Q) should be ensured. A planned 'burn down' of fuel may be necessary to achieve this.  In any case, actual torque required to hover out of ground effect shall not be greater than 90% torque before beginning confined area landing (CAL) operations, and shall not be greater than 95% torque before beginning external load operations.  This will allow a margin between power available (100%) and power required (Actual HOGE) to prevent settling with the external load or due to loss of wind effect in a CAL." Tactical FTI 1-3

To ensure you meet these limits, do the rest of the weight and balance then go through the chart backwards. Start at a HOGE on the left side at 90% torque, go over to your weight, then figure out how much gas you can bring to weigh that much given your assigned aircraft and crew.

What most instructors (in 28, at least) wanted you to do was complete one weight and balance as normal (for T4003 use 65g in the externals section--yes, there's virtually no way you'll have 65g when you start the actual external, but then again doing power checks without the load doesn't make a whole lot of sense, either), then make a copy of it and bring it with you in the aircraft. It is useful to have your effective operating weight calculated (including crew and rear crewmember), as well as the weight of fuel in 5g increments written down for quick reference. That way when you get out there and do your math, you just need to look at your actual fuel state, round up to the nearest 5g and add that number to your operating weight. Much easier than trying to multiply by 6.7 in the cockpit. Also note that the OAT chart has positive numbers on the right side, negatives on the left--don't use the wrong one.

=MAKE SURE YOU HAVE THE TACTICS CAI's DONE BEFORE T4001!!=
 * T4001
 * T4002
 * T4003