Electrics
DC power is provided by a starter-generator and a 16 amp/hr buffer-mounted storage battery. A second one is optional. The generator and the battery are coupled to the distribution bus by line conductors, which can only close if the ground power unit is disconnected.

Fuel
Kept in the spin-moulded polyamide fuel cell beneath the transmission deck. It goes through two booster pumps at the bottom of the tank, a fuel filter and filter bypass valve.
Capacities

Fuel (sg  Ltrs  US  Imp  kg lbs 
.79)  gals  gals 
Total  540 143  119  427 940 
Useable after fuel low lt on  60 15.8  13.1  47.4 104 
Unuseable  1.25 .33  .28  1 2.2 

Consumption is 173 lph for the B, 180 lph for the BA, 190 lph for the B1 and 200 lph for the B2.
The low fuel light in the B comes on at 15.8 US gals (approx 10-12%).
You can use ordinary petrol in emergencies, but only up to 25 hours within any period between overhauls, with a fuel temp up to 30 degs C. If possible, add 2% of mineral lubricating oil. Refer to the Flight Manual for full details.
Oil
You can’t mix mineral-based and synthetic oils. Main and tail gearbox synthetic lubricants are Mil-L-7808, AIR 3514, Mil-L-26399, D Eng RD 2797. Mineral-based is Mil-L-6086.
For the engine, use Mil-L-23699 for the whole flight envelope or Mil-L-7808, D Eng RD 2497, AIR 3514 or Aeroshell 390 below 15 degs C.
Hydraulics require Mil-H-83282 (synthetic) or 5606 (mineral-based).
Capacities

Oil  Ltr  US gal  Imp gal 
MGB  6.5  1.7  1.4 
TRGB  .33  .08  .07 
Engine  6.2  1.64  1.36 
Hydraulics  3  .79  .66 

CG Limits
The longitudinal CG starts at 124.8” aft of datum up to 4429 lbs, after which it reduces to 126” at 4850 lbs MAUW. The aft limit is 137.8” to 2646 lbs, changing to 135”at MAUW. The Datum is -133.8”forward of the main rotor head centreline. Lateral CG limits are from 7.08” left to 5.51” right in the B (the machines are different).
Be aware that, in the BA, the C of G graph for the cargo sling (or swing) indicates a maximum weight of 4960 lbs, as opposed to the 4988 lbs indicated on the front of the supplement.

Emergencies
Warning Lights
These things almost never come on. The words "Land ASAP" mean just what they say, but make sure you do so next to a suitable place to change an engine. That is, you need good access, and a pub for the engineers.
Light  Problem  Action 
F Filt  Fuel Filter pre-clogging  Reduce power. If light goes out, continue at reduced power. Otherwise land ASAP. 
CHIP TGB  Metal in TGB  Continue, but avoid prolonged hovering