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8.8 Helicopter Limitations

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Rate of Climb

The rate of climb data shown in the graphs are actual rates of climb measured with an altimeter on a standard day with a standard temperature lapse rate. Termed; Tapeline Rate of Climb. Both charts use a tapeline rate of climb at an indicated air speed of 57 knots.

There are two rate of climb charts, each represent a power setting. On page 11 Take-off Power and on page 12 Maximum Continuos Power. Both have the particle separator purge switched off and anti-ice off and both graphs use the same method to find rates of climb.

Refer to the BELL 206L-1 Long Ranger II Handbook to follow instructions about using the TOP and MCP Rate of Climb graphs on pages 11 and 12.

Using the Rate of Climb Charts
  • Using the Take-off Power or Maximum Continuos Power graph on pages 11 and 12.
  • Start by entering the graph from the temperature scale, located at the bottom left hand corner. Then move vertically up to intersect the Pressure Height.
  • Where the temperature intersects the Pressure Height, move horizontally across to the right to intersect the gross weight of the helicopter.
  • From the gross weight intersections move vertically down to find rate of climb (ROC). Note: The ROC answer has dropped the last two digits and you will need to multiply it by 100 to complete the answer, i.e. 11 is; 11 x 100 = 1100 fpm.
  • If there are one or more doors off, subtract only 100 ft/min from your answer. Any combination of doors off will slow the rate of climb of the helicopter due to the amount of drag created.
TOP Example

Find the rate of climb using Take-Off Power (TOP) with the following data. The OAT is 10° while operating at a pressure altitude of 12,000 ft with a gross weight of 3600 lb.

Answer 1070 fpm

MCP Example

Find the rate of climb using Maximum Continuos Power (MCP) with the following data. The OAT is 10° while operating at a pressure altitude of 12,000 ft with a gross weight of 3600 lb.

Answer 710 fpm

Service Ceiling

The Bell 206L-1 Long Ranger service ceiling is the highest altitude it can maintain a steady rate of climb at 100 fpm using maximum continuos power. If the particle separator is switched on it will deprive power from the engine resulting in an 800 ft reduction from the service ceiling.

Refer to the BELL 206L-1 Long Ranger II Handbook on page 20 to use the service ceiling graph.

For unit conversion refer to the ERSA.

Using The Service Ceiling Chart:
  • Start with the aircraft gross weight at the bottom of the graph.
  • Move vertically up until you intersect the OAT line or if given the ISA+ temperature line.
  • Move horizontally to the left and read the Pressure Altitude in feet for an answer.
  • If the particle separator is ON subtract 800 ft from the pressure altitude answer.

Find the service ceiling using maximum continuos power (MCP) with the following data:

  • OAT is 20°
  • Gross weight 3950 lb

Answer 1600 ft Pressure Altitude.

If the particle separator is ON subtract 800 ft from 1600 ft = 15200 ft P.A.