Halifax B. Mk.VI NP.753
(4 Hercules 100 engines)
Effect of "in-out" air cleaners on performance
Summary
| Tests were made from a take-off weight of 65,000 lb. on Halifax B Mk. VI NP.753, to determine the effect of special air intakes, incorporating "in-out" air cleaners, on climb and level speed performance. The results are given, compared with those for standard air intakes, in the following tables :- |
| Level speed MS supercharger gear, max. weak mixture, cruising conditions |
| Std. air intakes TAS mph | Special air intakes | |||
| Cold unfiltered air TAS mph | Hot unfiltered air TAS mph | Cold filtered air TAS mph | ||
| 14,200 ft (FTH with standard air intakes) | 258 | 258 | 243 | 228 |
| 14,000 ft (FTH using cold unfiltered air) | 258 | 257 | 243 | 229 |
| 11,700 ft (FTH using hot unfiltered air) | 252 | 251 | 248 | 240 |
| 10,400 ft (FTH using cold filtered air) | - | 247 | 244 | 243 |
| Level speed, FS supercharger gear, max. weak mixture, cruising conditions |
| Std. air intakes TAS mph | Special air intakes | |||
| Cold unfiltered air TAS mph | Hot unfiltered air TAS mph | Cold filtered air TAS mph | ||
| 22,100 ft (FTH with standard air intakes) | 266 | 266 | - | - |
| 22,300 ft (FTH using cold unfiltered air) | 265 | 266 | - | - |
| 19,400 ft (FTH using hot unfiltered air) | - | 256 | 247 | 242 |
| 18,600 ft (FTH using cold filtered air) | - | 254 | 245 | 244 |
| Level speed, FS supercharger gear, max. rich mixture, cruising conditions with special intakes. |
| Cold unfiltered air TAS mph | Hot unfiltered air TAS mph | |
| 8,800 ft. (FTH using cold unfiltered air) | 271 | 260 |
| 7,300 ft. (FTH using hot unfiltered air) | 263 | 260 |
| Level speed, combat power with standard air intakes |
| TAS mph | |
| 9,900 ft. FTH in MS supercharger gear | 279 |
| 19,600 ft. FTH in FS supercharger gear | 277 |
| Climb at 140 mph EAS - gills fully open to 19,000 ft. |
| Intake condition | Rate of climb at full throttle height MS gear | Rate of climb at full throttle height FS gear |
| Standard air intakes | 970 ft/min at 7400 ft. | 540 ft/min at 16200 ft. |
| Cold unfiltered air | 1010 ft/min at 7400 ft. | 670 ft/min at 16400 ft. |
| Hot unfiltered air | 980 ft/min at 5600 ft. | 540 ft/min at 1390 ft. |
| Cold filtered air | 960 ft/min at 5200 ft. | - |
