| Date: |
Flug. Nr.: |
Take-off: |
Landing: |
Duration |
Pilot:
|
| 14.10.42 |
22 |
1107 |
1134 |
27' |
Siedenbiedel |
| |
23 |
1207 |
1224 |
17' |
Siedenbiedel |
| |
24 |
1500 |
1556 |
56' |
Siedenbiedel |
| |
25 |
1701 |
1721 |
20' |
Siedenbiedel |
| Condition: |
| Engine BMW 801 D II/25543 |
| Take-off weight: 12,687 lbs. (G = 3867 kg) , s = 0.49 m |
| Armament: 2 MG 17, 2 MG 151 with ammunition. |
| Close engine cowl |
| Apparatus bay doors with split flaps are replaced with gill flaps with covered gills. |
| (Winter emergency equipment as per BSK 834). |
| 1.) |
Determination of the cylinder temperatures with combat power |
|
a.) |
in climb, |
|
b.) |
in level flight at 1,640 feet (500 meter) height. |
| 2.) |
Establishing level speeds. |
| 3.) |
Determining the rpm limit at which the maximum cylinder temperatures are not exceeded (stationary test). |
| 1a.) |
The climb at combat power, to determine the cylinder temperatures, had to be discontinued at 19,685 feet (6000 meters) altitude, since the short-term permissible
cylinder temperatures were exceeded (see Graph 1). 230° was reached, resulting in 240° when corrected to CINA conditions. |
|
Based on previous measurements, a further increase in temperature of about 10° is expected up to the reversal height of the cylinder temperatures.
This therefore results in highest cylinder temperatures of ~ 250° C in climb with the Winter emergency equipment at CINA conditions. |
|
Climbs with covered gills can therefore be carried out, without exceeding the 220° limit, only with an outside air temperature gradient which is 15° under the CINA-temperature gradient.
This corresponds to a sea level temperature of 0° C. |
|
| 1b.) |
Based on the hottest summer day, the temperatures near sea level in level flight are 205° C.
For the assumed operational temperature gradient tCINA – 15° C, the cylinder temperatures near sea level therefore reach a maximum of 175° C |
|
| 2.) |
Graph 2 shows level speeds flown with combat power: |
|
|
|
Full throttle height was |
Hb = 19,029 feet (5800 meters). |
|
|
Speeds obtained in full throttle height |
Vwc = 405 mph (651 km/h). |
|
|
At sea level (0 meters) |
Vwc = 336 (540 km/h). |
|
| 3.) |
The rpm limit on the stand, where the permissible cylinder temperatures are just reached, could not be run at the current air temperature (nearly CINA) for the
operating temperature (-15 CINA). However, it should, according to Graph 3, be at approximately 2100 + 2300 rpm, considerably above the specified warm up rpm.
Normal warming up can be done with the sealed gills for winter operations without overheating the cylinders. |
Wenzendorf, 24.10.1942.
Gt./Sch./-. |
|
