The Blohm & Voss Bv 138
Long-Range Patrol Flying Boat

Development

Based on a requirement by the Reichsluftfahrtministerium (RLM),in 1934 Dr. Richard Vogt, chief of development at the Hamburger Flugzeugbau (later Blohm & Voss, Dept. Aircraft Construction), drew up plans for three long-range patrol flying boats.
These were to have been fitted with heavy oil diesel engines, since this type of powerplant
provided a significant jump in range due to its thrifty fuel consumption rate.
The Junkers Jumo 205 was available at the time and although it only had an output of 600 hp, it was hoped that eventually the more powerful BMW 15 could be installed.
Dr. Vogt therefore proposed that two of the projects, P.8 and P.8a, be powered by two BMW 15s each, and as an alternative offered the P.12 with three Jumo 205s.
As a final measure, he also designed a project for the twin-hulled P.13 with four Jumo 205
engines.
The P.13 was rejected by the RLM, however, and this organization called for a new design along the lines of the P.8 project.
As it was questionable whether the BMW 15 would ever be made available, Dr. Vogt proposed building the following prototypes: Ha 138 V 2 with two BMW 15s, Ha 138 V 2 with two Daimler-Benz DB 600 (petrol-powered engines).
By March of 1935 the mockup of the Ha (later Bv) 138 V 1 was finished, but was now to have been fitted with two Jumo 206s in place of the BMW 15.
The RLM gave its approving nod and construction began.

Heinkel He 162, The "Volksjager"


On 10 July 1944 the leader of the Heinkel Projects branch, Siegfried Gúnter, presented his report 105/44 titled "P 1073 Jet Fighter" to the appropriate leadership of the factory in Rostock and Vienna.
This document maintained, among other things,
"the achievement of air superiority is dependant not only upon the number of single seaters but also upon the speed of the single seat fighter.
Should enemy jet single seat fighters be deployed, the Me 262 could probably not be counted on for air superiority, because its conventional construction with unswept wings and the placement of its engine nacelles give too much resistance - at low altitudes its fuel expenditure is quite large and its range quite small.
For these reasons, it is necessary to concentrate on a single-seat aircraft with the least possible amount of equipment and not limit fuel to so small a portion of the overall weight."
Gunter had calculated the following performances of his P 1073 project with two different engines:

with the Heinkel He S11 (still in development)
maximum speed : 1010 km/h
range with :
normal fuel tanks : 1000 km
drop tanks : 1650 Km

with the Jumo 004 C
maximum speed : 940 km/h