356 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1959 
THE LIFTPLANE—VTOL 
The biggest revolution in the coming design of useful aircraft will 
be the advent of the direct-lift airplane, sometimes awkwardly called 
VTOL. After some 10 years of intensive research, resulting in several 
bookshelves full of excellent NACA and other laboratory reports on 
how to make a fast airplane land vertically, it is only now that we are 
beginning to show the needed interest and the start of progress in this 
development. Boundary layer control is only one facet of the problem 
of landing vertically. Tilting wings, tilting Jet engines, and other 
ways are being developed. 
The helicopter is not quite the answer, simply because its speed is 
limited owing to the rotor configuration. Even if helicopters get up 
to a high cruising speed of 200 miles per hour, they will still have to 
compete with fixed-wing aircraft of over twice that speed. Through- 
out the history of aircraft development, there is one lesson that stands 
out clearly: high speed is always the successful characteristic of any 
type of operation, even on the shortest ranges. Slow aircraft, no mat- 
ter for what purposes, have never survived. 
On the other hand, the airplane as we know it is a very deficient 
vehicle because it cannot slow down, hover, or back up, as every other 
vehicle can do. The penalty we pay for this characteristic of having 
to keep going in order to stay up is great. More skill is needed in 
operation. Prepared airports must be provided, running up now to 
preposterous 10,000- and 15,000-foot-long runways, using up an 
amount of real estate that drives the airport to a distance from the 
city. So many planes want to land at the same one-track airport at 
the same time that very complex traflic-pattern and traffic-control 
problems arise. For jetplanes, as much as 100 square miles of airspace 
must be reserved for each plane while it awaits its turn to land on the 
one-track airport. All this because they cannot slow down below 
180 m.p.h.! 
Many objections to liftplanes (VTOL) are now being voiced. One 
is that the fuel consumption for vertical flying is utterly prohibitive. 
In the light of history, this objection belongs with those that were 
initially raised to monoplanes, to metal construction, and to slots 
and flaps. A simple analysis will show that while direct-lift by jet 
will need three or four times the thrust of the existing jet-engine 
configurations, and will therefore use three times the fuel, the actual 
fuel used by the jet transport in taxiing out to the end of a long 
runway, waiting for clearance, the long takeoff run, then climbing to 
1,000 feet, is almost as much as the direct-lift plane would use rising 
immediately to 1,000 feet from its pad at the loading ramp, with all 
engines full-out, and then shutting off its ift engines. 
Another objection in the same class as the earlier ones mentioned 
above is the weight of the extra jet engines for vertical thrust. 
