To explain the take-off/landing distances…. Our outline concept is S-STOL (Super-Short Take-Off and Landing). This is dictated by our target market
–light/medium aircraft carrier operators. The land based market is secondary in design terms simply because a carrier aircraft can operate from land
whereas it’s not always the case vice-versa. When we say small/light carriers we are talking about ones currently viewed as V/STOL only –like
those of Spain, Italy, Thailand, India and currently the UK (or in future terms whoever buys them when they are retired). We suppose that these
customers will not operate the X-47 UCAVs because their carriers are too small, have no arrester gear or no catapult as well as for political and/or
financial reasons. So there is a market for UCAVs able to operate from them –which with current (real) projects in development would be limited to
rotary ones. What is more, when their Harrier aircraft become old, the only project replacement will be the F-35 –same cost and political issues.
Spain and Italy wil buy at least some F-35s but India (small carriers to be retired?), Thailand and whoever buys the UK’s current V/STOL carriers (I
predict three different countries)??? And if there was a cheaper option then even Spain and Italy would both likely prefer a mixed fleet of F-35s and
less capable UCAVs.
Put yourself in Thailand’s shoes. You’ve recently brought a state of the art light carrier from Spain (HTMS Chakri Naruebet) and brought second
hand (and close to obsolete) AV-8A Harrier aircraft as the first step. All of a sudden the only V/STOL strike platform in serious development anywhere
in the worlds is the US F-35 which you probably won’t be able to afford.
Spanish light carrier Principe de Asturias (left with Harriers on deck) and the Thai “helicopter carrier” HTMS Chakri Naruebet:
There are also countries with ‘medium’ carriers like France, Brazil, Russia and in the future UK, India and China. Some of these carriers have
ski-jumps rather than catapults (Russia, India and China) but all have arrestor gear –this may negate the S-STOL requirement but a conventional
landing sub-variant could be developed.
Now, given geopolitics, we have identified the Brazil, Thailand, India, Spain and Italy as the key market. And our design (which is entirely
hypothetical of course) would be the only contender for that market.
So this concept UCAV must be able to operate from a small carrier using a ski-jump take-off and non-arrested landing. So there are two obvious
operating choices: a proper V/STOL platform able to hover, or a S-STOL platform able to land in like 30m without arrestor gear. The former option is
the most complicated and least novel so we’ve plumbed for the second.
Inherent within a S-STOL landing are:
1) Very slow approach speeds (sub-stall for most jets). If the aircraft can approach the carrier at 50kts and the carrier is steaming into a 10kts
headwind at 20kts then the effective landing speed is just 20kts(!). However, we have to be prepared for the worst case scenario which is an effective
landing speed of say 20% above the designed speed (=60kts).
2) Very good slow speed and high angle of attack handling
3) The ability to make this landing with a full weapons load and 20% fuel (=10,000lb or weapons plus 2,000lb of fuel –or better).
In order to meet this harsh specification, we are looking at high-lift wing forms, thrust vectoring main engine plus some form of additional downward
thrust (for take-off and as a ‘cushion’ on landing) in the form of either lift-jets, lift-fans or augmented thrust main engines.
Hope this clears things up. Thanks for the interest.