An alternative wing layout for carrier based planes along with an alternative engine arrangement for other planes.
I didn't want to highjack Planeman's interesting post on concept aircraft modeling so I thought a separate post was appropriate.
I've wondered for a while why carrier aircraft are not built in a biplane configuration.
Advantages would be:
Folding wings may not be required for storage.
The Harrier has a wingspan of about 30 feet. Both the Rafale N and the F-35B about 35. One of the X-32's principle design factors was a single
piece wing that allowed for a massive structural density and fuel volume (very thick supercritical design), without having to fold it's 36ft span.
Though things may change now that they have so grotesquely bloated their configuration, the original X-45/47 designs were deliberately made small
enough so that their wings did not have to fold.
Compare these to the F4U Corsair whose 41 foot span allowed as many as 120 aircraft on a carrier 1/3rd the size of present day Nimitz or TR (whose
airwing rarely numbers more than 40-50 airframes).
Bluntly the USN uses spotting factor as a club not a real measure of role performance or operational suitability. The politics of Variable Feast (boy
and their toys) aesthetics would have NavAir secretly laughing at your biplane's datedness even as they dreamed up some complaint by which it was
'too something' (heavy, tall, short, weak) to be hidden in their hangars, away from public view.
Differing airfoils on each wing would make for a gentler stall.
(One stalls before the other, so there's a touch more predictability.)
Depending on the slot effect between the wings, you would probably gain more lift with the wings fairly close together vertically.
Although too close may negate the gentler stall effect.
As others have stated, the Red Baron never pulled 9G at 400 knots. The disturbed flow coming off the LE is MASSIVE (tons of pressure) and so anything
washed by it would suffer increasingly greater divergent aerodynamic as well as inertial loading. Sometimes, this can be beneficial as when you are
using canard vortices to scrub wing roots for example. But usually 'close coupling of lift vectors on principal airfoils is a bad thing (being a
principal reason why even 100knot biplane airfoils are staggered).
As to stall, well, the notion that one airfoil will stall before the other also implies that any adverse roll or yaw (tip) or directional variable as
well as 'sag' in the lift curve as it does so will simply add moment as well as dead weight to the one still struggling to stay in the game.
The shorter wings are stiffer by a considerable degree than a longer wing and don’t require as much weight.
Yes, but the fuselage frames which support them and the longerons which must withstand the bending and twisting moment fore and aft of them must also
be beefier and more densely spaced across a nominally shorter loaded chord length (LE to TE) worth of attachment separation.
There are also penalties in clearing any external stores (much lower pylon:ground distance as well as increased risk to the wings from weapons or
tanks which can and do sometimes come 'up and over') while it is arguable that 'twice the wing' (count) does not equal twice the wing /area/ or
volume. As you must also double the skinning, internal spars/ribs and controls/actuators which means your effective wingloading goes up even as
internal fuel may decrease vs. the simpler trapezoid or cropped delta formats now in favor that make the total area a fraction of the base of a
triangle described by the total fuselage length instead of a rectangle whose narrowest side is transverse to it.
Although two wings may weigh more than a single wing, but if spar selection etc. was carefully done - as I expect it would - the weights may come out
the same or less.
Even if it did with the wings, I don't think you are considering the fuselage carry through beefing or the aerodynamic (area rule and fineness ratio)
penalties of having double the loaded frame stress in the same chordwise area.
Landing gear hinged on the fuselage end would help keep wing weight down.
This is true but it is not exclusively the province of biplane construction (F-16) nor is the narrow track necessarily a 'good thang' for naval ops
(F-8 and A-7) where there is a tendency to bunny hop from gear to gear right over the wires and there is simply not much of a stablity arm to keep
from dipping the wing into a scrape as you come in crabbed to the wind on the angle deck.
Do that on a biplane where the wing is /naturally/ lower to the groundline and there is next to NO sweep and you could be in for real trouble.
One problem with that configuration would be landing gear narrow track width which could create ground handling problems ala WW2's Spitfire and
Once you were down, the weight of the airframe would be a substantial stabilizer (provided air ops were possible at all in the given seaway). And
given you didn't have a P-factor on torque and residual power/pitch, ground looping shouldn't be a facor.
The big problem today would be access to an internal weapons bay as you need a fairly tall stance to clear a jammer or lowloader trailer past the bay
doors and between the gear legs without making the deck crew just /constantly/ cowtowed on their faces. Of course the RF interactions on the dual
airfoil structure might well spoil stealth anyway.
Another option would be two small jet engines which would allow a single wheel main gear with short struts to retract into the fuselage.
Not if you don't want the flex of the wings to have to 'push together' (cantilever) the full weight of the aircraft and the engines through two
pogos halfway out on the span or in your (tip?) power ods.
A pair of outrigger wheels ala Catalina PBY floats that retract into - or make - the wingtips or similar could be used for stability.
I must be misunderstanding your intent as to the MLG geometry. You DO NOT want a 'treetrunk' effect on a single strut (CTOL or CVTOL) gear for a
variety of reasons:
1. What takes the catload?
2. If the nose is unsupported, what keeps it from plowing deck as the arrestor catches?
3. If the wing mounts are at the CG, how do you hole their ring or boxframe supports to install gear there as well?
4. Wherefore the weaponsbay and engine maintenance access?
If the fuselage hinged landing gear was used, locating it forward taildragger style and installing a tail wheel that is well faired by a lower
vertical stabilizer may be an option.
Especially now that we are on the verge of truly effective automated landing systems (JPALS) so that pilot view over a raised nose is less imporant,
this may be true. But there are other penalties to consider such as spoiling lift to prevent 'float' as you come over the rounddown at what is apt
to be a near optimum AOA for the speed range.
If you mean to imply a full-length tail strut, then I have to question the ability to control castoring and avoid arrestor stripping while maintaining
an effective hook location.
You wouldn't want the lower vertical stab to be too long because then you'd run into rotation for takeoff problems that would considerably lengthen
takeoff distance from runways due to the much higher speed required.
Given that we are finally moving towards a 'pure' airfoil without empennage at all (ICE/FATE), my queston becomes 'what's that doing there?' Or
if you must have one, why not as a retractable implement way out on the wing where narrowing chord on a conventional swept/delta planform and perhaps
lower effective AOA both combine to magnify it's natural (increased displacement from centerline) yaw effectivess due to absent fuselage blanking and
possilbly active vortice flow?
On a biplane, the only way you can get even close to this is to hinge a set of cabane struts, fore, aft or both. If you don't you are looking at a
vertical tail that is in the wash of two very turbulent airfoils (lotsa camber for the decklanding requirement) and may be blanked by a tail-dragger
A little off from the biplane configuration thinking would be a jet fighter/bomber similar to the F-84 Twin Mustang of the Korean war era.
F-82 Twin Mustang.
Double fuselages work to increase available mission space for engines, weapons and fuel. However; they also /greatly/ magnify wetted area (imagine
two fuselage bodies in paint-me-a-thunderbird formation distances, at near supersonic speeds), frontal area and carry through structures on what is
effectvely three wings.
Engines would be medium to normal sized - for fighters - in a triple engine configuration.
More engines 'of an average size' is an acknowledgement of poor weight control. Which tends to lead to problems with fuel consumption and terrible
operating costs (three times the maintenance etc.).
The latter is acceptable in twin when the amount of work that that say an F-22 can do exceeds the costs of acquisition and ownership on what a pair of
F-35's can relative to both total fleet size and spares. Particularly in high-risk conditions such as naval ops there is also still a small margin
of 'reliability' factoring on SE recovery of damaged or failed twins. Under all other conditions, twins are unacceptable and a triplet installation
would never be even be /considered/ for a fighter (3,500lbs of metal with and SFC of 6-7? Baaah.).
That said, if you treated your airframe as a high altitude endurance UAV wherein tip mounted rotating jet pods in the thrustclass of a small bizjet or
even cruise missile were augmented by a single lift engine running electric lift fans, on the centerline (think Shin Meiwa) and NONE of them had to
generate high speed performance but merely control the STOL capabilities of say a modified LTA hybrid configuration.
You might be able to sell it.
SOLELY on the basis that there was no manned cabin so weight and compexity could be traded up in other areas.
Specifically, I would envision a system whereby the lift gas was burnt off as fuel and the 'biplane config' gradually assumed lift function within a
controllable span for graduated 'glide down recovery' and a rolling VL.
In such a system for instance, you might put your 'biplane' wing system fore and aft as a joined concept and then mount large swivelling antennas
within the matress-shaped, semirigid, fuel-tank/liftbags on the (hollow) centerline. This then providing 20-30 day cheap pseuodlite nav/comms over
more primitive regions where good basing infrastructure was not available and topography/environment too extreme to support conventional towers.
Pilot and o-pilot would be under separate canopies similar to the F-84.
WHY? Why double the weight of canopies and their explosive release structure? WHY? Put in a pilot whose ability to withstand 12-15hr (F-111 to
Tripoli) type mission radii is instantly questionable in a period when we may need a platform that can spend DAYS aloft, waiting for a
guerilla/terrorist/insurgent to think "He must have RTB'd by now!"
The simple fact is that modern air to ground combat is prosecuted very simplistically:
1. 'You' (the remote optics head on a robotic airframe) take a snapshot of a given area and lay a coordinate grid over it prior to shippng it to
some other command/tasking source. Just like a picturephone.
2. Junior, on the ground or in another aircraft, puts down his donut and says "Okay, X2/Y2 through X2/Y4, magnify!" based on his interpretation of
the moving blips. And then waits while you use a combination of physical and electronic zoom to resolve the dots into shapes he can recognize.
3. He then says "HAH! Bad Guy, track that sucker!" and waits for your confirmation of doing so.
4. After one last 'sanity check' to make sure that the moving blob (man on donkey or black SUV) is 'historicallly analogous' between the existing
and original target start-endpoints and that nobody /around/ the wormtrail of motion is collateral/friendly restricted. Junior authorizes a weapons
release after which a Joint Common Missile will flyout to roughly 15nm downrange in about a minute. As an alterative to a gliding SDB going 25-30nm
in about five.
IN NO INSTANCE IS A MAN 'OUT OF THE LOOP'. But nor is his presence required onboard a munition carrier whose first purpose is PRESENCE to take the
pictures and carry the munition. Not land to let the pilot out for a leg stretch and potty break.
What I'm envisioning is a doubled up F-16 style aircraft with a cranked delta wing on the outside and twin vertical stabilizers.
No. Biplanes exist to provide large amounts of low speed/transitional mode lift.
Conjoined fuselage airframes are cheapa$$ way to double the mission capacity (endurance or payload:range) without benefit of a proper clean-sheet
design evolution to remove the wasted (half of each fuselage and the centerwing) skin and structural mass.
NEITHER design is amenable to contemporary operations. Simply because as long as a man is onboard, you cannot maintain station times analogous with
the best of what modern design and materials/fabrication could achieve with him GONE from the picture.
Conversely, as a short endurance strike fighter, cheap is everything and adding structure just to make a neat shape blows out your budget so that the
other team can win the contract with an A-4 alternative to an A-3 mission capability.
Stealth capabilities may or may not be easy to accomplish in this aircraft, but one thing that is gained is loss of one engine won't slow the plane
down too much.
Depends on how far out from the centerline you are and how much trim penalty you must pay versus the natural increase in frontal and wetted area on
the airframe itself for the given Mach point. Lift AT Drag does not respond well to replicative system weight increases (F-16X2 = 600 square feet of
wing in a 40,000lb empty weight. F-22 = 840 square feet in a 50,000lb class airframe. Difference? 70% more fuel for twice the effective radius.
Four times the thrust. Internal low Drag+LO carriage. Planform controls of true stealth to negate burner use in an engaged defensive state.
Multi engine thinking in the B-17 was two-fold.
There were no engines with a high enough horsepower rating to pull the B-17 sized airplane to the performance levels desired.
Not sure what this applies to. Since the B.XVIII Mosquito with two 1,600hp Merlins could haul a similar bombload (4,000lbs) to a similar Berlin
radius at 300mph. And there are numerous similar examples (B-26 Marauder) wherein the IDIOCY of putting te men in a fat cabin to shoot guns which
were just shy of worthless meant huge trades in drag for range which in turn meant that not only were you flying -one- mission per day, but the
fighters had an easier time attacking a huge, 180-220mph, target which fired back all too pathetically from multiple angles. Than they would have
faced against a twin whose _cruising_ speed required time-limited combat power settings just for the privelege of taking turret fire in the forehead
as you slowly closed from behind.
In any case, today there are many engines which fit the bill of 'better the few than the many'. The B-52H puts out roughly 136,000lbst from it's
eight TF-33s. If I replace those with 4 GE-90 or Trent-1000 class engines, I am looking at anywhere from 200,000lbst to 280,000lbst. If I halve the
weight of the airframe, making it a flying lifting body to maintain the high-far lift curve, two such engines will DOUBLE the /thrust to weight ratio/
even as a more-pointy airframe means sonic-cruiser velocities of Mach 1+ to equal radii, with half the gas, twice a day.
All because I don't have to pay some 'union wages' on some dumba$$ 1950's job description for a nav+radar nav and EWO. All of whose jobs are
better done by automation in a two-crew cockpit.
As well as, loss of one engine was only 25% of available thrust as vs a 50% loss of thrust with one engine out in a twin engine configuration.
Snort. 25% of thrust means you are now a 150mph platform at 15,000ft instead of 200mph platform at 25,000. Which in turn assures that, as the
formation leaves you behind, what little intimidation factor the box-fire overlaps provided goes with it. And you are literally 'herraschluss'
/dogpiled/ by an enemy looking to pull your defenses apart from multiple aspects until you die like a deer ripped to pieces by maddened wolves.
Since we no longer use gorilla type raid packages of 1,000 planes and thus the entire force model is no longer /affordable/ as much as effective, I
still am not sure where exactly you're going with this.
An alternative engine setup for the triple engine fighter/bomber would be the center engine could be fairly large in terms of thrust and the outer
engines smaller to a reasonable degree.
And I will mount precision guidance on a ballistic or cruise missile and kill you where you land to spend 80% of your post-working day. My up front
investment will be high but the TENS OF BILLIONS worth of wingtip-to-wingtip, open-ramp, characterized airpower as we foolishly employed at places
like Aviano an PSAB will shock the world in terms of how little /operationally/ must be risked by the novice standup state to deny the
bully-superpower it's ability to dominate by air.
i.e. If your third engine is not lift+lift-cruise optimized to allow ops away from predictable basing modes and/or over LONG radii at higher speeds
(outside the reach of TBMs) don't waste th drag or systems cost metrics trying to justify it.
Afterburners would not be required and if they were, an afterburning center engine would probably do it.
Never mind trimming all three engines to a common Mach point/trust curve with these outboards running like a striped ape in every turn...
Fuel economy - or extended range - could be accomplished by throttling the center engine back and running on the two outer engines once you were at
Nope. You size your engine to a median thrust level/performance regime and then accept the penalties of all others. This is why the X-32 derivative
F119 suffered such bad economies in that it was designed around a roughly 50,000lbst military thrust curve at sea level for the worthess STOVL
'beginning and endpoint' optimum. At all other points in the envelope, the amount of work the core needed to do to keep the fan turning was more
than required for the (subsonic) cruise regime and thus the jet sucked down dinosaurs it didn't need to and lost effective radius.
Your problem comes from the opposite end of the spectrum in that the weight of the engines you DON'T need is a constant and thus the thrust levels
MUST be higher to mush all that mass through the air for no better reason than to say you have triple engine redundancy.
Psssst. When China fires a laser that ruptures the 10 mil thick aluminum or 20 mil composite skins over your integral wing tanks, 10 milliseconds
before flash vaporizing the contents of same into a 300m wide fireball, 'reserve power' won't mean a thing.
The main landing gear could be installed in the fuselage, but would probably work out better in the area between engines.
The front landing gear could be a single off the front of the center engine fuselage.
That would work if the center engine had air intakes to the side as on the single engine F-16.
The center fuselage nose would have the usual stuff within, radar dish etc.
An alternative for the single front landing gear could be a pair of front landing gears.
One in the forward end of each fuselage.
Advantages with this layout could be improved ground handling.
And since the usual gear won't come down problems is usually on the nose gear, you could probably land the plane and come to a stop before the plane
tipped - if at all - toward the recalcitrant nose gear.
I think we covered this. The trades you want to study are those relative to fps descent rates vs. multi or few locations of LIGHTWEIGHT gears.
Ideally, you will come down on four gears at about 4fps, completely level, at no more than 40-60mph. Once you reduce physical forces to the level of
automotive engineering, you can start to 'be inventive' by providing in-hub motors to both increase braking effectiveness and provide power-off
deckspotting or hangar movement without having to physically 'point' the aircraft in any given direction for a tow.
Twin cannons could be installed in the short wing area between engines and a total of four cannons of sufficient size would make for a very deadly
Sort of a high speed WartHog if you will.
Cannons are worthless. They have an effective range of under 4,000ft against aircraft. And under 12,000ft against ground targets. Both of which can
be bettered by any relevant guided weapon out there. They are NOT precision weapons which means collateral damage constraints are even higher than
for point-targeted systems. And these same shortcoming all serve to bring the aiframe into range of trashfire which further threatens to put your
100,000lb 'biplane' down in someone's playground or backyard bbq. All this for a system which holes the aiframes and adds explosive gun gas
venting problems across the board? Gee, /tanks/.
Missile racks and the like would be under the short wing area between engines as well as on the outer wings.
AIM-120 is almost thirteen feet long. GBU-39 is only six. You can't generalize, you MUST define specific carriage envelopes (ground clearances,
forward vs. dropfire, acoustics on launch) for each and every system.
If the cockpits were oriented far enough forward, the downward view for the pilots would be very good.
With virtual vision as typified by the camera under the Concorde and the DAS on the F-35, this is less important than commonly accredited. Take off
20 knots on the approach speed. Give me a weapons system that provides complete semispheric coverage under the fuselage and DOES NOT require me to
put the nose under the horizon line to attack. And I will be more grateful.
There are several options for the short wing area.
Landing gear as mentioned.
Missiles and the like could be stored inboard so extra drag generated by external racks could be avoided.
The main landing gear would probably be far enough back to allow this.
This area could also be utilized for fuel storage.
Far out thoughts in both cases?
Perhaps, but looking from here, as far as the biplane jet goes, I don't see too many problems.
I do believe there would be an advantage with this configuration.
And perhaps the triple engine fighter/bomber is a bit too far out, but if nothing else . . . food for thought.
You are too loose in your technical justifications, particularly as regards the native advantages of a biplane. You then use poor historical
casepoints to try and 'bend' a roles and mission argument around.
Craft your idea around one or the other but not both. Is a given force structure (U.S. or whomever) 'short' a mission capability which needs
serving? If so what _explicit_ airframe characteristics are required to accomplish that role? Now. Does your trijet meet those needs? Does your
To me, the preeminent factors which will effect future tactical airpower design are threefold:
HELs will make high altitude flight almost impossible over enemy terrain by 2050. Accurate and widespread ballistic weapons, along with mutual
overhead space targeting will make 'pizza hut delivery' occupation of any large signature area (10,000ft runway) ground feature within 2,000-3,000km
of a threat state impossible to achieve. You will displace to much smaller operating footprint.
There is literally ZERO reason for a pilot to be aboard any airframe today. Pulling him and 'sharing' the sensors and comms he once commnanded
among multiple aircraft will reduce airframe weight by 5-7,000lbs. Minimum.
3. Composite Economics.
The F-16 originally weighed around 17,000lbs, empty equipped. To design a similar airframe, today, while combining zero-inhabitancy, micro-munition
and modern composite engineering, should lead to weight threshold ONE THIRD as great. i.e an airframe which weighs 5-7,000lbs empty and perhaps 12-14
at typical takeoff.
THAT is the point at which you can begin to think about trading absolute (cruise) thrust for lighter weight L+LC designs in a fashion that (perhaps
through a 'Y' thrustline geometry) also affords real VTOL payback in terms of landing gear and structural reinforcement compensation on a forward
swept wing design amost entirely dependent on TVC for control as well as lift (engine cores are only a small element in an overall plenum box RALS or
TF based lift system).
In anycase, the utility of these airframes will likely be in their ability to 'pop up anywhere' and be throw-away expended with little thought as to
asset (3-5 million each) vs. gambited tactical value.
If you have a separate vision of how things will be, then by all means, share it.