Huh ?
Wings stay in the air (counterbalancing their weight) because that’s where the lift force apply. The wing fittings that attach the wing to the fuselage are there so that the fuselage stay in the air too, you know…
Lift force is what stresses the wing attachments, and you can’t go past some maximum value. Otherwise you no longer fly.
And yet, when you apply a 5G load, what is the load acting on the wing fittings? They have to sustain the stress applied due to the fuel and the payload hung off the wings.. While lift counteracts the inertia force, it still will exceed the wing fittings’ design limits. Otherwise what you’re saying is that weight limits specified by the manufacturers are just figures to be ignored. Load it up all you want and hope for the best. On the Rafale, the DFCS monitors the load and I don’t believe it will allow the pilot to exceed the structural weight limit of the aircraft.
PS: Refer this if you want link
Aircraft Authorised gross weight limits (also referred to as Certified weight limits) are laid down in the aircraft flight manuals (AFM) and/or associated certificate of airworthiness (C of A). The authorised or permitted limits may be equal to or lower than the structural design weight limits.
The Authorised Weight Limits that can legally be used by an operator or airline are those listed in the AFM and the weight and balance manual.
The Authorised (or Certified) weight limits are chosen by the customer/airline and they are referred to as the “purchased weights”. An operator may purchase a certified weight below the maximum design weights because many of the airport operating fees are based on the aircraft AFM maximum allowable weight values. An aircraft purchase price is, typically, a function of the certified weight purchased.
Maximum weights established, for each aircraft, by design and certification must not be exceeded during aircraft operation (ramp or taxiing, takeoff, en-route flight, approach, and landing) and during aircraft loading (zero fuel conditions, centre of gravity position, and weight distribution).
Weights could be restricted on some type of aircraft depending on the aircraft handling requirements; for example aerobatic aircraft, where certain aerobatic manoeuvres can only be executed with a limited gross weight.
In addition, the authorised maximum weight limits may be less as limited by centre of gravity, fuel density, and fuel loading limits.
F-16 can do that.
And you’ll invalidate the manufacturer’s warranty by doing something like that. :rolleyes:
Yes, that is the point, hope you get it, read toocool post also
No, the point is that no one will fill up their internal tanks to the limit while also carrying the max payload that the aircraft can carry.
If you can prove it otherwise, such as with a particular mission where a pilot has exceeded the MTOW after taking off by refuelling in mid-air, please do.
actually, MTOW means “Maximum Take Off Weight” because you have structural capabilities of the landing gear and the structure supporting it (all the weight rests on that small three points, when the aircraft is on the ground), but once in the air, you fill up your tanks, what will happen? wing fittings won’t be stressed so much, as stores aren’t hanging on the fuselage only but are spread over the wings.
and adding fuel will fill up internal tanks, so, the fuselage part won’t be “overweight” since it would be the same even with wing stations empty and the aircraft very far from its MTOW
yet, when you perform a 5G maneuver even at MTOW, you’re already at the limits of the structure and the hardpoints on the wings (which is why the FCS restricts it to 5G, otherwise there is no reason to prevent a 9G maneuver at MTOW). The wing fittings that attach the wing to the fuselage will be very heavily stressed if you fill up the wing tanks in addition to the payload at the hardpoints.
Try as i may, i can’t see how internal fuel can be related to structural limit when they have already tested 12g with weapons
With full internal fuel and a full payload, the wing fittings and structures would be stressed higher than what they would have been designed to. Besides, the Gripen won’t even GO NEAR 12g with a full payload and anywhere near its MTOW. Its FBW itself would restrict the Gripen to somewhere around 4-5G at the max, and that too at nowhere near its MTOW. Exceeding that MTOW is just not going to happen. I don’t see how you guys cannot understand this simple fact. This is how it is with ALL fighters.
As written by Chris Yeo during his Gripen evaluation flight, even at a Take-off weight of 10,600 kg, the Gripen is restricted to 5Gs, and that is primarily to prevent the airframe from over-stressing itself.
During the evaluation… The aircraft’s configuration was two dummy wingtip missiles, a full centreline 1,100 litre (290USsgal/ 880kg) fuel tank and full internal fuel (2,280kg). The empty mass was 7,100kg, making take-off weight around 10,600kg.
…
At take-off mass, the aircraft was limited to 5g by the full external fuel tank. As the tank emptied below 200kg, the g-limit started to increase progressively to a maximum of 7.5g of the FCS standard tested. The two-seater’s limit will be increased to 8.5g in the near future. As the gun tracking exercise began the g-limit was 7g. The g and incidence limits are regulated automatically by the FCS.
and for the Rafale
The DFCS is a “g” demand system with +9.0g/29° angle of attack (AoA) limit in air-to-air mode and +5.5g/20° AoA limit in both of the two air-to-ground/heavy stores modes (ST1 and ST2) to cater for forward or aft centre of gravity. The aircraft continuously “recognises” the load it carries, but indicates and leaves the final DFCS mode selection to the pilot. Minus g limit in all modes is -3.2
How do you know that? What is the structural limit of the Gripen?
Designers design an aircraft’s parts to a given weight multiplied by a given G load to arrive at a static load to apply. Weight limits such as MTW, MTOW, MLW exist for a reason. If you didn’t know this, its not really my fault.
I believe Gripen should be able to take off with half-empty tanks and a full bomb load and then fill the tanks in the air thereby circumventing the MTOW threshold?
I don’t think that can happen either. The structural limit would be exceeded in that way.
What they could do is to burn whatever fuel they have on board during the ingress part of the mission and then refuel to a limit that brings them back to MTOW..assuming that tanker support is nearby and available of course.
and then by the time they get back to base if the bombs and missiles are still onboard, then burn fuel so that you’re below your MLW by the time you land.
Does the NG have a fuel dump system onboard?
When someone is using data he has to do so in a correct way.
Gripen NG 16,5 tons MTOW – 7,1 tons empty = 9,4 tons “payload”
F-18C 25,4 tons MTOW – 10,8 tons empty = 14,6 tons “payload”Installed thrust for MTOW ~10 tons for the NG = 0,61
Installed thrust for MTOW ~16 tons for the C = 0,63In short by a similar installed thrust the C offers 1/3 more “payload” capability to deal with. 😎
You’re right on the money here. The F-18C is clearly better in this regard.
Here is data
F-18C empty weight 10.810 kg + 7.031 kg bombs + 4.926 kg fuel 12.100×2 lbs mil thrust A/B 18.000×2 lbs
Gripen NG empty weight 7.100 kg + 7.200 kg bombs + 3.130 kg fuel 15.000 lbs mil thrust A/B thrust 22.500 lbs
Your figures for the Gripen NG don’t add up- the Gripen NG weights you’ve given total up to 17430 kgs. The MTOW of the Gripen NG is 16500 kg. That means that the NG will never be able to carry that much payload, with full fuel.
Oh dear.
Time for the ignore button.
A lot of others came to that conclusion a while ago :D..they say never wrestle with a pig. you end up dirty, the pig enjoys it.
How about each aircraft’s radar (India was not over pleased with the M2000 radar, allegedly)?
source?
The US offered the F-16 in contest with the Mirage.
No, India did look at the F-20 Tigershark, but apparently US export controls were not forthcoming. Later on, when it was offered, India didn’t want it since it had the LCA program instead.
what does Jackie really want?
India to re-open the tender so Typhoon could win?
Very unlikely that the Typhoon would win even if the tender was reopened. The rumours of the differences in the life cycle costs seemed quite high. AND, the Typhoon would require a whole lot of investment to bring it to the level that the IAF wants the MRCA at.
The point is that Rafale is more expensive than Typhoon, and not, as we’d always been led to believe, cheaper.
It’s only €12 m per aircraft (just less than 10%), and if I were French, I’d be sanguine that my Government had bought an aircraft better suited to French needs, and had managed a complex programme better, resulting in the earlier delivery of important capabilities.
The disparity in unit production prices is bigger (closer to 20%), and it’s that that makes Dassault’s ability to be L1 in India the more interesting, and it’s that that makes people suspect subsidy or dumping.
Even assuming that you were right about the costs of the Typhoon and Rafale (and that seems to be a big assumption) you forget that its not just the upfront costs that were assessed in the evaluation. The Rafale was judged as having a lower lifecycle cost than the Typhoon.