Pakistan pulls JF 17 Thunderbird out of Bahrain air show

Nuvneet Kundu

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Yes- only nine engineers.BTW have we ever seen a model of so called 'JF' in a Pakistani wind-tunnel ??
Pakistan doesn't have a wind tunnel. The only wind tunnel Pakistan has is their anus.

Even India got a wind tunnel fairly recently. Note that a lot of testing for Tejas happened in American wind tunnels. Now that we have our own wind tunnel, we can test the AMCA, stealth bomber and hypersonic missile concepts. Until a few months ago, we didn't even have a supersonic rocket assisted boost system to test rockets on ground level analog simulators. The Kaveri engine was tested on an Il-76 testbed in Russia because we didn't have a testbed.

Here's the Kaveri test :
 

HariPrasad-1

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The delta is a bit more nuanced than that. The drag coefficient for a delta wing only impedes flight at low speeds-low altitude flight profile, but does better than other wing types in high speed, high altitude, high maneuver flight profiles.

Once the plane catches speed, there is a change in how the fluid dynamics work in favor of the delta. Check this :





https://en.wikibooks.org/wiki/Fluid_Mechanics_Applications/A02:_Delta_Wing_Aircraft_Aerodynamics

The primary advantage of the delta wing is that, with a large enough angle of rearward sweep, the wing’s leading edge will not contact the shock wave boundary formed at the nose of the fuselage as the speed of the aircraft approaches and exceeds transonic to supersonic speed. The rearward sweep angle vastly lowers the airspeed normal to the leading edge of the wing, thereby allowing the aircraft to fly at high subsonic, transonic, or supersonic speed, while the over wing speed of the lifting air is kept to less than the speed of sound. Some other advantages of Delta wings are:-

  • Rise in Transsonic drag is gradual and peak drag in supersonic flight is reduced
--Lift is spread over the broader chord
--Senstivity of Drag to Mach Number is redued greatly
--Satisfactory cross sectional area can be achieved very easily

  • Change in lift component CL and lift curve slope CLα with the value of Mach Number M is gradual.
  • A very high stall angle is achieved by increasing the angle of atack, as a flow energising vortex is generated by the leading edge of the wing at high angles of attack.
  • It allows for light wings with high bending and torsional stiffness.
--More volume for fuel and gear is available in thicker wings.
--Fluttering and aileron reversal problems are wholly eliminated.

  • Acceptable level of maneuverability and ease of handlingis achieved because of low wing loading.
  • Wingspan is small and hence does not require folding.
  • Available area for external storage is large enough.
  • It is easy ,simple and relatively inexpensive to manufacture.
  • The addition of canards to the aircraft increases the overall lift,hence enabling the aircraft to perform extreme maneuvers and at the same time improving the low speed handling and lowering the landing speed


Couple that with relaxed static stability and you have a plane that is probably the most suitable plane for emerging victorious in dog fights.

Awesome. Simply awesome. .......
 

pmaitra

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I believe that g (Not G) is a measure of change in velocity. It comes from 2 components. 1) Change in speed (If linear and 2) Change in direction. If the change in direction is low at high speed than also g pulled will be high. To perform high g at low speed, you need to change direction a lot. so it is not very advisable to say gs pulled at so and so speed. my two cent.
Change in velocity in a given time would be acceleration, and when divided by 10 m/s^2, gives us the g value, where g is acceleration due to gravity. This affects the force experienced by the pilot.

When making a turn, centrifugal force acts on the plane. This also affects the force experienced by the pilot.

Now, not all pilots weight the same, so, usually, the mass portion (F = ma) from force is not included, and only the acceleration is used, and that acceleration is expressed in terms of acceleration due to gravity.

So, basically, the force experienced by one pilot while on earth would be 1g (x his mass), thus would be pulling 1g, and the same pilot, experiencing an acceleration twice the acceleration due to gravity, would be experiencing 2g.
 

HariPrasad-1

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http://tarmak007.blogspot.in/

A vertical loop in 16 seconds(8-55 seconds),

A horizontal loop in 20-22 seconds, plus a negative G turn at 8-26 seconds

Some fantastic maneuvers

1) Take off Just 10 secont 5.31 to 5.41 second
2) Vertical climb 10 second at 6 min.
3) another vertical climb like rocket for 20 second 6.45 to 7.05 second
4) Negative g pull 8.24 second
5) Vertical loop 17 second at 8.55 second
6) Double spin 11.17 to 11.19 second
7) One suddern change in direction from + g to -g direction at 11.23 second
 

HariPrasad-1

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Change in velocity in a given time would be acceleration, and when divided by 10 m/s^2, gives us the g value, where g is acceleration due to gravity. This affects the force experienced by the pilot.

When making a turn, centrifugal force acts on the plane. This also affects the force experienced by the pilot.

Now, not all pilots weight the same, so, usually, the mass portion (F = ma) from force is not included, and only the acceleration is used, and that acceleration is expressed in terms of acceleration due to gravity.

So, basically, the force experienced by one pilot while on earth would be 1g (x his mass), thus would be pulling 1g, and the same pilot, experiencing an acceleration twice the acceleration due to gravity, would be experiencing 2g.
Velocity = displacement / time
Acceleration= change in velocity i.e velocity/ time
acceleration when applied on mass becomes force i.e m*a
g is a measure of acceleration due to gravity which is 9.8m/second ^2
so simply when 8 g is pulled than it means that change in velocity is 9.8*8m/sec^2 which is around 80m/sec^2.

In other word we may say that if change in velocity is 80m/second ^2 than it can be said that 8 g are pulled.

It may happen in 2 ways

1) plane is flying straight . it increases its speed by 80m/sec than it can be said to have pulled 8 g
2) if it change the direction than also velocity is changed though linear velocity is same.
a) If it changes direction at high speed with a low change in angle some g is pulled.
b) to pull same g at low speed, you need to turn at high degree.
 

Senyor Sandeep

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India should equip Afghanistan with upto 100 Tejas Mk 1 and ask them to test JF 17 in a dog fight with Pakis. Let us see how many mosquitoes are shot down by a hand full of Tejas.
 

Nuvneet Kundu

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India should equip Afghanistan with upto 100 Tejas Mk 1 and ask them to test JF 17 in a dog fight with Pakis. Let us see how many mosquitoes are shot down by a hand full of Tejas.
We are having a hard time getting our own airforce to induct 100 Tejas fighters, not to mention HAL will have a tough time building so many. We are building at a maximum rate of 3 planes per year. Parrikar has said that he will double the rate. So that's still 30 planes in 5 years.

@HariPrasad-1 How many Tejas (total Mk1 + Mk2) has India ordered for itself, sir?
 

Kharavela

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Do you know that all the 3 pilots who have gone there to showcase Tejas, are from Navy, not a single airforce guy. Isn't that shameful?
Small Correction:
From IN — Cmde. Jaideep Maolankar, presently head of the National Flight Testing Centre, Bangalore, and the service’s chief test pilot, Captain Shivnath Dahiya,
From IAF - Group Captain Madhav Rangachari.
 

tejas warrior

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We are having a hard time getting our own airforce to induct 100 Tejas fighters, not to mention HAL will have a tough time building so many. We are building at a maximum rate of 3 planes per year. Parrikar has said that he will double the rate. So that's still 30 planes in 5 years.

@HariPrasad-1 How many Tejas (total Mk1 + Mk2) has India ordered for itself, sir?
We will have total 20 Tejas Mk1 & 100 Mk1-A on order as of now.

However am concerned with HAL delivery timelines. They do not match promise.

till March-15: SP1 (Handed over to IAF)
Apr-15 to March-16 : SP2 (Expected to be handedover but Only one LCA is expected to be produced in this 1 year ?)
Apr-16 to March-17 : SP3 - SP?
Apr-17 to March-18 : SP? - SP?
Apr-18 to March-19 : SP? - SP?

Can someone having idea, please update this with source of information.
 

ersakthivel

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I believe that g (Not G) is a measure of change in velocity. It comes from 2 components. 1) Change in speed (If linear and 2) Change in direction. If the change in direction is low at high speed than also g pulled will be high. To perform high g at low speed, you need to change direction a lot. so it is not very advisable to say gs pulled at so and so speed. my two cent.
https://books.google.co.in/books?id=f-vML_ZQWsIC&pg=PA708&lpg=PA708&dq=g+onset+rates+for+fighter+planes&source=bl&ots=Gg4sVQ0-rU&sig=Q70MMj9BmdzQNT5VFZFFqEBpSQU&hl=en&sa=X&ved=0ahUKEwiOxJX6x73KAhXICo4KHXmjAgQQ6AEIQzAJ#v=onepage&q=g onset rates for fighter planes&f=false

http://medind.nic.in/iab/t10/i2/iabt10i2p10.pdf


I was referring to something called g onset rates,

ANd peak Gs pulled to evade a air to air missile mostly tops out at 8Gs and tejas with 8gs is okay for that.--"The mean peak + Gz in most air combat situation was 6.73 G with a range of 5.54 to 8.03 G ."

'The maximum onset rate ranged from 1 to 4.7 G/s with a mean of 2.54 G/s. The average maximum offset rate was 2.2 G/s with a range of 1 to 3.96 G/s. This is comparable with the maximum onset rates of other ASFs of IAF. Previous studies [5, 6] have documented a maximum onset rate of up to 3.83 G/s for Mig-29 and 5.51 G/s for Mirage 2000 aircraft. Thus the aircrew of ASFs of IAF are exposed to very high rates of onset of acceleration during specific combat missions.'

Analysis of the Gz profile during ACM revealed that the aircraft crossed 6 G in 83% and 7 G in 36% of combat situations. Further it was found that the pilot spent a mean duration of 3.65 sec between 6 G and 7 G, while he spent 2.12 sec above 7 G (Ref Table 3).

Even though the aircraft is capable of pulling high sustained G (7G 15 sec or 8G 10sec) and all it’s pilots have been trained in the IAM centrifuge to hack HSG, such high G load was not observed in this study. This can be explained on the basis of better manoeuvring capabilities and advanced missile launch envelop simulated by the aircraft.


The aerodynamic configuration and TVC capabilities along with a highly effective digital FBW system allows the aircraft to manoeuvre at very low speed, in very less airspace and in a very shorter period of time. This along with an advanced radar and better missile envelope allows the aircraft the ease of achieving the position of advantage, thus explaining the lesser duration of time spent at high Gz levels.
 
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abingdonboy

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We are having a hard time getting our own airforce to induct 100 Tejas fighters, not to mention HAL will have a tough time building so many. We are building at a maximum rate of 3 planes per year. Parrikar has said that he will double the rate. So that's still 30 planes in 5 years.

@HariPrasad-1 How many Tejas (total Mk1 + Mk2) has India ordered for itself, sir?
We will have total 20 Tejas Mk1 & 100 Mk1-A on order as of now.

However am concerned with HAL delivery timelines. They do not match promise.

till March-15: SP1 (Handed over to IAF)
Apr-15 to March-16 : SP2 (Expected to be handedover but Only one LCA is expected to be produced in this 1 year ?)
Apr-16 to March-17 : SP3 - SP?
Apr-17 to March-18 : SP? - SP?
Apr-18 to March-19 : SP? - SP?

Can someone having idea, please update this with source of information.
From HAL and the DM themselves- 2017 owards will see production rates of 16/year. In 2016, we may see 8/year.

The IAF has a confirmed order of 100 Mk.1As, they won't wait almsot 20 years for this order to be completed.
 

Illusive

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Typical Fatooo quam......... at least they are gifted liars :laugh:
 

HariPrasad-1

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We are having a hard time getting our own airforce to induct 100 Tejas fighters, not to mention HAL will have a tough time building so many. We are building at a maximum rate of 3 planes per year. Parrikar has said that he will double the rate. So that's still 30 planes in 5 years.

@HariPrasad-1 How many Tejas (total Mk1 + Mk2) has India ordered for itself, sir?
Tejas Mk 1 is ordered 100+. Earlier there were rumors that some 120 MK2 are ordered but I am not sure how many will be ordered. MK1 shall improve a lot with time. If we can slash 500 kg from MK1+ and carry out the aerodynamic changes, Mk1 in itself shall be a great plane.
 

Nuvneet Kundu

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Tejas Mk 1 is ordered 100+. Earlier there were rumors that some 120 MK2 are ordered but I am not sure how many will be ordered. MK1 shall improve a lot with time. If we can slash 500 kg from MK1+ and carry out the aerodynamic changes, Mk1 in itself shall be a great plane.
Also, the radar, electronic warfare package, missiles, targeting system, everything will keep improving anyway even if the airframe remains the same. We still use MiG 21 modified Bisons and upgraded Mirage 2000 which are still capable of taking on JF17 anyday.
 

sorcerer

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Missed: Tejas fight with Thunder
OUR SPECIAL CORRESPONDENT
New Delhi, Jan. 21: Defence minister Manohar Parrikar today missed, along with aviation-watchers, a possible competition between India's home-built Light Combat Aircraft Tejas and Pakistan's China-built JF-17 Thunder at an airshow in Bahrain.

The Tejas, yet to be commissioned into the Indian Air Force despite three decades of development, is on its first international deployment to an airshow.

"As per my primary report, it is appreciated by other countries who are interested. I also believe that other countries have withdrawn their participation," Parrikar said after reviewing Republic Day parade preparations at the National Cadet Corps camp here this morning. He did not name Pakistan or China.

But defensenews.in, a US-based web portal that reports on global defence industry developments, wrote: "Fearing a major blowout by critics of the lowcost, cheap quality Chinese made Pakistani JF-17 copied from the vintage MiG-21, Pakistan decided to pull out from the Bahrain International Airshow and save itself from humiliation at a global scale."

Defensenews reported that both the LCA Tejas and the JF-17 Thunder were allotted the same exhibition pad (number 15) to park the aircraft in the Sakhir Air Base. The aircraft would have competed with their flight performance before an international audience.

http://www.telegraphindia.com/1160122/jsp/nation/story_65245.jsp
 

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