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Pentagon grounds F-35 fleet after runway fire

Dude, come back. I was just busting balls a little. That's what I do here. I LOVE Indians. Really. Although, what's up with the Russian flag ? :chilli:
My father works in Indian consulate in Moscow. Spent Some time there Now back India:-)
 
With a plethora of problems besetting the project and the exorbitant cost it does seem to be a white elephant. What has been achieved from when the first flight took off in 2006? Its been 8 long years and they can't even get the simple Auxiliary air inlet (AAI) doors' hinges to operate till date? WTF?

Not as if Lockheed Martin is a new kid on the block. They've been manufacturing planes since the Wright Brothers took off! But it's bizarre how and why these simple glitches cannot be resolved!
The Lightweight Fighter program was announced in 1971. The first F-16 was developed as a YF-16 prototype back in 1972. The first YF-16 was brought out on December 13, 1973 to make its first test flight at Fort Worth and was air freighted by C-5A to Edwards AFB on January 8, 1974. It made it’s first official flight on February 2, 1974. On January 1975 the Secretary of the U.S. Air Force announced that the F-16 had been selected for full-scale engineering development. The first developed F-16A made its first flight on August 7, 1978, and the new F-16s were delivered to the Air Force ten days later. The first F-16 to enter service was delivered the USAF’s 388th Tactical Fighter Wing at Hill AFB, Utah, on January 1979.
 
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Note that the navy went on with the USAF rejected YF-17 to develop the F18

The Lightweight Fighter program was announced in 1971. The YF-17 prototype was rolled out at Hawthorne on 4 April 1974; its first flight came on 9 June 1974. On 2 May 1975 the Navy announced its selection of the YF-17. Since the LWF did not share the design requirements of the VFAX, the Navy asked McDonnell Douglas and Northrop to develop a new aircraft from the design and principles of the YF-17. On 1 March 1977 Secretary of the Navy W. Graham Claytor announced that the F-18 would be named "Hornet". McDonnell Douglas rolled out the first F/A-18A on 13 September 1978. The first production F/A-18A flew on 12 April 1980. The Hornet entered operational service with USMC squadron VMFA-214 on 7 January 1983, and with Navy squadron VFA-25 in March 1983
 
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How it Works: F-35 High Angle of Attack Testing

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For every student who doesn’t care much for Geometry, there’s a fighter pilot who ‘gets’ its importance. Angles and equations determine speed and position in modern air combat. They become the difference between the ‘quick’ and the ‘dead’ once the fight is engaged. The 5th Generation tactical fighter aircraft men and women will operate in the coming decades must be able to handle the toughest flight regimes for mission success and survival.

Flying at high angles of attack (AoA), or “High Alpha,” a modern fighter aircraft gains enhanced nose-pointing capability, which allows the pilot to track and acquire enemy aircraft in aerial combat. The ability to accurately and rapidly point their aircraft’s nose is key to outmaneuvering their enemy, while locking on to them with their radar or heat-seeking missiles to take the decisive shot, most likely at a beyond-visual range.


‘Angle of Attack’ is the angle between an aircraft wing’s chord line, or the imaginary straight line joining the wing’s leading and trailing edges, and the aircraft’s flight path. It is not to be confused with the relation of the aircraft to the Earth as this is called the attitude, which is seldom, if ever, the same as the angle of attack. When the angle is small, the aircraft is said to be at a low angle of attack. When the angle is large, the aircraft is said to be at a high angle of attack. Two variables can change the amount of lift generated by a wing in a given configuration: the speed of air flowing over the airfoil and the angle of attack. Some military aircraft are able to achieve very high angles of attack, but at the cost of drag. This provides the aircraft with great agility, although such maneuvers slow the aircraft down.

The aircraft, when pushed beyond its control, can seem to defy the laws of physics and the principles of flight. The inadvertent loss of control at high angles of attack happens frequently and the aircraft and pilot can be killed due to their failure to recover from out-of-control flight conditions. ‘Departures’ from controlled flight may occur unintentionally in high-G maneuvers (aka “pulling Gs”). The gravitational load bearing on the pilot can cause him or her to pass out from the rapid onset as it drains the blood flow to their brain, removing oxygen. It could happen from a nose-high deceleration to zero airspeed in trying to gain the geometric advantage over their enemy in combat maneuvering. Or a steep spiral may be mistaken to be a spin, causing the recovery flight control surfaces to be misapplied. Whatever the circumstances, departures from controlled flight all too often end in catastrophe. For this reason, pilots must be familiar with every facet of high angle of attack flying and their aircraft must be checked out to the limits of its endurance.

The F-35’s high AoA testing pushes the aircraft beyond both the positive and negative maximum command limits, including intentionally putting the aircraft out of control in several configurations. This includes initially flying in the stealthy ‘clean’ wing configuration, followed by testing with external air-to-air pylons and missiles, and then with open weapon bay doors, all creating additional drag on the aircraft.

The F-35’s high angle of attack testing began in late October 2012, with the aircraft pushing to its production AoA limit of 50 degrees nose high. Test pilots take the aircraft beyond this limit to evaluate its characteristics in recovering from out-of-control flight conditions.

“High AoA testing produces some of the most challenging environments for the engine because the intake gets bad air,” explained David Nelson, lead F-35 test pilot for Lockheed Martin at the U.S. Air Force Flight Test Center at Edwards AFB, California. “The bad air creates a potential for producing a flameout, which is basically an engine shutdown. For that reason, air start testing preceded high AoA testing.”

For all testing, recovery from ‘out of control’ flight has been 100 percent successful without the use of the spin recovery chute, which was installed to maximize safety.
The F-35’s high AoA testing pushes the aircraft beyond both the positive and negative maximum command limits, including intentionally putting the aircraft out of control in several configurations. This includes initially flying in the stealthy ‘clean’ wing configuration, followed by testing with external air-to-air pylons and missiles, and then with open weapon bay doors, all creating additional drag on the aircraft.

The F-35’s high angle of attack testing began in late October 2012, with the aircraft pushing to its production AoA limit of 50 degrees nose high. Test pilots take the aircraft beyond this limit to evaluate its characteristics in recovering from out-of-control flight conditions.

“High AoA testing produces some of the most challenging environments for the engine because the intake gets bad air,” explained David Nelson, lead F-35 test pilot for Lockheed Martin at the U.S. Air Force Flight Test Center at Edwards AFB, California. “The bad air creates a potential for producing a flameout, which is basically an engine shutdown. For that reason, air start testing preceded high AoA testing.”

For all testing, recovery from ‘out of control’ flight has been 100 percent successful without the use of the spin recovery chute, which was installed to maximize safety.
Source:Lockheed Martin Official
 
Note that the navy went on with the USAF rejected YF-17 to develop the F18

The Lightweight Fighter program was announced in 1971. The YF-17 prototype was rolled out at Hawthorne on 4 April 1974; its first flight came on 9 June 1974. On 2 May 1975 the Navy announced its selection of the YF-17. Since the LWF did not share the design requirements of the VFAX, the Navy asked McDonnell Douglas and Northrop to develop a new aircraft from the design and principles of the YF-17. On 1 March 1977 Secretary of the Navy W. Graham Claytor announced that the F-18 would be named "Hornet". McDonnell Douglas rolled out the first F/A-18A on 13 September 1978. The first production F/A-18A flew on 12 April 1980. The Hornet entered operational service with USMC squadron VMFA-214 on 7 January 1983, and with Navy squadron VFA-25 in March 1983
A pretty interesting documentary.

 
How I would have loved to have seen Viggens all over the place ...
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LONDON — Inspectors now believe they know the cause of the fire that damaged an F-35A the morning of June 23, but remain unclear on why the incident occurred.

The fire was caused by “excessive” rubbing of fan blades inside the F135 engine that powers the plane, Frank Kendall, the Pentagon’s head of acquisitions, told reporters today in London. The news was reported by multiple outlets, including Reuters.

However, the bigger question remains about whether the incident was a one-off situation or whether it is the result of a previously unknown fleet-wide defect. Sources indicated to Defense News it is likely not a major flaw across all the planes, but investigators continue to work the issue.

Kendall is expected to give more details Monday during a public event at the Farnborough International Airshow.

The fire , which heavily damaged the F-35A model known as AF-27, eventually led to the grounding of the entire F-35 fleet on July 3. That in turn caused the jet to miss its much-ballyhooed international debut at the Royal International Air Tattoo last week.

As the planes remain grounded, a follow-up appearance at the Farnborough International Airshow is also now in doubt, with organizers already ruling it out for Monday.

This is the second recent fan-related incident for F135 engine, designed by Pratt & Whitney. However, the last incident occurred in a different part of the engine, making it unlikely the two are related.

Bennett Crosswell, the head of Pratt’s military engine group, defended his company’s work on the platform Sunday.

“This is a challenging time for us as we go through this investigation, but overall when you look at the engine and how it’s done, mission readiness is over 98 percent in flight test, and high-nineties for operational use,” Crosswell said. “The engine is delivering, and we have to continue to do that going forward.”

“We’re focused on all our programs, but certainly the f-35 program is the largest program going forward. It’s still in development, in production and in sustainment. Being focused on all three phases and continuing to deliver for our customer, that’s really an important focus for us.”
 

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