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STOVL JSF Jumps Closer to Flight Test

Our boy Steve Trimble posted a piece this morning on a series of hover pit tests conducted by Lockheed Martin with it’s F-35B prototype — they’re calling it the BF-1.

Hover pit tests completed two days ago moved the first short-takeoff-and-vertical-landing (STOVL) variant of the Lockheed Martin F-35 within days or weeks of its first flight.

A Lockheed spokesman confirms the propulsion system for the STOVL demonstrator named BF-1 completed a series of conversions from conventional mode to vertical landing mode.

The tests were conducted at Lockheeds hover pit, where the aircraft is tethered to the ground on top of a steel grate. The pit allows Lockheeds engineers to measure vertical thrust generated by the engine.

The hover pit is the last major stop before the first flight event for BF-1, which has been scheduled for late May or early June.

Despite the need to complete hover pit tests before first flight, the lift-fan that helps power the aircraft during STOVL mode will not be engaged in a flight test for several more months. BF-1 will fly in conventional mode throughout the first flight.

This is pretty exciting because to most observers, this is the most endangered model of the F-35 (though some could argue each has its own equal level of program risk based largely on available funds in each of the services).

But in terms of technical risk, the STOVL JSF clearly has a lot to prove. The lift fan concept is an intriguing one, and if it works, could prove far less risky for the kinds of expeditionary operations its “B” model customers intend for it.

Getting the aircraft airborne has wider implications for Lockheed. The US Department of Defense has linked the release of production funding for the first batch of six F-35B low rate initial production (LRIP) aircraft to completing the first flight event.

In addition, BF-1 is the first weight-optimized airframe produced after Lockheed re-designed all three variants in 2005 to reduce or offset weight by as much as 2,268kg (5,000lbs).

The F-35B, on order by the US Marine Corps, the UK Royal Air Force and UK Royal Navy, is the first western aircraft to combine supersonic speed with the STOVL capability.

I’ve had the good fortune to have observed this program from its initial stages back when it was Boeing vs Lockheed in the concept demonstrator phase. I saw the LM version in the hover pits at its Skunkworks facility out in Cali back then and have been eagerly awaiting the real thing for a long time.

The Marines are gonna be psyched when this thing gets into production since clearly the AV-8B is more than ready for retirement.
(Gouge: NC)
– Christian

{ 13 comments… read them below or add one }

bro May 29, 2008 at 12:25 am

“first western aircraft”? Is there a non-western aircraft that can do that?

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Mike Schofield May 29, 2008 at 7:14 am

Yes, there has:
Dassault Mirage III - France - Mach 1- 1960
EWR VJ 101C - Mach 1 - Germany/Based on F-104 starfighter- mid 1960′s
YAK-141 or (YAK-41)- Just at the fall of the USSR

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Ian M. Guajardo May 29, 2008 at 2:47 pm

The DOD and Lockheed-Martin needs to push forward in the edevelopment and introduction of the F-35B for the US Marine Corps and Royal Navy. I am looking forward to see the first F-35Bs flying off the USS Wasp! Who knows as a result of the successful development of the F-35B maybe other nations such as Spain, India, and Thailand may purchase these aircraft to replace their current AV-8A first generation Harriers and Sea Harriers?
The Marine Corps ground pounders are going to really apprciate the capabilities of this unique aircraft when it is deployed with the FMF.

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DONALD HEINKE, Sr. May 29, 2008 at 6:54 pm

SEEMS LIKE THE U.S. IS ALMOST ALWAYS BEHIND IN THE SPECIALTY AIRCRAFT. GOOD IDEA ON GIVING THE THRUST VECTORING IN OTHER MODELS.
THE AV-8B’S MAY BE OLD, BUT THE’RE STILL GETTING THE JOB DONE. THE’RE LIKE THE CH-46′S, THEY NEED A LITTLE TLC, BUT WHEN THE’RE NEEDED, THEY DO A HELL OF A JOB. THE AIR FORCE NEEDS NEW A-10′S, NOT CONFIGURED F-35A’S. THE KISS PRINCIPLE WORKS EVERY TIME.
SEMPER FI

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randymar75 May 29, 2008 at 9:14 pm

Yes, there has:
Dassault Mirage III - France - Mach 1- 1960
EWR VJ 101C - Mach 1 - Germany/Based on F-104 starfighter- mid 1960′s
YAK-141 or (YAK-41)- Just at the fall of the USSR
Posted by: Mike Schofield at May 29, 2008 07:14 AM
What are you referring to?
If it is the FACT that this is the first mach 1 VSTOL aircraft. Than you need to check facts. No aircraft has ever transitioned in flight from a vertical take off, to level flight, broken the sound barrier, and landed vertically. This was accomplished by the F-35 in Dec of 06.
This is an aircraft I do not want because of cost, as a Marine all I want is something that will get down and dirty, like the A-10.
Didn’t McNamarra try this with the F-4? Although a good airframe in the end, I know a lot of aviators thought it was a turkey that flew like a brick.
We have 3 services that fly, with different needs. This will never and can never be accomplished with one aircraft.
besides I don’t want Navy or Air Force junk.
Semper Fi

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NTG August 16, 2010 at 9:21 am

"This is an aircraft I do not want because of cost."
"I don't want Navy or Air Force junk"

Now you know how the rest of us feel about the Osprey.

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TCL_CAP May 30, 2008 at 8:18 am

Though the Yak jump jet actually saw service on the old “Kiev” and “Moskva” class ships, it seems that there has never been a really successful design (from east or west) which incorporated a seperate lift fan. The thrust vectoring design of the Harrier is lighter and (in my personal opinion) better. Yes I have heard about the center of the Harrier body being an IR missile magnet, but it is an amazing design. I wish the F-35 could have used that principle, along with improved IR countermeasures.
I just hope that technology can overcome the weight penalties of the lift fan assembly. It’s like carrying around a Cessna Caravan engine (dead weight) right behind the pilot that you only use to hover. For the Marine that has to fly it, thats fuel left on the ground (one of the most useless things in aviation).
I’m an Air Force guy and I think this plane CAN work out great for AF and even for the Navy, with it’s sea legs of course (e.g. HEAVY landing gear). But, I don’t see the Marines loving it. They will make it work (they always do), but it will not be ideal.
I have to agree with an earlier post that an A-10 derivative needs to come out, but I don’t expect it. The CAS mission can now be flown by B-52′s with JDAMS or even a UAV, so this entire discussion may be moot. With the impending political situation, the F-35 may never enter active service.
Just my thoughts.

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Rhyno327/lrsd May 31, 2008 at 10:28 am

This is an aircraft the Marine Corps needs. Its avionics are superior to the Harrier, and it is more versatile. As for the A-10, there will always be a spot for it. Just hearing the growl of that 20mm cannon will uplift ur spirits, while the enemy runs like hell. Remember, the conflicts we are engaged in now will repeat it self, somewhere, someday. The ability to fly low and slow, and absorb punishment is its greatest asset. Using them at nite, with the upgrades its gotten, make it more deadly.

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ADyer May 31, 2008 at 2:21 pm

“The thrust vectoring design of the Harrier is lighter and (in my personal opinion) better. Yes I have heard about the center of the Harrier body being an IR missile magnet, but it is an amazing design. I wish the F-35 could have used that principle, along with improved IR countermeasures.
I just hope that technology can overcome the weight penalties of the lift fan assembly. It’s like carrying around a Cessna Caravan engine (dead weight) right behind the pilot that you only use to hover. For the Marine that has to fly it, thats fuel left on the ground (one of the most useless things in aviation).”
While the lift fan in the forward fuselage is dead weight and wasted space in forward flight, that is a trade off that must be made to achieve STOVL capability. It is a trade off also made by the harrier. The special vectoring nozzles and the associated equipment weigh a great deal more than a conventional jet pipe does, and the whole setup, Pegasus engine, nozzles, and reaction control pipes to the wingtips, uses far more space and weight than a conventional engine does.
Furthermore, the JSF concept is not so different from the harrier. The forward nozzles on the harrier draw air from behind the enlarged low pressure compressor, well before the combustion stage. The F-35B just has that “part” of the engine as a separate lift device. In both cases you have unburned air being accelerated downward by a fan powered by the aircraft’s power plant.
Barring some massive leap forward in technology (think repulsor lifts from Star Wars) STOVL aircraft will always have to trade something in for the ability to take off and land vertically. In the case of the F-35B this is fuel capacity, giving it shorter legs than the A and C models. This disadvantage is mitigated or negated by the fact that the lack of a requirement for a long landing strip allows the F-35B to be based at locations close to the battle that no other jet can manage, be it forward operating bases or ships too small to handle standard carrier aircraft.

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Bob May 31, 2008 at 4:47 pm

Re: VSTOL aircraft, the Russians had one in the 1970′s/80′s NATO name Forger. Not a great plane.I also love the A-10, but it has a 30mm, not 20mm cannon.

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Ejectionseatfixe May 31, 2008 at 8:34 pm

I believe all of this has already been thought through way before it took its first flight. Unlike the Harrier, the F35 has had newer technology on its side from the beginning of assembly since now, lightweight airframe technology came about, and theres considerable thrust to weight advantage wayyyy over the AV8B. Of course, there will be quite a bit more fuel consumption while in vertical flight, but nowhere near what it was when the AV8B was engineered. I think the Marines will be very pleased with what they are getting.
Oh, and the Marines have been flying Navy hand-me downs since the 60′s, so you might not want, youve got it already…lol

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jf May 31, 2008 at 11:04 pm

randymar75 i dont understand why you’re calling USAF and USN planes “junk” when in the same comment said you like the US AIR FORCE A-10. idk i’m just a lil baffled and offended that you’d call USN and AF planes junk…

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randymar75 June 1, 2008 at 6:57 am

randymar75 i dont understand why you’re calling USAF and USN planes “junk” when in the same comment said you like the US AIR FORCE A-10. idk i’m just a lil baffled and offended that you’d call USN and AF planes junk…
Posted by: jf at May 31, 2008 11:04 PM
This is easy to answer. First the Air Farce didn’t want the A-10. They were ordered to receive it. It wasn’t the pretty airframe the USAF was used too. Second when they wanted to retire it back in 90, The Marines asked the SecNav if we could take them over. That is when the Air Farce said “No, No we’ll keep them.” Guess they finally felt needed! This is one of the most successful CAS aircraft in history and at every turn the Air Farce wants to get rid of it. Just because they want their new toys. Maybe that’s why Marines have had the second motto of “We have done so much, with so little, for so long. We are now qualified to do everything, with nothing.” The USAF should be “we spend all this money and the Navy still has more planes.” As far as the Navy goes, well that is my interservice rivalry. Yes Marines are department of the Navy, the Men’s Department.

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