BF-02 Supersonic

Unread postPosted: 11 Jun 2010, 16:29
by neptune
rayraley: RT @LockheedMartin: Another #F-35 milestone: First STOVL variant flew supersonic (Mach 1.05) yesterday at PAX River NAS #LM

:D

RE: BF-01 Supersonic

Unread postPosted: 11 Jun 2010, 17:10
by dragorv
Zoom zoom zoom... :D

Unread postPosted: 11 Jun 2010, 17:32
by svenphantom
The question I am having is, Did it use AB or was it a mil power?

Unread postPosted: 11 Jun 2010, 23:06
by That_Engine_Guy
More like BOOM, not zoom....

svenphantom wrote:The question I am having is, Did it use AB or was it a mil power?

Why? A clean Viper w/PW-229 or GE-129 can break MACH in MIL. Nothing impressive there.

One needs to remember the F-35/F135 is NOT designed as a 'super-cruise' platform. The F-22/F119 on the other hand can 'super-cruise' near the vMAX of the F-35...

TEG

Unread postPosted: 12 Jun 2010, 00:11
by Tinito_16
Any pics? I'd love to see that bad girl with the condensation cloud around it :crazypilot:

Unread postPosted: 17 Jun 2010, 03:45
by g3143
I would kick it into full afterburner and see what it can really do. lets see if it go mach 1.6 for its max or it can go much faster then that.

Unread postPosted: 17 Jun 2010, 11:58
by wrightwing
g3143 wrote:I would kick it into full afterburner and see what it can really do. lets see if it go mach 1.6 for its max or it can go much faster then that.


I'm sure once the envelope opens up, they'll take it up to see what it'll do. I'm guessing there are other test points that have much higher priority though.

Unread postPosted: 23 Jun 2010, 18:47
by Asif

F-35B BF-2 flew faster than the speed of sound for the first time on June 10th, 2010. The supersonic milestone was achieved on the 30th flight. USMC pilot Lt. Col. Matt Kelly climbed to 30,000 feet and accelerated to Mach 1.07 in the off-shore supersonic test track near NAS Patuxent River, Maryland. [USN photo by Liz Goette]

Unread postPosted: 27 Jun 2010, 00:43
by popcorn
Anyone know what the problem is with the liftfan driveshaft necessitating a redesign? How big a problem is it and waht impact will it have on the test schedule? The USMC expects to go IOC December 2012.

Unread postPosted: 27 Jun 2010, 00:52
by seruriermarshal
I hear they have replace liftfan driveshaft .

Unread postPosted: 27 Jun 2010, 01:20
by LMAggie
popcorn wrote:Anyone know what the problem is with the liftfan driveshaft necessitating a redesign? How big a problem is it and waht impact will it have on the test schedule? The USMC expects to go IOC December 2012.

Got a source?

Unread postPosted: 27 Jun 2010, 01:27
by popcorn
I don't have a subscription so can't provide any details, sorry.

http://defense.iwpnewsstand.com/websear ... 10_june23d)%3E

Unread postPosted: 27 Jun 2010, 01:35
by spazsinbad
popcorn, I don't have a subscription either however someone has posted this tidbit:

DOD, Lockheed Agree On Redesign Of JSF Drive Shaft Critical To Marine Corps Plans

http://defense.iwpnewsstand.com/insider ... e=06242010

"The Defense Department and Lockheed Martin have agreed to a new design of a component critical to the Marine Corps’ variant of the Joint Strike Fighter — a drive shaft connecting the main engine to the vertical lift fan that will be incorporated into the F-35B if test flights in the coming months validate recent durability concerns.

On June 10, plans for a new drive shaft passed muster with government and contractor officials conducting a critical design review. They gave the green light to proceed with the production of the new component, which if necessary may be incorporated into Joint Strike Fighter aircraft built under the next production batch -- low rate initial production lot 4, according to a Lockheed official.

“Delivery of the first redesigned drive shaft for testing is scheduled for late 2010,” John Kent, a spokesman for Lockheed Martin, said in a written response to questions from InsideDefense.com.”

To me IF is a BIG word. :D Here is the link again:

http://defense.iwpnewsstand.com/insider ... e=06242010

Unread postPosted: 27 Jun 2010, 02:45
by VarkVet
spazsinbad wrote:To me IF is a BIG word.


Yaaa! … Either redesign it, or time change it at more frequent intervals if issues are surfacing!

That is one component you don’t want to try and save money on … I’m sure it’s one catastrophic drive shaft failure per aircraft it lets go in flight!

Unread postPosted: 27 Jun 2010, 03:50
by spazsinbad
I have read that the drive shaft in STOVL flight is closely monitored by the automatic ejection system. IF the drive shaft fails in the STOVL condition the pilot is automatically ejected - no matter what. Otherwise if close to the ground he has no time to reacte, think or whatever. He has to go, get out and walk (swim/paddle).

Unread postPosted: 27 Jun 2010, 04:29
by VarkVet
spazsinbad wrote:I have read that the drive shaft in STOVL flight is closely monitored by the automatic ejection system.


Not smart in my book as sensors are difficult to design and prone to failure!

Wow … I distinctively remember watching the video of a pilotless Harrier on BBC news sometimes in the 90’s. An American C-130 took the footage. I can’t find any video on the net!

A HUGE Bristol Channel rescue operation involving hundreds of coastguards,lifeboatmen and aircrew was underway today after a pilot ejected leaving his RAF jet to fly on for an hour before Crashing into the sea. Two RAF Nimrod maritime patrol aircraft, four rescue helicopter`s, three lifeboats Including the Mumbles boat and dozens of land-based Coastguard teams were involved In the search, which is continuing. The RAF Harrier jump jet had taken off from a Dunsfold airstrip, near Guillord, and the last voice contact with the British Aerospace civilian test pilot was when the aircraft was 15 miles north of Southampton. The Harrier crashed 240 mile`s out at sea and, given Its terminal speed of 400 knots, could have been flying pilotless for up to an hour. The drama began at 6 p.m. when a U.S. Military transport plane's crew spotted the GR5 Harrier south of Ireland noticed the canopy had gone the pilot was missing. The pilot, who had not named, had been undertaking. predelivery test fight in the British Aerospace-bull Harrier. A B.A. spokesman said they were extremely concerned for his safety.

Source: http://www.coastguard.ukf.net/jetair.html

Unread postPosted: 27 Jun 2010, 04:46
by spazsinbad
VarkVet, smart or not that is the system. Also there is a pilot controlled sensitivity switch for smart ejection but what it does exactly I don't know yet. Vaguely I recall reading that a guess was that it could be more sensitive for less aware newbie pilots whilst experienced pilots could dial down sensitivity to allow possible corrective action before ejecting.

BTW there have been any number of 'not appropriate or appropriate in the circumstances' ejections over the years - rightly or wrongly - where the aircraft without aircrew. has continued on to crash at some future point. Has happened a few times within view of flight deck of many USN aircraft carriers for example.
____________

One example of the scuttlebutt about the 'auto eject' feature:

http://www.airwarriors.com/forum/showth ... 14&page=34

"A group of Harrier guys were picking the brains of a group of JSF engineers are few years ago when they were socializing the lift fan design. What happens when the clutch fails, we asked? They assured us that it was designed to be fail-proof. Since complexity tends to be the natural enemy of reliability we again asked - so, really, what happens when it fails? They again insisted it couldn't fail. We just gave them the stink eye for a minute and then one of them piped up with - "Well there is an auto-eject mode on the seat that is only triggered in the event of lift fan or clutch failure". Seems that if the lift fan were to fail or the clutch were to give out, the subsequent pitch rate would be impossible to beat with a manual ejection. So in that scenario, HAL takes care of business for you. At least that was the selling point, no idea if that design feature is still incorporated."

Unread postPosted: 27 Jun 2010, 05:44
by VarkVet
spazsinbad wrote:VarkVet, smart or not that is the system. Also there is a pilot controlled sensitivity switch for smart ejection but what it does exactly I don't know yet. Vaguely I recall reading that a guess was that it could be more sensitive for less aware newbie pilots whilst experienced pilots could dial down sensitivity.

One example of the scuttlebutt about the 'auto eject' feature:
At least that was the selling point, no idea if that design feature is still incorporated."


Great … this is getting better all the time (if you’re not bullshitting)
I was planning to go to bed early so I could get up early and watch Germany play England in the World Cup!
Now I’m going to have nightmares because I’m thinking if HAL has a “bug” up his a$$, he will be littering the countryside with coherent pilots and smoking holes! Regardless of the sensitivity switch! :doh:

Unread postPosted: 27 Jun 2010, 06:26
by spazsinbad
VarkVet, why would I B/S?
_____________

"Smart ejection seat from Martin-Baker on display

http://www.ejection-history.org.uk/proj ... s/2004.htm

An aircraft ejection seat (pictured) that thinks for itself is on display for the first time at Farnborough 2004. Ejection seat and escape technology manufacturer Martin-Baker is showing its Mk16E for the Lockheed Martin F-35 Joint Strike Fighter at Stand D3, Hall 4.

Currently in an advanced stage of development, the seat will provide an escape system able to eject pilots in the event of problems during short take-offs and vertical landings.

An on-board computer selects the best mode of seat operation by monitoring the aircraft's speed and altitude. This gives the pilot the best chance of survival in emergencies. And where the pilot is unable to react quickly enough to a rapidly developing crisis, an automatic ejection capability kicks in.

Hovering
If retained for production, this automatic system will eject the pilot if the aircraft departs from previously established parameters, during transition from conventional to vertical flight and vice versa, and while hovering.

The seat can be adjusted vertically and tilted to accommodate the size and weight of its occupant and has full life support. Its design also reduces the aircraft's weight and manufacturing costs.

Also on display at the stand are the US16LA seat for the Raytheon T-6A, and the K16K seat for the Korean-built KAI T-50.

by ISABEL LESTO - source: Flight International 19th July 2004"
_______________

http://www.martin-baker.co.uk/products/ ... --JSF.aspx

"SPECIFICATIONS - US16E - JSF
Auto eject system Active on STOVL variant only
&
HOW IT WORKS:
- Seat firing handle pulled/Auto eject initiated (STOVL only) causing seat initiation cartridges to fire"

Unread postPosted: 27 Jun 2010, 06:44
by seruriermarshal
VarkVet wrote:
spazsinbad wrote:To me IF is a BIG word.


Yaaa! … Either redesign it, or time change it at more frequent intervals if issues are surfacing!

That is one component you don’t want to try and save money on … I’m sure it’s one catastrophic drive shaft failure per aircraft it lets go in flight!


Or you talk about F136 ? If F135 failure .

Unread postPosted: 27 Jun 2010, 07:11
by apg77
svenphantom wrote:The question I am having is, Did it use AB or was it a mil power?


I suspect that F-35 need use AB to supersonic.
It's said that F-35A need more than 60s from 0.8M to 1.2M.
use the same time, F-16 can accelerate from 0.8M to 1.6M.
F-35's supersomic performance maybe as bad as F/A-18E/F.

Unread postPosted: 27 Jun 2010, 08:16
by popcorn
spazsinbad wrote:popcorn, I don't have a subscription either however someone has posted this tidbit:

DOD, Lockheed Agree On Redesign Of JSF Drive Shaft Critical To Marine Corps Plans

http://defense.iwpnewsstand.com/insider ... e=06242010

"The Defense Department and Lockheed Martin have agreed to a new design of a component critical to the Marine Corps’ variant of the Joint Strike Fighter — a drive shaft connecting the main engine to the vertical lift fan that will be incorporated into the F-35B if test flights in the coming months validate recent durability concerns.

On June 10, plans for a new drive shaft passed muster with government and contractor officials conducting a critical design review. They gave the green light to proceed with the production of the new component, which if necessary may be incorporated into Joint Strike Fighter aircraft built under the next production batch -- low rate initial production lot 4, according to a Lockheed official.

“Delivery of the first redesigned drive shaft for testing is scheduled for late 2010,” John Kent, a spokesman for Lockheed Martin, said in a written response to questions from InsideDefense.com.”

To me IF is a BIG word. :D Here is the link again:

http://defense.iwpnewsstand.com/insider ... e=06242010


Thanks a lot Spaz, very helpful.

Unread postPosted: 27 Jun 2010, 09:08
by spazsinbad
seruriermarshal said: "Or you talk about F136 ? If F135 failure ." AFAIK the 'drive shaft connecting the main engine to the vertical lift fan' is common to both engines - so engines are not the issue in this instance.

Unread postPosted: 27 Jun 2010, 09:41
by seruriermarshal
spazsinbad wrote:seruriermarshal said: "Or you talk about F136 ? If F135 failure ." AFAIK the 'drive shaft connecting the main engine to the vertical lift fan' is common to both engines - so engines are not the issue in this instance.


I mean just about new drive shaft to old drive shaft .

Unread postPosted: 27 Jun 2010, 15:56
by wrightwing
apg77 wrote:
svenphantom wrote:The question I am having is, Did it use AB or was it a mil power?


I suspect that F-35 need use AB to supersonic.
It's said that F-35A need more than 60s from 0.8M to 1.2M.
use the same time, F-16 can accelerate from 0.8M to 1.6M.
F-35's supersomic performance maybe as bad as F/A-18E/F.


I suspect those numbers are a bit on the conservative side first of all, and the F-35 is capable of supersonic speeds at military power, at sea level. We'll have to wait and see what it can do at 35-45k feet.

Unread postPosted: 27 Jun 2010, 22:16
by butters
In regards to a lift fan failure - You'd better have a quick reaction auto eject system in place when* that happens during hover. With 20K + thrust bellowing out at right angle to the aft fuselage at near-zero airspeed, that thing is gonna go into a somersault before you can say "Gulp!".

As far as the perfomance specs being 'conservative', does anyone remember any recent fighter program where the operational a/c top speed significantly exceeded public projections? Thought not...

BTW, the 'suspicion' that the F-35 will be supersonic on mil power at S/L is more accurately termed a 'fantasy'. Sea level supercruise... :roll:

JL

*Cuz you know its gotta happen when you're pumping the kind of horsepower found in a light frigate thru a lightweight shaft/tranny.

Unread postPosted: 28 Jun 2010, 01:12
by spazsinbad
butters, the buzz is that sensors in engine and elsewhere monitor 'health' of system. When indications of impeding failure exceed a limit then 'auto eject'. Sure an extremely sudden catastrophic failure will not be good; that is the case in many other situations, also with any aircraft (that may or may not have predictive health sensors or other safety systems). You would guess I guess that the extreme situation described by you is the reason why such 'safety systems' exist. Bear in mind if one end fails then it is likely the other end will shut down to help prevent the dire situation described, helping 'auto eject'.

Unread postPosted: 28 Jun 2010, 03:51
by bjr1028
VarkVet wrote:
spazsinbad wrote:I have read that the drive shaft in STOVL flight is closely monitored by the automatic ejection system.


Not smart in my book as sensors are difficult to design and prone to failure!l


So are aircraft with complex propulsion systems.

Unread postPosted: 28 Jun 2010, 05:29
by Prinz_Eugn
VarkVet wrote:
spazsinbad wrote:I have read that the drive shaft in STOVL flight is closely monitored by the automatic ejection system.


Not smart in my book as sensors are difficult to design and prone to failure!l


You know what are also prone to failure? People.

How many pilots have died in functioning airplanes from G-LOC or being plain disoriented? An automated eject system, even though it might not be perfect, has an excellent chance of saving a lot of lives.

Unread postPosted: 28 Jun 2010, 05:46
by Conan
butters wrote:
As far as the perfomance specs being 'conservative', does anyone remember any recent fighter program where the operational a/c top speed significantly exceeded public projections? Thought not...


Do F/A-18F Rhinos hitting M1.84 in high speed trials in India count?

Unread postPosted: 28 Jun 2010, 05:55
by lampshade111
I thought the F-35 was supposed to have better acceleration than the F-16? Honestly I think a Mach 1.2-1.3 speed without AB should have been a requirement.

Unread postPosted: 28 Jun 2010, 06:21
by spazsinbad
Prinz_Eugn said: "You know what are also prone to failure? People. How many pilots have died in functioning airplanes from G-LOC or being plain disoriented? An automated eject system, even though it might not be perfect, has an excellent chance of saving a lot of lives."

http://www.pprune.org/archive/index.php ... 13926.html (scroll down page for JSF/Harrier insights) Here is onesuch+1:

NigelOnDraft "I'm rarely for these "auto" things, but in VSTOL jet, suspect a good idea here. A GR3 was lost at Witt early 90s after an HP blade failure in the hover. The ensuing rapid decay (instant?) of RPM, and the detached blade removing Hyd systems etc. made the "brick" calculation above pretty accurate. The pilot did survive, but very seriously injured, and heroic efforts by fire and medics to extract him. From that date, whenever I approached the hover, I'd remind myself that at the first sign of Eng Failure, I'd have to be "out". Problem was if you tried to make any diagnosis, it would probably be your last thought! On the other hand, a loud noise, or warning etc could well be spurious or unrelated - not helped in the GR7 by all warnings being the same colour (no red v yellow warnings). No RPM or JPT "gauge" either - all digits, so hard to make a "snapshot" assessment. Fortunately never came to it.... So for JSF, if a reliable system detecting a substantial loss of thrust, whilst in the hover regime can be developed, a good thing."
&
BOAC "I remember clearly (2 weeks before my MB tie) the unfortunate young Harrier pilot who had an uncontrollable roll control excursion in the hover at 50'. He ejected quickly but not before the roll angle was such to negate the vertical rise of the seat. The point being NOT that he could have survived staying aboard, but that the a/c attitude MIGHT be wrong for the moment of an 'auto' ejection and it possibly could be improved? In his case, of course, this auto function would not have been relevant since there was no engine problem.

We all tried the same failure in the sim subsequently, and found that the 'older and more experienced' you were, the later one ejected, trying to 'sort it out'. IMHO there is a definite argument for a correctly programmed auto function in the hover."

Unread postPosted: 28 Jun 2010, 14:01
by wrightwing
lampshade111 wrote:I thought the F-35 was supposed to have better acceleration than the F-16? Honestly I think a Mach 1.2-1.3 speed without AB should have been a requirement.


I don't believe that it was a requirement so much as a byproduct.

Unread postPosted: 28 Jun 2010, 15:40
by butters
Conan wrote:
butters wrote:
As far as the perfomance specs being 'conservative', does anyone remember any recent fighter program where the operational a/c top speed significantly exceeded public projections? Thought not...


Do F/A-18F Rhinos hitting M1.84 in high speed trials in India count?


I would say not, considering that it seems to have been a one time event that took place in unusually ideal conditions with an elite crew at the controls of a meticulously tuned demo aircraft. Here's the internal Boeing memo*:

A Boeing-leased U.S. Navy F/A-18F set a new Super Hornet speed record in Bangalore Monday, during the opening day of flight evaluations in India’s highly coveted 126 aircraft Medium Multi-Role Combat Aircraft (MMRCA) competition.

The Super Hornet, flown by Boeing F/A-18 pilot Mike "Sting" Wallace and Weapons Systems Officer U.S. Navy Lt. Cmdr. Michael "Spock" Chenoweth of VFA 122, hit a speed of 1.84 Mach, shattering the previous record of 1.76 Mach.

"Up in the control tower, they were looking (at the radar screens) in disbelief as it was happening," said Bret Marks, the F/A-18 program manager for India. "We were confident that when we got here we’d impress the Indian Air Force with the capabilities of the Super Hornet and setting a new speed record with the first flight set the stage."

Boeing Tech Fellow, Mike Heller, who persuaded the team it was possible, said India provided a rare chance to do a speed run.

"The engines perform best in the coldest air," said Heller. "And the air is coldest at 50,000 feet nearest the equator."

My point expressly concerned operational a/c in normal conditions, not exceptional aircraft in exceptional conditions. The SuperBug record is all about the latter. That's why it's news...

JL

*I got the quote from another site, rather than the primary source, so I can't attest to its accuracy...

Unread postPosted: 28 Jun 2010, 16:11
by SpudmanWP
It should count as this was not a "Streak Eagle" type of speed run. This was an operational F-18 and represented what the Indian's would be getting if they purchased the fighter.

Unread postPosted: 28 Jun 2010, 16:29
by wrightwing
butters wrote:
Conan wrote:
butters wrote:
As far as the perfomance specs being 'conservative', does anyone remember any recent fighter program where the operational a/c top speed significantly exceeded public projections? Thought not...


Do F/A-18F Rhinos hitting M1.84 in high speed trials in India count?


I would say not, considering that it seems to have been a one time event that took place in unusually ideal conditions with an elite crew at the controls of a meticulously tuned demo aircraft. Here's the internal Boeing memo*:

A Boeing-leased U.S. Navy F/A-18F set a new Super Hornet speed record in Bangalore Monday, during the opening day of flight evaluations in India’s highly coveted 126 aircraft Medium Multi-Role Combat Aircraft (MMRCA) competition.

The Super Hornet, flown by Boeing F/A-18 pilot Mike "Sting" Wallace and Weapons Systems Officer U.S. Navy Lt. Cmdr. Michael "Spock" Chenoweth of VFA 122, hit a speed of 1.84 Mach, shattering the previous record of 1.76 Mach.

"Up in the control tower, they were looking (at the radar screens) in disbelief as it was happening," said Bret Marks, the F/A-18 program manager for India. "We were confident that when we got here we’d impress the Indian Air Force with the capabilities of the Super Hornet and setting a new speed record with the first flight set the stage."

Boeing Tech Fellow, Mike Heller, who persuaded the team it was possible, said India provided a rare chance to do a speed run.

"The engines perform best in the coldest air," said Heller. "And the air is coldest at 50,000 feet nearest the equator."

My point expressly concerned operational a/c in normal conditions, not exceptional aircraft in exceptional conditions. The SuperBug record is all about the latter. That's why it's news...

JL

*I got the quote from another site, rather than the primary source, so I can't attest to its accuracy...


It sounds to me that the only special condition was the latitude at which the speed run was conducted. It wasn't a stripped down plane, or one with higher output engines.

Unread postPosted: 28 Jun 2010, 17:20
by butters
I didn't say it was specially modified ala the 'Streak Eagle', I said it was meticulously prepped for a singular event, but have it your way.

I'm sure that the USN operational tacticians will enjoy knowing that the line SuperBugs are M 1.84 birds and will formulate combat doctrine accordingly...

JL

Unread postPosted: 28 Jun 2010, 17:26
by apg77
lampshade111 wrote:I thought the F-35 was supposed to have better acceleration than the F-16? Honestly I think a Mach 1.2-1.3 speed without AB should have been a requirement.

At subsonic field , the test show that F-35A's acceleration and climbing is better than F-16.
But no news about supersonic and sound barrier field.

Any news about X-35's supersonic performance?
it has similar aerodynamics, with light weight and less powerful engine, so its data may be quite similar to F-35.

Unread postPosted: 30 Jun 2010, 15:16
by wrightwing
butters wrote:I didn't say it was specially modified ala the 'Streak Eagle', I said it was meticulously prepped for a singular event, but have it your way.

I'm sure that the USN operational tacticians will enjoy knowing that the line SuperBugs are M 1.84 birds and will formulate combat doctrine accordingly...

JL


Define meticulously prepped. It was a stock Super Hornet, without any modifications. That's the takeaway.

Unread postPosted: 30 Jun 2010, 15:51
by SpudmanWP
apg77 wrote:
lampshade111 wrote:I thought the F-35 was supposed to have better acceleration than the F-16? Honestly I think a Mach 1.2-1.3 speed without AB should have been a requirement.


at subsonic field , the test show that F-35A's acceleration and climbing is better than F-16.
but no news about supersonic and sound barrier field.


Actually, the F-35's performance has always been stated in the "transonic" region. That is mach .8 - 1.2

Image

Unread postPosted: 30 Jun 2010, 15:58
by apg77
SpudmanWP wrote:
Actually, the F-35's performance has always been stated in the "transonic" region. That is mach .8 - 1.2

Image


from the pic, the F-35 transonic acceleration is much worse than F-16 and F/A-18C?

Unread postPosted: 30 Jun 2010, 16:22
by mil_hobbyist
apg77 wrote:from the pic, the F-35 transonic acceleration is much worse than F-16 and F/A-18C?


If you think about the relative performance of the three F-35 variants, I think it's clear that in the bottom chart, less is more.

Unread postPosted: 30 Jun 2010, 16:28
by SpudmanWP
It represents the time to go from speed X to speed Y, hence "less is more".

This is why the CTOL version has a smaller number than the CV, it accelerates better than the CV and STOVL.

Unread postPosted: 30 Jun 2010, 16:39
by wrightwing
apg77 wrote:
SpudmanWP wrote:
Actually, the F-35's performance has always been stated in the "transonic" region. That is mach .8 - 1.2

Image


from the pic, the F-35 transonic acceleration is much worse than F-16 and F/A-18C?


You're reading the bottom chart incorrectly. The shorter lines represent quicker acceleration.

Unread postPosted: 30 Jun 2010, 16:41
by SnakeHandler
I don't know why everyone is so obsessed with top speed and supercruise. Time spent above .95 should be minimized and above 1.2(ish) is wasted on me anyway. For my money, I want a jet that can get fast quickly and efficiently but it doesn't need to stay there. Just one reporter's opinion.

Unread postPosted: 30 Jun 2010, 16:51
by SpudmanWP
Somewhere I saw a quote from a USAF general that says something like "The number of times the F-15 went above Mach 1.2 in combat can be counted on one hand".

Subsonic/transonic performance is much more important than supersonic most of the time.

Unread postPosted: 01 Jul 2010, 03:09
by apg77
SpudmanWP wrote:It represents the time to go from speed X to speed Y, hence "less is more".

This is why the CTOL version has a smaller number than the CV, it accelerates better than the CV and STOVL.


I am doubt about it.

so far as I know, the are some data as below:
1- F-16C's transonic acceleration is much better than F/A-18C.
2- F-35A's transonic acceleration is similar with F-35B. they have similar aerodynamics and engines, but F-35B is heavier.
3--F-35C 's transonic acceleration is worse with F-35A/B, for its bigger wings.

so in the chart ,
less is worse.
F-16C is not compared with F/A-18C.
F-35A is only compared with F-16C,
F-35B/C are only with F/A-18C.

SnakeHandler wrote:I don't know why everyone is so obsessed with top speed and supercruise. Time spent above .95 should be minimized and above 1.2(ish) is wasted on me anyway. For my money, I want a jet that can get fast quickly and efficiently but it doesn't need to stay there. Just one reporter's opinion.


I agree with you, high speed is not very important.

SpudmanWP wrote:Somewhere I saw a quote from a USAF general that says something like "The number of times the F-15 went above Mach 1.2 in combat can be counted on one hand".

Subsonic/transonic performance is much more important than supersonic most of the time.


transonic is important , but it seems that F-35's transonic performance is not as good as F-16.

Unread postPosted: 01 Jul 2010, 03:37
by munny
I'm a bit dubious about that acceleration graph too. Less might actually be LESS acceleration. The F-35C is a heavier aircraft and probably higher drag than the B.

It would mean the F-18C has a much lower acceleration than the F-16C which might be true due to its TWR being lower and larger, draggier airframe.

Unread postPosted: 01 Jul 2010, 04:18
by spazsinbad
http://www.livescience.com/technology/0 ... -jets.html
via:
http://www.f-16.net/f-16_forum_viewtopic-t-12412.html

"The F-35 will be able match most of the same high AOA manoeuvres as the Raptor, although it will not be able to do so as quickly as the more powerful jet in some cases. Turning at the higher Gs and higher speed portions of the flight envelope, the F-35 will "almost exactly match a clean Block 50 F-16 and comes very close to the Raptor", Beesley said.

...the four current test pilots for F-35 have been most impressed by the aircraft's thrust and acceleration. In the subsonic flight regime, the F-35 very nearly matches the performance of its' larger, more powerful cousin, the F-22 Raptor, Beesley explained. The "subsonic acceleration is about as good as a clean Block 50 F-16 or a Raptor- which is about as good as you can get." Beesley said.

The outstanding handling, acceleration, and the maximum speed of the aircraft is useable in a combat configuration unlike in legacy fighters. Beesley said that recently he flew an F-35 test flight with a full internal load of two 2000 lbs JDAMs, and two AIM-120 missiles. The aircraft "felt like it had a few thousand pounds of extra fuel" but otherwise Beesley said there was practically no degradation in the aircrafts' performance."

Probably a waste of time to quote someone who has flown the aircraft I guess...

"While supersonically the F-35 is limited to a seemingly unimpressive Mach 1.6 in level flight, Davis explains that the JSF is optimized for exceptional subsonic to supersonic acceleration. Transonic acceleration is much more relevant to a fighter pilot than the absolute max speed of the jet, Davis said. Davis, who was previously the program manager for the F-15 Eagle, explains that while the Eagle is a Mach 2 class fighter, it has rarely exceed the threshold of Mach 1.2 to Mach 1.3 during it's entire 30 year life span. Additionally, the time the aircraft has spent in the supersonic flight regime can be measured in minutes rather than hours- most of the supersonic flights were in fact during specialized flights such as Functional Check Flights (FCF)."

Unread postPosted: 01 Jul 2010, 04:55
by apg77
I have read this article before,I also think that high speed is not inportant.
this article shows that F-35's subsonic performance is very good.
let's wait the transonic test result, F-35 is still a good plane enen this result is not good.

There are two types of F/A-18C ,each equiped with F404-GE-400 or F-404-GE-402 engines. The F404-GE-402 can improve its transonic acceleration.
Which type does this chart mentioned?

Unread postPosted: 01 Jul 2010, 07:20
by SpudmanWP
apg77 wrote:
SpudmanWP wrote:It represents the time to go from speed X to speed Y, hence "less is more".

This is why the CTOL version has a smaller number than the CV, it accelerates better than the CV and STOVL.


I am doubt about it.

so far as I know, the are some data as below:
1- F-16C's transonic acceleration is much better than F/A-18C.
2- F-35A's transonic acceleration is similar with F-35B. they have similar aerodynamics and engines, but F-35B is heavier.
3--F-35C 's transonic acceleration is worse with F-35A/B, for its bigger wings.

so in the chart ,
less is worse.
F-16C is not compared with F/A-18C.
F-35A is only compared with F-16C,
F-35B/C are only with F/A-18C.


You need to take a class on chart reading ;)

Here is the same chart that has been annotated for ease of reading.

Image

Just like in golf, lower is better. The F-16 is lower than the F-18 and the F-35 B/C are also lower than the F-18. As you can see, the F-35 has the lowest number than of all the jets on the list, just as we would expect.

Unread postPosted: 01 Jul 2010, 07:46
by apg77
SpudmanWP wrote:You need to take a class on chart reading ;)

Here is the same chart that has been annotated for ease of reading.


You misunderstood what I said.

these info are getted from other source, not from this chart.
but this chart should include them.
1- F-16C's transonic acceleration is much better than F/A-18C.
2- F-35A's transonic acceleration is similar with F-35B. they have similar aerodynamics and engines, but F-35B is heavier.
3--F-35C 's transonic acceleration is worse with F-35A/B, for its bigger wings.

You can devide the chart into 2 parts.
The same length in left and right part have different value.

In this chart, because F-35B's length is longer than F-35C and F-35B'a transonic acceleration is better than F-35C, can conclude that longer is better.
because F--35A's length is shorter than F-35B and F-35B'a transonic acceleration is worse than F-35C, can conclude that length in upper part and down part have different value.

Unread postPosted: 01 Jul 2010, 08:10
by SpudmanWP
Who says the F-35B has better Trans Accel than the F-35C?

Unread postPosted: 01 Jul 2010, 12:49
by wrightwing
apg77 wrote:
SpudmanWP wrote:It represents the time to go from speed X to speed Y, hence "less is more".

This is why the CTOL version has a smaller number than the CV, it accelerates better than the CV and STOVL.


I am doubt about it.

so far as I know, the are some data as below:
1- F-16C's transonic acceleration is much better than F/A-18C.
2- F-35A's transonic acceleration is similar with F-35B. they have similar aerodynamics and engines, but F-35B is heavier.
3--F-35C 's transonic acceleration is worse with F-35A/B, for its bigger wings.

so in the chart ,
less is worse.
F-16C is not compared with F/A-18C.
F-35A is only compared with F-16C,
F-35B/C are only with F/A-18C.


That chart is pretty clear. The A, B, and C models will out accelerate an F-16 or F-18, the A, B, C models have better instantaneous and sustained turn rates than the F-16 or F-18. THAT is the take away.

Unread postPosted: 01 Jul 2010, 13:00
by wrightwing
apg77 wrote:
You misunderstood what I said.

these info are getted from other source, not from this chart.
but this chart should include them.
1- F-16C's transonic acceleration is much better than F/A-18C.
2- F-35A's transonic acceleration is similar with F-35B. they have similar aerodynamics and engines, but F-35B is heavier.
3--F-35C 's transonic acceleration is worse with F-35A/B, for its bigger wings.

you can devide the chart into 2 parts.
the same length in left and right part have differnct value.


We understand what you're saying. What we're saying is that you're wrong.
If you look at that chart, the F-16 is quicker than the F-18, but all 3 models of the F-35 are quicker than either the F-16 or F-18. It doesn't matter if you look at the chart the way Lockheed Martin originally had it, or if you cut it into 2 parts like you did. The F-35 in all variants is the quicker aircraft. That chart does show that the F-35A is the quickest model, and then C, then the B.

Unread postPosted: 01 Jul 2010, 13:38
by apg77
wrightwing wrote:
We understand what you're saying. What we're saying is that you're wrong.


I think that you are wrong.
let's wait test results.

Unread postPosted: 01 Jul 2010, 19:39
by johnwill
And ALL these charts are so much Madison Avenue advertising agency crap until fuel state, weapon load, speed, and altitude are provided.

Unread postPosted: 01 Jul 2010, 20:05
by wrightwing
apg77 wrote:
wrightwing wrote:
We understand what you're saying. What we're saying is that you're wrong.


I think that you are wrong.
let's wait test results.


What's your source, or is it just a hunch? The manufacturer is the one making this claim(and they build 4 of the 5 aircraft in question).

Unread postPosted: 02 Jul 2010, 06:14
by apg77
Ultimate Fighter: Lockheed Martin F-35 Joint Strike Fighter
Bill Sweetman

However, the F-35C is likely to be slower in acceleration then the F-35A, particularly at transonic speeds, because of its larger wing.

Unread postPosted: 02 Jul 2010, 06:31
by SpudmanWP
That is exactly what the chart I posted says.

From quickest to slowest (in the chart anyways):

1. F-35A (Baseline time to go from X to Y = 1)
2. F-35C (X to Y = 1.20)
3. F-35B (X to Y = 1.50)
4. F-16C (X to Y = 1.64)
5. F/A-18C (X to Y = 1.69)

Unread postPosted: 02 Jul 2010, 12:43
by wrightwing
apg77 wrote:
wrightwing wrote:
apg77 wrote:
wrightwing wrote:
We understand what you're saying. What we're saying is that you're wrong.


I think that you are wrong.
let's wait test results.


What's your source, or is it just a hunch? The manufacturer is the one making this claim(and they build 4 of the 5 aircraft in question).


this chart is the source, you just misunderstood the chart.


Let's apply a little logic to this debate- if your understanding of the chart is true, why would LM highlight this information in a presentation? The whole point of that presentation is to show that all 3 F-35 models offer superior performance to either F-16s or F-18s, in all 3 categories. Think of it this way, the length of those bars represents time to a given speed, with the longer bar representing a greater amount of time. It is not I that is misunderstanding the chart.

Unread postPosted: 02 Jul 2010, 13:24
by wrightwing
apg77 wrote:
wrightwing wrote:
Let's apply a little logic to this debate- if your understanding of the chart is true, why would LM highlight this information in a presentation? The whole point of that presentation is to show that all 3 F-35 models offer superior performance to either F-16s or F-18s, in all 3 categories. Think of it this way, the length of those bars represents time to a given speed, with the longer bar representing a greater amount of time. It is not I that is misunderstanding the chart.


LM uses the chart to show the F-35's performance , including its advantages and disadvantages.

No disadvantages were shown though, which is what we're trying to tell you. The longer bar represents a greater amount of time, not a greater amount of acceleration. Otherwise the F-35B would be the quickest of all 3, and the F-18 would be quicker than an F-16, using your logic.

Unread postPosted: 02 Jul 2010, 13:27
by wrightwing
apg77 wrote:
wrightwing wrote:
apg77 wrote:Ultimate Fighter: Lockheed Martin F-35 Joint Strike Fighter
Bill Sweetman

However, the F-35C is likely to be slower in acceleration then the F-35A, particularly at transonic speeds, because of its larger wing.


Who here has claimed otherwise? The A is the quickest, then the C, then the B. For the record, Bill Sweetman is hardly an unbiased source with regard to the F-35.


because of its larger wing =>F-35C's wing is bigger than F-35B, too.

that's physical law, it's really un-biased.


I wasn't using this as an example of his bias. I was merely pointing out that he's a highly vocal critic of the F-35, so any info that you hear from him must be assessed knowing his bias. Much like Winslow Wheeler, Pierre Sprey are biased against anything more complicated than a lightweight, day fighter, and Carlo Kopp is biased against anything that isn't Russian, an F-22, or an F-111.

Unread postPosted: 02 Jul 2010, 14:13
by apg77
wrightwing wrote:Otherwise the F-35B would be the quickest of all 3, and the F-18 would be quicker than an F-16, using your logic.


my logic?

I devide the chart to 2 part, you forget it.

wrightwing wrote:No disadvantages were shown though, which is what we're trying to tell you.

many disadvantages have been shown.
max speed 1.6M,
range 1,200 nm
...

Unread postPosted: 02 Jul 2010, 14:26
by dragorv
I honestly don't see those as disadvantages....

Unread postPosted: 02 Jul 2010, 14:51
by checksixx
Gentleman...the aircraft is not far enough along in test to even validate any GUESSES by anyone. There is certainly no reason to release those numbers publicly once they do know them. We (including me) don't have a need to know. Some of the test points/info will be released...base your opinion on hard data. No need to get nasty with each other.

Unread postPosted: 02 Jul 2010, 15:07
by wrightwing
apg77 wrote:
wrightwing wrote:
Otherwise the F-35B would be the quickest of all 3, and the F-18 would be quicker than an F-16, using your logic.


my logic?

I devide the chart to 2 part, you forget it.


If you change the chart from how it was originally presented, then it loses the original intent. It didn't escape my attention, it's just incorrect to do so. You may as well start relabeling the data too, in order to show that you know more than the author of the presentation.

Unread postPosted: 02 Jul 2010, 15:18
by wrightwing
apg77 wrote:
wrightwing wrote:

No disadvantages were shown though, which is what we're trying to tell you.


many disadvantages have been shown.
max speed 1.6M,
range 1,200 nm
...


You're mixing info up again. If we use miles per hour rather than Mach, then it helps keep things from being as ambiguous. LM says that the F-35 will reach 1200mph. That works out to M1.8. The max speed figures when listed refer to with a combat load(i.e. 5500lbs internal weapons, and high fuel state), not the maximum speed that the plane can reach unloaded, and with 50% fuel. That range figure is way off too. The combat radius for the F-35A is between 673-751nm. The C model has an even longer range.
The maximum range is more than 2x the combat radius(as the radius doesn't include the combat time on station, which'll generally be several minutes of afterburner use, and aggressive manuevers, or the amount of reserve fuel 20-30 minutes). This means that the straight line range at optimal cruise speed would be quite a bit more than merely a factor of 2.

Unread postPosted: 02 Jul 2010, 16:21
by apg77
http://www.military.com/features/0,15240,186349,00.html

The exact performance of the current F-35A configuration -- also known as the 240-4 -- are classified.
But a similar earlier standard (240-3) was credited with
acceleration from Mach 0.8 to Mach 1.2 at 30,000 ft. in 61 sec.;
it's much worse than F-16.

Unread postPosted: 02 Jul 2010, 16:27
by apg77
acceleration from Mach 0.8 to Mach 1.2 ,
F-16C use about 32s,
F/A-18C use about 52s,
F/A-18E/F use more,

but when these fighters have to carry tanks, bombs, pods...it must use much more time.
so 61s is not very bad,
it's still " like F-16/F/A-18"

Unread postPosted: 02 Jul 2010, 16:30
by apg77
wrightwing wrote:
You're mixing info up again. If we use miles per hour rather than Mach, then it helps keep things from being as ambiguous. LM says that the F-35 will reach 1200mph. That works out to M1.8. The max speed figures when listed refer to with a combat load(i.e. 5500lbs internal weapons, and high fuel state), not the maximum speed that the plane can reach unloaded, and with 50% fuel. That range figure is way off too. The combat radius for the F-35A is between 673-751nm. The C model has an even longer range.
The maximum range is more than 2x the combat radius(as the radius doesn't include the combat time on station, which'll generally be several minutes of afterburner use, and aggressive manuevers, or the amount of reserve fuel 20-30 minutes). This means that the straight line range at optimal cruise speed would be quite a bit more than merely a factor of 2.


I know your idea.
I think that F-35A/C's range is 1,800nm or more.

Unread postPosted: 02 Jul 2010, 16:54
by Prinz_Eugn
Radius and range are the most abused and misunderstood terms ever in aircraft performance statistics. Well, that and wing loading and thrust-to-weight ratio. Oh, plus max speed. And weight.

Okay, but they're in the top ten.

Unread postPosted: 03 Jul 2010, 00:06
by popcorn
SpudmanWP wrote:
apg77 wrote:
lampshade111 wrote:I thought the F-35 was supposed to have better acceleration than the F-16? Honestly I think a Mach 1.2-1.3 speed without AB should have been a requirement.


at subsonic field , the test show that F-35A's acceleration and climbing is better than F-16.
but no news about supersonic and sound barrier field.


Actually, the F-35's performance has always been stated in the "transonic" region. That is mach .8 - 1.2

Image


Interesting chart Spudman. Do you know when it was prepared by any chance. Is it based on simulations or actual flight tests?

Unread postPosted: 03 Jul 2010, 01:05
by SpudmanWP
Since the F-35s have only gone up to Mach 1.07, I am sure that it is based mostly on simulation data.

The presentation has a create date of 12/10/2009.

Unread postPosted: 03 Jul 2010, 04:05
by popcorn
SpudmanWP wrote:Since the F-35s have only gone up to Mach 1.07, I am sure that it is based mostly on simulation data.

The presentation has a create date of 12/10/2009.

Thanks, good to know.