Lockheed: Many F-35B landings won’t be vertical

Discuss the F-35 Lightning II
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by spazsinbad » 17 Jun 2011, 06:30

The attached ZIPPED text only file has all the guff from AV-8B NATOPS, only the CL Conventional Landing has been entered here as an example.

AV-8B Harrier II Conventional Landing (CL). http://info.publicintelligence.net/AV-8B-000.pdf
A standard CL, figure 7-5, requires substantially greater distance to stop than a SL or RVL. Landing distance available is a critical consideration when performing a CL. The brakes are designed primarily for V/STOL and are marginal for a CL without PNB [Power Nozzle Braking]; therefore, No PNB CLs should be used only as an emergency procedure.
Refer to Performance Data, A1-AV8BB-NFM-400, for stopping distance with and without PNB.
Approaching 180 -
1. Nozzles - AFT
2. Flaps - Recheck in AUTO
3. AOA - 10-12°
Off the 180 -
4. Adjust flight path with stick
At 30-50 feet AGL -
5. Control AOA with throttle
6. Set Attitude - Witches Hat on to 2° above
the horizon
7. Control ROD with throttle
At touchdown -
8. Throttle - IDLE
9. Nosewheel Steering - ENGAGE WHEN
ROLLING STRAIGHT AND PEDALS ARE
NEUTRALIZED
10. Nozzles - AS REQUIRED (up to full braking
stop)
NOTE
Porpoising on touchdown will normally be damped out by selection of the braking stop. Do not use wheel brakes while conducting PNB.
11. Trim - MINIMUM 2° ND
12. Throttle - AS REQUIRED (for PNB a
maximum of 60% (406) to 70% (408))
At 60 kts -
13. Throttle - IDLE
14. Nozzles - HOVER STOP
15. Brakes - APPLY
16. Water - OFF
17. Nozzles - LESS THAN 60° WHEN
SLOW
7.7 POSTFLIGHT
7.7.1 After Landing
When clear of the active runway -
1. Trim - 4° ND
2. Flaps - CRUISE FOR TAXI
3. Water - OFF
_______________________________________

Rolling Vertical Takeoff (RVTO).
An RVTO may be performed in those instances when a VTO is desired but the takeoff surface is deemed unsuitable. The RVTO requires approximately 100 feet of ground roll and should be made as nearly into the wind as possible. RVTO can be performed up to hover weight...

Conventional Takeoff.
The CTO can be used when configuration or environmental conditions preclude use of any other takeoff type (i.e., crosswinds or asymmetric loadings). The CTO is restricted to gross weights that will not cause the wheel/tire limitation speed of 180 KGS to be exceeded on the takeoff roll.
Attachments
AV-8B Harrier NATOPS T-O & Land.zip
(7.34 KiB) Downloaded 541 times
AV-8BconventionalLandingNATOPS256.gif
Last edited by spazsinbad on 17 Jun 2011, 18:34, edited 3 times in total.


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by battleshipagincourt » 17 Jun 2011, 15:43

aaam wrote:Here's the key: The relevant period to calculate is from the point the STOVL starts its conversion to shutdown. If a STOVL is brought in using conventional procedures (which may be the norm for peacetime use) it's going to have a higher fuel burn than if it takes advantage of its capabilities. There may be reasons to do this in peacetime.


Fuel burn is the least of anyone's worries in peacetime. The major benefits for doing conventional landings are in having the ability to bring back more fuel and weaponry than with VL, not to mention reducing wear on the fighter. If one is simply looking at fuel loss alone, then choosing VL will always mean dumping excess fuel. What a conventional landing spends in taxiing to and from the runway really pales in comparison to what is saved overall by not engaging the lift fan.

aaam wrote:Something else that may also figure in is that although it'll be easier and probably safer to operate, the F-35B, with its more complex operation may not have all the flexibility of the Harrier in this mode.


How do you mean?


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by That_Engine_Guy » 18 Jun 2011, 19:48

One also will need to consider engine usage/maintenance.

Vertical landings will require the engine to use MUCH higher power settings than conventional or 'short' landings. This increases high-cycle fatigue, and increases the turbine operating temperatures, which in turn takes a toll on engine life. (Mainly 'cycle' tracked on today's fighter engines)

More cycles per year equates to more overhauls over the life of the program, driving up life-cycle costs. A fleet of engine overhauls done every 6-8 years is tremendously more expensive than overhauls done every 10-12. (Why do you think the USAF and others are now buying the PW-229 EEP engines with 6K Cycle overhauls?)

Just because the airframe/engine CAN perform VL, doesn't mean it will. Just because it has an AB doesn't mean it's used every flight. Just because it CAN go MACH (whatever) doesn't mean it will very often. It's smart to have these things in the design, but the less you use them the better off your aircraft, and bottom line, will be.

Keep 'em flyin' :thumb:
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[Airplanes are] near perfect, all they lack is the ability to forgive.
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by spazsinbad » 18 Jun 2011, 23:32

Agree that less VLs will be performed due to the 'easy to fly' and 'automatic VL push the button' features of the F-35B; as well as the easy to do conventional landing features of the same. YET... VLs need to be practiced when ashore because, for some of the time, they will be needed for the ashore / embarked ops that the aircraft is designed to do. However I will stress - compared to the Harrier family - less VLs ashore will need to be practiced for sure. But like every one else on this board I'm only guessing. :D Makes sense to reduce engine wear and tear where possible and I'm certain this philosophy will be the norm in practice for reasons described by all on this thread.

[Addition] One thing to keep in mind about 'being kind to the aircraft/engine'... A lot more 'flying' will be done in simulators to help keep the aircraft flying in tip top condition in reality, along with all the good 'aircraft health' monitoring stuff keeping it in good nick.


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by butters » 19 Jun 2011, 00:03

If it's anything like the F-22 in terms of operating costs and down time, most of the 'flying' will be of the simulated variety. Esp with the Bee model, which, IIRC, has so far achieved a sparkling MTBF rate of 24 minutes...


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by That_Engine_Guy » 19 Jun 2011, 00:29

butters wrote:If it's anything like the F-22 in terms of operating costs and down time, most of the 'flying' will be of the simulated variety. Esp with the Bee model, which, IIRC, has so far achieved a sparkling MTBF rate of 24 minutes...


OH NO!?! not 24 minutes....

Guess that's why they're called pre-production? :doh:

Give it a chance! They've got 5 jets for the test program. Not like they're just out flying touch-and-go's or combat sorties. These are TEST sorties where 150 engineers are watching hundreds or thousands of test parameters and as soon as one person 'see's something' they need to figure out what's going on.

It's like saying the Space Shuttle Columbia only flew twice it's first year, or that it took from 1969 (program launch) until 1982 before NASA flew an 'actual mission' with a shuttle.

It took 5 years from the initial flight of the YF-16 until the USAF took delivery of the first F-16A in 1979.

See I can use numbers too.

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[Airplanes are] near perfect, all they lack is the ability to forgive.
— Richard Collins


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by butters » 19 Jun 2011, 15:58

Yeah, the Space Shuttle - The revolutionary do-everything spacecraft that was going to make space travel and exploration both cheap and safe. Which was retired after a catastrophic failure rate of 40% (Two destroyed with the loss of all crew out of the five operational craft built) and an average cost of $1.5B USD per mission. Great example... :roll:

As for the F-16- Seems to me you're making my argument for me. After all, the X-35 (Generally equivalent to the YF-16 in that both prototypes were/are significantly different from their mass-produced counterparts) first flew way back in 2000, but now the most recent predictions state that even the simplest of the Three Little Pricey Piggies will not achieve operational status until 2018. And at a cost that has ballooned so much and fast that no one can offer any firm numbers on what the things will cost, either to buy or to operate. That doesn't sound much like the bio of the incredibly successful Viper to me...

Still, no need to go smacking yourself in the forehead. Just get some better numbers to use. :lol:


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by sferrin » 19 Jun 2011, 16:34

butters wrote:Yeah, the Space Shuttle - The revolutionary do-everything spacecraft that was going to make space travel and exploration both cheap and safe. Which was retired after a catastrophic failure rate of 40% (Two destroyed with the loss of all crew out of the five operational craft built) and an average cost of $1.5B USD per mission. Great example... :roll:

As for the F-16- Seems to me you're making my argument for me. After all, the X-35 (Generally equivalent to the YF-16 in that both prototypes were/are significantly different from their mass-produced counterparts)


I take it you don't know the difference between "X" and "Y" in aircraft designations? You might want to educate yourself.
"There I was. . ."


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by LMAggie » 19 Jun 2011, 16:45

The Space Shuttle is considered by many to be one of the greatest engineering marvels in human history. If you think it was a failure I think you need to step back and recalibrate yourself.
“Its not the critic who counts..The credit belongs to the man who does actually strive to do the deeds..”


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by madrat » 19 Jun 2011, 16:51

And it was predicted that the Space Shuttle would have a catastrophic failure ever hundred missions, something it's lived up to regrettably; traveling low earth orbit is inherently dangerous.


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by shep1978 » 19 Jun 2011, 17:33

LMAggie wrote:The Space Shuttle is considered by many to be one of the greatest engineering marvels in human history. If you think it was a failure I think you need to step back and recalibrate yourself.


Indeed, I can't quite comprehend just how ignorant one needs to be to consider the space shuttle a catastrophic failure. Remarkable.


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by butters » 19 Jun 2011, 18:35

shep1978 wrote:
LMAggie wrote:The Space Shuttle is considered by many to be one of the greatest engineering marvels in human history. If you think it was a failure I think you need to step back and recalibrate yourself.


Indeed, I can't quite comprehend just how ignorant one needs to be to consider the space shuttle a catastrophic failure. Remarkable.


What you obviously cannot also comprehend is the English language. Because I did not say that the Space Shuttle was a "catastrophic failure", I said that it had a catastrophic failure RATE of 40%. Which it did. Unless, of course, you do not consider the sudden and total destruction of a craft with the loss of all on board to fit within the definition of 'catastrophic'.

And BTW, in terms of what its advocates claimed it would be - ie; a safe, reliable, and inexpensive means of transporting people and cargo into space - it was a failure.
Last edited by butters on 19 Jun 2011, 18:42, edited 1 time in total.


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by butters » 19 Jun 2011, 18:41

LMAggie wrote:The Space Shuttle is considered by many to be one of the greatest engineering marvels in human history. If you think it was a failure I think you need to step back and recalibrate yourself.


So was Howard Hughes' Spruce Goose when it was built.

Marvelous engineering does not in and of itself guarantee against something being a boondoggle.

JL


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by butters » 19 Jun 2011, 18:49

sferrin wrote:
butters wrote:Yeah, the Space Shuttle - The revolutionary do-everything spacecraft that was going to make space travel and exploration both cheap and safe. Which was retired after a catastrophic failure rate of 40% (Two destroyed with the loss of all crew out of the five operational craft built) and an average cost of $1.5B USD per mission. Great example... :roll:

As for the F-16- Seems to me you're making my argument for me. After all, the X-35 (Generally equivalent to the YF-16 in that both prototypes were/are significantly different from their mass-produced counterparts)


I take it you don't know the difference between "X" and "Y" in aircraft designations? You might want to educate yourself. Then again, judging by most of your posts seem to think you know everything already so maybe not. Troll on.


As is your wont, you take it wrong. I do know the difference between X and Y in DOD a/c terminology, and I also know that the 'X' label of the JSF competitors had as much to do with politics as with engineering or nomenclature protocols.

Did you happen to note that I made a point of explaining why I considered the prototypes to be functionally equivalent despite the disparity in their designations?


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by LMAggie » 19 Jun 2011, 21:39

butters wrote:
LMAggie wrote:The Space Shuttle is considered by many to be one of the greatest engineering marvels in human history. If you think it was a failure I think you need to step back and recalibrate yourself.


So was Howard Hughes' Spruce Goose when it was built.

Marvelous engineering does not in and of itself guarantee against something being a boondoggle.

JL


So I guess by your definition the entire space program was a boondoggle. JFK's remarks about the space program have been forgotten.
“Its not the critic who counts..The credit belongs to the man who does actually strive to do the deeds..”


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