EMALS & JPALS for the JSF

[spazsinbad]

'outlaw162' said: "...Just give me an old ADF. " - But but then you will have to learn MORSE CODE!

[outlaw162]

How primitive.

Just a quick story about in-flight validation and the 'human' element:

Way back in the 90s, the Atlantic City test bunch with their LAAS configured 727 loaded with all the test equipment and technicians in the back came in to OKC to run some LAAS testing. They set up the ground facility, and all the data, ground and airborne, both FMS and display that could be pre-loaded for OKC had been.

They used our 727 Instructors as test subjects to fly while they monitored the system performance. I flew the first run and we turned south out of the airfield to set up the first run to 35R at OKC. We fooled with the display for awhile and something didn't look quite right. Steering commands were questionable for the downwind phase of flight.

Shortly, a technician came up and said, "We've got to do some recalibration. As it's set right now, the system has the airport about 60 NM south of here."

No big deal in OK where it's flat all the way to Texas, but probably would have caused some problems at Rifle or Gunnison in Colorado. Don't remember if they got everything reset in 90 minutes.

I'm sure everything goes more smoothly now, but, conditions permitting, I would rather have the arrivals looked at by a specifically instrumented flight check aircraft in clear wx, than have the first attempt with a 100 mil aircraft end up in a granite cloud as a result of a laptop keystroke misadventure.

edit: But with the high resolution terrain databases, at least you'll know at exactly what elevation you hit the rocks

[outlaw162]

But but then you will have to learn MORSE CODE!

Actually, other than the occasional NDB approach on the yearly instrument check-ride, in the F-100 we used the ADF primarily for listening to AM radio music. Music to drop bombs by or do BFM....

The Eagles' "Take It to the Limit" was particularly inspirational.

(I sure do miss it. )

[spazsinbad]

But but then you will have to learn MORSE CODE!

Actually, other than the occasional NDB approach on the yearly instrument check-ride, in the F-100 we used the ADF primarily for listening to AM radio music. Music to drop bombs by or do BFM.... The Eagles' "Take It to the Limit" was particularly inspirational. (I sure do miss it. )

Yep - the transition from Vampire/Venom to Macchi/A4G was great. ADF to TACAN but only on the MB326H could we tune in the local music radio for good listening during the mucho boring high altitude racetrack sorties over a calibrating ship.

[marauder2048]

How primitive.

Just a quick story about in-flight validation and the 'human' element:

Way back in the 90s, the Atlantic City test bunch with their LAAS configured 727 loaded with all the test equipment and technicians in the back came in to OKC to run some LAAS testing. They set up the ground facility, and all the data, ground and airborne, both FMS and display that could be pre-loaded for OKC had been.

They used our 727 Instructors as test subjects to fly while they monitored the system performance. I flew the first run and we turned south out of the airfield to set up the first run to 35R at OKC. We fooled with the display for awhile and something didn't look quite right. Steering commands were questionable for the downwind phase of flight.

Shortly, a technician came up and said, "We've got to do some recalibration. As it's set right now, the system has the airport about 60 NM south of here."

No big deal in OK where it's flat all the way to Texas, but probably would have caused some problems at Rifle or Gunnison in Colorado. Don't remember if they got everything reset in 90 minutes.

I'm sure everything goes more smoothly now, but, conditions permitting, I would rather have the arrivals looked at by a specifically instrumented flight check aircraft in clear wx, than have the first attempt with a 100 mil aircraft end up in a granite cloud as a result of a laptop keystroke misadventure.

edit: But with the high resolution terrain databases, at least you'll know at exactly what elevation you hit the rocks

Yeah..let's bring in some highly vulnerable flight check aircraft and wait for clear weather and make sure that
the competent enemy that necessitated the seizure of this airbase in the first place is cool with that.

I'm sensing opposition couched in job-security terms here. Not technical terms.

[outlaw162]

I'm retired.....comfortably.

You know, you mentioned RAND. As a high school student, I used to participate as a subject in tests at both RAND and Systems Development Corp for a modest amount of spending cash.

On one visit after school, the test involved playing tic-tac-toe, ostensibly with one of the other members of the test group. You played ten games and got $5 for each one you won.

I figured splitting $50 was preferable to winning nothing, so I lost the first game on purpose. Whoever or whatever was on the other end understood the gesture and we alternated wins. Sure enough, I won $25, plus the usual pay for test subjects. A number of the participants, unwilling to lose, won nothing....against what I'm guessing was actually a computer.

I'm gathering you would have been in that group.

[marauder2048]

I'm retired.....comfortably.

It's a pity we can't do anything more for the senile except make them comfortable.

You know, you mentioned RAND. As a high school student, I used to participate as a subject in tests at both RAND and Systems Development Corp for a modest amount of spending cash.

It was controversial but RAND did conduct subject tests on lobotomy patients.

On one visit after school, the test involved playing tic-tac-toe, ostensibly with one of the other members of the test group. You played ten games and got $5 for each one you won.

I figured splitting $50 was preferable to winning nothing, so I lost the first game on purpose. Whoever or whatever was on the other end understood the gesture and we alternated wins. Sure enough, I won $25, plus the usual pay for test subjects. A number of the participants, unwilling to lose, won nothing....against what I'm guessing was actually a computer.

Yet somehow you didn't scoop Newell and Simon on the subject and win the Turing Award.

You was robbed!

[outlaw162]

Do I detect a bit of hostility?

For a Comm Squadron dude, you certainly profess to have a considerable amount of knowledge about actual flying.

Do you enjoy watching the F-35s takeoff and land? Do you get pictures?

Oops, a bit of drool on my chin, 'scuse me while I go find a kleenex.

[spazsinbad]

Youse guys are a HOOT!

[usnvo]

My guess is that RAYTHEON have developed a better LAND JPALS on their own initiative (considering ARMY/USAF dropped out earlier) so that land/expeditionary JPALS is better than the old land specification, hence two way data link as per:

I believe you are right. The "new" land JPALS is basically the shipboard version with all the shipboard specific stuff left off. This allows the land based version to be smaller but also to direct the aircraft to any spot on any landing field in the 20nm radius vicinity. It can also deliver straight, curved, or segmented approaches to avoid terrain, tactical threats, etc, so clearly the system is sending the landing profile to the aircraft.

The CVN version, besides the multiple GPS antennas to determine differential GPS, has sensors for roll, pitch, heave, speed, heading, turn rate, etc. Hence the two way datalink requirement since the aircraft needs to know where the ship will be when they get there.

The "new" shore based version still has the datalink but doesn't have the sensor stuff for moving ships (well actually it probably uses the exact same software and just zeros the inputs for motion but I digress). The 20nm limit is probably an issue with the DGPS accuracy and communications limitations. The further you are from the DGPS reference station, the greater your error.

Neither the ship or aircraft is tracking each other, the aircraft is using DGPS from the ship to calculate its own position much more accurately and precisely than normal while using the datalinked information on the approach and the ships movement (or airfields lack of movement) to calculate how to fly to arrive at the designated point in space.

Here is a video from AFA 2018 discussing the "new" JPALS and the Raytheon guy clearly says it works the same as the shipboard version. https://www.military.com/video/military ... 7250563001.

[spazsinbad]

Thanks the video was noted earlier this thread however being non-'merican some of the dialog with noise ununderstan.

Page 22 this thread: viewtopic.php?f=22&t=14115&p=402125&hilit=iTtVf+qZVro#p402125

JPALS Precision Approach and Landing Expeditionary for USAF https://www.youtube.com/watch?v=iTtVf-qZVro

[outlaw162]

It can also deliver straight, curved, or segmented approaches to avoid terrain, tactical threats, etc, so clearly the system is sending the landing profile to the aircraft.

Does the ground based installation quickly create and send a missed approach profile should one be required? Off the boat it's fairly straight forward....you can go straight ahead for 'a thousand miles' with nothing but sea level elevation. It can deliver accuracy. It doesn't create.

Can it send aircraft specific profiles....compatible with their displays and steering command system and approach category? F-16, F-18, V-22, C-17, helo, etc.? Does the ground based augmentation system provide the minimums associated with the specific approach and missed approach to the pilot or do you just make those up when you get there? The missed approach can be particularly aircraft specific as a function of the minimum climb rates which can be attained. Does the ground based system know the aircraft performance capability?

The profile options for the airfield are pre-determined and coded into the specific aircraft mission computer/FMS and then the assigned or directed one is selected by the pilot just like any coded RNAV approach including the associated missed approach profile specific to the approach....just more accurate track positioning as a result of the ground based system. There are ways to create waypoints on the fly and manually vary the GPA for terrain if necessary, but this is also done on board the aircraft. You don't just 'show up' and have the ground based system suddenly create the approach du jour for you.

That HMDS isn't receiving anything from JPALS, the display is presented based on the selected approach profile in the mission computer/FMS.

Here's a non-tactical ground based profile:

[spazsinbad]

The installation on specific aircraft will be done as necessary AFAIK. How it will be done is unknown. I'll guess potential customers / aircraft have to show an interest to be included. I'll reckon computers do a lot of the stated work. IF the expeditionary/ground based JPALS require a lot of work before use then I'll guess there will be less interest. For a given airfield probably no problem however the USAF have already rejected the old JPALS version (for lack of money/interest?).

[outlaw162]

then I'll guess there will be less interest.

No, it's a fantastic system. It's just that there's more to it than dropping a couple of boxes on the ground and having the dude with the AR strapped to his back go to work on his laptop. It's a quantum leap in precision approach capability, however still with all the safety considerations and requirements associated with any precision landing system. Flying is dangerous.

[spazsinbad]

Given all the caveats expressed I will suggest 'Raytheon knows this' - how the safety concerns are ameliorated is beyond my knowledge at this point. IF the USAF express interest NOW then there must be something in it - maybe pretty pictures?

At the risk of repeating an article already posted I'll post this bit and the 3 page PDF from whence it came below. One may note that over the last several years the JPALS articles are extremely repetitive. Someone has to pay for cut/paste.

Precision recovery
30 April - 6 May 2019 Flight International; GARRETT REIM

“...The [JPALS] landing system can be added to any aircraft with a GPS, an inertial navigation system, a software reprogrammable radio and enough computing power, says Jaynes [CJ Jaynes, Raytheon executive technical adviser for JPALS].

EXPEDITIONARY USE
In January 2019, Raytheon demonstrated a portable version of JPALS guiding in a USMC short take-off and vertical landing F-35B to a touchdown at Yuma Proving Ground in Arizona. In attendance were personnel from the USN, USMC and US Air Force (USAF), says the company.

Those services are interested in JPALS as a way to rapidly set up and facilitate air traffic control operations at expeditionary bases, which are part of a Pentagon idea to make the position of air forces unpredictable – a strategy to keep near-peer adversaries such as China or Russia on their heels should war break out. In particular, the USAF is showing strong interest, says Jaynes.

“The reason the air force is interested is they are developing a concept of operations called ‘agile basing’, where they intend to bring in their air wing, maybe stay in a location for 24 to 48h, and then move the entire air wing to a new location,” she says.

The USMC is also interested because it could play a role in the Pacific theatre, says Cleveland. “This system is perfect for that island hopping,” he says.

The expeditionary version could be packed in ruggedised cases or integrated into a Humvee or Polaris RZR light tactical allterrain vehicle, either of which could be quickly air dropped.

“The goal is to have [a] multi-runway, multi-aircraft [capability], with the ultimate goal we envision an end space where you can handle up to 50 aircraft with that landing system,” says Jaynes. “And you could touch down [at] points within 20nm of that ground station.”

For a second demonstration of the expeditionary version of JPALS at NAS Patuxent River in Maryland on 8 and 9 May [2019], Raytheon has invited back all of the US military services, plus international development partners on the Joint Strike Fighter programme. “Any country that’s buying an F-35 – whether it’s an A, B or C model – is a potential customer for this,” says Jaynes.”

Source: 30 April - 6 May 2019 Flight International Magazine