Mil Airshow Airplanes & Software

kontiki

kontiki

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Kontiki
I've had enough exposure to modern military aircraft to understand their control law software is modifiable. Years ago I supported some mil flight test operations, I support transport fly by wire aircraft now.

I have no idea to what degree the military line pilots get to select the software load on mission or patrol flights.

Yesterday, I was out watching the local annual airshow performances. It made me wonder if a performance team like the Blue Angels operated with special software loads. Likewise, when there is a one off line aircraft like an F-35 or F-22 visiting for a solo performance, are they flying some sort of safety related software load.

I can see where tweaks to ensure they stay within the box and at minimum altitudes without aerodynamic or engine stalls could be very helpful. Can anybody fill me it?
 
Nothin special, just line aircraft. Those mil jets are used for normal training during the week then sent off for the airshow on the weekend. They try really hard to keep the ones with the special paint jobs ready to roll for the shows but everything breaks occasionally and I. That case they just use any other jet that’s ready.

The physical config for the jets are different though. “Demo clean” - no pylons, no missiles, no tanks, targeting pods, etc. No big difference for 5th gen folks but a huge difference for F16/A10/F18
 
I really doubt they would want to have multiple software loads for flight controls. That would make training much more complicated between individual aircraft, as each would have specific handling characteristics.

The only modification I know of is the Blue Angel's F-18s. They have a spring force of about 50 pounds pulling the stick forward. This constant tension helps the pilots fly a little more accurately since the flight controls system automatically trims the aircraft.
 
F-16 and F-35 all use current operational software. The only place you would find them flying anything else is at the factory or a flight test site, and under very controlled conditions.
 
The only thing that is modified on the F-16 when we fly a factory demo, is "Bingo fuel" setting....that's it. We short load fuel per the demo requirements and the pilot sets the bingo point.
 
I read that the Blues got early Super Hornets that we’re used in training and had different software than fleet Hornets. Also read they upgraded that software as well. Of course the spring and removal of the cannon with smoke being the two major changes.

I was planning on hitting the Millington show yesterday but they don’t allow fly-ins. Been 30 years since I was stationed there. Time flys.
 
kontiki said:
Yesterday, I was out watching the local annual airshow performances. It made me wonder if a performance team like the Blue Angels operated with special software loads. Likewise, when there is a one off line aircraft like an F-35 or F-22 visiting for a solo performance, are they flying some sort of safety related software load.
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According to an article in the local P'cola News Journal, they do. The article was printed shortly before the B.A.s received their new Super Hornets. I recall that there were some software and hardware alterations.

Recently, the Blues received another Super Hornet that was in the shooting of Top Gun.
 
Long vid but they cover some of the differences with a Blue Angel F-18 vs a fleet F-18.

 
The German Army did performances with their military Bolkow 105s. Flown by a Sergeant who did a routine similar to the Red Bull's. Actually, it was a pair of 105s They both had identical markings to include tail numbers. They were swapped out between performances so that an ultra-microscopic inspection could be pulled between performances.
I had a little "bootleg" time in the BO 105 years ago. That pilot told me that after about 4 or 5 hours, it transforms itself from a BO 105 to an ME 105. Another pilot clued me in on the helicopter technique for pulling out at the bottom of a loop.
 
In practice no. Modern jets have DAF (dial a function) when in flight test mode, which is enabled via a super double secret setting. ;) But those gains are preprogrammed and change based on the test cards and are typically null in operational loads.
 
Velocity173 said:
I read that the Blues got early Super Hornets that we’re used in training and had different software than fleet Hornets. Also read they upgraded that software as well. Of course the spring and removal of the cannon with smoke being the two major changes.

I was planning on hitting the Millington show yesterday but they don’t allow fly-ins. Been 30 years since I was stationed there. Time flys.
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To clear up any confusion, there is a lot of different "software" in an F/A-18. The difference they are speaking to is the mission computer software. The Blues jets are low lot, early build Rhinos that have not been modified to carry the advanced mission computers that most of the fleet uses now. So think Legacy Hornet mission computers. The MC's run stuff like the radar, tactical systems, etc. It plays into weapons and mission related stuff, and how you interface with the aircraft and what you see on the displays. The FCS software is completely different, and there are 2 FCS computers which are separate boxes. FCS software was most recently changed a year or so ago. Where they tie together is that legacy mission computers can only interface with a downgraded version of the current FCS software, differences being specifically related to PLM (also called "magic carpet"). There hasn't been an update to the flight control laws aside from PLM for over a decade. In short, the Blues jets are flying the same FCS software that everyone else is, for all practical purposes. There is no FCS law that enables them to do anything that a fleet bird can't.

The question is a good one though. I think a qualitative description of FBW (or really Fly-By-Control in the case of the F/A-18) in a fighter vs a transport cat aircraft is maybe useful. I imagine a lot of folks here have a general understanding, at least anecdotally, of how FBW is implemented in aircraft such as the Airbus. Voting member, lots of nannying, etc. A fighter, at least the F/A-18, is quite a different experience. The laws that exist are there almost solely to keep you from putting yourself in an unrecoverable situation. Same thing as a Bus in terms of intent, but in practice, there is nothing keeping me from departing the airplane, getting into a spin, pulling 10+ G's, or really much else. What the laws will do is better facilitate a recovery, and they will also do their best to prevent me from getting there in the first place......but they don't really restrict what you can do. In a practical sense, the laws will not prevent me from exceeding airframe limitations, other than the G limiter, which can also be either intentionally overridden, or accidentally exceeded (a rapid aft stick pull at high airspeed and light GW will often spike a quick over-G, i.e. the g limiter couldn't keep up with the inputs). So I'd say that in the airshow environment, the only thing that FCS law modification would do is potentially make the aircraft less forgiving. You already have full authority to operate the aircraft to the limits of the certified flight envelope, which itself is based on structural loads and aerodynamic characteristics (i.e. real limits).
 
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35 AoA said:
To clear up any confusion, there is a lot of different "software" in an F/A-18. The difference they are speaking to is the mission computer software. The Blues jets are low lot, early build Rhinos that have not been modified to carry the advanced mission computers that most of the fleet uses now. So think Legacy Hornet mission computers. The MC's run stuff like the radar, tactical systems, etc. It plays into weapons and mission related stuff, and how you interface with the aircraft and what you see on the displays. The FCS software is completely different, and there are 2 FCS computers which are separate boxes. FCS software was most recently changed a year or so ago. Where they tie together is that legacy mission computers can only interface with a downgraded version of the current FCS software, differences being specifically related to PLM (also called "magic carpet"). There hasn't been an update to the flight control laws aside from PLM for over a decade. In short, the Blues jets are flying the same FCS software that everyone else is, for all practical purposes. There is no FCS law that enables them to do anything that a fleet bird can't.

The question is a good one though. I think a qualitative description of FBW (or really Fly-By-Control in the case of the F/A-18) in a fighter vs a transport cat aircraft is maybe useful. I imagine a lot of folks here have a general understanding, at least anecdotally, of how FBW is implemented in aircraft such as the Airbus. Voting member, lots of nannying, etc. A fighter, at least the F/A-18, is quite a different experience. The laws that exist are there almost solely to keep you from putting yourself in an unrecoverable situation. Same thing as a Bus in terms of intent, but in practice, there is nothing keeping me from departing the airplane, getting into a spin, pulling 10+ G's, or really much else. What the laws will do is better facilitate a recovery, and they will also do their best to prevent me from getting there in the first place......but they don't really restrict what you can do. In a practical sense, the laws will not prevent me from exceeding airframe limitations, other than the G limiter, which can also be either intentionally overridden, or accidentally exceeded (a rapid aft stick pull at high airspeed and light GW will often spike a quick over-G, i.e. the g limiter couldn't keep up with the inputs). So I'd say that in the airshow environment, the only thing that FCS law modification would do is potentially make the aircraft less forgiving. You already have full authority to operate the aircraft to the limits of the certified flight envelope, which itself is based on structural loads and aerodynamic characteristics (i.e. real limits).
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Thanks for clearing that up. Hey, didn’t you go to Growlers? What’s up with the wing fence on those but standard F-18 doesn’t have it?
 
If you think getting a civil aircraft certified is difficult, you should see the crazy amount of stuff needed to get software approved for a military aircraft. The chances of having special software or control laws settings tables are low.

Unless you have a "letter," there are FAA standards involved also, especially for navigation systems.
 
IK04 said:
If you think getting a civil aircraft certified is difficult, you should see the crazy amount of stuff needed to get software approved for a military aircraft. The chances of having special software or control laws settings tables are low.
...
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That is not consistent with not my experience/observation civilian vs military aircraft avionics software. sorry - it would be inappropriate for me to go into details.
 
Velocity173 said:
Thanks for clearing that up. Hey, didn’t you go to Growlers? What’s up with the wing fence on those but standard F-18 doesn’t have it?
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Yessir. I honestly don't know the answer to your question. It is very subtle, but the leading edges are also slightly different in the G compared to the E/F (sawtooth on the Super Hornet, blended on the G). My *guess* is for high AoA stability/control reasons, but I could be wrong. The Hornet had something very similar, what we called the "LEX fences". These were installed to stop the vortex coming off the LEXs at high AoA from buffeting the vertical stabs and causing structural damage.

Edit: also typo in my previous. Meant to say "Control-by-wire" rather than "fly by control".....haha
 
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Velocity173 said:
What’s up with the wing fence on those but standard F-18 doesn’t have it?
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I'm not sure I'm going to address the correct question here, and it is OT but here goes. I supported F18-E/F flight test on E2 in EMD for about a year. The early F18s (pre E/F) models had a large vortex generator on the skinnier strake. According to a McBoeing teammate that had been there forever, before that strake was there, they were flying some weapons separation test points and one of the cameras came loose and swiveled around out of place. After the flight they reviewed the film anyway (older digital wasn't fast enough).

He said they saw for the very first time a mini tornado like vortex form at the leading edge of the lex and it would travel back to the vertical stabalators causing extreme bending to the point it looked the tips would almost touch. Apparently, no one had ever seen this before. As a result there was an emergency study and eventually corrective actions. One was the installation of the huge vortex generator on the strake to break up that vortex. The other (that I'm aware of) was the installation of the 3 huge cleats at the inboard base of the stabalators.

You can see the cleats on the top of the fuselage at the base of the stabs in this time waster youtube video (0:51) when they look aft topside on the older F-18s. My role was civil service EE data acquisition and sensors. I know squat about those airplanes.

 
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kontiki said:
He said they saw for the very first time a mimi tornado like vortex form at the leading edge of the lex and it would travel back to the vertical stabalators causing extreme bending to the point...
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It looks something like this:
309908main_EC89-0096-206_full.jpg

and you can see the LEX fence just ahead of the wing root leading edge where the vortex "kinks" doing its thing, bursting the vortex.

Nauga,
and a freight train over the canopy
 
kontiki said:
I'm not sure I'm going to address the correct question here, and it is OT but here goes. I supported F18-E/F flight test on E2 in EMD for about a year. The early F18s (pre E/F) models had a large vortex generator on the skinnier strake. According to a McBoeing teammate that had been there forever, before that strake was there, they were flying some weapons separation test points and one of the cameras came loose and swiveled around out of place. After the flight they reviewed the film anyway (older digital wasn't fast enough).

He said they saw for the very first time a mini tornado like vortex form at the leading edge of the lex and it would travel back to the vertical stabalators causing extreme bending to the point it looked the tips would almost touch. Apparently, no one had ever seen this before. As a result there was an emergency study and eventually corrective actions. One was the installation of the huge vortex generator on the strake to break up that vortex. The other (that I'm aware of) was the installation of the 3 huge cleats at the inboard base of the stabalators.

You can see the cleats on the top of the fuselage at the base of the stabs in this youtube video when they look aft topside on the older F-18s. My role was civil service EE handling data acquisition and sensors. I know squat about those airplanes.

Click to expand...

Yeah I was aware of that before. I was asking about the wing fence on the G. Halfway down the wing. It’s not on the E/F.
 
Velocity173 said:
Yeah I was aware of that before. I was asking about the wing fence on the G. Halfway down the wing. It’s not on the E/F.
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The wing fence on the G is the result of the Transonic Flying Qualities Improvement (TFQI) that fixed transonic wing drop and buffet in the Super Hornet. The E/F solution is a perforated wing fold fairing, but that induces some airframe vibration that is acceptable for a wingtip missile, but not with the added mass / electronic equipment of the G’s -218 pod. The TFQI fence and leading edge smoothed out the transonic buffet, and solved the wing drop, but there’s no such thing as a free lunch, and there are some small drawbacks that limit its usefulness to the G vice the E/F.
 
RhinoDrvr said:
The wing fence on the G is the result of the Transonic Flying Qualities Improvement (TFQI) that fixed transonic wing drop and buffet in the Super Hornet. The E/F solution is a perforated wing fold fairing, but that induces some airframe vibration that is acceptable for a wingtip missile, but not with the added mass / electronic equipment of the G’s -218 pod. The TFQI fence and leading edge smoothed out the transonic buffet, and solved the wing drop, but there’s no such thing as a free lunch, and there are some small drawbacks that limit its usefulness to the G vice the E/F.
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I find it interesting. Prior to now I didn't realize the G had such differences from an F. I just assumed it was an F with pods and sensors mounted on the hard points.
 
I have the same problem when I approach transonic in my Velocity. Been wondering if I should install a wing fence or VGs to rectify the issue. Wing fence it is.
 
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RhinoDrvr said:
It also has no gun, a higher max trap weight, and a nerdier crew ;-)
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:D

@midwestpa24 for practical flying qualities purposes, I have never noticed a big difference between it and the Rhino in clean, CL tank/pylons only configuration, though both fly differently than the Hornet did (in subtle ways). That being said, the "battle grizzly" configuration (2 ext tanks, 3 ALQ-99 pods, 1-2x AGM-88 HARM/AARGM) flies very differently, other than maybe pretty similarly to the "5-wet" tanker configuration of a Rhino.....which is to say both fly like dump trucks.
 
RhinoDrvr said:
It also has no gun, a higher max trap weight, and a nerdier crew ;-)
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It has a lower nerd quotient than the Prowler though as there were three of us ECMOs in the Fighting Drumstick. :p
 
35 AoA said:
Yessir. I honestly don't know the answer to your question. It is very subtle, but the leading edges are also slightly different in the G compared to the E/F (sawtooth on the Super Hornet, blended on the G). My *guess* is for high AoA stability/control reasons, but I could be wrong. The Hornet had something very similar, what we called the "LEX fences". These were installed to stop the vortex coming off the LEXs at high AoA from buffeting the vertical stabs and causing structural damage.

Edit: also typo in my previous. Meant to say "Control-by-wire" rather than "fly by control".....haha
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Whatsa LEX?
 
35 AoA said:
:D

@midwestpa24 for practical flying qualities purposes, I have never noticed a big difference between it and the Rhino in clean, CL tank/pylons only configuration, though both fly differently than the Hornet did (in subtle ways). That being said, the "battle grizzly" configuration (2 ext tanks, 3 ALQ-99 pods, 1-2x AGM-88 HARM/AARGM) flies very differently, other than maybe pretty similarly to the "5-wet" tanker configuration of a Rhino.....which is to say both fly like dump trucks.
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Are crews cross qualified in the F or G, or are they more specifically assigned? Does the G belong to specific squadrons separate from other Rhinos?
 
midwestpa24 said:
Are crews cross qualified in the F or G, or are they more specifically assigned? Does the G belong to specific squadrons separate from other Rhinos?
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G's are specific and assigned to VAQ squadrons - The E's and F's are assigned to VFA squadrons but each squadron only flies one type.

In Navy parlance

V = Fixed Wing
F = Fighter
A = Attack
Q = Electronic Warfare (F/A-18G) /Electronic Reconnaissance (EP-3) / Command and Control (E6B)
 
Bob Noel said:
That is not consistent with not my experience/observation civilian vs military aircraft avionics software. sorry - it would be inappropriate for me to go into details.
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When was the last time you tried to get software approved from a military application? MUCH has changed in the last few years.
 
midwestpa24 said:
Are crews cross qualified in the F or G, or are they more specifically assigned? Does the G belong to specific squadrons separate from other Rhinos?
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Until last year, the F/A-18A-D Hornet, F/A-18E/F Super Hornet, and EA-18G Growler were separate NATOPS qual’s. You could maintain multiple, but you ended up taking 3 checkrides a year to maintain them all.

Last year the Super Hornet and Growler were combined, so now any crew qual’d in one can fly the other. In practice, the mission differences would prevent operational folks from swapping back and forth, but for administrative flying (ferries etc) crews are now cross qualified. Test squadrons also allow crews to get cross qualified. The Legacy Hornet remains a separate qual, as it should, as it has some legitimate differences that warrant a few days of school and familiarization.
 
To further confuse the discussion, operational VFA squadrons are either E or F, not both. So you have single seat squadrons with no WSOs, and then a lesser amount of F/2-seat squadrons with WSOs. I only say that to touch on the "specifically assigned" part of your question. In practice, VFA and VAQ don't really cross pollenate, though it has happened here and there, and like Rhino said, it is pretty common for VX-land (test) to fly both Rhino and Growler. I'm one of the weird cases of someone crossing that stream, though my transition occurred when I left active duty and transitioned to flying in the reserves.

The combined NATOPS is cool, though it is kind of weird in practice. I went to Key West last summer to guest instruct at an east coast FRS fighter det. I was "ACM current" for the first BFM event, in spite of the fact that it had been almost 2 years since I had flown a Super Hornet, based on G currency. Granted I mostly instruct BFM or A/A in the G anyway, but it had been a long time since I'd thought about AIM-9 or the gun.... :)
 
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