Midair Warning

On Saturday, July 11, 2015 at 1:18:17 PM UTC-5, Darryl Ramm wrote:
On Saturday, July 11, 2015 at 8:00:12 AM UTC-7, wrote:
There is much more wrong with the Power Flarm comment.
I have Flarm.
Transponder targets do not provide the information that Flarm targets have.
One has to actually visually search for the transponder target.
At the speeds the F-16 was travelling....Flarm is iffy.

The Flarm part of this thread is going a bit off the rails. PowerFLARM is not targeted at GA use (certainly not in the USA), for very good reasons. Well maybe the few GA aircraft that should have PowerFLARM are tow planes.

AFAIK the F-16C is not equipped with 1090ES Out, it is equipped with a very capable military/IFF transponder that supports Mode S and will show up as a PCAS alert on a PowerFLARM... given all the usual requirements like the transponder the F16 would need to be being interrogated etc. If the USAF eventually equips their fighters with 1090ES out then a PowerFLARM would provide much more useful warning (surprise! cost and complexity of installing ADS-B out affects the military as well).

PCAS is just not a very effective warning against a fast jet like an F-16 (even if flying 250 knots), you have no clue what direction the treat is in, you may not get much warning time, the jets may maneuver rapidly vertical (outside of the PCAs warning box), they are camouflaged, small and and difficult to see. There are ADS-B based options that a GA aircraft could deploy that would (via TIS-B) better show the F-16 traffic (but they also are not perfect), but the cost and hassle of installing those is likely not appealing to many lower-end GA aircraft owners.

Flarm does not need to be "raised to the FAA's attention".. the FAA is well aware of what Flarm is, including the FAA folks who worked on the recent TABS TSO. The soaring community would seriously harm it's reputation by proposing PowerFLARM for use in GA aircraft, it is just not suitable for that, not in the unique USA ADS-B market. FLARM certainly knows that and is not marketing the product for GA users in the USA. And likewise transponder and ADS-B solutions are not suitable for use in gliders for glider-glider traffic awareness. Unfortunately we are stuck in that space spanning two worlds and for some glider owners/pilots that means, and will increasingly mean, equipping with both PowerFLARM and a transponder and maybe other parts of the ADS-B puzzle (like possibly TABS if that takes off).

I totally agree with your assessment of the limited value of PCAS for high speed collision threats like F-16s.

Assuming that this Cessna was within range of an ADS-B ground station, a low cost ADS-B solution (both IN and OUT) connected to an iPhone or iPAD app like ForeFlight could have given the Cessna pilots a good warning of the traffic that was heading straight towards them.

Hopefully the new FAA interest in low cost ADS-B based beacon technology will result in some serious cost reductions, so that this technology is affordable by everyone.

On Saturday, July 11, 2015 at 11:46:37 AM UTC-7, Mike Schumann wrote:
On Saturday, July 11, 2015 at 1:18:17 PM UTC-5, Darryl Ramm wrote:
On Saturday, July 11, 2015 at 8:00:12 AM UTC-7, wrote:
There is much more wrong with the Power Flarm comment.
I have Flarm.
Transponder targets do not provide the information that Flarm targets have.
One has to actually visually search for the transponder target.
At the speeds the F-16 was travelling....Flarm is iffy.

The Flarm part of this thread is going a bit off the rails. PowerFLARM is not targeted at GA use (certainly not in the USA), for very good reasons.. Well maybe the few GA aircraft that should have PowerFLARM are tow planes..

AFAIK the F-16C is not equipped with 1090ES Out, it is equipped with a very capable military/IFF transponder that supports Mode S and will show up as a PCAS alert on a PowerFLARM... given all the usual requirements like the transponder the F16 would need to be being interrogated etc. If the USAF eventually equips their fighters with 1090ES out then a PowerFLARM would provide much more useful warning (surprise! cost and complexity of installing ADS-B out affects the military as well).

PCAS is just not a very effective warning against a fast jet like an F-16 (even if flying 250 knots), you have no clue what direction the treat is in, you may not get much warning time, the jets may maneuver rapidly vertical (outside of the PCAs warning box), they are camouflaged, small and and difficult to see. There are ADS-B based options that a GA aircraft could deploy that would (via TIS-B) better show the F-16 traffic (but they also are not perfect), but the cost and hassle of installing those is likely not appealing to many lower-end GA aircraft owners.

Flarm does not need to be "raised to the FAA's attention".. the FAA is well aware of what Flarm is, including the FAA folks who worked on the recent TABS TSO. The soaring community would seriously harm it's reputation by proposing PowerFLARM for use in GA aircraft, it is just not suitable for that, not in the unique USA ADS-B market. FLARM certainly knows that and is not marketing the product for GA users in the USA. And likewise transponder and ADS-B solutions are not suitable for use in gliders for glider-glider traffic awareness. Unfortunately we are stuck in that space spanning two worlds and for some glider owners/pilots that means, and will increasingly mean, equipping with both PowerFLARM and a transponder and maybe other parts of the ADS-B puzzle (like possibly TABS if that takes off).

I totally agree with your assessment of the limited value of PCAS for high speed collision threats like F-16s.

Assuming that this Cessna was within range of an ADS-B ground station, a low cost ADS-B solution (both IN and OUT) connected to an iPhone or iPAD app like ForeFlight could have given the Cessna pilots a good warning of the traffic that was heading straight towards them.

Define low-cost, an actually installed ADS-B Out Solution in a certified aircraft, in the price-point of a C-150M may not to be "low-cost" to many owners.

Could have, yes. But as with all technology it has limitations, including needing to be both within ADS-B ground station and SSR coverage (hopefully should have been OK in this case... but lets see what actual altitude the collision happened at), and the small vertical coverage area (the ADS-B coverage pancake or cylinder) won't catch fast vertically maneuvering jets (also should have been OK in this case assuming the F-16 was doing standard instrument approaches). And the traffic warning system needs to be a bit more than a tablet, you need the audio alarms wired into the audio panel/headphones or similar. Something so seemingly simple, but often missing from many tablet type installs I've seen in light aircraft (you need an audio panel with appropriate inputs, older ones don't have that).

With any fast jet traffic situation probalby the most effective thing is you want *them* to know you are there. And in this case that relied on SSR and ATC, and so far it looks like the Cessna was equipped perfectly reasonably with a transponder. What the NTSB and Air Force investigations find will be interesting and hopefully useful in preventing similar accidents in future.

On Saturday, July 11, 2015 at 2:46:37 PM UTC-4, Mike Schumann wrote:
On Saturday, July 11, 2015 at 1:18:17 PM UTC-5, Darryl Ramm wrote:
On Saturday, July 11, 2015 at 8:00:12 AM UTC-7, wrote:
There is much more wrong with the Power Flarm comment.
I have Flarm.
Transponder targets do not provide the information that Flarm targets have.
One has to actually visually search for the transponder target.
At the speeds the F-16 was travelling....Flarm is iffy.

The Flarm part of this thread is going a bit off the rails. PowerFLARM is not targeted at GA use (certainly not in the USA), for very good reasons.. Well maybe the few GA aircraft that should have PowerFLARM are tow planes..

AFAIK the F-16C is not equipped with 1090ES Out, it is equipped with a very capable military/IFF transponder that supports Mode S and will show up as a PCAS alert on a PowerFLARM... given all the usual requirements like the transponder the F16 would need to be being interrogated etc. If the USAF eventually equips their fighters with 1090ES out then a PowerFLARM would provide much more useful warning (surprise! cost and complexity of installing ADS-B out affects the military as well).

PCAS is just not a very effective warning against a fast jet like an F-16 (even if flying 250 knots), you have no clue what direction the treat is in, you may not get much warning time, the jets may maneuver rapidly vertical (outside of the PCAs warning box), they are camouflaged, small and and difficult to see. There are ADS-B based options that a GA aircraft could deploy that would (via TIS-B) better show the F-16 traffic (but they also are not perfect), but the cost and hassle of installing those is likely not appealing to many lower-end GA aircraft owners.

Flarm does not need to be "raised to the FAA's attention".. the FAA is well aware of what Flarm is, including the FAA folks who worked on the recent TABS TSO. The soaring community would seriously harm it's reputation by proposing PowerFLARM for use in GA aircraft, it is just not suitable for that, not in the unique USA ADS-B market. FLARM certainly knows that and is not marketing the product for GA users in the USA. And likewise transponder and ADS-B solutions are not suitable for use in gliders for glider-glider traffic awareness. Unfortunately we are stuck in that space spanning two worlds and for some glider owners/pilots that means, and will increasingly mean, equipping with both PowerFLARM and a transponder and maybe other parts of the ADS-B puzzle (like possibly TABS if that takes off).

I totally agree with your assessment of the limited value of PCAS for high speed collision threats like F-16s.

Assuming that this Cessna was within range of an ADS-B ground station, a low cost ADS-B solution (both IN and OUT) connected to an iPhone or iPAD app like ForeFlight could have given the Cessna pilots a good warning of the traffic that was heading straight towards them.

Hopefully the new FAA interest in low cost ADS-B based beacon technology will result in some serious cost reductions, so that this technology is affordable by everyone.

Sorry for sounding like a Luddite, but, not EVERYONE has a smartphone/IPad in their possession.
I think the FAA (and others) need to realize that not EVERYONE has this "baseline" equipment. While it's "nice to have", I'm also supporting 3 other people in my house.
I have no "real job" currently, even when I did, I had better things to spend my money on.

Keep pushing this thought (smartphone/IPad) and you can yet drive EVEN MORE pilots out of flying.
Then you have the perfect situation...... no planes, no conflicts....... thus, no need for a few thousand dollars for collision avoidance.

If you think, "I'm too cheap", then help me pay house bills, college expenses, etc., THEN I can consider spending money towards FLYING!.

Sorta gives credence towards, "Flying is a rich/old man sport"........

BTW, I've been flying sailplanes sine the early 70's, partly through my time/money as well as my mother and a LOT of others.

PS, "No silver spoon here". Although I will admit, I have a LOT of great opportunities over the decades. For that, I'm very thankful.....

PPS, I own a Nomex suit, so, flame away....... ;-)

"Under 10,000ft, under 250kts"

Unless the aircraft flight manual states otherwise. I think the F-16
flies 300 KIAS in the traffic pattern. Any Viper drivers out there to
chime in?

On 7/11/2015 11:36 AM, Charlie M. (UH & 002 owner/pilot) wrote:
On Saturday, July 11, 2015 at 11:00:12 AM UTC-4, wrote:
There is much more wrong with the Power Flarm comment.
I have Flarm.
Transponder targets do not provide the information that Flarm targets have.
One has to actually visually search for the transponder target.
At the speeds the F-16 was travelling....Flarm is iffy.
"Under 10,000ft, under 250kts", granted, that's still ~450'/second if you're not moving, even more if you're head on.
I would guess the jet was even slower than 250kts "in the pattern".

While I agree that we should try to learn from this accident, sometimes "crap happens" regardless of how many "roadblocks to crap" we throw up.

--
Dan Marotta

Having watched and flown with F-16s in a pattern, I would guess that they're more like 120 in the pattern.

On Saturday, July 11, 2015 at 6:20:55 PM UTC-7, SoaringXCellence wrote:
Having watched and flown with F-16s in a pattern, I would guess that they're more like 120 in the pattern.

I'm not sure why we are talking pattern numbers, this mid-air collision was not near the pattern at KCHS, it occurred outside KCHS Class C airspace. And whether the F-16 was actually flying an instrument procedures at the time, actually under approach radar control, etc. at the actual time of the accident is not clear AFAIK (the flight mission was apparently to practice instrument approaches, it does not mean the pilot was doing that at the time of the mid-air, but could have been... that area is part of instrument approaches into KCHS).

For some (better than usual "journalism", but it still has problems) coverage of this see James Fallows article... http://www.theatlantic.com/national/...he-sky/397880/

As clarified there, and by the USAF in other news coverage, the F-16C was out of Shaw AFB en-route to KCHS and it sounds like had not actually yet got to KCHS/executed an instrument approach--but I may be reading too much into that.

I'm not sure why Fallows thinks this collision might have happened in an MOA, local news sources describe the mid-air as happening over Lewisfield Plantation in Moncks Corner, SC, which is approximately 33°9′36″N 79°59′37″W, something like 20 nautical miles outside the GAMECOCK MOA, and quite close to Berkeley County Airport (KMKS) where the Cessna 150 had apparently departed.

FWIW, Class C airspace has a 20nm uncharted procedural outer area, which means that they have approach radar to 20 miles, and hat would include the point where the mid air occurred. --bob

On Saturday, July 11, 2015 at 7:51:02 PM UTC-7, Bob Pasker wrote:
FWIW, Class C airspace has a 20nm uncharted procedural outer area, which means that they have approach radar to 20 miles, and hat would include the point where the mid air occurred. --bob

Yes, if he was in fact doing an approach at the time... which it seem fair to assume, and you would hope he would be talking to approach even if not, but who knows, the radar and audio tapes should really help solve this one quickly. Even a good idea of the altitude of the mid-air would answer a lot of the possible scenario questions I have.

if he was in fact doing an approach at the time

the RADAR works whether you're on approach or not

On Saturday, July 11, 2015 at 8:39:21 PM UTC-7, Bob Pasker wrote:
if he was in fact doing an approach at the time

the RADAR works whether you're on approach or not

I do know how RADAR works, in lots more detail than we need to get into here. But SSR surveillance only "works" in any useful collision avoidance sense if:

1. The transponders in both aircraft are on and operating correctly, (I'll skip for now any discussion about the KCHS Approach ASR-8(?) primary radar limitations/performance issues)
2. The aircraft are at a suitable height (and location) for SSR coverage for that ATC facility
3. One or both pilots are talking to approach/ATC
4. Approach/ATC provides them with some traffic warning/separation instructions, and
5. The pilot(s) are able to use that warning/instructions to avoid each other

Which is why there are lots of relevant questions about what exactly was happening, which AFAIK at the moment can only be guessed at, including.... Was the F-16 flying an approach or otherwise talking to KCHS Approach (and on VHF/UHF?)? Was the F-16 actually in IMC? Just exiting IMC? Was the Cessna 150 on flight following/talking to KCHS Approach (on the same frequency so they could hear the F-16?)? What altitude did the collision happen at? When/did the F-16 hand off from Shaw RAPCON to KCHS Approach? Were both transponders and encoders actually working correctly? What traffic warning/separation did Approach provide if anything? What were the pilots reactions to any warning? etc., etc., etc.