737 vs glider

FWIW, I had a close encounter with an F-15 a few years ago. Local ATC had been sending inbound military traffic over our class D airspace at 3500 feet. I called local ATC, their response was "if you do not have a transponder I cannot see you". New young controllers rely totally on the technology. We have since had several get meetings and now have a great relationship with them.

Also gliders when circling have a ground speed that is less than 40 mph so the radar software ignores the contact. So "type and altitude unknown" call will not be made.

C5

No wonder piper cubs are painted yellow,.

Seems even old glider pilots rely more on ATC keeping them from conflict
than with keeping a good eye outside.Â* It's not just an affliction of
the young.

On 11/17/2017 6:45 AM, wrote:
FWIW, I had a close encounter with an F-15 a few years ago. Local ATC had been sending inbound military traffic over our class D airspace at 3500 feet. I called local ATC, their response was "if you do not have a transponder I cannot see you". New young controllers rely totally on the technology. We have since had several get meetings and now have a great relationship with them.

Also gliders when circling have a ground speed that is less than 40 mph so the radar software ignores the contact. So "type and altitude unknown" call will not be made.

C5

--
Dan, 5J

Some 20 years ago I was coming in to land a glider at a smallish airport in NE US, where I was towed out of earlier that day, and when I was crossing the field at pattern altitude a pair of military jets passed UNDER me. It was July 3. and they were practicing for the next day's official fly-by. I was not pleased.


On Friday, November 17, 2017 at 8:45:13 AM UTC-5, wrote:
FWIW, I had a close encounter with an F-15 a few years ago. Local ATC had been sending inbound military traffic over our class D airspace at 3500 feet. I called local ATC, their response was "if you do not have a transponder I cannot see you". New young controllers rely totally on the technology. We have since had several get meetings and now have a great relationship with them.

Also gliders when circling have a ground speed that is less than 40 mph so the radar software ignores the contact. So "type and altitude unknown" call will not be made.

C5

I was on downwind to land my Taurus on a small strip in the Virginia Blue Ridge Mountains. My transponder started blinking which does not normally happen in mountain valleys. Then two F-16s whizzed by at the same (very low) altitude not much more that 500 ft away. I do not know if they saw me. I have an appointment to get ADS-B installed next week and wonder if it will help.

The reason you transponder was blinking is probably that the F-16s were interrogating you - almost all US fighters have transponder interrogators and can trigger your transponder - your location is then shown on the fighter's radar display (correlated to a radar hit if it is looking there). With a radar lock, the pilot will then see you highlighted in his HUD or helmet.

Some of you seem to think the military doesn't care about midairs and is nonchalant about zooming around at low level. That is totally wrong - dead is dead whether you are in a 1-26 or an F-35! And the systems in mil aircraft put civilian aircraft to shame. For example, the F-15E that I'm most familiar with has a transponder working on Modes 1, 2, 3 (A % C), 4, 5, and S; an interrogator that can look for all those modes, a radar that can pick you up well over 100 miles away; a targeting pod that can identify you visually; a huge bubble canopy so you can actually see out (much like a glider but unlike just about any other civilian plane - especially airliners) and two highly trained and motivated aircrew that really don't want to hit you.

If you don't have either a transponder or a PowerFLARM in you glider, you are a big part of the problem.

And yes, military is getting ADS-B in it's aircraft - but that takes time and money. You want a tax hike to pay for it? I do, but I doubt you could convince Congress!

Kirk
66

On Friday, November 17, 2017 at 1:30:58 PM UTC-5, kirk.stant wrote:

Some of you seem to think the military doesn't care about midairs and is nonchalant about zooming around at low level. That is totally wrong - dead is dead whether you are in a 1-26 or an F-35! . . .
If you don't have either a transponder or a PowerFLARM in you glider, you are a big part of the problem.
Kirk
66

snip

What he said. I've had transponders in all the gliders I've owned since 1996, and for sure the military guys ARE paying attention! Once while ridge soaring on a ridge in the middle of the Shenandoah Valley, I spotted a couple of jets right off the deck coming in my general direction (yes, the xponder was blinking lilke all get-out). I watched both of them swing away, rock there wings at me, and drop right back down on their course.
The Curmudgeon

Tax hike? No.Â* How about a welfare reduction?

Otherwise, great information!

On 11/17/2017 11:30 AM, kirk.stant wrote:
I was on downwind to land my Taurus on a small strip in the Virginia Blue Ridge Mountains. My transponder started blinking which does not normally happen in mountain valleys. Then two F-16s whizzed by at the same (very low) altitude not much more that 500 ft away. I do not know if they saw me. I have an appointment to get ADS-B installed next week and wonder if it will help.
The reason you transponder was blinking is probably that the F-16s were interrogating you - almost all US fighters have transponder interrogators and can trigger your transponder - your location is then shown on the fighter's radar display (correlated to a radar hit if it is looking there). With a radar lock, the pilot will then see you highlighted in his HUD or helmet.

Some of you seem to think the military doesn't care about midairs and is nonchalant about zooming around at low level. That is totally wrong - dead is dead whether you are in a 1-26 or an F-35! And the systems in mil aircraft put civilian aircraft to shame. For example, the F-15E that I'm most familiar with has a transponder working on Modes 1, 2, 3 (A % C), 4, 5, and S; an interrogator that can look for all those modes, a radar that can pick you up well over 100 miles away; a targeting pod that can identify you visually; a huge bubble canopy so you can actually see out (much like a glider but unlike just about any other civilian plane - especially airliners) and two highly trained and motivated aircrew that really don't want to hit you.

If you don't have either a transponder or a PowerFLARM in you glider, you are a big part of the problem.

And yes, military is getting ADS-B in it's aircraft - but that takes time and money. You want a tax hike to pay for it? I do, but I doubt you could convince Congress!

Kirk
66

--
Dan, 5J

I'm curious how this happens. ATC sees gliders on their radar in Tucson. Wouldn't they SW flight get a traffic alert with "type and altitude unknown"? from ATC. ATC has the job of deconflicting and should worst case it as the unknown traffic is the same altitude as the 737. We have been contacted by Tucson TRACON and they would like to meet in order to share their concerns over transponder equipped gliders being at 10,000' over Pinal Airpark (KMZJ). We haven't met yet but take a look at the proximity to the Tucson Class C. A long ways away and they're complaining about us that are transponder equipped. Seems like a bad omen.

Randy "AV8"

On Tuesday, September 26, 2017 at 11:32:33 AM UTC-7, LOV2AV8 wrote:
I'm curious how this happens. ATC sees gliders on their radar in Tucson. Wouldn't they SW flight get a traffic alert with "type and altitude unknown"? from ATC. ATC has the job of deconflicting and should worst case it as the unknown traffic is the same altitude as the 737. We have been contacted by Tucson TRACON and they would like to meet in order to share their concerns over transponder equipped gliders being at 10,000' over Pinal Airpark (KMZJ). We haven't met yet but take a look at the proximity to the Tucson Class C. A long ways away and they're complaining about us that are transponder equipped. Seems like a bad omen.

Randy "AV8"

There should be no surprise at all that this can happen. ATC requires transponders in aircraft to provide reliable seperation and gliders are very hard to visually see and can be at altitudes and in locations that have high traffic densities of fast jets and airliners.

Can primary radar see gliders? Sure. Sometimes.

Is that anything as effective (or frequent useful at all in practice) as having a transponder and seeing the glider via SSR? No.

And having a transponder also makes the glider visible to TCAS, the wonderful last resort tool to help avoid mid-air collisions. And having a transponder makes your aircraft visible via TIS-B to ADS-B In and Out equipped aircraft in busy airspace (i.e. will should have ADS-B ground station coverage).. Primary radar is not relayed to TIS-B or anything else.

ATC may or may not see gliders on primary radar. And if they do approach primary radar does not provide altitude data. Primary radar relies on doppler discrimination to see aircraft against ground clutter, what that looks like varies dramatically depending on the area/terrain. Gliders don't fly often fast towards or away from the radar antenna, and they stop and thermal slow where they may disappear off the display. Operators may have to turn up the doppler discriminator significantly to reduce target clutter caused by things like traffic on freeways or wind power generators. The later for example makes gliders flying to the East of Travis AFB totally invisible to primary radar, all in a very busy area full of traffic coming into and out of the San Francisco Bay Area. Travis RAPCON (who provide civil as well as military ATC in that area) love gliders with transponders....

When you talk to those ATC folks, which is certainly a good idea, ask for a tour of their facility and have them show you what they are dealing with and ask them about ground clutter, and have them show you the primary radar and doppler discriminator effects.

For transponder equipped gliders it may be that they want to understand your operations a bit more, might want folks to be in radio communications with ATC, etc. Talking to them is the only way of finding out. It can really helps to have somebody from the glider community who is an experienced power pilot, ideally with an instrument rating or airline experience etc. to be in those conversations.

As I'll point out in other posts, you should not be just looking at Class C or simmilar proximity, you should be looking at STAR and SID procedures as well when evaluating local traffic risks. Of course traffic can come from anywhere at any time, but STAR and SID routes give you a good idea where lots of traffic is expected to be.

Funny you mention STAR's. Dingo is a point 10 miles NW of El Tiro gliderport and most traffic comes right over the top of us on the 115 degree heading. El Tiro has been operating sailplanes for 34 years. Victor 105 and Victor 16 are both to our west and east and would go a long way to deconflict traffic. .

Dingo 5 arrival
https://resources.globalair.com/dtpp...00430dingo.pdf