Class E Airspace and Transponder Collision avoidance

Speedbird1

Filing Flight Plan
Joined
Apr 14, 2019
Messages
4
Display Name

Display name:
Speedbird1
Hello...

If a GA airplane is flying in class E airspace at 6,000 under VFR without a transponder and is on a collision path with say an Airliner, would TCAS still work (I assume not), would ATC be able to see the GA plane on radar?

With a potential closure rate of 350 kts (250kts for say an airbus A320 and 100kts on a C-172) things obviously happen fast; however, assuming the Airbus is under an IFR flight plan and operating below 10,000ft are there any procedures in place to stop this, aside from the obvious (looking out the window)? I'm not IR but wondering, if you are flying on a IFR flight plan under VMC conditions, are you required to scan outside still?

TIA!
 
Last edited:
1) No, TCAS works off the other aircraft’s transponder. 2) Yes, if under radar coverage the aircraft will be seen by ATC as a primary target (blip). Minus some ARTCC radar (ARSR-4) that primary target will have no speed or altitude. Obviously no ID either.

Yes, still required to see and avoid while operating IFR in VMC.
 
Last edited:
Hello...

If a GA airplane is flying in class E airspace at 6,000 under VFR without a transponder and is on a collision path with say an Airliner, would TCAS still work (I assume not), would ATC be able to see the GA plane on radar?

With a potential closure rate of 350 kts (250kts for say an airbus A320 and 100kts on a C-172) things obviously happen fast; however, assuming the Airbus is under an IFR flight plan and operating below 10,000ft are there any procedures in place to stop this, aside from the obvious (looking out the window)? I'm not IR but wondering, if you are flying on a IFR flight plane under VMC conditions, are you required to scan outside still?

TIA!

YES, you must still scan for traffic.
 
I was in Class E at 3,000'MSL coming back to Arlington from Port Townsend. Thats the general area where Boeing conducts a lot of test flights. So, its not unusual to see a 777 doing climbing and descending turns and such. Its all routine VFR "see & avoid" type stuff. No worries, except you don't want to get caught in their wake turbulance.

I don't have a transponder. The only avionics I have is a handheld radio. As I was crossing between the peninsula and the southern tip of Whidbey Island, I saw that I was going to pass a 777 at roughly the same altitude and opposite direction. We weren't going to pass close enough to conflict. But, I was pretty certain those guys would see me as long as someone was looking out the front.

Sure enough, when we got to the closest point, I rocked my wings and he did the same. Pretty cool!

By the way, I've asked Seattle approach previously if they could see my primary target on radar. They said they had me for a few seconds. But, lost me as I crossed the shorline. I was at 2,200'msl.
 
If a GA airplane is flying in class E airspace at 6,000 under VFR without a transponder and is on a collision path with say an Airliner, would TCAS still work (I assume not), would ATC be able to see the GA plane on radar?

With a potential closure rate of 350 kts (250kts for say an airbus A320 and 100kts on a C-172) things obviously happen fast; however, assuming the Airbus is under an IFR flight plan and operating below 10,000ft are there any procedures in place to stop this, aside from the obvious (looking out the window)? I'm not IR but wondering, if you are flying on a IFR flight plane under VMC conditions, are you required to scan outside still?
Unless you are under 3000AGL you should be following the hemispheric rule and have 500 feet separation. Have fun riding the wake turbulence from the Airbus, though.

Also, the size of the Airbus should make up for the closure rate so unless you turn into its path or vice versa then things shouldn't happen as fast as you think.

And as been already answered, yes you are still required to scan outside.
 
Thanks for all the answers. As always, expect the unexpected! I was flying a route home once, Eastbound (080, at 5,500) and had a guy (in level flight) coming right at me. I avoided, s/he didn't even see me (or at least acted like s/he didn't) . I always figure, just because the altitude rule applies, doesn't mean people follow it!
 
https://www.ntsb.gov/_layouts/ntsb....v_id=20060906X01297&ntsbno=LAX06FA277A&akey=1

The passenger in seat #7 tightened his lap belt and the inboard attachment end came out from between the seat cushions. He jumped up from seat #7 and sat down in seat #5 and buckled the lap belt. When he went to tighten that belt, the inboard attachment end came out from between the seat cushions. He then grabbed onto the attached portion of the seatbelt, leaned over in the prone position, and held on.

I'd really hate to be that guy.
 
Back
Top