I found this on the net, it might annoy many here, but nevertheless, 90% of the truth is still not the truth
Soviet planes had several iterations of ejection seats, including but not limited to K-22, KS, KM-1, KT-1, K-36 etc.
Here's how a K-22, a seat used in MiG-19 worked:
One couldn't help but noticing that a separate stabilizing/main chute deployment parachute exists.
The venerable MiG-21 used several different seats, with early models having KS, which in the later models, including MiG-21bis, were upgraded to KM-1 ejection seat. And it's my pleasure to inform the entire congregation of "Second Chute Church" that after the ejection the seat also deploys it's own parachute and lands in the immediate vicinity of the pilot. "Why would they do that?", one may wonder? Well you see, the seat carried the survival kit for the pilot (НАЗ-7), so it had to land near the pilot for him to be able to use that, as neatly illustrated by this caricature from the polish magazine. Whoever doubts me may type all that text manually into translator. I didn't do that, because I believe it will be pretty identical to the russian sources I found online.
They say that the picture is worth that a thousand words, so let me post some for your entertainment:
Exhibit 1: LNA Fishbed shot down in Libya this summer, pilot ejected, survived, captured. Run a reverse image search to read the details. Please note the holy second chute:
Exhibit 2: Libyan Air Force Flogger (MiG-23 also used KM-1) shot down over Benghazi in spring 2011, pilot ejected, survived. Run a reverse image search to read the details. Please note the holy second chute:
Now to the videos, I found one quite interesting and informative. It's mainly about Soviet K-36 (an impressive specimen to say the least!), but I believe there's footage of Fishbed also (maybe KM-1, maybe modified to accept K-36) at 0:55 mark:
Exhibit 3a: @00:55-01:03 a single person ejects from a plane that looks a lot like Fishbed then transforms into two separate chutes, because the seat has it's own
Exhibit 3b: @01:47-01:54 we see footage of Fullback ejection. It apparently uses older generation of K-36 seat, because two ejected dummies are separatee from their seats... which soon after deploy their own chutes, doubling the number of chutes. Note that the seat chutes are slightly different from persons' chutes. I hope none of you are going to claim a four-seater Fullback exists.
Exhibit 3c: @01:55-02:00 we are treated to a footage of ejection from the tail of a "flying lab". I believe this is also an early gen K-36. As one can notice (watch at 0,25 speed) the seat deploys it's own chute and can be seen dangling near by the pilot in the upper right corner after disappearing from the frame for a second.
"Well why don't you see seat having their own chutes in some well documented crashes at airshows?" Well, I got two versions for that. Either it's disabled/removed because the pilots don't need survival kit at the airshow, OR they were equipped with later gen K-36 (called K-36M, K-36D and K-36D-3,5) which got rid of the seat chute in lieu of strapping survival kit (upgraded to НАЗ-8) directly to the pilot:
Actually, one can see footage @01:16-01:19 of ejected pilot with a raft dangling beneath him after two Fulcrums collided at 1993 RIAT. Or one can look up footage of Fencer shot down by Turks. It also features two pilots parachuting down with rafts dangling beneath them. Su-24 was the first aircraft to feature K-36 seat and thus is eligible to be upgraded to newer K-36 models.
So there you have it: the second chute apparently seen by the locals (but so far absent from any footage) is not a conclusive proof of the second downed aircraft, since MiG-21 would have produced two chutes by itself.