July 29, 2002
Ukraine Crash

I finally got a good look at some video of the Ukraine crash. As usual, the press monkeys are just making a big deal over how many people got killed and that the government is arresting everyone in sight. Here's some stuff that hasn't been covered so far:

  • Recent accounts state that the engines went silent, and then the plane augered in. Engines are rather important to an airplane's survival, so it's usually pretty hard to turn them off even on purpose. A MiG-29 augered in at a Paris airshow some years ago after a double birdstrike. It's possible that happened here, but an Su-27 is a lot bigger than a MiG-29. Mechanical failure will be the thing they look most closely at.
  • The video I see shows the plane decending vertically with the nose pointed at the horizon (hold your hand flat, point it at the wall, then move your hand down toward the floor), then there is a positive control movement. The plane banks left (as you bring your hand down, roll it left). This indicates the pilot had positive control even after engine-out.
  • Most importantly, the pilot and WSO (Weapon System Officer, the one that runs all the electronics) are still inside the plane as it hits the ground. An ejection seat means never having to say you're sorry. You want out, you get out fast. These guys were sticking with this crate after a wingtip had already hit the ground.
  • You can see a corner of a parachute as the plane cartwheels across the tarmac. The guys didn't get out until the plane was well beyond saving.

So what does all that mean? Something happened that knocked the engines out or caused the throttles to go to idle. No engines means you're going in, get out now. The positive control movement says to me these guys chose to stay with the plane, probably because they saw they were heading for the crowd. Unfortunately you can't climb when you got no engines, and they went in anyway. But these guys stayed with it until after the plane had actually hit.

Some REMF mechanic or fueler is wetting his pants right now, because it was his screwup that caused the accident. The organizers are wetting their pants because they didn't define the aerobatic area properly to exclude the spectator area. The CO's are wetting their pants because they didn't jot every i and cross every t to ensure things were right.

But the poor bastard pilot and WSO (what the hell was a WSO doing riding along on an airshow hop anyway?) who laid their asses on the line may end up taking the fall, because they aren't connected enough to avoid prosecution nor anonymous enough to fade into the background.

Caveat: I am not a pilot. I play one on the computer a lot, I read aviation resources voraciously, and I have an eye toward detail. The video is also not complete by a long shot. Take this all with your regular extra-large grain of salt. Personally, I'm waiting on my Aviation Leak issue, which will have the non-monkey coverage you need to make a real judgement.

Posted by scott at July 29, 2002 07:29 PM

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I agree, very strange accident. The pilot seems to have some control but the plane just doesn't want to fly any more. Perhaps without the engines the fly-by-wire doesn't work properly, so although you have some control over attitude the aerodynamics are all wrong and you lose lift.

There was a report that the aircraft had struck another aircraft on the ground shortly before the problem and that debris from that collision killed the engines. There was a picture of a transport aircraft near the crash site with a tarp over its nose, but I don't know if that was the aircraft in question.

Coming so soon after the Ukranians shot down a Russian airliner, I get the impression that there's going to be plenty of blame to go around on this one.

If you see a decent report on what happened, do post an executive summary for us, won't you?

Posted by: Robert UK on July 31, 2002 01:49 PM

AvWeek ran pictures of what was left of the airliner that got shot down. Seems the SA-5 is filled with ball-bearings, because there were dozens of perfectly circular holes about as big as two fingers all over it. Looked like a tin can that got hit with a shotgun. A really big shotgun.

In a modern jet the control surfaces are all powered, usually by hydraulics. When the engines quit so does the hydraulic pressure, and then the stick gets set in concrete. That's what makes the positive control so strange... they shouldn't have been able to control it at all. I can only think that either the engines were still turning and something else went wrong, or the Su has some sort of fancy backup widget to keep things running.

Will keep an eye out and report what I read!

Posted by: scott on July 31, 2002 06:37 PM

Everyone talks about 'getting a Sidewinder up the tailpipe' as if the missile explodes inside the plane (although Rapier does exactly that). Infact at the last moment the missile veers off slightly and explodes along side the plane in an effort to disable the crew, on the grounds that they probably have spare aircraft but not crews for them. I don't know exactly but I assume SA-5 does something similar. The warheads are basically giant-sized hand grenades rigged to produce a ring of fragments.

Warbirds usually have wire backups incase the hydraulics get shot out, but presumably the handling changes radically without the servos. Although if anything it looks like he pulls up too hard causing a stall, which is what made me wonder about the secondary aerodynamics - it could pull a huge angle of attack with the avionics stabilising things but stalled without that.

There's a nice anecdote on the 'Project Cancelled' on the Fairey Delta II. The Delta II didn't have a wire backup for the flight controls. On a test flight the fuel system failed causing the engine to shutdown. The only backup was a hydraulic accumulator that held about enough energy for about 500 control movements. The test pilot managed to land safely by making really small movements on the controls.

Posted by: Robert UK on July 31, 2002 07:22 PM

I dunno... early models of the sidewinder seemed to quite merrily smack the ass off the target drones they were chasing. But these were all, like, 9B, 9C models probably. Bomber-killers.

What I found surprising was the warhead ain't all that big. Airplanes are just a wrong turn away from getting torn apart by the wind, so it doesn't take much to knock them down if you can get close enough. If you shot any AA missle at, say, a tank, I'm not sure the guys inside would even know anything hit them. BONK

Thats why I laugh so hard when I think about the dumbass helicopter that got tagged by an LGB 2000 lb. bomb in the Gulf war. One-tenth of that amount would've been plenty to kill it. I bet they were picking bits of that thing out of the walls of the next village.

Posted by: scott on July 31, 2002 07:49 PM

There are some combined AA/AT systems (Roland? can't remember) presumably they just put a shaped charge cone in the front of the fragmentation warhead (pretty sure they don't use different missiles). Probably wouldn't kill a modern MBT from the front, though.

My uncle told me about a gun camara tape he saw from the Gulf War (if you're reading this on the Way Back Machine, perhaps I should say the First Gulf War :). If you recall the RAF Tornadoes couldn't get their LGB's to guide. Turned out the aerodynamics on the LTD pod were wrong causing the head to nod and disrupt the laser. So the brought in Buccaneers (over 40 years old at the time) with Pave Spike pods. Initially the Bucc's just lased (for an 'assist') but later they put bombs on them too. One of their 'kills' was an aircraft.

Apparently the target was a transport on an apron. The bomb didn't fuse, but on the tape you can clearly see the raised tail falling backwards to the ground. Good enough for an aircraft kill sticker, not bad for a ground-attack bird with a dud weapon!

Posted by: Robert UK on July 31, 2002 08:36 PM
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