Words of Advice:

"Never Feel Sorry For Anyone Who Owns an Airplane."-- Tina Marie

If Something Seems To Be Too Good To Be True, It's Best To Shoot It, Just In Case." -- Fiona Glenanne

Flying the Airplane is More Important than Radioing Your Plight to a Person on the Ground
Who is Incapable of Understanding or Doing Anything About It.
" -- Unknown

"There seems to be almost no problem that Congress cannot, by diligent efforts and careful legislative drafting, make ten times worse." -- Me

"What the hell is an `Aluminum Falcon'?" -- Emperor Palpatine

"Eck!" -- George the Cat

Thursday, March 16, 2017

RVSM Can Fuck You Up

"Reduced Vertical Separation Minimums" has airplanes in oceanic flight separated by a thousand feet in altitude. What happens when two airplanes, going in opposite directions, pass each other and the one at the higher altitude is a lot larger?

It can fuck up the other airplane's day. An A-380 over the Arabian Sea passed over a Challenger 604 a couple of months ago. Challengers aren't tiny airplanes, at 48,000lbs, but that's a toy compared to an A-380 at over a million pounds. The Challenger hit the A-380's wake and rolled several times. Both engines initially flamed out, the airplane lost 10,000' in altitude before the pilots fully recovered it and made an emergency landing in Oman. There were injuries, one serious, and the airplane was damaged beyond repair.

I don't know if transoceanic ATC worried overly much about wake turbulence, but I guess they're doing so now.


CenterPuke88 said...

This is the problem with the GPS navigation systems. On "direct" flights and segments, aircraft seldom pass head-on, superimposed. On the point to point segments, the increased navigational accuracy means that opposite direction aircraft are often exactly superimposed.

When I was learning to fly, at the start of the GPS era, we tended to fly to the right of the course centerline...the same way they taught on VOR airways...not too much right, but just a little, "in case".

I've become much more cautious with crossing flight paths now, offering small turns or 500 foot climbs more often as a heavy or super crosses over an other aircraft's path.

LRod said...

Uh, RVSM isn't just oceanic any more. It's in use all over the U.S.

Even 2,000' wasn't enough to prevent visual anomalies back in the old days. Airplanes passing each other in opposite direction in the 30s (Flight Levels) often had the illusion of the higher oncoming aircraft looking as if it were climbing through the lower one's altitude. Earth's curvature, and all.

Granted, optical illusions aren't the same as actual physical effects, but, still.

I was gone before the 380s entered service, but I just recently learned they're not "heavy"--they're "super", as the Center Guy alludes. And they get an extra mile (I believe) in the terminal areas.


CenterPuke88 said...

Anyone entering the Terminal Airspace behind a Super is now at least 10 miles in trail and the in trail minimum of 7 now applies below FL240 and 250K.

In thinking about Comrades point, I suspect this was a same direction issue, where the A-380 overtook the CL30 and then shook it like a terrier shakes a rat. Domestic RVSM tends to still have 2,000 feet between same direction/superimposed flights, simply because of IAFDOF...oceanic often runs everyone in one direction on a track and uses ALL of the altitudes (thus, the 1,000 spacing). I bet small aircraft pilot will start watching the wind more closely and cheating upwind if a heavy or a super cruises over them.