Airliners flying into known turbulence - is it sometimes economically acceptable?

Question

A few years ago, I was a passenger in a 767 flying between Australia & NZ. Shortly after t/o the flight deck came on to tell us that the company had told them that the a/c was needed back at base asap, so the trip would be relatively quick. About half way into the trip, we encountered turbulence severe enough to cause a pretty dramatic wing drop, what felt like sig altitude loss and loud engine spooling. It was during meal time and all the meal trays crashed onto the floor- people were vocally anxious (some screaming) and a PA ann told the FAs to drop down & secure. I don't think that anyone was injured and shortly afterwards the flight deck came on and explained that they had clipped the edge of a storm cell and that drycleaning bills would be picked up by the company!

My question is - since storm cells are detectable by cockpit radar, is there such a thing as a 'safe' distance from them, and is that distance acceptably reduced in airline ops?

Answer 1

No pilot worth his employment should ever fly into a known storm cell (thunderstorm, CB), but all will fly into known turbulence.  The question is how severe is the turbulence.  I have flown many times into 'light chop' or 'light turbulence' to save time and fuel if going around would be costly in time or gas.  Turbulence is such a broad term.  I don't know many pilots (maybe some military who don't have passengers) who would like to go into moderate turbulence, and no airline pilot will go into severe turbulence if he has another path available.  Sometimes, however, it is unavoidable.  There is no "turbulence detector" on the flight deck and it is not always associated with cloud.  Sometimes, after you enter an area of turbulence, you have no choice but to keep going through it to get to the other side.  Remember that pilots are people too and hate a bumpy ride as much as the next guy.  We are constantly listening to the radios to see if others are reporting turbulence to see if we can avoid it with an altitude change or a minor course deviation.

Cheers

Answer 2

The general rule of thumb is to clear any storm by at least 20 nautical miles from the edge of the precipitation returns (not the center of the storm).  When clearing a storm from above, it's recommended to allow 1,000 feet for every 10 knots of wind aloft, i.e. if the winds are 60 knots, clear the storm top by 6,000 feet.  These distances are never (or should never be) sacrificed for the sake of saving time.

There shouldn't be any airline out there that would intentionally go near or through thunderstorms to save time.  That's not negotiable for most people.  I don't think the pilots actually knew about the storm there because they would have warned people about it and have the flight attendants discontinue meal service well ahead of the time they got that close to storms.

The only time I have "clipped" the edge of a storm was a rapidly developing storm.  There was nothing showing up on my radar.  I was flying in clouds, so it was an embedded storm that I couldn't see with my eyes.  Suddenly, my radar went from nothing to yellow and red about 8 miles in front of me within a matter of about 20 seconds.  I made an immediate 90 degree turn away from it, but I still got a few good jolts out of it, even though I did not go through it.

The even trickier turbulence is clear air turbulence.  Turbulence doesn't always come from storm cells.  Clear air turbulence is experienced far more often and it poses a problem because it cannot be detected - pilots must rely on the reports of other pilots.  Often, the turbulence can extend in areas hundreds of miles long and at altitude ranges of tens of thousands of feet.  There's often just no way to avoid it.  Many injuries happen each year as a result of clear air turbulence.  It's never because something on the airplane failed - it's always because people are walking around or aren't buckled up.

To directly answer your question, no, airlines shouldn't fly into known turbulence like that just for economic reasons.  Some pilots may feel the pressure to take shortcuts, but all training warns against those mental traps and it goes against just about any company's policies.