Question: Why do modern jets have wing tips that point upward at 90 degrees? It seems like jets for the past 30 years have flown fine with flat wings.
— submitted by reader Dennis, Frederick, Md.
Answer: The wing tips you describe are called winglets. Winglets make wings more efficient by taking some of the energy from the wingtip vortex and creating lift and forward energy, allowing lower fuel burn.
Q: Why do some of the models of current passenger jets have winglets and others don't?
— Frank Breveglieri, Spring Lake , Mich.
A: Winglets are becoming more common due to the cost of fuel. The function of a winglet is to harness the energy in the wingtip vortices. By utilizing these vortices, fuel efficiency is improved. Usually a winglet can improve the fuel burn by over 2%. Over a short time, the winglet saves more fuel than the cost of installing it.
Q: What's the difference between winglets and sharklets?
— Charlie, Manchester,N.H.
A: The name is the only real difference. They accomplish the same thing.
Q: In your recent column about who gets to ride in the jumpseat, you forgot to include cadet pilots who fly on observation flights after their technical course and before their initial simulator training. I myself am a cadet pilot and will soon be going on a few observation flights.
— Azam Khan, Pakistan
A: Yes, in some countries cadet pilots can ride jumpseat. Unfortunately, not all countries allow it.
As we train the next generation of pilots I hope we are wise enough to allow them to learn all they can from the vast experience of the senior pilots flying today. Allowing jumpseat observation flights is one good way.
MORE: Read previous columns
John Cox is a retired airline captain with U.S. Airways and runs his own aviation safety consulting company, Safety Operating Systems.