Things That Go Bump in the Night

"Snap...........snap...............snap!"
My attention was instantly focused on this new noise!

It's another of those old aviation adages: At night, the engine goes into "automatic rough". This means while flying at night, pilots are likely to be listening so closely to the sounds their aircraft makes, they'll notice normal vibrations and sounds and think they've not heard them before.

Good helicopter pilots are attuned to their machines in this way ALL of the time. So many things on helicopters move to do their jobs, the machines are wonders of noise and vibrations!
Abnormal sounds and vibrations need immediate attention!

I was teaching Jeff to land on inclined ground......."slope landings".
In my 35 years of teaching in helicopters, I've learned to watch a students' technique when doing this difficult task. In order to do them well, you must be comfortable with coordinating all the controls together. Many helicopter pilots never get completely comfortable with landing on sloping ground.

Jeff was one of those "naturals". He learned everything so quickly, there was a cockiness about him that concerned me a little. It was true with slopes too........he concentrated on trying to do each landing perfectly.

"Snap........snap........snap!"
There it was again!
This, in a practically new R22! And once the bugs are worked out of a new R22, they are as dependable as your new Ford or Chevy!

So to Jeff:
"Did you hear that?"
He cocked an ear for a moment and answered, "Hear what?"
"That snapping sound. I heard a snap, snap, snap.....rhythmic.......
about once a second."

He brought the little bird to a stable hover and we both listened.
The engine hummed like a sewing machine.
No unusual vibrations.......no "snaps"!

So we went back to approaching the uneven ground........
"Snap...........snap...........snap..........snap!"

"There Jeff! Hear that?"

Again, back to a normal hover......... four ears attuned to all the noises and vibrations.

"I don't hear anything out of the ordinary", Jeff replied.
"Okay, let's do one more and we'll do some hovering autorotations."

And as soon as he started his gentle descent........
"Snap..........snap...........snap..............snap!" This time I didn't say a thing.....I just listened to try to determine where the noise was coming from.

"Snap.........snap...........snap."

It was coming from my right.
Strange. Not, as I expected, from the rear of the helicopter!

"Snap.........snap!"

I turned to look at Jeff. He was vigorously attacking a piece of "Juicy Fruit"!

My student was one of those that worked a little bubble of air into his gum as he chewed, then popped that bubble with a resounding "Snap"!

Like some of the teachers I had encountered in my early school days, I stuck my hand toward him, palm up............"okay, spit it out!"

No more strange noise in the cockpit. And from that point on, I "preflighted" Jeff to insure there was no "Juicy Fruit" on board when we started our lesson!