Chimes

You know the chime that accompanies the seatbelt sign when it cycles on or off? It happens to be my text message alert tone right now-appropriate, I suppose. Well, there's a slightly more annoying sound in the cockpit that is supposed to represent various different alerts such as:

HF and VHF SELCAL - When air traffic control needs to get a hold of us, they have the option of sending a SELCAL (selective calling) ding that alerts us. Upon hearing the ding, we need to look either on the forward EICAS screen where the engine information is displayed for a clue as to what the ding was, or overhead to see if the SELCAL light is on. Unfortunately, some earlier airplanes didn't have that EICAS notification feature, so we only have the overhead to differentiate the sounds.

Flight Attendant Call - We aren't immediately sure if it's ATC calling with a flight level change or if a flight attendant is checking to see if we need a bathroom break. The look around the cockpit for the various clues to the source can be amusing to someone riding in the jumpseat.

During the preflight, it's a regular ding-fest. As we request the flight plan data to be uploaded to the airplane, dings come in rapidly (I've lost count at eight dings in less than a minute) for these items and more:

Forecasted winds at altitude uplink
Route uplink
Takeoff performance data uplink

Unfortunately, this is a time when the crew-chief on the ground calls us through a headset plugged in at our nose wheel. We may easily think it's another nuisance ding and not answer him as these flight plan items are coming in.

As we taxi out, we could also miss a flight attendant call when the latest ATIS information is delivered or we get our load closeout information, which includes the number of people on board, the weight of the airplane and our stabilizer trim setting.

Inflight, these dings create a Pavlovian response. Around an hour after takeoff, flight attendants usually call with meal choices for us. Just as your mouth starts to water after hearing the ding, it's always a letdown to discover that it was just the other guy updating the winds in the FMC.

Years ago, I met two Boeing engineers while I was riding in the back of an MD-80 to Dallas. On my left was an engineer who was the liaison for Boeing to the FAA as they made changes to the cockpit flight computer known as the FMC and to my right was an engineer who did the actual programing of any new features in the box.

They were excited to tell me about the new CPDLC or Controller Pilot Data Link Communication feature they were testing out on one of our 757s. The idea was that an Air Traffic Controller could send us a text message that would tell us to climb, descend, turn or change our speed. The test program would only be for Miami and a few of our 757s. Later this innovative concept expanded to other air traffic facilities for use primarily with the 777 and some newer Airbuses. After the test period, it was deactivated on the 757.


I couldn't believe my luck. Finally I could give them some input about the ding issue.

"When ATC contacts you via this CPDLC thing, I would imagine there would be a ding?" I asked.

"Yes!" one of them said proudly.

I then prodded them on how we were supposed to differentiate the different dings for different functions, all sounding exactly the same, as they came in.

The engineer asked why we didn't just look at the EICAS screen as it would either say, CPDLC, FMC, Ground Call, or Flight Attendant.


I explained that this was nice, but that more than half of our 757s didn't have this EICAS 'ding alert' feature.

His partner jumped in, describing the studies Boeing had done that indicated that humans could only differentiate between five different sounds in a cockpit.

I sighed and pleaded for a simple telephone ring for the flight attendant call that comes in on the handset, and then for a few different tones for the rest. If I were to mistake the FMC alert for the HF radio call with these new sounds, how would that be different to what we have now?

I felt bad for them. Pilots love Boeing products so I think they were a bit taken aback. I dropped the subject and stretched out in the middle seat of the MD-80. I certainly wasn't going to mention my second peeve to them. That is:

Dim and Dimmer

Depending on the airplane and configuration, there are between 32 and 34 different dimming switches and knobs to change the lighting intensity on the 757 and 767 cockpit lights. Of course, I knew you'd think I was exaggerating, so I made a quick video showing each light and dimming knob from a recent flight.



Don't get me wrong. I've written earlier about how much I love the 757 and these annoyances are amusingly minor in the grand scheme of airplane design. Maybe flying the MD-80 for a while will give me a new level of appreciation for this grand airplane.

Cockpit Chronicles takes you along on some of Kent's trips as an international co-pilot on the Boeing 757 and 767 based in New York. Have any questions for Kent? Check out the Cockpit Chronicles Facebook page or follow Kent on Twitter @veryjr.