Narrative:

Our company operates several embraer 135ER transports. The problem I am reporting involves the altitude alerter warning tone on the newer aircraft in our fleet. The tone is so loud that it blocks out any ATC transmissions while it does its 'beep, beep, beep' signal 1000 ft before reaching the selected altitude. The vol and duration of the alert is sufficient to block out a normal ATC instruction. While no violations have happened yet, we frequently have to ask ATC for a repeat. The problem is particularly annoying on departures with several intermediate level offs. I wonder if other operators of this type aircraft have the same problem. Also, I find it hard to believe that FAA certification standards would allow an altitude alerter to block radio calls. Perhaps NASA can explore this issue. Callback conversation with reporter revealed the following information: reporter advised that the company policy is to use headsets at all times and reinforced his concerns that, even with the headsets in use, the alert is so loud that he had just this day missed two ATC communications and had to have them repeated. He also advised that he had received mixed reports as to whether the volume is adjustable. He emphasized that earlier delivered examples of the same aircraft had a much quieter aural level that was loud enough to get your attention, but not to obliterate other aural messages in the cockpit environment. He felt the level of the alert to which he objected was appropriate to a 'warning' when the aircraft deviates from a cleared altitude but totally inappropriate as a normal 'information alert' when approaching such an altitude in the course of normal operations.

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Original NASA ASRS Text

Title: PLT OF E135 REPORTS THAT ALTITUDE AURAL WARNING ON LATEST MODEL IS TOO LOUD, TOO PROLONGED AND MAY BE A HAZARD IN THAT IT COULD OBSCURE ATC TRANSMISSIONS.

Narrative: OUR COMPANY OPERATES SEVERAL EMBRAER 135ER TRANSPORTS. THE PROBLEM I AM REPORTING INVOLVES THE ALTITUDE ALERTER WARNING TONE ON THE NEWER AIRCRAFT IN OUR FLEET. THE TONE IS SO LOUD THAT IT BLOCKS OUT ANY ATC TRANSMISSIONS WHILE IT DOES ITS 'BEEP, BEEP, BEEP' SIGNAL 1000 FT BEFORE REACHING THE SELECTED ALTITUDE. THE VOL AND DURATION OF THE ALERT IS SUFFICIENT TO BLOCK OUT A NORMAL ATC INSTRUCTION. WHILE NO VIOLATIONS HAVE HAPPENED YET, WE FREQUENTLY HAVE TO ASK ATC FOR A REPEAT. THE PROBLEM IS PARTICULARLY ANNOYING ON DEPARTURES WITH SEVERAL INTERMEDIATE LEVEL OFFS. I WONDER IF OTHER OPERATORS OF THIS TYPE AIRCRAFT HAVE THE SAME PROBLEM. ALSO, I FIND IT HARD TO BELIEVE THAT FAA CERTIFICATION STANDARDS WOULD ALLOW AN ALTITUDE ALERTER TO BLOCK RADIO CALLS. PERHAPS NASA CAN EXPLORE THIS ISSUE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR ADVISED THAT THE COMPANY POLICY IS TO USE HEADSETS AT ALL TIMES AND REINFORCED HIS CONCERNS THAT, EVEN WITH THE HEADSETS IN USE, THE ALERT IS SO LOUD THAT HE HAD JUST THIS DAY MISSED TWO ATC COMS AND HAD TO HAVE THEM REPEATED. HE ALSO ADVISED THAT HE HAD RECEIVED MIXED REPORTS AS TO WHETHER THE VOLUME IS ADJUSTABLE. HE EMPHASIZED THAT EARLIER DELIVERED EXAMPLES OF THE SAME ACFT HAD A MUCH QUIETER AURAL LEVEL THAT WAS LOUD ENOUGH TO GET YOUR ATTENTION, BUT NOT TO OBLITERATE OTHER AURAL MESSAGES IN THE COCKPIT ENVIRONMENT. HE FELT THE LEVEL OF THE ALERT TO WHICH HE OBJECTED WAS APPROPRIATE TO A 'WARNING' WHEN THE ACFT DEVIATES FROM A CLEARED ALTITUDE BUT TOTALLY INAPPROPRIATE AS A NORMAL 'INFORMATION ALERT' WHEN APPROACHING SUCH AN ALTITUDE IN THE COURSE OF NORMAL OPERATIONS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.