EMB170/190 Drivers

[BrickTop]

Well that was an absolutely ignorant post!


As a few 170/190 pilots who actually know what the heck is going on have said before, the noise comes from a rubber piece that attaches to the top of the doors. It follows the contour of the doors, and is about 1/2 to 3/4 of an inch thick. This piece does not affect pressurization, or structural integrity. The leading edge of these rubber pieces fray over time as they are exposed to the slipstream and to the high speed dirt kicked up by other planes' jet blast while taxiing. When these leading edges fray, they begin to vibrate, and eventually airflow can get under the entire leading edge and really make some noise. Depending on where the fray is occuring, different airspeeds and angels of attack will trigger the noise. Some planes will make noise in the climb, some in slow cruise flight, some in fast cruise, some in the decent, some at 270kts, some at 310 kts. Each occurance is different, as each rubber piece frays at a somewhat different spot, and may have been left unfixed for a longer time. Aft door vibrations are not easily heard up front, and we need the FAs to notify us of the problem- super reliable. The front door problems are easily detectable by the flight crew. When Mx comes out, they often just trim the deteriorating piece with a pair of scissors, which is surprisingly effective.

When you board a 170/190 next time, look at the door. Along the top, fixed to the door itself, is a grey piece of textured rubber that follows the curve of the door. This is the culprit.

Hard to believe were talking about the same issue. This noise literally sounds of the airplane vibrating it's way apart. A door seal would have a higher pitched whine upwards of 1-8khtz this sound is a low pitch square waveform sound below 300htz that resonates and vibrates the entire front cabin. Again like an N1 vibration or out of sync bypass fans.

 

[Farfugnügen]

You decend at 320? I don't know about the 170...but the 190 redlines at 320...the damn speed tape is so sensitive, we'd get the "High speed" all the time.

"If you ain't clackin', you're slackin'!"

 

[Browntothebone]

Hard to believe were talking about the same issue. This noise literally sounds of the airplane vibrating it's way apart. A door seal would have a higher pitched whine upwards of 1-8khtz this sound is a low pitch square waveform sound below 300htz that resonates and vibrates the entire front cabin. Again like an N1 vibration or out of sync bypass fans.

I've experience that exact same thing the times I've rode on the 170. But the resonance is definately not below 300Hz. It's at least 500Hz. I have a minor in audio engineering, so I know of what I speak.

 

[BrickTop]

I've experience that exact same thing the times I've rode on the 170. But the resonance is definately not below 300Hz. It's at least 500Hz. I have a minor in audio engineering, so I know of what I speak.

I don't doubt you do but I also own an operate an audio engineering business and have been a front of house engineer for over 10 years. I have keen recognition of the audio spectrum as well. I say we bring on board an RTA microphone and target the exact frequency(s)

 

[Minimaniac]

Hard to believe were talking about the same issue. This noise literally sounds of the airplane vibrating it's way apart. A door seal would have a higher pitched whine upwards of 1-8khtz this sound is a low pitch square waveform sound below 300htz that resonates and vibrates the entire front cabin. Again like an N1 vibration or out of sync bypass fans.

Again, we are not referring to the pressurized door seal. The rubber piece in question is about 7 inches high, 3 feet wide, and 1/2 inch deep. The piece is entirely externally mounted, is about as rigid as rubber gets, and is shaped to lay flat against the top of the door, and overlap onto the fuselage by about 3 inches. Go look at some pictures on airliners.net of the 170, and along the top side of every door you will see the piece I am referring to. Since the piece is attached to the door, and the door moves, it is not physically attached to the fuselage. The rigid nature of the piece tends to ensure a flush, airtight fit. However, over time the leading edge begins to fray and/or lose rigidity. The result is the movement of this leading edge in flight. This yields a very loud, relatively deep, and tangibly detectable vibration. The leading edge of the piece can be similar to the size of an access panel edge, and gives a somewhat similar sound and feel to an open panel in the slipstream.

Again, go look at pictures of the 170, look above the doors, and you will the piece.

http://www.airliners.net/photo/US-A...69514/L/&sid=8a18ebf69a49ad6dda95c59800b82591

The dark gray arched piece that appears to make up the upper edge of the cabin door is the piece I am talking about.

http://www.airliners.net/photo/US-A...91877/L/&sid=8a18ebf69a49ad6dda95c59800b82591

http://www.airliners.net/photo/Unit...34926/L/&sid=8a18ebf69a49ad6dda95c59800b82591

 

[Browntothebone]

I think it's actually a leaking Fetzer valve.

 

[BrickTop]

Again, we are not referring to the pressurized door seal. The rubber piece in question is about 7 inches high, 3 feet wide, and 1/2 inch deep. The piece is entirely externally mounted, is about as rigid as rubber gets, and is shaped to lay flat against the top of the door, and overlap onto the fuselage by about 3 inches. Go look at some pictures on airliners.net of the 170, and along the top side of every door you will see the piece I am referring to. Since the piece is attached to the door, and the door moves, it is not physically attached to the fuselage. The rigid nature of the piece tends to ensure a flush, airtight fit. However, over time the leading edge begins to fray and/or lose rigidity. The result is the movement of this leading edge in flight. This yields a very loud, relatively deep, and tangibly detectable vibration. The leading edge of the piece can be similar to the size of an access panel edge, and gives a somewhat similar sound and feel to an open panel in the slipstream.

Again, go look at pictures of the 170, look above the doors, and you will the piece.

http://www.airliners.net/photo/US-A...69514/L/&sid=8a18ebf69a49ad6dda95c59800b82591

The dark gray arched piece that appears to make up the upper edge of the cabin door is the piece I am talking about.

http://www.airliners.net/photo/US-A...91877/L/&sid=8a18ebf69a49ad6dda95c59800b82591

http://www.airliners.net/photo/Unit...34926/L/&sid=8a18ebf69a49ad6dda95c59800b82591

I see what youre refering to now. I do see how that could cause bizzare airflow resulting in vibrations. Supprised Embraer has not addresed this.

 

[Browntothebone]

How come they wear David Clarks?

 

[DOVPILOT]

RJs have spoilers, slats, go faster than .75? What a crock of shee-it. Commuter airlines should be restricted to turboprops.

Can I get a AMEN Brother!!!!

 

[trainer8]

The E170 has had a history of ECS pack problems. The packs are located right under the first 5 rows or in some configurations, the first class section.

In 2005, US Airways/MDA inop'd the forward galley sink on the E170. Embraer designed the forward galley sink drains to jettison liquids through a heated mast on the belly about 10 feet forward of the #2 ECS pack NACA scoop. In flight, FAs would take their excess coffee and soda and pour them down the drain. It would be injested by the #2 ECS pack.

Their was a succession of #2 ECS failures and when MTC gutted the compressor turbines, they found lots and lots of coffee grounds. Prior to the ECS failing, there was a deep rumble that you could feel in the airframe indicative of the bearings going bad in the compressor turbine.

Also, as posted by LearLove and others, the E170/190 has a history of bad door seals, both cabin and the forward cargo door. Probably 80% of the E170/175s at Republic Airways are extremely flatulent as you climb to altitude, most of them a low frequency constant moaning.

I had a NetJets jump seater in Row 7 who was convinced we had a panel separate from the aircraft on climb, based on vibrations he sensed at his seat. It was the 1L door seal and it quieted down getting into the flight levels and reappeared again on decent, though not as loud.

It's worth it to write them up as the are irritating to the passengers and especially the A FA who has to have the noise in close proximity to her station.

T8