Reverse Thrust: Vibrations, Shudders, Loud Noise normal?
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BOAC and BEA days
I remember the days when the good old chaps up front with their handlebar moustaches and wonderfully English accents would take the time to explain to the SLF what wierd and wonderful noises to expect whilst flying, particularly during landing.
'on landing you will experience an increase in engine noise, there is no need to be alarmed as this is perfectly normal and caused by the reverse thrust braking mechanism of the engines' or words to that effect.
Now we're in the days of 'everyday routine air travel', pre-recorded safety briefings, forward looking onboard cameras and strengthened flightdeck doors is it an assumption that the passengers all know what makes an airframe creak, squeak, whir, bir, shake rattle and roll!
A comforting word from an experienced professional goes a long way.
'on landing you will experience an increase in engine noise, there is no need to be alarmed as this is perfectly normal and caused by the reverse thrust braking mechanism of the engines' or words to that effect.
Now we're in the days of 'everyday routine air travel', pre-recorded safety briefings, forward looking onboard cameras and strengthened flightdeck doors is it an assumption that the passengers all know what makes an airframe creak, squeak, whir, bir, shake rattle and roll!
A comforting word from an experienced professional goes a long way.
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A few things about reversers...
Thanks to everyone above to have given me my refresher course...
Now my turn to open the "squawk box"...
xxx
Thrust reversers achieve TWO (2) things...
When deployed (i.e. "idle") - they cancel (or "block") the residual idle thrust...
With power - they vector the thrust in a somewhat "forward" direction resulting in a braking vector...
xxx
There are two types of reversers...
(1) Clamshell type - look the picture above of the KLM Fokker twinjet...
This type is used for low bypass engines, and mounted on the turbine exhaust.
(2) Cascade type - look at the picture of the 737 (?) above...
This mostly used for high bypass engines, to deflect FAN air towards forward direction.
xxx
In the 747, originally, each engine had a set of FAN and TURBINE reversers. The turbine reversers (on the exhaust) were often subject to malfunctions. Most, if not all airlines decided to suppress the TURBINE reversers, and kept only the FAN reversers - Think of it this way = very little thrust comes from the turbine exhaust, most of the thrust comes from the fan anyway. Very little "effectiveness" got lost with this modification.
xxx
For the old timer crews or passengers, I flew the DC8-60/70s, in which the inboard reversers (engines nº 2 and 3) could be use IN-FLIGHT as air brakes (on the DC8, spoilers/speed brakes cannot be used in flight). The use of reversers in the air was quite "drastic" with noise and vibrations, so that we made a cabin announcement anytime we had to resort to the use of reversers in flight.
xxx
Happy contrails
Now my turn to open the "squawk box"...
xxx
Thrust reversers achieve TWO (2) things...
When deployed (i.e. "idle") - they cancel (or "block") the residual idle thrust...
With power - they vector the thrust in a somewhat "forward" direction resulting in a braking vector...
xxx
There are two types of reversers...
(1) Clamshell type - look the picture above of the KLM Fokker twinjet...
This type is used for low bypass engines, and mounted on the turbine exhaust.
(2) Cascade type - look at the picture of the 737 (?) above...
This mostly used for high bypass engines, to deflect FAN air towards forward direction.
xxx
In the 747, originally, each engine had a set of FAN and TURBINE reversers. The turbine reversers (on the exhaust) were often subject to malfunctions. Most, if not all airlines decided to suppress the TURBINE reversers, and kept only the FAN reversers - Think of it this way = very little thrust comes from the turbine exhaust, most of the thrust comes from the fan anyway. Very little "effectiveness" got lost with this modification.
xxx
For the old timer crews or passengers, I flew the DC8-60/70s, in which the inboard reversers (engines nº 2 and 3) could be use IN-FLIGHT as air brakes (on the DC8, spoilers/speed brakes cannot be used in flight). The use of reversers in the air was quite "drastic" with noise and vibrations, so that we made a cabin announcement anytime we had to resort to the use of reversers in flight.
xxx
Happy contrails
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BelArgUSA,
Way to go! a true gentleman no doubt.
Would you per chance happen to have (or had) a handlebar moustache? I'm sure the SLF were grateful to have had a thoughtful commander who kept them informed during the flight (even today it can be a traumatic experience for many even in calm flight conditions).
Boy I miss the good old days!
Way to go! a true gentleman no doubt.
Would you per chance happen to have (or had) a handlebar moustache? I'm sure the SLF were grateful to have had a thoughtful commander who kept them informed during the flight (even today it can be a traumatic experience for many even in calm flight conditions).
Boy I miss the good old days!
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That explains it. There should be a warning on any coverage of the US campaign or election..."Watching this program has been shown in the State of California to reduce intelligence and cause brain lesions, warts, and gas."
Watching the campaign coverage from home is annoying, and I usually turn it off. Watching it abroad is just embarassing.
Watching the campaign coverage from home is annoying, and I usually turn it off. Watching it abroad is just embarassing.
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How quaint and typical of an American to consider that anyone outside the US must be "watching it abroad."
When you watch TV at home you're watching it domestically. When you travel outside your own country, you're watching it abroad.
There's nothing typically American about considering being abroad, to be abroad...it is after all, abroad.
Your own folks were abroad and causing a little trouble when they were soundly defeated and sent home with their tail between their legs (by us), of course. Now to come see you on your island, we have to go abroad.
I should add that the quality of your fish and chips is falling. Do something abou that, will you? And do try to keep a stiff upper lip while you listen to those cabin anouncements. They're important, you know.
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Your own folks were abroad and causing a little trouble when they were soundly defeated and sent home with their tail between their legs (by us), of course. Now to come see you on your island, we have to go abroad.
Sahha u grazzi
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Ah, it's Malta for you. You must be an expert in world affairs, then. We all know how Malta defines current events.
It also explains why you travel so much...what else could one do?
It also explains why you travel so much...what else could one do?
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In the old days
Most of the 75 to 90% of recriminations did not exist in the old days...
Most flight crews were nice - and so were the passengers...
In the old days, all we had to do was to fly airplanes, and tell passengers about reversers.
Nowadays, we are too busy pushing buttons and programming the FMS.
xxx
I recall the good old days... before Osama forced us to change security policies... I never failed inviting passengers (and their kids - take your cameras) for a visit in the flight deck and see the view from the front windows... the cockpit door remained unlocked. If they wanted to hijack us to Cuba, ok, I would go shake hands with Fidel and get some Romeo y Julieta cigars as gifts for friends...
xxx
Even the little ladies who were scared of airplanes were invited to sit on the jump seat behind me, for takeoff and landing... to see how simple airplane flying was. You see, terrorists did not book travel for all-inclusive tours to Cancun, or Punta Cana, so I was not concerned about their AK-47s in their carry-on...
xxx
I remember never failing to visit the cabin as well, and shake hands with passengers, and answering questions. Occasionally, we were delayed for departure, and I was not afraid to offer a word to passengers waiting in the boarding area, as to the why of our delays... This is not what the geeks and nerds call CRM and SOP nowadays, this is being civilized and respectful of the passengers (who paid a travel agent, which pays my airline which pays me a salary). Welcome aboard, ladies and gentlemen.
xxx
Sorry BladePilot - no handlebar mustache under my nose, but I probably belong to the same brotherhood... I am just known to smoke a cherry or maple tobacco in my pipe (on non-smoking flights) - and as to getting fired, that's ok... I probably violated at least one rule on every flight, never had an accident and now... retiring from flying in 67 days anyway...
xxx
Happy contrails
Most flight crews were nice - and so were the passengers...
In the old days, all we had to do was to fly airplanes, and tell passengers about reversers.
Nowadays, we are too busy pushing buttons and programming the FMS.
xxx
I recall the good old days... before Osama forced us to change security policies... I never failed inviting passengers (and their kids - take your cameras) for a visit in the flight deck and see the view from the front windows... the cockpit door remained unlocked. If they wanted to hijack us to Cuba, ok, I would go shake hands with Fidel and get some Romeo y Julieta cigars as gifts for friends...
xxx
Even the little ladies who were scared of airplanes were invited to sit on the jump seat behind me, for takeoff and landing... to see how simple airplane flying was. You see, terrorists did not book travel for all-inclusive tours to Cancun, or Punta Cana, so I was not concerned about their AK-47s in their carry-on...
xxx
I remember never failing to visit the cabin as well, and shake hands with passengers, and answering questions. Occasionally, we were delayed for departure, and I was not afraid to offer a word to passengers waiting in the boarding area, as to the why of our delays... This is not what the geeks and nerds call CRM and SOP nowadays, this is being civilized and respectful of the passengers (who paid a travel agent, which pays my airline which pays me a salary). Welcome aboard, ladies and gentlemen.
xxx
Sorry BladePilot - no handlebar mustache under my nose, but I probably belong to the same brotherhood... I am just known to smoke a cherry or maple tobacco in my pipe (on non-smoking flights) - and as to getting fired, that's ok... I probably violated at least one rule on every flight, never had an accident and now... retiring from flying in 67 days anyway...
xxx
Happy contrails
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BelArgUSA
You will be missed.
I hope that you are only missed in the air and not on here.
Unfortunately, I never experienced the "elegant" era of air travel, but my 32 years memories do extend back to a time when flying was a nice experience and your colleagues and you were a joy to meet.
Julian Pettifer wrote a book named "Diamonds in the Sky" and crew of your era were (and still are), although I quote his title out of context.
Very best wishes to you.
You will be missed.
I hope that you are only missed in the air and not on here.
Unfortunately, I never experienced the "elegant" era of air travel, but my 32 years memories do extend back to a time when flying was a nice experience and your colleagues and you were a joy to meet.
Julian Pettifer wrote a book named "Diamonds in the Sky" and crew of your era were (and still are), although I quote his title out of context.
Very best wishes to you.
Last edited by Final 3 Greens; 11th Sep 2008 at 21:44.
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The Knights of Malta...
Final 3 Greens -
xxx
I know Malta quite well, did 6 month based there as chief pilot of ACMI of two 727s in the mid 1980s - to KM airlines... Was in a hotel in Bouguibba (spelling?) and did not fail to get a car bumper sticker and a T-shirt "I love Gozo"...
xxx
Would love to visit again... who knows...?
Valetta - the Blue Grotto - A beautiful cathedral in, was it Medina (top of the hill)...?
But this time as SLF and tourist, and enjoy the great seafood.
Happy contrails
xxx
I know Malta quite well, did 6 month based there as chief pilot of ACMI of two 727s in the mid 1980s - to KM airlines... Was in a hotel in Bouguibba (spelling?) and did not fail to get a car bumper sticker and a T-shirt "I love Gozo"...
xxx
Would love to visit again... who knows...?
Valetta - the Blue Grotto - A beautiful cathedral in, was it Medina (top of the hill)...?
But this time as SLF and tourist, and enjoy the great seafood.
Happy contrails