Quite an uncontained engine failure
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Why the open mic all the time? There is a lot of it?
KenV:
"Why the open mike all the time"
I might be able to help. As a TRE/TRI for many years I cannot remember how many "loss of cabin pressure" drills I have run in the simulator. Some crews can make an absolute
of the exercise because they are unable to hear one another properly when wearing oxygen masks especially on emergency flow.
I have spent hundreds of hours teaching pilots to use a high level of discipline in the use of intercom in such circumstances. The background noise created when one of the pilots involved keeps an "open mike" is considerable. So, it is vital to use the intercom/transmit switch in the off position unless you have something vital to say and then, as soon as you have said it, switch off again.
This is particularly essential when reading and responding to checklists.
It should come as no surprise that the ex-military pilots came out tops on this front. They were much more used to wearing oxygen masks and had learned the discipline well. The average civilian pilot only ever used an oxygen mask once in a blue moon and possibly never in anger.
As you might have gathered, I am ex-military and in my day it was not unusual to have five crew members communicating with one another with oxygen masks on.
"Why the open mike all the time"
I might be able to help. As a TRE/TRI for many years I cannot remember how many "loss of cabin pressure" drills I have run in the simulator. Some crews can make an absolute
of the exercise because they are unable to hear one another properly when wearing oxygen masks especially on emergency flow.I have spent hundreds of hours teaching pilots to use a high level of discipline in the use of intercom in such circumstances. The background noise created when one of the pilots involved keeps an "open mike" is considerable. So, it is vital to use the intercom/transmit switch in the off position unless you have something vital to say and then, as soon as you have said it, switch off again.
This is particularly essential when reading and responding to checklists.
It should come as no surprise that the ex-military pilots came out tops on this front. They were much more used to wearing oxygen masks and had learned the discipline well. The average civilian pilot only ever used an oxygen mask once in a blue moon and possibly never in anger.
As you might have gathered, I am ex-military and in my day it was not unusual to have five crew members communicating with one another with oxygen masks on.
I have spent hundreds of hours teaching pilots to use a high level of discipline in the use of intercom in such circumstances. The background noise created when one of the pilots involved keeps an "open mike" is considerable. So, it is vital to use the intercom/transmit switch in the off position unless you have something vital to say and then, as soon as you have said it, switch off again.
This is particularly essential when reading and responding to checklists.
This is particularly essential when reading and responding to checklists.
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Hi Tech,
Thanks for bringing out bringing out safety points. The differential pressure in Fan cowling is a good point. I suggest the cowling be made of Titanium:
1) With titanium protracted turn around inspection is not required
2) Engineers can stand on the cowling.
3) Engine aerodynamic profile will be less bulky.Less drag is created eventual fuel efficiency improvements
4) When sheet metal is bent it improves stress, whereas Composites weakens.
5) It is alarmng to hear this has occured before on other engine.
6) By employing Composites on fan cowling, a few kilograms of weight may be saved, but using Titanium, passenger lives can be saved.
7) I guess FAA is listening
Thanks for bringing out bringing out safety points. The differential pressure in Fan cowling is a good point. I suggest the cowling be made of Titanium:
1) With titanium protracted turn around inspection is not required
2) Engineers can stand on the cowling.
3) Engine aerodynamic profile will be less bulky.Less drag is created eventual fuel efficiency improvements
4) When sheet metal is bent it improves stress, whereas Composites weakens.
5) It is alarmng to hear this has occured before on other engine.
6) By employing Composites on fan cowling, a few kilograms of weight may be saved, but using Titanium, passenger lives can be saved.
7) I guess FAA is listening
Thought police antagonist
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Hi Tech,
Thanks for bringing out bringing out safety points. The differential pressure in Fan cowling is a good point. I suggest the cowling be made of Titanium:
1) With titanium protracted turn around inspection is not required
2) Engineers can stand on the cowling.
3) Engine aerodynamic profile will be less bulky.Less drag is created eventual fuel efficiency improvements
4) When sheet metal is bent it improves stress, whereas Composites weakens.
5) It is alarmng to hear this has occured before on other engine.
6) By employing Composites on fan cowling, a few kilograms of weight may be saved, but using Titanium, passenger lives can be saved.
7) I guess FAA is listening
Thanks for bringing out bringing out safety points. The differential pressure in Fan cowling is a good point. I suggest the cowling be made of Titanium:
1) With titanium protracted turn around inspection is not required
2) Engineers can stand on the cowling.
3) Engine aerodynamic profile will be less bulky.Less drag is created eventual fuel efficiency improvements
4) When sheet metal is bent it improves stress, whereas Composites weakens.
5) It is alarmng to hear this has occured before on other engine.
6) By employing Composites on fan cowling, a few kilograms of weight may be saved, but using Titanium, passenger lives can be saved.
7) I guess FAA is listening
https://www.premix.com/why-composite...composites.php
Both Riverman and Hi Tech summate the engineering / maintenance aspects very well, and certainly with regard to possible causes of damage to composites with delamination being the hidden from routine inspections source. By the time you get to see de-lam, it's too late and the damage is done.
Likewise an innocuous dent ( Visible impact damage ) on the surface, but underneath, and invisible until a detailed inspection is carried out using NDT, the damage may be catastrophic.
Titanium is impractical for use in an intake, Kevlar however is, and it's also a time consuming nightmare to work with as any engineer who has been involved with the material will testify.
As for bending metal, no matter how much effort is applied to alleviate the problem, stress corrosion will be induced from the onset of the manufacturing process.
I formerly trained engineers in corrosion inspections and rectification techniques, both metal and composites, so my reply to you is not purely theory based and is intended to help remedy the misunderstanding within your summary.
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Thank you. Titanium is costly hence designers are reluctant to use it. However to arrest flying debris from high speed compressor and turbine discs composites is a poor choice, the incident proves it.
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1. While pricey, titanium has many unique properties. If those properties are desirable or necessary in a design, aircraft designers will not hesitate to use titanium.
2. Nacelle cowlings are NOT intended nor designed to "arrest flying debris from high speed compressor and turbine discs." The engine's fan and turbine case are so intended and so designed.
3. Composite fibers are an ideal ballistic material. Consider that ALL bullet proof vests are made of composite fibers, and essentially ALL armored vehicles have spall liners made of composite fibers.
Last edited by KenV; 20th Apr 2018 at 16:06.
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Another possibility: In some airplanes (e.g., 747 Classic) a switch must be thrown to switch from boom mike to the mike in the mask. If this airplane was not equipped with the newer masks with automatic switching (switch is in the cover of the mask compartment, and activates when the mask is pulled out), she might have forgotten this step in the fray. I've been there, done that!
I noted that as soon as the controller said that he was only getting static, the next transmission from the airplane was clear. Either he jogged her memory or she finished doing the other stuff she had to do - like FLY THE AIRPLANE. Don't forget the priorities: Aviate, Navigate, Communicate, in that order.
I noted that as soon as the controller said that he was only getting static, the next transmission from the airplane was clear. Either he jogged her memory or she finished doing the other stuff she had to do - like FLY THE AIRPLANE. Don't forget the priorities: Aviate, Navigate, Communicate, in that order.
