757-200 performance
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757-200 performance
Not sure if this is the right forum but here goes...
A B757-200 is taking off on a short airfield in south east Africa.
The aircraft is around 3-4 tonnes overweight.The weather is
calm with a slight haze.Temperature is 32c.Crew were expecting
54 pax but ended up with 232,four over their seating capacity,
but had to go.
Before V1,fire bells go,and there is indications of a fire in the
number two engine.
Aborting the take-off is not an option.They have to go.
Could any pilot with experience on this type of aircraft tell me
how they would expect the aircraft to react,and the chances of getting airborne would be.How much strengh would be required
to pull the columb back.
There was no load sheet or trim available,so what flap setting
would be used?
With the Captain flying,and aborting not an option,and with the fire bells ringing out,what would the first officer do?
On finally getting sort of airborne,the right main gear hits an
approach beacon.Would you retract the gears not knowing
of the damage or limp on with gear down?
The aircraft was due to fly to France,but has to clear this country which means flying 270 miles.
I know this all sounds crazy,but I have had to change the last chapter in my book.It was to end in disaster,but my publisher wants a sequel,keeping the same two pilots,and cabin crew in tact.I have done as much research as I can,but libraries and book shops don't have much technical data.
One last question to any 747 pilots.In chapter two,the same Captain as above,suffered a number three engine surge at three thousand feet on take off.I have heard of it and believe it is like
a car backfiring.Would this normally cause a shutdown or would you normally carry on.I know there is other forums on 3 engine
flying,but I wrote this chapter back in November,and the aircraft does continue to NYK.It has to for chapter five.Just wondering what the flight engineer would be calling and whether you would shut the engine down.
I would add that my book is purely fiction,and book one has only two fatalities,but nothing to do with the airline or the crew.
I am trying to portray the crew as proffesional as possible,which is why I need help in doing that.Just need to spice up a few chapters to keep the people not putting it down by the swimming pool next year.
Any help would be really appreciated.
A B757-200 is taking off on a short airfield in south east Africa.
The aircraft is around 3-4 tonnes overweight.The weather is
calm with a slight haze.Temperature is 32c.Crew were expecting
54 pax but ended up with 232,four over their seating capacity,
but had to go.
Before V1,fire bells go,and there is indications of a fire in the
number two engine.
Aborting the take-off is not an option.They have to go.
Could any pilot with experience on this type of aircraft tell me
how they would expect the aircraft to react,and the chances of getting airborne would be.How much strengh would be required
to pull the columb back.
There was no load sheet or trim available,so what flap setting
would be used?
With the Captain flying,and aborting not an option,and with the fire bells ringing out,what would the first officer do?
On finally getting sort of airborne,the right main gear hits an
approach beacon.Would you retract the gears not knowing
of the damage or limp on with gear down?
The aircraft was due to fly to France,but has to clear this country which means flying 270 miles.
I know this all sounds crazy,but I have had to change the last chapter in my book.It was to end in disaster,but my publisher wants a sequel,keeping the same two pilots,and cabin crew in tact.I have done as much research as I can,but libraries and book shops don't have much technical data.
One last question to any 747 pilots.In chapter two,the same Captain as above,suffered a number three engine surge at three thousand feet on take off.I have heard of it and believe it is like
a car backfiring.Would this normally cause a shutdown or would you normally carry on.I know there is other forums on 3 engine
flying,but I wrote this chapter back in November,and the aircraft does continue to NYK.It has to for chapter five.Just wondering what the flight engineer would be calling and whether you would shut the engine down.
I would add that my book is purely fiction,and book one has only two fatalities,but nothing to do with the airline or the crew.
I am trying to portray the crew as proffesional as possible,which is why I need help in doing that.Just need to spice up a few chapters to keep the people not putting it down by the swimming pool next year.
Any help would be really appreciated.
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prb46,
I will try and help. I have over 12,000 hours on this type of aircraft. Unfortunetaly as is so often the case, reality needs to be suspended for dramatic effect. Reality often lacks entertainment value and so the two rarely go hand in hand. You are using a number of terms that don't make much sense in the context you are presenting them, anyway here goes !
From a performance point of view the 757 is something of a star performer. Most takeoffs are derated by anything up to 20% of maximum rated power. Obviously any derated settings are a function of a number of factors. Runway length, runway slope, contamination factors, obstacles in the extended take off area, altitude, temperature, aircraft weight, tire limit speeds, brake energy limits,etc. From a "limiting runway" the ability to derate is obviously reduced as each of these factors impacts on the performance calculation. The information you provide is insufficient to make a meaningful calculation but presumably it would be a full power take off !
You say the crew were expecting 54 pax but 232 turned up. Presumably this was in "extremis" with gun toting bandits at their heals. A 757-200 holds around 34 tonnes of fuel. It has an (empty weight) of around 59 tonnes, a maximum landing weight of 90 tonnes and a maximum take off weight that varies from each certificated aircraft but generally tops out at about 113 tonnes, but bear in mind this is restricted by the factors in the first paragraph.
This aircraft was flying from south east africa to France ? How long is a piece of string ? The fuel capacity of the aircraft would give it a maximum range of around 8 hours with minimum reserves and a very light payload (54pax) that is about 4000 miles. ( You might want to measure the distance ?). On this full fuel assumption, your aircraft with 54 passengers and a standard amount of luggage would weigh around 98 or 99 tonnes! Then another 178 last minute changes turn up ! Well I assume they didn't bring all their worldly chattels with them, so that would be another payload lump of around 14 tonnes. So the take off weight would now be in the order of 113 tonnes ! As you can see this is now at the maximum certified take off mass of the aircraft. However I appreciate that such niceties are of minor concern to our heroes ?
( continued in chapter 2)
I will try and help. I have over 12,000 hours on this type of aircraft. Unfortunetaly as is so often the case, reality needs to be suspended for dramatic effect. Reality often lacks entertainment value and so the two rarely go hand in hand. You are using a number of terms that don't make much sense in the context you are presenting them, anyway here goes !
From a performance point of view the 757 is something of a star performer. Most takeoffs are derated by anything up to 20% of maximum rated power. Obviously any derated settings are a function of a number of factors. Runway length, runway slope, contamination factors, obstacles in the extended take off area, altitude, temperature, aircraft weight, tire limit speeds, brake energy limits,etc. From a "limiting runway" the ability to derate is obviously reduced as each of these factors impacts on the performance calculation. The information you provide is insufficient to make a meaningful calculation but presumably it would be a full power take off !
You say the crew were expecting 54 pax but 232 turned up. Presumably this was in "extremis" with gun toting bandits at their heals. A 757-200 holds around 34 tonnes of fuel. It has an (empty weight) of around 59 tonnes, a maximum landing weight of 90 tonnes and a maximum take off weight that varies from each certificated aircraft but generally tops out at about 113 tonnes, but bear in mind this is restricted by the factors in the first paragraph.
This aircraft was flying from south east africa to France ? How long is a piece of string ? The fuel capacity of the aircraft would give it a maximum range of around 8 hours with minimum reserves and a very light payload (54pax) that is about 4000 miles. ( You might want to measure the distance ?). On this full fuel assumption, your aircraft with 54 passengers and a standard amount of luggage would weigh around 98 or 99 tonnes! Then another 178 last minute changes turn up ! Well I assume they didn't bring all their worldly chattels with them, so that would be another payload lump of around 14 tonnes. So the take off weight would now be in the order of 113 tonnes ! As you can see this is now at the maximum certified take off mass of the aircraft. However I appreciate that such niceties are of minor concern to our heroes ?
( continued in chapter 2)
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A few thoughts, I am not a jet pilot however mayby I can offer some thoughts. I have flown the 757-200 level d sim for 20 hours, with engine failures/fires etc.
I will obviously bow to superior knowledge of others!!
Take off probably Flap 15.
Regarding engine fire before V1... take off success will depend how far before V1 the fire/failure is. Just because you have an engine fire doesn't mean you have lost the thrust from that engine... however a loss of thrust from one engine significantly before V1 and electing to continue would be bad!
If the captain is flying during the take-off (I will assume therfore Captain is pilot flying), the FO would most probably call the failure e.g.. "Engine fire number 1" For your take-off they continue with a fire before V1. FO would make standard calls "V1 ....Rotate....positive climb". Captain callls 'gear up.' So the gear has hit a light. Well on one engine, overweight in hot conditions at flap 15 I would personally get the gear up to help actually climb! The lights are designed to break so hopefully not to do serious damage if an aircraft hits them.
Just to give you some idea the takeoff might proceed something like this...
At some point early in the climb captain would call to restate the emergency. FO would state 'Engine fire number 1' the captain would ask for the fire checklist engine number 1. The Fo would call and action the checklist from memory with the captain monitoring. e.g.
FO: Number 1 thrust lever close
Cpt: Confirm
FO shuts number 1 thrust lever (this could be the first moment thrust is lost from the engine on fire!)
FO: Number one fuel cock close
Cpt: Confirm
FO: Closes fuel cock
FO: Number one fire handle pull
Cpt: Confirm
FO pulls fire handle.
If fire still exists Fo would turn the fire handle to release one of fire extinguishers on the engine...starts the stopwatch. In 30 seconds if the fire still going, turn the handle the other way and hope for the best!
I will obviously bow to superior knowledge of others!!
Take off probably Flap 15.
Regarding engine fire before V1... take off success will depend how far before V1 the fire/failure is. Just because you have an engine fire doesn't mean you have lost the thrust from that engine... however a loss of thrust from one engine significantly before V1 and electing to continue would be bad!
If the captain is flying during the take-off (I will assume therfore Captain is pilot flying), the FO would most probably call the failure e.g.. "Engine fire number 1" For your take-off they continue with a fire before V1. FO would make standard calls "V1 ....Rotate....positive climb". Captain callls 'gear up.' So the gear has hit a light. Well on one engine, overweight in hot conditions at flap 15 I would personally get the gear up to help actually climb! The lights are designed to break so hopefully not to do serious damage if an aircraft hits them.
Just to give you some idea the takeoff might proceed something like this...
At some point early in the climb captain would call to restate the emergency. FO would state 'Engine fire number 1' the captain would ask for the fire checklist engine number 1. The Fo would call and action the checklist from memory with the captain monitoring. e.g.
FO: Number 1 thrust lever close
Cpt: Confirm
FO shuts number 1 thrust lever (this could be the first moment thrust is lost from the engine on fire!)
FO: Number one fuel cock close
Cpt: Confirm
FO: Closes fuel cock
FO: Number one fire handle pull
Cpt: Confirm
FO pulls fire handle.
If fire still exists Fo would turn the fire handle to release one of fire extinguishers on the engine...starts the stopwatch. In 30 seconds if the fire still going, turn the handle the other way and hope for the best!
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(Chapter 2)
V1 is an accelerate/stop distance speed. If properly calculated and subsequently executed the aircraft should be able to stop on the remaining runway available provided the reject actions have already been initiated. Beyond this speed the aircraft should be able to continue with one engine failed and achieve a height of 15 feet or more at the end of the runway. ( In fact this is very simplistic the definition is much more involved). In your example it sounds as if V1 sounds good, but is totally meaningless since it isn't seeming relevant to the situation.
Before V1 fire bell goes. and there is an indication of a fire in the right engine. Unless there was a power loss the bell and warning lights and eicas mesage would in fact be the indications.
If V1 has been properly applied and calculated then getting airborne ought to be no problem at all. If there was a power loss well before V1 ( and again how long is a piece of string), then V1 is irrelevant as the heroes have chosen to ignore it, but to continue with the take off into unknown territory. Bear in mind that an engine fire in itself may well not result in power loss to begin with.
The 757 has 3 hydraulic systems pressured to 3000 psi. The flying controls are powered from these systems. There is no manual reversion. you ask what the chances of the aircraft getting airborne would be ? Hard to say without knowing all the parameters and how long the runway is, as are they taking off without any due regard to these factors. It is a bit like asking how long will you survive if you drive at 100 mph on country roads ? The "strength to pull back" would not be much of a factor since even the trim on a fully loaded 757 would not be likely to vary much within the normal take range.
Certainly if you were forced to rotate before Vr due to the rapidly approaching end of the runway. This would likely require a pull back on the stick that resulted in overrotating the aircraft. What then happens if taken to the limit is the aircraft will reach its geometry limit and the tail will strike the runway. ( You see them doing this on certification tests ). Once airborne with a damaged aft fuselage, the tail end might well be the first thing to strike any obstructions.
"Approach beacons" are not what you think they are. They are normally situated well away from the runways. You mean the approach lighting stanchions. If a gear hit one of these ( and again, it is more likely to be the aft fuselage) then it would probably destroy it and may well damage the tyre and gear.
You ask what the First officer would do ? Having not calculated much so far one can only wonder, but for the purpose of the story... The first officer would apply full power to both engines. Once airborne he would retract the gear. If an emergency turn was required he might normally ensure it was complied with and reported to ATC ( not here I suspect !). He would then ( above about 500 agl ) cancel the warnings and then identify the failure. susequent to this the aircraft would be cleaned up ( flaps retracted ) and the relevant checklists carried out.
As you will appreciate it is very difficult to answer these points with any real credulity, without taking into account a host of actual factors. However as the objective is to attempt to be as factual as possible whilst remaining readably entertaining, then it requires a better undertanding of the assumed circumstances. If you want I will be happy to assist for nothing more than a credit in your book.
Good luck with it.
V1 is an accelerate/stop distance speed. If properly calculated and subsequently executed the aircraft should be able to stop on the remaining runway available provided the reject actions have already been initiated. Beyond this speed the aircraft should be able to continue with one engine failed and achieve a height of 15 feet or more at the end of the runway. ( In fact this is very simplistic the definition is much more involved). In your example it sounds as if V1 sounds good, but is totally meaningless since it isn't seeming relevant to the situation.
Before V1 fire bell goes. and there is an indication of a fire in the right engine. Unless there was a power loss the bell and warning lights and eicas mesage would in fact be the indications.
If V1 has been properly applied and calculated then getting airborne ought to be no problem at all. If there was a power loss well before V1 ( and again how long is a piece of string), then V1 is irrelevant as the heroes have chosen to ignore it, but to continue with the take off into unknown territory. Bear in mind that an engine fire in itself may well not result in power loss to begin with.
The 757 has 3 hydraulic systems pressured to 3000 psi. The flying controls are powered from these systems. There is no manual reversion. you ask what the chances of the aircraft getting airborne would be ? Hard to say without knowing all the parameters and how long the runway is, as are they taking off without any due regard to these factors. It is a bit like asking how long will you survive if you drive at 100 mph on country roads ? The "strength to pull back" would not be much of a factor since even the trim on a fully loaded 757 would not be likely to vary much within the normal take range.
Certainly if you were forced to rotate before Vr due to the rapidly approaching end of the runway. This would likely require a pull back on the stick that resulted in overrotating the aircraft. What then happens if taken to the limit is the aircraft will reach its geometry limit and the tail will strike the runway. ( You see them doing this on certification tests ). Once airborne with a damaged aft fuselage, the tail end might well be the first thing to strike any obstructions.
"Approach beacons" are not what you think they are. They are normally situated well away from the runways. You mean the approach lighting stanchions. If a gear hit one of these ( and again, it is more likely to be the aft fuselage) then it would probably destroy it and may well damage the tyre and gear.
You ask what the First officer would do ? Having not calculated much so far one can only wonder, but for the purpose of the story... The first officer would apply full power to both engines. Once airborne he would retract the gear. If an emergency turn was required he might normally ensure it was complied with and reported to ATC ( not here I suspect !). He would then ( above about 500 agl ) cancel the warnings and then identify the failure. susequent to this the aircraft would be cleaned up ( flaps retracted ) and the relevant checklists carried out.
As you will appreciate it is very difficult to answer these points with any real credulity, without taking into account a host of actual factors. However as the objective is to attempt to be as factual as possible whilst remaining readably entertaining, then it requires a better undertanding of the assumed circumstances. If you want I will be happy to assist for nothing more than a credit in your book.
Good luck with it.
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Quote:
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"You ask what the First officer would do ? Having not calculated much so far one can only wonder, but for the purpose of the story... "
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Very dry Mr Bealzebub... in fact talking of dry tanks...did the FO order any more fuel for the 14 extra tonnes of self loading? I rather suspect in the heat of the moment...he may not have done.
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"You ask what the First officer would do ? Having not calculated much so far one can only wonder, but for the purpose of the story... "
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Very dry Mr Bealzebub... in fact talking of dry tanks...did the FO order any more fuel for the 14 extra tonnes of self loading? I rather suspect in the heat of the moment...he may not have done.
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Many thanks for your replies.
The main problem with writing a novel is to keep the reader
enthralled,but also to make it as realistic as possible.To do that the publisher keeps asking you to go in another direction.
The B757 in question has no radio contact with the tower,and after a near miss with a landing Antonov,which managed a go-around,had no choice but to take off blind.
They are three days late due to waiting for parts to cure a bird strike that happened after landing.The parts never arrived due
to the civil war that was getting worse,and the reason that the pax figure escalated,is that all british and french people were desperate to leave.
The captain had fuelled the aircraft after landing,based on the lower pax figure,and that the engine would be repaired.
I have based the take-off to be a rated one,but this would mean nothing to a reader who does not fly,so presumably would have to make it a full powered take-off?
With a male captain and female first officer,the middle of the book was fairly easy to write.Been to a few crew parties myself.
Made easier by the fact the same crew stick together for the period of the book.
BEALZEBUB
The book is due to be published in America in Feb of next year and in the UK in the last two weeks of April,to make the beginning of the holiday season.Certainly will put you on the credit list.Still have many questions if you are prepared to help.
You may wonder why I have chosen the 757 as the aircraft in my novel.I was with Monarch when they had the first one delivered and thought it a wonderful beast.If any aircraft can do what I am asking then that seems the logical one.
Thanks again for your help
CosmosSchwartz
Thanks for reply.No it\'s not a UK airline,and it\'s not doing a routine flight.How many books do you think would sell with a title of \'A day in the life of a of a UK pilot\'?
The aircraft holds 228 pax seats if I am correct.The four extra were not invited,but you would have to read the book to find out why they were there.
The airport is deserted so you may wonder who took the front steps away?All will be revealed
Cheers
The main problem with writing a novel is to keep the reader
enthralled,but also to make it as realistic as possible.To do that the publisher keeps asking you to go in another direction.
The B757 in question has no radio contact with the tower,and after a near miss with a landing Antonov,which managed a go-around,had no choice but to take off blind.
They are three days late due to waiting for parts to cure a bird strike that happened after landing.The parts never arrived due
to the civil war that was getting worse,and the reason that the pax figure escalated,is that all british and french people were desperate to leave.
The captain had fuelled the aircraft after landing,based on the lower pax figure,and that the engine would be repaired.
I have based the take-off to be a rated one,but this would mean nothing to a reader who does not fly,so presumably would have to make it a full powered take-off?
With a male captain and female first officer,the middle of the book was fairly easy to write.Been to a few crew parties myself.
Made easier by the fact the same crew stick together for the period of the book.
BEALZEBUB
The book is due to be published in America in Feb of next year and in the UK in the last two weeks of April,to make the beginning of the holiday season.Certainly will put you on the credit list.Still have many questions if you are prepared to help.
You may wonder why I have chosen the 757 as the aircraft in my novel.I was with Monarch when they had the first one delivered and thought it a wonderful beast.If any aircraft can do what I am asking then that seems the logical one.
Thanks again for your help
CosmosSchwartz
Thanks for reply.No it\'s not a UK airline,and it\'s not doing a routine flight.How many books do you think would sell with a title of \'A day in the life of a of a UK pilot\'?
The aircraft holds 228 pax seats if I am correct.The four extra were not invited,but you would have to read the book to find out why they were there.
The airport is deserted so you may wonder who took the front steps away?All will be revealed
Cheers
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prb46,
There is always the amazing story of Capt Ed Daly piloting a 727-100 with over 300 people on board! Evacuees stuffed in the cabin, cargo holds, landing gear wells. There are many accounts written (I think there was even a book), and well documented. Hopefully, this will give you some more information for your book. Don't forget to send me an autographed copy!!
http://www.worldair.com/investors/history2.html
The “Last Flight From Da Nang” garnered worldwide media attention as Daly and the World crew fought off thousands of would-be passengers seeking refuge on the aircraft, dodged bullets and grenades, and ultimately carried more than 300 people to safety in Saigon.
There is always the amazing story of Capt Ed Daly piloting a 727-100 with over 300 people on board! Evacuees stuffed in the cabin, cargo holds, landing gear wells. There are many accounts written (I think there was even a book), and well documented. Hopefully, this will give you some more information for your book. Don't forget to send me an autographed copy!!
http://www.worldair.com/investors/history2.html
The “Last Flight From Da Nang” garnered worldwide media attention as Daly and the World crew fought off thousands of would-be passengers seeking refuge on the aircraft, dodged bullets and grenades, and ultimately carried more than 300 people to safety in Saigon.
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I did expect some sarcasm.Yes the original plan was to be a 225 but given the short runway and not knowing anything about the performance of the aircraft,decided against it.The thought of a 225 pulling up at 200 feet and retracting it's huge undercarriage as it goes over you and banking to the left,held some appeal.
That's why it's not easy writing a book about a highly professional crew facing up to an impossible situation.The book never blames the crew and all including cabin crew shine through.But I am not writing 'Handling the big jets',I am writing a book that holiday makers will read.
It is not just about aircraft performance.It has some sex as well,but I don't think I need to ask any questions about paragraph 17!!I am also very well quallified in the operatonal and crewing side of an airline.The earlier two chapters I received will mean that once again I will be working all night.I am off to Africa next week where I hopefully can study another side of the book.I have no intention of degrading the industry,and no intention that holiday makers would rather take the ferry home!!
You guys at the front and back shine through.
JC2354
I think you know where I am coming from.Many thanks and I will do the research.The aircraft in my book is only four over,but if he can get a 727 away anything is possible.If you live in Las Vegas I will bring you a copy!!
I did expect some sarcasm.Yes the original plan was to be a 225 but given the short runway and not knowing anything about the performance of the aircraft,decided against it.The thought of a 225 pulling up at 200 feet and retracting it's huge undercarriage as it goes over you and banking to the left,held some appeal.
That's why it's not easy writing a book about a highly professional crew facing up to an impossible situation.The book never blames the crew and all including cabin crew shine through.But I am not writing 'Handling the big jets',I am writing a book that holiday makers will read.
It is not just about aircraft performance.It has some sex as well,but I don't think I need to ask any questions about paragraph 17!!I am also very well quallified in the operatonal and crewing side of an airline.The earlier two chapters I received will mean that once again I will be working all night.I am off to Africa next week where I hopefully can study another side of the book.I have no intention of degrading the industry,and no intention that holiday makers would rather take the ferry home!!
You guys at the front and back shine through.
JC2354
I think you know where I am coming from.Many thanks and I will do the research.The aircraft in my book is only four over,but if he can get a 727 away anything is possible.If you live in Las Vegas I will bring you a copy!!
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Yes, I'm in Las Vegas, and yes, bring me a copy of the book.
I found another, more informative, site for the 727 information. Even has a video of it!
Good luck!
http://fromtheflightdeck.com/Reviews/727/World727/
I found another, more informative, site for the 727 information. Even has a video of it!
Good luck!
http://fromtheflightdeck.com/Reviews/727/World727/
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Bealzebub
Following your responce have made several changes.
From what I understand is that however heavy the aircraft the pulling back will not be a problem.
If that is the case I take it that the aircraft itself will take longer to respond.
If the keys are rapidly coming towards you,and you pull back fully and have enough speed I would presume the aircraft could over rotate,resulting in a tail strike.From memory I believe the 757 has
a bar on it's underside to take any big pressure off such an event happening.
I would then take it that the aircraft would be in a steep climb,so rather than the undercarriage hitting any obstacle,it would be the rear end,but given the fact the flight will proceed at a fairly low level,would it cause any major problem to the crew?
Once again thanks for your help
Following your responce have made several changes.
From what I understand is that however heavy the aircraft the pulling back will not be a problem.
If that is the case I take it that the aircraft itself will take longer to respond.
If the keys are rapidly coming towards you,and you pull back fully and have enough speed I would presume the aircraft could over rotate,resulting in a tail strike.From memory I believe the 757 has
a bar on it's underside to take any big pressure off such an event happening.
I would then take it that the aircraft would be in a steep climb,so rather than the undercarriage hitting any obstacle,it would be the rear end,but given the fact the flight will proceed at a fairly low level,would it cause any major problem to the crew?
Once again thanks for your help
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"Response" I wouldn't normally mention it, but as you are an author. 
The aircraft reaction to control input obviously varies depending on the speed. For example at rest or at low speed pulling back on the yolk will do nothing perceptably. At or close to Vr the aircraft will rotate promptly. To rotate at significantly lower speeds will require more input to achieve the effect. If there is not enough speed the aircraft will not lift off. You can only rotate so far before the whole thing becomes geometry limited as the tail end will scrape along the runway in a "firery orange shower of hot sparks". The 757-200 has no bar or anything else to protect itself if this happens. I have never actually done it, but I believe there is a water drain mast that hits first and detaches, followed promptly by the aft fuselage making contact .
The aircraft would be airborne at a higher angle of attack than usual, but not in a steep climb. Remember you damaged it by insisting it rotated to its geometry limit far too early and it now needs to accelerate to an initial climb speed. Having also damaged the back end ( and possibly the aft pressure bulkhead), you wouldn't want to pressurise it too much either. There is a drill to carry out a bit later that deals with this problem.
Having damaged the aft end of the aircraft, it is up to you ( the author) how much of a problem this will cause. It might be anything from scored aluminium ( scratching) to ruptured hydraulic lines.
If you let me know where this aircarft was flying from and its first intended destination, I will try and come up with some numbers for you. They probably wouldn't stand up to expert scrutiny, but should lie somewhere in the ballpark ( or around the pool in this case ).
The aircraft reaction to control input obviously varies depending on the speed. For example at rest or at low speed pulling back on the yolk will do nothing perceptably. At or close to Vr the aircraft will rotate promptly. To rotate at significantly lower speeds will require more input to achieve the effect. If there is not enough speed the aircraft will not lift off. You can only rotate so far before the whole thing becomes geometry limited as the tail end will scrape along the runway in a "firery orange shower of hot sparks". The 757-200 has no bar or anything else to protect itself if this happens. I have never actually done it, but I believe there is a water drain mast that hits first and detaches, followed promptly by the aft fuselage making contact .
The aircraft would be airborne at a higher angle of attack than usual, but not in a steep climb. Remember you damaged it by insisting it rotated to its geometry limit far too early and it now needs to accelerate to an initial climb speed. Having also damaged the back end ( and possibly the aft pressure bulkhead), you wouldn't want to pressurise it too much either. There is a drill to carry out a bit later that deals with this problem.
Having damaged the aft end of the aircraft, it is up to you ( the author) how much of a problem this will cause. It might be anything from scored aluminium ( scratching) to ruptured hydraulic lines.
If you let me know where this aircarft was flying from and its first intended destination, I will try and come up with some numbers for you. They probably wouldn't stand up to expert scrutiny, but should lie somewhere in the ballpark ( or around the pool in this case ).
Last edited by Bealzebub; 2nd Mar 2005 at 13:14.
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Bealzebub
As the 757 is quite a long aircraft,would the pilots know of a tail scrape,or just the pax down the back?
If the take off speed is too low after this event,but the aircraft has got airborne,would it not just have an angle of attack but not actually getting anywhere.
I am thinking of I believe an Airbus somewhere near Paris at an airshow that overflew and didn't climb out.
In this event would you get a stall warning,and how would you get the extra power to continue given the problems this crew have already faced?And also if there is a stall warning,is it the same as the gpws system?Sorry,I meant does it shout out to you?
I would add that they have to get airborne,in a dramatic fashion,
so I really need what you think would be a realistic escape given all the consequences.
Sorry for the spelling mistake,but that's what publishers are paid for!
Many thanks again
As the 757 is quite a long aircraft,would the pilots know of a tail scrape,or just the pax down the back?
If the take off speed is too low after this event,but the aircraft has got airborne,would it not just have an angle of attack but not actually getting anywhere.
I am thinking of I believe an Airbus somewhere near Paris at an airshow that overflew and didn't climb out.
In this event would you get a stall warning,and how would you get the extra power to continue given the problems this crew have already faced?And also if there is a stall warning,is it the same as the gpws system?Sorry,I meant does it shout out to you?
I would add that they have to get airborne,in a dramatic fashion,
so I really need what you think would be a realistic escape given all the consequences.
Sorry for the spelling mistake,but that's what publishers are paid for!
Many thanks again
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Hello All,
To be honest, I'm not a pilot but I have a fair amount of knowledge because I do flight simulation. I have to admit, based on the facts given, and assuming that an engine actually failed with an overweight situation and the engine warning coming before V1, the take-off should be aborted period!
I mean, I'm sure the novel is interesting but there is a limit to what a qualified and responsible pilot would do in real life, right? How could an aircraft which is overweight take-off on one engine?! ... not to mention how on Earth it was allowed to leave the gate at all when it was overweight to begin with.
In any case - good luck with your novel. Hope it sells well!
John
To be honest, I'm not a pilot but I have a fair amount of knowledge because I do flight simulation. I have to admit, based on the facts given, and assuming that an engine actually failed with an overweight situation and the engine warning coming before V1, the take-off should be aborted period!
I mean, I'm sure the novel is interesting but there is a limit to what a qualified and responsible pilot would do in real life, right? How could an aircraft which is overweight take-off on one engine?! ... not to mention how on Earth it was allowed to leave the gate at all when it was overweight to begin with.
In any case - good luck with your novel. Hope it sells well!
John
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Not so far fetched Byrna et al,
The time and place shall remain undisclosed but we powered back off stand (actually a set of steps on the fwd door) and as we taxied to the runway the captains brief was "what ever happens we take off"
. A/C type B757-200 RB211-535E4
I would only add that if one intends to go regardless, then one wouldn't mess about with a derate. Full power will get you up to speed faster and give more runway if anything untoward should occur.
Edited to protect the guilty
The time and place shall remain undisclosed but we powered back off stand (actually a set of steps on the fwd door) and as we taxied to the runway the captains brief was "what ever happens we take off"
. A/C type B757-200 RB211-535E4I would only add that if one intends to go regardless, then one wouldn't mess about with a derate. Full power will get you up to speed faster and give more runway if anything untoward should occur.
Edited to protect the guilty
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Many thanks for that Mono.I would have to add that the aircraft is not on a pier,or facing inwards,but on a remote stand,so is able to move forward at will.The steps are removed in the end.
This actually takes place in the very last chapter,and with what the crew have already gone through,and will be going through,
I never thought of a reverse taxi,but have seen it done.Is it not
against most SOP's now?If I added most things, I know I will be slated by pilots saying'Come on,this just wouldn't happen'
John
I think you have got the wrong end of the stick!I am well aware that any crew facing an emergency situation prior to V1 would
abort and come to a happy end on the runway,employ shutes
and get everyone off.
This crew are departing an airfield in South East Africa,which is facing the same problem in many ways as airlines had to do in Sri- Lanka,where 27 people were killed on the airfield and I believe five aircraft were destroyed.To abort would put everyone in a more serious
situation.
So appreciate your comments,but given the scenario,this is why the guys up front shine through.
Just hope it never happens in reality
Cheers PRB
This actually takes place in the very last chapter,and with what the crew have already gone through,and will be going through,
I never thought of a reverse taxi,but have seen it done.Is it not
against most SOP's now?If I added most things, I know I will be slated by pilots saying'Come on,this just wouldn't happen'
John
I think you have got the wrong end of the stick!I am well aware that any crew facing an emergency situation prior to V1 would
abort and come to a happy end on the runway,employ shutes
and get everyone off.
This crew are departing an airfield in South East Africa,which is facing the same problem in many ways as airlines had to do in Sri- Lanka,where 27 people were killed on the airfield and I believe five aircraft were destroyed.To abort would put everyone in a more serious
situation.
So appreciate your comments,but given the scenario,this is why the guys up front shine through.
Just hope it never happens in reality
Cheers PRB
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757 powerbacks are an approved if not often used procedure.
There is no doubt that if some brave soul is happy to move the steps that would be safer. However powerback is a possibility.
There is no doubt that if some brave soul is happy to move the steps that would be safer. However powerback is a possibility.
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Please QED
Quote: 757 powerbacks are an approved procedure
So why can't reverse thrust be employed all the way down to taxing speed on the roll out? Surely the stand...(however remote prb46)..is an area where litter contamination would be at the greatest risk. (aisde from the thread) I would like to know why this is an approved procedure. Surely the runway is not a higher risk then the apron or stand?
I have no idea about this but would appreciate an explanation
Many Thanks
So why can't reverse thrust be employed all the way down to taxing speed on the roll out? Surely the stand...(however remote prb46)..is an area where litter contamination would be at the greatest risk. (aisde from the thread) I would like to know why this is an approved procedure. Surely the runway is not a higher risk then the apron or stand?
I have no idea about this but would appreciate an explanation
Many Thanks
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I know nothing of the 757, but it can on the 737: recommended procedure is to be at reverse idle at 60kts and cancel at 'normal taxi speed'. I guess intake height off the ground will be one deciding factor, as will idle RPM.
