Limitations on special Boeing 737-800 series
ex-Tanker
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2 points
1. If Ryan change their procedures and the poor ATC guys have to ask here what is going on - then Ryan's coord. with its partner bodies is poor.
2. Tongue in cheek, in case someone comments - you can keep 1.5 margin by flying straight and level innit?
FC.
2. Tongue in cheek, in case someone comments - you can keep 1.5 margin by flying straight and level innit?
FC.
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Rumours concerning RYR
Hi everybody!
I have been told by RYR management that this is due to a quite unusual incident:
A RYR B738 flying FL360 next to or on top of a thunderstorm encountered some turbulences. At the same time OAT was increasing (ISA + 20°C), maybe due to the convection of the CB, and they started to pick up ice on the wings (very unusual at this level)
. Then they were unable to maintain the speed with full thrust and asked for emergency descend. Hopefully, the crew saw it coming and the stall was just avoided. 
Let’s wait & see the official report!
… Nevertheless, when I did my transition from the 737 classic to the NG, I was quite impressed by the fact that the 738 has difficulties to regain the speed when it is lost at high altitude (in climb or level flight) and it also has significant less margin concerning the high speed buffer (apparently, if you overshoot the Vmo/Mmo limit, you are not going to stall the airplane immediately because the first restriction is the airflow around the stabilizer).
Any comments ??
I have been told by RYR management that this is due to a quite unusual incident:
A RYR B738 flying FL360 next to or on top of a thunderstorm encountered some turbulences. At the same time OAT was increasing (ISA + 20°C), maybe due to the convection of the CB, and they started to pick up ice on the wings (very unusual at this level)
. Then they were unable to maintain the speed with full thrust and asked for emergency descend. Hopefully, the crew saw it coming and the stall was just avoided. Let’s wait & see the official report!
… Nevertheless, when I did my transition from the 737 classic to the NG, I was quite impressed by the fact that the 738 has difficulties to regain the speed when it is lost at high altitude (in climb or level flight) and it also has significant less margin concerning the high speed buffer (apparently, if you overshoot the Vmo/Mmo limit, you are not going to stall the airplane immediately because the first restriction is the airflow around the stabilizer).
Any comments ??
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Re-checked is quite right about the incident. Also a factor was the crews selection of WAI which automatically adjusted the margin to stall. OFDM is a great tool, and is being used in FR by the CP in a very responsible way. I believe we are trying to get boeing to remove the WAI Vs feature above a certain FL.
ps Carmoisine, you need to evaluate your own lack of performance by allowing a Captain to operate outside of sops without filing a report! Your situation is not like Cliodhnas.
ps Carmoisine, you need to evaluate your own lack of performance by allowing a Captain to operate outside of sops without filing a report! Your situation is not like Cliodhnas.
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RAT 5
Cliodna Duggan was an FO in Ryanair who was sacked for leaving an aircraft after a disagreement with a Captain whom she alleged in court had both verbally and physically abused her. He disconnected the autopilot a number of times without telling her (she was PF) during an instrument approach into Prestwick. It later transpired that this same individual had done the same to a number of other co-pilots, none of whom had reported it to anyone. She was sacked after a typical Ryanair 'kangaroo court'. She then took a High Court action against FR which was settled after about an hour on the floor of the court because FR couldn't afford to have the full story come out in open court. FR agreed in the settlement that she had "acted in the best interests of flight safety, and of Ryanair and its passengers". However, she remained sacked and that is the real issue. The chairman of the local IALPA branch, Martin Duffy, had been sacked a week previously after a similar FR "hearing", for allegedly refusing to position to STN in a jumpseat. Her father, who was the Chief Pilot at the time, departed FR shortly afterwards. The message went out loud and clear to all pilots - do what you're told in this company or else.
It is this type of response that has determined the "safety culture" in Ryanair. The whole aviation world is aware of it but nobody, including the IAA and the UK CAA, seems prepared to do anything about it except for the remarkable Capt John Goss. The other good ones just leave for Emirates etc which is exactly what MOL wants.
Cliodna Duggan was an FO in Ryanair who was sacked for leaving an aircraft after a disagreement with a Captain whom she alleged in court had both verbally and physically abused her. He disconnected the autopilot a number of times without telling her (she was PF) during an instrument approach into Prestwick. It later transpired that this same individual had done the same to a number of other co-pilots, none of whom had reported it to anyone. She was sacked after a typical Ryanair 'kangaroo court'. She then took a High Court action against FR which was settled after about an hour on the floor of the court because FR couldn't afford to have the full story come out in open court. FR agreed in the settlement that she had "acted in the best interests of flight safety, and of Ryanair and its passengers". However, she remained sacked and that is the real issue. The chairman of the local IALPA branch, Martin Duffy, had been sacked a week previously after a similar FR "hearing", for allegedly refusing to position to STN in a jumpseat. Her father, who was the Chief Pilot at the time, departed FR shortly afterwards. The message went out loud and clear to all pilots - do what you're told in this company or else.
It is this type of response that has determined the "safety culture" in Ryanair. The whole aviation world is aware of it but nobody, including the IAA and the UK CAA, seems prepared to do anything about it except for the remarkable Capt John Goss. The other good ones just leave for Emirates etc which is exactly what MOL wants.
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What's going on here?
I haven't read this thread before but got just halfway through it before I thought "I wonder if this has to do with being much heavier than the sheet".
Are some here talking about coffin corner? Or something similar where margins for safe resolution tend to zero? I sincerely hope not.
I mentioned in another thread how I reckon I have been personally responsible for 140kg on a flight when the sheet probably only says 100 total for me.
I've seen some of these flights are almost completely full. Isn't that maybe 189 pax? I'm tall but not obese, but a hell of a lot of passengers are thesedays, and some on every flight seem to be moving half their houses right up the steps into the cabin (the other half being in the hold we presume).
Last night I overheard some regular golfer pax talking about inconsistency in charging for excess baggage. Sometimes charged, sometimes not they agreed. They called it pot luck.
1. Forget the hand baggage for a moment (but note it is still relatively easy to board with 20 kg).
2. What is the authorised average weight plotted per passenger with the low cost high load factor models we are talking about? I recall that some authorised models used to assume just 65kg.
3. I'd now like to know how the exact total baggage weight checked in please (via normal channel and fragile) is reflected on the dispatcher's load sheet. Unlike with some airlines, there was no weight shown on my luggage tag last week. In the authorised models is there an average assumed per bag if it isn't charged as excess?
Could someone enlighten us generalists as to what's going on?
I haven't read this thread before but got just halfway through it before I thought "I wonder if this has to do with being much heavier than the sheet".
Are some here talking about coffin corner? Or something similar where margins for safe resolution tend to zero? I sincerely hope not.
I mentioned in another thread how I reckon I have been personally responsible for 140kg on a flight when the sheet probably only says 100 total for me.
I've seen some of these flights are almost completely full. Isn't that maybe 189 pax? I'm tall but not obese, but a hell of a lot of passengers are thesedays, and some on every flight seem to be moving half their houses right up the steps into the cabin (the other half being in the hold we presume).
Last night I overheard some regular golfer pax talking about inconsistency in charging for excess baggage. Sometimes charged, sometimes not they agreed. They called it pot luck.
1. Forget the hand baggage for a moment (but note it is still relatively easy to board with 20 kg).
2. What is the authorised average weight plotted per passenger with the low cost high load factor models we are talking about? I recall that some authorised models used to assume just 65kg.
3. I'd now like to know how the exact total baggage weight checked in please (via normal channel and fragile) is reflected on the dispatcher's load sheet. Unlike with some airlines, there was no weight shown on my luggage tag last week. In the authorised models is there an average assumed per bag if it isn't charged as excess?
Could someone enlighten us generalists as to what's going on?
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Well forgive my impatience but I'll start answering some of my own questions - yes we are talking about coffin corner and yes weight is a very significant factor, isn't it? I see "have another coffee" long ago answered my question about questionability of using standard pax and baggage weights on loadsheets.
Now then, which one of you practising low cost PPs is going to tell me how you or the FMC really knows the exact weight of your aircraft before or after you sign the load sheet thesedays, say to the nearest 10%?
Or maybe a different question - if you add up the 'lost' 40 kg per passenger that I said might apply when me and my 188 2006-sized mates fly what difference might that make? Oh ... thats the same thing ... deary me!
So how much difference might 7 tonnes make to the manoeuvre margins at FL410 if we inadvertently plan no more than the theoretical max allowed up there on the day and head straight up there without knowing we are carrying all the extra?
I see that "have another coffee" reckons 3 tonnes is enough to make a significant difference. Maybe that's roughly where his 3 tonnes comes from. You can't plan to go to FL410 with more than about half load of pax and their bags? I was multiplying 189x40kg. Take 100x30kg as unrecorded extra load and maybe that's pretty close to what you PPs actually encounter?
Never mind the theory - how do you PPs actually know when you actually are up in that corner. You get warnings I assume triggered by some of the parameters you may incorrectly have programmed into the FMC? What safe ways out are there if you do actually stall or get some warning of onset? Is there some kind of physical high speed buffet/low speed buffet convergence stall warning system that actually picks up the physical condition at the wing irrespective of how incorrect the load data was?
I thought high altitude stalls were extremely dangerous?? Or are they no big deal anymore?
Now then, which one of you practising low cost PPs is going to tell me how you or the FMC really knows the exact weight of your aircraft before or after you sign the load sheet thesedays, say to the nearest 10%?
Or maybe a different question - if you add up the 'lost' 40 kg per passenger that I said might apply when me and my 188 2006-sized mates fly what difference might that make? Oh ... thats the same thing ... deary me!
So how much difference might 7 tonnes make to the manoeuvre margins at FL410 if we inadvertently plan no more than the theoretical max allowed up there on the day and head straight up there without knowing we are carrying all the extra?
I see that "have another coffee" reckons 3 tonnes is enough to make a significant difference. Maybe that's roughly where his 3 tonnes comes from. You can't plan to go to FL410 with more than about half load of pax and their bags? I was multiplying 189x40kg. Take 100x30kg as unrecorded extra load and maybe that's pretty close to what you PPs actually encounter?
Never mind the theory - how do you PPs actually know when you actually are up in that corner. You get warnings I assume triggered by some of the parameters you may incorrectly have programmed into the FMC? What safe ways out are there if you do actually stall or get some warning of onset? Is there some kind of physical high speed buffet/low speed buffet convergence stall warning system that actually picks up the physical condition at the wing irrespective of how incorrect the load data was?
I thought high altitude stalls were extremely dangerous?? Or are they no big deal anymore?
Last edited by late developer; 24th Oct 2006 at 20:53. Reason: FLzeros!
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Why are you directing your questions at the LCCs? They are ruled by the JAA just like any other airline. You do have a point but tell me what do other more respectable airlines do then?
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Ehm pardon? It may have escaped your attention, but not mine, that all significant airlines are now LCCs and respectability became a myth when Quantas lost that tag somewhere along the way. So then, for the avoidance of doubt, would ANY PP like to comment in detail about what exactly goes on in the office on this subject. I would particularly like to hear from 737-800 pilots because I happen to risk my life in them far more than other types and by no coincidence, that seems to be the type in question in this thread.
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Okay I fly the 800 for Ryanair. You are right that some pax carry more than their fair share of extra weight, be it on their bodies or in the overhead lockers or in the holds. Equally though there are many walk ons with no extra weight. In RYR we use 80 kgs per adult pax which is a good average between male and female, children are 30kgs and infants nil.
Now where you do have a point is when the balance is not equal and that all pax are male carrying the kitchen sink into the airplane. The male bit cant be changed or altered but the kitchen sink is primarily the airports/checkins responsibility backed up by our cabin crew who regularly redirect things into the hold.
For your peace of mind after 13 years in low cost, I have never had an all male pax load, and that if I ever expect the a/c is overloaded or misloaded then I check fuel flow which we can do for the specific weight down to the nearest kilo from the onboard QRH. I havent found a problem with weight yet except for mistakes on loadsheets.
The BMI accident was one of the first to teach us not to overfill the hat bins as when you do a lot of people loose the top of their heads!! So it is an industry problem in general to try and reduce hand luggage, and you do have a point. Also the cabin crew are in such a rush normally that these issues can sometimes be overlooked, but on the other hand the RYR policy of charging for excess baggage at checkin means the eagle eyed check in staff, who are on bonuses for their extra baggage spotted, probably offsets the cabin crew.
Overall it seems to work, which is the main thing!
Regards
Now where you do have a point is when the balance is not equal and that all pax are male carrying the kitchen sink into the airplane. The male bit cant be changed or altered but the kitchen sink is primarily the airports/checkins responsibility backed up by our cabin crew who regularly redirect things into the hold.
For your peace of mind after 13 years in low cost, I have never had an all male pax load, and that if I ever expect the a/c is overloaded or misloaded then I check fuel flow which we can do for the specific weight down to the nearest kilo from the onboard QRH. I havent found a problem with weight yet except for mistakes on loadsheets.
The BMI accident was one of the first to teach us not to overfill the hat bins as when you do a lot of people loose the top of their heads!! So it is an industry problem in general to try and reduce hand luggage, and you do have a point. Also the cabin crew are in such a rush normally that these issues can sometimes be overlooked, but on the other hand the RYR policy of charging for excess baggage at checkin means the eagle eyed check in staff, who are on bonuses for their extra baggage spotted, probably offsets the cabin crew.
Overall it seems to work, which is the main thing!
Regards
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JB, I am really pleased you have engaged with my amateur attempts at queries on this. Thank you very much indeed for your candid response.
I hear what you say. It's a long time since I worked back from a graph of fuel flows to obtain an accurate weight. The Quick Reference Handbook is exactly that, a quick reference, and I am left wondering what inbuilt errors there may be if you are in the climb at some lower level, potentially loaded/trimmed not quite as ideally as you planned, working back your fuel flow observations on a QRH graph of climb performance which might not take into account all the variables of the actual (partially unknown) configuration.
Meantime, with your commercial manager's hat on (and I accept that you are expected to be commercial on behalf of your employer) you are continually re-evaluating whether you will soon be able re-confirm to ATC that you still want that planned FL410 or are going to have to ask for another level. Is that generally how it goes in the office ten minutes after take-off?
So you make several re-evaluations of your weight as you traject up through the troposphere relying upon Boeing's graphs and your winglet manufacturer's modified graphs to give you hard data about your likely weight to the nearest kilo (using standard assumptions) plus of course your load sheet and all the other pilot observations you have made since the last time you knew it had no load and an exact known quantity of fuel. Right so far?
Let me rewind a bit. Never mind the full on FL410 - lower levels can still be problematica, eh? You have a turnaround time of 25 minutes - you achieve less sometimes. You started the inbound late. It's night. You've had great tailwinds on the inbound. You made up some of the delay you've been carrying since fog this morning. It's snowing here and runway clearance have been working non-stop tonight and the moment you landed they were back out there to keep it clear for the outbound. You must be working like Trojans behind that door if the runway conditions are marginal, the outbound load is high and you have not burned off as much inbound fuel as you had hoped because you had tailwinds. It was only an hours flight. Your employer wants you to tank some fuel too if you can. So
1. are you sure you can still take-off on this runway with the heavy pax load in their heavy coats with goodness knows extra weight hidden underneath, and in their pockets, already at the gate and their bags already being loaded?
2. can you still plan to get above those headwinds going back? Where in or above the Tropopause (forgive me I've forgotten if its a line or a zone!) will you find the fastest track now? Is it pushing performance?
3. The destination runway closes at 00:00hrs Local. (Oh that old chestnut!)
4. Despite the headwinds you think you can still get back before it closes.
5. What are your diversion planning obligations? You know it is 50/50 that your destination will now not be operational when you get back. More fuel? Are you really sure you still allowed to excecute a flight plan to this destination with what you know right now? Or must you plan for another destination and another divert?
6. If you execute a plan for high altitude the numbers say you are still legal for the original destination. Which flight level was that?
7. More fuel?
8. The refueller has gone and the dispatcher has asked you to sign.
9. Doors closed. Time to go.
10. The runway crew have done a magnificent job. It's very white but it's clear. The braking efficiency check they've just done is marginal but ok. Another couple of tonnes and it wouldn't have been. But this is a military installation - it's long. You go.
A full 35 seconds from full power to rotate, despite the dense air.
Now you are in the climb. How heavy are you? I mean really?
How are we doing? Not so hot. They've routed us direct across this part. Great. But we really need that high level. Gonna be bumpy up there. Wish we were lighter and could go higher still. What are we using today? 1.25, 1.3, 1.5, 1.45?
How heavy now? Where's the right QRH chart?
15 minutes since airborne and still 50/50 we will get in before 00:00 if we go high. There'll be a hold when we get there. Bound to be if we are one of the stragglers in the usual 2300 to 2330 flock coming home to roost and bed. Everybody's been running late since this morning. How much fuel did we got?
Fuel flow? QRH says how heavy now?
Safe to go up there using 1.3 today? How rough is that air at that level tonight?
Do we got good data programmed in for everything else?
We do? Fuel flow again. How heavy are we? I mean really?
And that gives us what margins up there?
OK looks tight but looks good.
OK ... they are clearing us now for climb to that level. We'll take it? We'll take it.
JB I may have it all wrong. Maybe I should have chosen a hot example not a cold one?
But is any of my imagination run riot as above about right?
I really don't know what the risk is. That's why I have asked. I'd like to know. I watched TopGun a few times. Out of the envelope and it's curtains for Goose and the airframe, eh? F14s in combat is one extreme. But just how much of an upset can you 738 drivers imagine with the typical errors we've been discussing? Maybe it'd just be a walk in the park?
Say those numbers were still a bit wrong despite your worked-back-from fuel flow QRH plotting. It's bumpy up there but you can still read the graphs and maybe it's not too bad. So when the onset of an upset occurs, it's a surprise. What's the first sign of an upset in the corner? Is it the clackers someone mentioned? What do you do? Get on the radio and ask for a descent? Or descend immediately whilst your co-pilot immediately radios an emergency descent? I really would like to know.
I have read about 12 knot margins between high speed and low speed buffet. That sounds so thin but I guess an autopilot can nail it. I have read here that speed lost at high altitude in a 738 is hard to regain as if that is a good thing, but if are just about to unexpectedly drop out behind the low speed curve and you want faster to get back in the envelope then surely that 738 characteristic's a bad thing if you can't get what you need?
You have a relatively new wing, don't you? You have winglets. You have QRH with some winglet data and some no-winglet Boeing data. I've seen one PP asking others "Are you test pilots?"
I have read on PPrune about incidence of 1.6g to -0.02g in 2 seconds (slightly lower altitudes I guess).
Combine something like that with a typical error in weights and a 12 knot buffer zone then what kind of upset are we talking about? Again, I'd just like to know what I am up for when I pay BAA £39 to park, and my airline £7 including tax each way. That sounds a kinda crazy way to run a railway to most people, so much so that they run lemming-like to the web site daily and then do the most creative things to avoid the £39 which is nuts and spend hours researching how maybe they can save £4 by booking in advance or even handing the keys to a local entrepeneur who will park it securely at some roadside in Bishops Stortford! If only they knew, eh?
I am sure if most people really understood how high and low speed buffet was managed last week, and then compared it to this week and then compared that to South West, they'd think that was all kinda crazy too! Some might say FL390 is crazy, FL410 is nuts, but I don't mind FL350. Maybe some might even lobby for some extra breathing space and airspace and R&R for guys like yourself, JB!
I just had a crazy idea (another one!) for a subtle variation of the oleo model.
It goes something like this:
When we book online we should be asked to select from three extra dropdown boxes:
(i) what error in loadsheet take-off weight we are prepared to accept (+-2%, +-5%, +-10%) and
(ii) what high altitude manoeuvre (buffer?) zone (min 12kts, min 50kts, min 100kts) and
(iii) what manoeuvre load factor (1.3, 1.45, 1.5)
then receive a price accordingly. Afterall, we can't buy proper smoking hole insurance without disclosing on a scale of 1 to 10 how risk averse we are
It would mean that if the scaredy cats booked early they'd probably get whacked with a big price, eh?
And if they nevertheless paid that price then in order to accommodate them all the golfers and skiers on the flight would get their excess bags weighed and charged big time
I hear what you say. It's a long time since I worked back from a graph of fuel flows to obtain an accurate weight. The Quick Reference Handbook is exactly that, a quick reference, and I am left wondering what inbuilt errors there may be if you are in the climb at some lower level, potentially loaded/trimmed not quite as ideally as you planned, working back your fuel flow observations on a QRH graph of climb performance which might not take into account all the variables of the actual (partially unknown) configuration.
Meantime, with your commercial manager's hat on (and I accept that you are expected to be commercial on behalf of your employer) you are continually re-evaluating whether you will soon be able re-confirm to ATC that you still want that planned FL410 or are going to have to ask for another level. Is that generally how it goes in the office ten minutes after take-off?
So you make several re-evaluations of your weight as you traject up through the troposphere relying upon Boeing's graphs and your winglet manufacturer's modified graphs to give you hard data about your likely weight to the nearest kilo (using standard assumptions) plus of course your load sheet and all the other pilot observations you have made since the last time you knew it had no load and an exact known quantity of fuel. Right so far?
Let me rewind a bit. Never mind the full on FL410 - lower levels can still be problematica, eh? You have a turnaround time of 25 minutes - you achieve less sometimes. You started the inbound late. It's night. You've had great tailwinds on the inbound. You made up some of the delay you've been carrying since fog this morning. It's snowing here and runway clearance have been working non-stop tonight and the moment you landed they were back out there to keep it clear for the outbound. You must be working like Trojans behind that door if the runway conditions are marginal, the outbound load is high and you have not burned off as much inbound fuel as you had hoped because you had tailwinds. It was only an hours flight. Your employer wants you to tank some fuel too if you can. So
1. are you sure you can still take-off on this runway with the heavy pax load in their heavy coats with goodness knows extra weight hidden underneath, and in their pockets, already at the gate and their bags already being loaded?
2. can you still plan to get above those headwinds going back? Where in or above the Tropopause (forgive me I've forgotten if its a line or a zone!) will you find the fastest track now? Is it pushing performance?
3. The destination runway closes at 00:00hrs Local. (Oh that old chestnut!)
4. Despite the headwinds you think you can still get back before it closes.
5. What are your diversion planning obligations? You know it is 50/50 that your destination will now not be operational when you get back. More fuel? Are you really sure you still allowed to excecute a flight plan to this destination with what you know right now? Or must you plan for another destination and another divert?
6. If you execute a plan for high altitude the numbers say you are still legal for the original destination. Which flight level was that?
7. More fuel?
8. The refueller has gone and the dispatcher has asked you to sign.
9. Doors closed. Time to go.
10. The runway crew have done a magnificent job. It's very white but it's clear. The braking efficiency check they've just done is marginal but ok. Another couple of tonnes and it wouldn't have been. But this is a military installation - it's long. You go.
A full 35 seconds from full power to rotate, despite the dense air.
Now you are in the climb. How heavy are you? I mean really?
How are we doing? Not so hot. They've routed us direct across this part. Great. But we really need that high level. Gonna be bumpy up there. Wish we were lighter and could go higher still. What are we using today? 1.25, 1.3, 1.5, 1.45?
How heavy now? Where's the right QRH chart?
15 minutes since airborne and still 50/50 we will get in before 00:00 if we go high. There'll be a hold when we get there. Bound to be if we are one of the stragglers in the usual 2300 to 2330 flock coming home to roost and bed. Everybody's been running late since this morning. How much fuel did we got?
Fuel flow? QRH says how heavy now?
Safe to go up there using 1.3 today? How rough is that air at that level tonight?
Do we got good data programmed in for everything else?
We do? Fuel flow again. How heavy are we? I mean really?
And that gives us what margins up there?
OK looks tight but looks good.
OK ... they are clearing us now for climb to that level. We'll take it? We'll take it.
JB I may have it all wrong. Maybe I should have chosen a hot example not a cold one?
But is any of my imagination run riot as above about right?I really don't know what the risk is. That's why I have asked. I'd like to know. I watched TopGun a few times. Out of the envelope and it's curtains for Goose and the airframe, eh? F14s in combat is one extreme. But just how much of an upset can you 738 drivers imagine with the typical errors we've been discussing? Maybe it'd just be a walk in the park?
Say those numbers were still a bit wrong despite your worked-back-from fuel flow QRH plotting. It's bumpy up there but you can still read the graphs and maybe it's not too bad. So when the onset of an upset occurs, it's a surprise. What's the first sign of an upset in the corner? Is it the clackers someone mentioned? What do you do? Get on the radio and ask for a descent? Or descend immediately whilst your co-pilot immediately radios an emergency descent? I really would like to know.
I have read about 12 knot margins between high speed and low speed buffet. That sounds so thin but I guess an autopilot can nail it. I have read here that speed lost at high altitude in a 738 is hard to regain as if that is a good thing, but if are just about to unexpectedly drop out behind the low speed curve and you want faster to get back in the envelope then surely that 738 characteristic's a bad thing if you can't get what you need?
You have a relatively new wing, don't you? You have winglets. You have QRH with some winglet data and some no-winglet Boeing data. I've seen one PP asking others "Are you test pilots?"
I have read on PPrune about incidence of 1.6g to -0.02g in 2 seconds (slightly lower altitudes I guess).
Combine something like that with a typical error in weights and a 12 knot buffer zone then what kind of upset are we talking about? Again, I'd just like to know what I am up for when I pay BAA £39 to park, and my airline £7 including tax each way. That sounds a kinda crazy way to run a railway to most people, so much so that they run lemming-like to the web site daily and then do the most creative things to avoid the £39 which is nuts and spend hours researching how maybe they can save £4 by booking in advance or even handing the keys to a local entrepeneur who will park it securely at some roadside in Bishops Stortford! If only they knew, eh?
I am sure if most people really understood how high and low speed buffet was managed last week, and then compared it to this week and then compared that to South West, they'd think that was all kinda crazy too! Some might say FL390 is crazy, FL410 is nuts, but I don't mind FL350. Maybe some might even lobby for some extra breathing space and airspace and R&R for guys like yourself, JB!
I just had a crazy idea (another one!) for a subtle variation of the oleo model.
It goes something like this:
When we book online we should be asked to select from three extra dropdown boxes:
(i) what error in loadsheet take-off weight we are prepared to accept (+-2%, +-5%, +-10%) and
(ii) what high altitude manoeuvre (buffer?) zone (min 12kts, min 50kts, min 100kts) and
(iii) what manoeuvre load factor (1.3, 1.45, 1.5)
then receive a price accordingly. Afterall, we can't buy proper smoking hole insurance without disclosing on a scale of 1 to 10 how risk averse we are
It would mean that if the scaredy cats booked early they'd probably get whacked with a big price, eh?
And if they nevertheless paid that price then in order to accommodate them all the golfers and skiers on the flight would get their excess bags weighed and charged big time
Last edited by late developer; 24th Oct 2006 at 20:52. Reason: FLzeros!
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late developer, chill out man , sit back relax and buy a few of our bulls-eye baggies and fill yerself full of booze from a plastic bag. Incidentally has anyone worked out why we now use 10 degrees of bank above F300 in HDG SEL but we are allowed to let LNAV command 30 or whatever ? I guess the aircraft can't stall in LNAV . . .Duh ? Incidentaly, when you are using 10 degrees. . .well you are aren't you ? be very careful when given heading changes over France. My experience so far suggests that they expect us to turn a bit quicker than we now do if we are to maintain normal seperation. All in all, think I prefer a bit of buffet to a RA.
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So who says we are just glorified bus drivers?
Your perspective as an amateur is rather too well informed me thinks?
I will try and reassure you with regards to some of your points, but it will be short as I have to fly.
Your scenario is extremely realistic when compared to some of the LOFT ( Line oriented flight training) that we run every 6 months in the simulator; Marginal contaminated runway takeoffs/landings, minimum legal fuel dispatch, closed or closing airfields, pushy dispatchers, unforecast weather leading to enroute diversions (into nasty little airfields), jet upsets and high altitude engine failure, medical emergencies, crew incapacitiation etc etc are all practised regularly.
All your `what if` scenarios are pretty well covered IMHO and when you go down to the wire on certain things like performance you must remember that it is not an exact science so the regualtors build in margins for exactly your type of worries, overloaded, poor crew reaction time, Friday airplane etc.
But to cut it short as I really have to go, if I thought my airplane was too heavy for the phase and position of flight I would simply add a couple of tons to the FMC whilst we worked out where the mistake was made. Normally the dispatcher can be contacted and if he has stuck on a few tons in the aft hold without telling us, then we can get back to business. What you may not be able to appreciate is that unlike a fully laden jumbo, our 800s operate in general around 66 tons which is 13 tons below the absolute max that can be bought from boeing (papework job to buy more weight = same airplane). Therefore there is such a lot of spare performance these things would be easily covered in your suggested scenarios. I remember being involved with a Recurrent Training scenario a few years ago where the training dept wanted to train pilots to recognise a max aft CG situation, hoping it would also lead to a tailstrike in order for crews to recover and follow the QRH etc. We ran the scenario in the sim with a 36% aft CG and found most line pilots didnt even notice the difference. I also flew the sim with flaps up and 36% CG on a takeoff using Flap 1 speed and still didnt hit the tail using normal rotation rates. So the point is the airplane is damn good and the crews are pretty good and it would take a lot of unusual events for a crew to get out of shape with this over weight thing. But not impossible! If it can be done it will be done sooner or later, but more likely on a heavy hot and high 777 or 380 etc.
If on the other hand, we were flying Tupolev 154s in a Russian environment be afraid be very afraid!!
Your perspective as an amateur is rather too well informed me thinks?
I will try and reassure you with regards to some of your points, but it will be short as I have to fly.
Your scenario is extremely realistic when compared to some of the LOFT ( Line oriented flight training) that we run every 6 months in the simulator; Marginal contaminated runway takeoffs/landings, minimum legal fuel dispatch, closed or closing airfields, pushy dispatchers, unforecast weather leading to enroute diversions (into nasty little airfields), jet upsets and high altitude engine failure, medical emergencies, crew incapacitiation etc etc are all practised regularly.
All your `what if` scenarios are pretty well covered IMHO and when you go down to the wire on certain things like performance you must remember that it is not an exact science so the regualtors build in margins for exactly your type of worries, overloaded, poor crew reaction time, Friday airplane etc.
But to cut it short as I really have to go, if I thought my airplane was too heavy for the phase and position of flight I would simply add a couple of tons to the FMC whilst we worked out where the mistake was made. Normally the dispatcher can be contacted and if he has stuck on a few tons in the aft hold without telling us, then we can get back to business. What you may not be able to appreciate is that unlike a fully laden jumbo, our 800s operate in general around 66 tons which is 13 tons below the absolute max that can be bought from boeing (papework job to buy more weight = same airplane). Therefore there is such a lot of spare performance these things would be easily covered in your suggested scenarios. I remember being involved with a Recurrent Training scenario a few years ago where the training dept wanted to train pilots to recognise a max aft CG situation, hoping it would also lead to a tailstrike in order for crews to recover and follow the QRH etc. We ran the scenario in the sim with a 36% aft CG and found most line pilots didnt even notice the difference. I also flew the sim with flaps up and 36% CG on a takeoff using Flap 1 speed and still didnt hit the tail using normal rotation rates. So the point is the airplane is damn good and the crews are pretty good and it would take a lot of unusual events for a crew to get out of shape with this over weight thing. But not impossible! If it can be done it will be done sooner or later, but more likely on a heavy hot and high 777 or 380 etc.
If on the other hand, we were flying Tupolev 154s in a Russian environment be afraid be very afraid!!
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we do fly all the time on TU 134, TU 154, YAK 42, and we know how to check in with 30kg overweight without it going on the record - then add another 15kg in the duty-free. Then the belly freight with gestimated weight ...
Has there ever been an actual physical cross-check of calculated data when a cap suspects overweight with the relatively simple expedient of electronic load cells ?
Has there ever been an actual physical cross-check of calculated data when a cap suspects overweight with the relatively simple expedient of electronic load cells ?
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Oh, and as you've seen, I tend to think a lot and then spoil it all by expressing a rather large proportion of it Not many employers necessarily like that. So then, I am resigned to just hurtle around the sky in 738s as a paying passenger a dozen or more times a year until I get really scared or run out of money for the car park!
So the point is the airplane is damn good and the crews are pretty good and it would take a lot of unusual events for a crew to get out of shape with this over weight thing.
Actually I remember one explanation after we had deplaned and been told to expect to wait for an engineer to be flown from the UK, and had each been issued a free half sandwich. Then got shepherded back on just a few minutes later and when we were sitting comfortably again the boss said: "Ladies and Gentlemen we are pleased to inform you that we have solved the problem - actually we discovered another problem which was impacting upon the first! Both problems are now resolved and I think we can go." Da-da! So that'll be alright then!
Reminds me of the "new" '365' trains introduced ten years ago from Kings Cross to Cambridge. They too were nice bits of kit to ride in and had good drivers but far too frequently and for as long as I used them, six times out of ten they just couldn't get the blasted things to move on command after they'd hitched two together ... some inevitable but never fully understood glitch which was always solved eventually by something like "Ladies and Gentlemen if you will be seated please there will be a jolt as I shall try again to recouple, and if that doesn't work, I'll pull the plug and reboot the damn thing. Do not be alarmed if the doors close and the lights go out! Normal service will be resumed when I have reminded the computer what we are here for today!"
And I always felt sorry for the machine when the strip messaging above the door retrograded to something like "Good Morning. My name is HAL.... I am a type 365 locomotive.... I was built in 1995 in Crewe....." and the journey then commenced with no more fuss! Thankfully I never cruised any higher than about 5 feet in one of those.
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A crew would nearly never be able to detect an overweight aircraft just by the amount of taxy power you are using as slope, square wheels etc make it very difficult to assess and again a 2 ton overload is very insignificant in terms of taxy thrust required.
Warning lights during taxy are probably 99 times out of a 100, these days, warnings generated by on board computers that go around sensing and checking systems internally. On the 800 it is called the PSEU, which stands for proximity sensing electronics unit. It monitors micro switches in doors, air /ground logic (sometimes the plane thinks its in the air or vice versa), and the takeoff configuration warning system. Its brother is called the FSEU (flap slat electronic unit) which monitors the health of the proximity sensors on the flap positions versus the actual commanded position of the flaps. As you taxy out, micro switches and proximity sensors etc are exposed to vibration which, if they are faulty or sometimes not, then sends a message to the flight deck in the form of a warning light. To date I have had half a dozen of these warnings, and getting less as the manufacturer improves the product, but mine have all been false warnings and were reset by powering down the computers and rebooting! Yep, just like windows. Actually I have more than 12000 hours on the 737 and have been stuck out of base due to technical reasons, not including birds strikes, just 6 times! Thats why the Boeing is better than the airbus and preferred by the low cost guys like us that dont have an expensive engineer in every destination to reboot the computers or fix a genuine problem. If we break down then we are grounded, but look at the dispatch reliability, it is amazing!
The 154 is statistically the most dangerous passenger airplane in the world. It has killed, with the help of the crew, the design and the unreliability of the engines, thousands of people. Thats why you shouldnt fly in any of the old soviet a/c. The airmanship and skill required to fly these things safely is far greater than the achievable airmanship and ability demonstrated by the average crew!
The 800 will also tip on its tail if everyone is sitting down the back end of the plane with no baggage in the front hold. The typical scenario that this will happen is during an on board fracas perhaps, when a pax goes berserk. The police get on and hold everyone behind the incident for interviewing. If this is behing the over wing exits the recipe is set. And yes it has happened at Ryanair, but luckily the captain (an excellent South African pilot) was ahead of the game, and only the bottom step of the airstairs came off the ground.
Phew!! Hope this is helping to calm the nerves! Cant do much about the car park payments though
Warning lights during taxy are probably 99 times out of a 100, these days, warnings generated by on board computers that go around sensing and checking systems internally. On the 800 it is called the PSEU, which stands for proximity sensing electronics unit. It monitors micro switches in doors, air /ground logic (sometimes the plane thinks its in the air or vice versa), and the takeoff configuration warning system. Its brother is called the FSEU (flap slat electronic unit) which monitors the health of the proximity sensors on the flap positions versus the actual commanded position of the flaps. As you taxy out, micro switches and proximity sensors etc are exposed to vibration which, if they are faulty or sometimes not, then sends a message to the flight deck in the form of a warning light. To date I have had half a dozen of these warnings, and getting less as the manufacturer improves the product, but mine have all been false warnings and were reset by powering down the computers and rebooting! Yep, just like windows. Actually I have more than 12000 hours on the 737 and have been stuck out of base due to technical reasons, not including birds strikes, just 6 times! Thats why the Boeing is better than the airbus and preferred by the low cost guys like us that dont have an expensive engineer in every destination to reboot the computers or fix a genuine problem. If we break down then we are grounded, but look at the dispatch reliability, it is amazing!
The 154 is statistically the most dangerous passenger airplane in the world. It has killed, with the help of the crew, the design and the unreliability of the engines, thousands of people. Thats why you shouldnt fly in any of the old soviet a/c. The airmanship and skill required to fly these things safely is far greater than the achievable airmanship and ability demonstrated by the average crew!
The 800 will also tip on its tail if everyone is sitting down the back end of the plane with no baggage in the front hold. The typical scenario that this will happen is during an on board fracas perhaps, when a pax goes berserk. The police get on and hold everyone behind the incident for interviewing. If this is behing the over wing exits the recipe is set. And yes it has happened at Ryanair, but luckily the captain (an excellent South African pilot) was ahead of the game, and only the bottom step of the airstairs came off the ground.
Phew!! Hope this is helping to calm the nerves! Cant do much about the car park payments though
