FLIGHT SAFETY article "Twin Trouble"
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FLIGHT SAFETY article "Twin Trouble"
After reading this article, i was wondering if anyone else agreed with the writers practice of holding the aircraft on the runway until blue line is reached. This seems odd to me for a number of reasons.....
1) I've yet to fly an aircraft that would like being held on the ground 30 knots after normal rotate speed..
2) It would be an uncomfortable and unprofessional takeoff, hammering along and then launching into the sky...
3) It is not practical on shortish and or unimproved surfaces...
4) It is extra wear and tear on the aircraft...
5) Surely, if you follow the normal procedure for your aircraft then at the time when you would be rotating at blueline(some 5 to 10 seconds after normal rotate) then you would have a bit of height (potential energy) which is easily converted to kinetic energy (speed).....
6) If you had an engine failure JUST after takeoff after rotating at blueline you would definately struggle to stop on the remaining length whereas if you rotated at the normal speed you may have a chance of stopping after aborting.....
Just a few of my thoughts on this practice, but i would be interested to see how others operate and their views on the matter.
WRW
1) I've yet to fly an aircraft that would like being held on the ground 30 knots after normal rotate speed..
2) It would be an uncomfortable and unprofessional takeoff, hammering along and then launching into the sky...
3) It is not practical on shortish and or unimproved surfaces...
4) It is extra wear and tear on the aircraft...
5) Surely, if you follow the normal procedure for your aircraft then at the time when you would be rotating at blueline(some 5 to 10 seconds after normal rotate) then you would have a bit of height (potential energy) which is easily converted to kinetic energy (speed).....
6) If you had an engine failure JUST after takeoff after rotating at blueline you would definately struggle to stop on the remaining length whereas if you rotated at the normal speed you may have a chance of stopping after aborting.....
Just a few of my thoughts on this practice, but i would be interested to see how others operate and their views on the matter.
WRW
Disagree. I fly light piston twins so I:
* Rotate at the speed specified in the manual to achieve Vtoss by 50'.
Rationale: Vmcg & Vmca establish a lower limit for rotating. Vr gives a buffer above this. Achieving Vtoss is part of achieving performance chart figures. Anything faster wastes some of the chemical energy we're trying to convert into potential & kinetic energy.
* Gear up not before Vxse on long runways where a re-land is still feasable. If a short runway then gear up as soon as positive climb established.
NB: 'Gear up' is my change over point between trying to continue flight if an engine fails or accepting a controlled forced landing.
Rationale: The a/c is not certified to give a guaranteed performance in the take off configuration. Using a long runway gives the opportunity to land on after a failure. Once a land on is not possible then leaving the wheels down any longer than necessary wastes some of that precious chemical to kinetic/potential energy conversion.
Conversly, getting the wheels up too early ie before at least Vxse leads to a lack of performance due wrong speed + landing on the belly.
Given adequate runway length then delaying to Vxse leaves open the ability to land while below a critical performance speed and having achieved that performance speed to enable continued flight.
If a short runway that doesn't allow a land-on option then leaving the gear down any longer than necessary wastes some of that precious energy.
* Climb at Vy until a safe height for single engine manoevring is achieved. Vx if obstacle clearance is required.
Rationale: Vy gives the most least wasteful conversion of fuel energy to altitude/speed. Any faster wastes more energy due to increasing drag. Ditto slower. Gaining more speed (kinetic energy) requires increasingly more energy for each extra knot. Gaining altitude the energy cost is constant per foot gained (ignoring the small Ke gain due TAS effects).
* Cruise climb once above LSALT.
* Rotate at the speed specified in the manual to achieve Vtoss by 50'.
Rationale: Vmcg & Vmca establish a lower limit for rotating. Vr gives a buffer above this. Achieving Vtoss is part of achieving performance chart figures. Anything faster wastes some of the chemical energy we're trying to convert into potential & kinetic energy.
* Gear up not before Vxse on long runways where a re-land is still feasable. If a short runway then gear up as soon as positive climb established.
NB: 'Gear up' is my change over point between trying to continue flight if an engine fails or accepting a controlled forced landing.
Rationale: The a/c is not certified to give a guaranteed performance in the take off configuration. Using a long runway gives the opportunity to land on after a failure. Once a land on is not possible then leaving the wheels down any longer than necessary wastes some of that precious chemical to kinetic/potential energy conversion.
Conversly, getting the wheels up too early ie before at least Vxse leads to a lack of performance due wrong speed + landing on the belly.
Given adequate runway length then delaying to Vxse leaves open the ability to land while below a critical performance speed and having achieved that performance speed to enable continued flight.
If a short runway that doesn't allow a land-on option then leaving the gear down any longer than necessary wastes some of that precious energy.
* Climb at Vy until a safe height for single engine manoevring is achieved. Vx if obstacle clearance is required.
Rationale: Vy gives the most least wasteful conversion of fuel energy to altitude/speed. Any faster wastes more energy due to increasing drag. Ditto slower. Gaining more speed (kinetic energy) requires increasingly more energy for each extra knot. Gaining altitude the energy cost is constant per foot gained (ignoring the small Ke gain due TAS effects).
* Cruise climb once above LSALT.
Last edited by Tinstaafl; 20th Apr 2003 at 01:08.
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Tinstaafl
Hmmm haven't had a chance to really study the article, but a quick scan made me a little uncomfortable.
Their heart was in the right place, but many have been led to hell in a handbasket by those so motivated.
You already know my feelings on this subject .
Thats as clear and succint exposition of the reality and dilemma as I've ever seen.
I'll spend some time having a closer look at the article now.
I hope the mob around here check in a have a look and a long chat about this it's about that time again.
Hmmm haven't had a chance to really study the article, but a quick scan made me a little uncomfortable.
Their heart was in the right place, but many have been led to hell in a handbasket by those so motivated.
You already know my feelings on this subject .
Thats as clear and succint exposition of the reality and dilemma as I've ever seen.
I'll spend some time having a closer look at the article now.
I hope the mob around here check in a have a look and a long chat about this it's about that time again.
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Hold the aircraft on the runway until blue line speed?????? No thankyou........ If I start this practice then there is a better chance of getting killed running of the end of a short runway then getting killed during an EFATO.........
I'm not surprised that a CASA magazine has printed this. It only shows how our government has done everything in its power to de skill the aviation safety regulator.
I'm not surprised that a CASA magazine has printed this. It only shows how our government has done everything in its power to de skill the aviation safety regulator.
I have not read said article yet (its probably still chasing me around the country).
Similar to above, my procedure for a light piston twin is:
1. Full power prior to Brakes Release for shorter runways (if surface permits, if not use add an acceleration distance buffer for the TODR, or go out to the thresholdand clear an area of stones under each prop with a broom, board or shoe!)
2. Rotate at recommended flight manual speed
3. When airborne and accelerating in ground effect, retract the gear
4. Accelerate towards best ANGLE of climb Multi Engine (this speed varies with weight and presssure alt - check flight manual)
5. Accelerate when clear of obstacles to best RATE of climb Multi Engine (this speed also varies with weight and pressure alt)
6. Retract flap soon after a positive rate of climb is identified (depends on the aircraft whether to retract during the acceleration to Vx or delay it. Read the performance charts to see what they are predicated on).
7. Climb to a safe height (Circuit height in VMC or LSALT in IMC) at Multi Engine Best RATE of climb.
8. Reduce to cruise climb power/settings speeds.
The basic philosophy is converting all the excess thrust and power (depending on the climb out phase) into height. ANY speed in excess of the manufacturers recommendation (in that mysterious book called the flight manual) will incur excess drag. This drag is wasted energy!
The author of said article can have his excess energy wasted in drag. I will keep mine all in height. Its more useful when things go wrong....
**There was a detailed pprune thread about this in early 2000 after I was thrown a C402 and sent out bush. I started asking questions and got no straight answers, and came on here and was told by both Tinny and Gaunty the above... The thread has disappeared into the PPrune ether though.
Similar to above, my procedure for a light piston twin is:
1. Full power prior to Brakes Release for shorter runways (if surface permits, if not use add an acceleration distance buffer for the TODR, or go out to the thresholdand clear an area of stones under each prop with a broom, board or shoe!)
2. Rotate at recommended flight manual speed
3. When airborne and accelerating in ground effect, retract the gear
4. Accelerate towards best ANGLE of climb Multi Engine (this speed varies with weight and presssure alt - check flight manual)
5. Accelerate when clear of obstacles to best RATE of climb Multi Engine (this speed also varies with weight and pressure alt)
6. Retract flap soon after a positive rate of climb is identified (depends on the aircraft whether to retract during the acceleration to Vx or delay it. Read the performance charts to see what they are predicated on).
7. Climb to a safe height (Circuit height in VMC or LSALT in IMC) at Multi Engine Best RATE of climb.
8. Reduce to cruise climb power/settings speeds.
The basic philosophy is converting all the excess thrust and power (depending on the climb out phase) into height. ANY speed in excess of the manufacturers recommendation (in that mysterious book called the flight manual) will incur excess drag. This drag is wasted energy!
The author of said article can have his excess energy wasted in drag. I will keep mine all in height. Its more useful when things go wrong....
**There was a detailed pprune thread about this in early 2000 after I was thrown a C402 and sent out bush. I started asking questions and got no straight answers, and came on here and was told by both Tinny and Gaunty the above... The thread has disappeared into the PPrune ether though.
Last edited by compressor stall; 20th Apr 2003 at 12:48.
Grandpa Aerotart
Don't knock a little extra speed guys. Yes I read that article and don't remember him saying stay on the ground until blue line. Any article that did would be consigned to the bin as the rantings o an unthinking pilot.
1/. Holding the aircraft on the ground until blue line is plain dumb on a short runway and essentially counterproductive on a long one. It's a very bad habit IMO. It's the same mentality that causes people to approach at Blue Line, I've seen it!!...guys, often Instructors, landing Barons at YSBK in rain and barely getting it stopped. Some guys want to touch down at redline too...why?
2/. IMO after lift off get the wheels up as soon as positive rate of climb established and the let the aircraft accelerate in a gentle climb. Why climb at Vy/Vx? These numbers are essentially certification speeds which have very little meaning in day to day operations...how often have you operated off a runway where TODA=TODR? I have operated piston twins for thousands of hours in PNG and the answer for me is hardly ever...in Australia it would be a lot less of an issue.
99.9% of pilots faced with a real engine failure will sit there dumbfounded for a few seconds and in that time, if you are at Vy/Vx/Vyse the speed will bleed off and, in a typical piston twin you will have no way of getting those knots back other than to lower the nose...and if you are at less than a few hundred feet you will a/. Not have the altitude or, b/. most low experience pilots will not be prepared to lose that height and stagger on slowly bleeding speed until the inevitable happens...a VMCA induced loss of control or assy stall, depending on the DA.
If, on the other hand, you let the aircraft accelerate immediately and have Vyse + 10 or 15 knots asap when you lose an engine you will have time to get the failed engine secured and then peg Blue line as the speed bleeds back toward that figure. Even if there is a big tree off the end of the runway there is no requirement to climb steeply to miss it by 100s of feet...let the speed build up and ease the aircraft over it...think about how much you 'have' to miss it by!! Not much..even in 20.7.1b aircraft it's only 35'. Flight Manuals give TODR to clear a 50' obstacle...think about how low 50' is and then have a think about why you are climbing at Vx/Vy for more than a few seconds after liftoff!!!!
I would suggest that the difference in time/distance taken to achieve 50' after lift off no matter what you do is not worth worrying about.
If you actually find yourself lined up on a runway which is just long enough and has terrain/tall timber coincident with TODA I would suggest you have farked up big time just being there in the first place!!
Wheels up asap and accelerate straight to cruise climb unless there is a real good reason to do otherwise. Even departing at night towards a reasonable high, by Oz standards, LSALT...just do a climbing turn at a comfortable speed and depart overhead. Use the circuit/circling area to allow nice wide buffers in both altitude and speed.
And DO NOT rush that first power reduction after lift off...not because 'that's when it will fail' but because you want maximum power to get away from the ground at a speed comfortably in excess of Vy/Vx/Vyse. If the Flight Manual says you have a 5 minute limit at takeoff power (very rare in light piston twins) then why pull it back after 1 minute? If it's an IO520/550 why pull it back at all? Max continuous is balls to the wall on those engines...leave em there!!
Most twins used in commercial ops these days (C402/PA60/Barons/Chieftains etc) will, if loaded properly for the ambient conditions climb on one or at least maintain height on one engine, and if you are too heavy the ROD is very low and you should have time for a controlled belly landing at Vmca +.
Chuck.
1/. Holding the aircraft on the ground until blue line is plain dumb on a short runway and essentially counterproductive on a long one. It's a very bad habit IMO. It's the same mentality that causes people to approach at Blue Line, I've seen it!!...guys, often Instructors, landing Barons at YSBK in rain and barely getting it stopped. Some guys want to touch down at redline too...why?
2/. IMO after lift off get the wheels up as soon as positive rate of climb established and the let the aircraft accelerate in a gentle climb. Why climb at Vy/Vx? These numbers are essentially certification speeds which have very little meaning in day to day operations...how often have you operated off a runway where TODA=TODR? I have operated piston twins for thousands of hours in PNG and the answer for me is hardly ever...in Australia it would be a lot less of an issue.
99.9% of pilots faced with a real engine failure will sit there dumbfounded for a few seconds and in that time, if you are at Vy/Vx/Vyse the speed will bleed off and, in a typical piston twin you will have no way of getting those knots back other than to lower the nose...and if you are at less than a few hundred feet you will a/. Not have the altitude or, b/. most low experience pilots will not be prepared to lose that height and stagger on slowly bleeding speed until the inevitable happens...a VMCA induced loss of control or assy stall, depending on the DA.
If, on the other hand, you let the aircraft accelerate immediately and have Vyse + 10 or 15 knots asap when you lose an engine you will have time to get the failed engine secured and then peg Blue line as the speed bleeds back toward that figure. Even if there is a big tree off the end of the runway there is no requirement to climb steeply to miss it by 100s of feet...let the speed build up and ease the aircraft over it...think about how much you 'have' to miss it by!! Not much..even in 20.7.1b aircraft it's only 35'. Flight Manuals give TODR to clear a 50' obstacle...think about how low 50' is and then have a think about why you are climbing at Vx/Vy for more than a few seconds after liftoff!!!!
I would suggest that the difference in time/distance taken to achieve 50' after lift off no matter what you do is not worth worrying about.
If you actually find yourself lined up on a runway which is just long enough and has terrain/tall timber coincident with TODA I would suggest you have farked up big time just being there in the first place!!
Wheels up asap and accelerate straight to cruise climb unless there is a real good reason to do otherwise. Even departing at night towards a reasonable high, by Oz standards, LSALT...just do a climbing turn at a comfortable speed and depart overhead. Use the circuit/circling area to allow nice wide buffers in both altitude and speed.
And DO NOT rush that first power reduction after lift off...not because 'that's when it will fail' but because you want maximum power to get away from the ground at a speed comfortably in excess of Vy/Vx/Vyse. If the Flight Manual says you have a 5 minute limit at takeoff power (very rare in light piston twins) then why pull it back after 1 minute? If it's an IO520/550 why pull it back at all? Max continuous is balls to the wall on those engines...leave em there!!
Most twins used in commercial ops these days (C402/PA60/Barons/Chieftains etc) will, if loaded properly for the ambient conditions climb on one or at least maintain height on one engine, and if you are too heavy the ROD is very low and you should have time for a controlled belly landing at Vmca +.
Chuck.
Last edited by Chimbu chuckles; 22nd Apr 2003 at 07:42.
Chuck
In the piston twin I have spent the most time in, (MTOW at ISA/MSL) Vy is 105knots and Vyse is 96 knots. That gives a 9 knot sh!t fark factor. Hence my adhering to the speeds above.
I have not had the wide exposure to different types that you have, and as such I am curious to know if other types have the same ratio.
I still prefer to peg Vy and get up sooner. That 100-200 feet extra height (over a cruise climb) when the engine quits approaching circuit altitude/LSALT may just make life easier. I would also be flying the circular departure path you so eruditely suggest.
CS
*retyped as the previous one did not register after the BB was shut for maintenance
I have not had the wide exposure to different types that you have, and as such I am curious to know if other types have the same ratio.
I still prefer to peg Vy and get up sooner. That 100-200 feet extra height (over a cruise climb) when the engine quits approaching circuit altitude/LSALT may just make life easier. I would also be flying the circular departure path you so eruditely suggest.
CS
*retyped as the previous one did not register after the BB was shut for maintenance
If you can't save the engines then save the airframe."
DF.
Grandpa Aerotart
Then stallie you have the 10-15Kt buffer I'm suggesting in that aircraft..a B58 Baron hs 4 kts between Vy (104) and Vyse(100)...I can't remember the exact numbers for all the piston twins I've flown but from memory the Islander was 65 for just about everything but we climbed them out at 90 odd.
Speed is life in an assy twin...if you have extra altitude as well great but speed is the important one...higher speed means less control deflection/less drag/ better short term performance, while you get your sh1t in a nice pile.
Bik, I wasn't aware the Cessna 210M/N was a piston twin
As I stated in my last post...if there is a (engine) manufacturers limit then follow it. That does not mean a pavlovian reduction to some artificial 'METO' power setting at 1000' is appropriate!!
The Baron's MCP is full throttle/2700rpm, pulling power at 1000' to 25/25 is not required by the manufacturer and is merely what generations of pilots have been led to believe is right and good....it's not right and it's not good for the engine.
Why is it that pilots believe that a crash is inevitable in a Piston twin if one fails below some arbitrary speed/altitude? I would suggest that it is partly a hang over from the early days of light piston twins when it was fairly true and partly because pilots don't actually explore the FM but tend to allow well intentioned advice and old wives tales to dictate how they will fly and react to certain scenarios.
Early twins like the Commanche, Apache, Seminole etc certainly left you with few options but how many of those are still being used for commercial ops these days.
Barons, Islanders, Chieftains, C404s, Aerostars are the common aircraft piston types and Twin Otters, Kingairs, Conquests are the predominant turbine equivelents that, while turbine powered, are still FAR 23 and therefore don't have those reserves of performance that 'gaurantee' flying away from an engine cut at V1.
Flown properly they all will though!!
All that changes is the decison point...V1 in a FAR 25 type and, basically 'gear up' in FAR 23 type. Before those points you reject the takeoff...in the former you will (probably) stop within ASDA while in the later you takes what ya get!!!
I have had engine failures in the worst place, just airborne/gear up in the C402 and Aerostar...in the Cessna I was just under MTOW and in the Deathstar I was 'just'
over...both times I flew away, completed a circuit and landed 'uneventfully'. Mates have had engine failures in all manner of piston twin and done the same...one 'significanty' over MTOW on a C404...he got around the circuit and landed ok...shaking with adrenaline overdose but essentially OK.
The common thread with all of us was a system of intial and recurrent training within a 'Supplemental' Airline/Reg 203 organisation...not so common these days...the piston twins have all been handed to barely viable charter outfits with less than impressive training...either initial or recurrent.
A Baron 58 will, according to it's performance graphs, be capable of a 'postive' rate of climb on one engine, with the other feathered, flap up and GEAR DOWN up to 1600' PA and 40deg C at MTOW. With the gear up it should climb at bettter than 2.5% at MTOW, MSL and 30DegC.
And I don't believe that holding the dead engine up with 5deg bank does all that much either....theory says you then need less rudder because you brought the drag line closer to the longitudinal axis but you have also reduced the verticle component of lift...I tend to think this is one of those things that has passed into folk lore and is perpetuated by the old wives network.
Certainly when sh1ts were trumps I never remembered to do that and it seemed to make no apprecable difference. Ball in the middle/wings level/full power/speed at blue line...if it climbs great..if not look for somewhere soft for a touchdown at Vmca +...I think you will be pleasantly surprised at how well they go on one.
In FAR 25 you are 'gauranteed' 2.4% minimum (twin engine) in the second segment provided you meet certain WAT limits...you would be amazed how often even airlines tend to assume more than is deemed acceptable by the pilots in order to do flights with viable commercial loads...various airlines that operate wide bodies in and out of Kathmandu is one example that I have personaly witnessed having had to design a special procedure for the Part 25, generally overpowered, Falcon I operated in and out of there.
So in Part 25 you are 'gauranteed' acceptable performance..in Part 23 you are not....but study your AFM and see what performance you can expect under various WAT scenarios...why throw away a perfectly good aeroplane for no reason other than "But I was told..."
Even a Duchess I flew recently on a IF renewal would climb at 2.5% (SE) with two fat bastards and lotsa fuel...nice little aeroplane.
Chuck.
Speed is life in an assy twin...if you have extra altitude as well great but speed is the important one...higher speed means less control deflection/less drag/ better short term performance, while you get your sh1t in a nice pile.
Bik, I wasn't aware the Cessna 210M/N was a piston twin
As I stated in my last post...if there is a (engine) manufacturers limit then follow it. That does not mean a pavlovian reduction to some artificial 'METO' power setting at 1000' is appropriate!!The Baron's MCP is full throttle/2700rpm, pulling power at 1000' to 25/25 is not required by the manufacturer and is merely what generations of pilots have been led to believe is right and good....it's not right and it's not good for the engine.
Why is it that pilots believe that a crash is inevitable in a Piston twin if one fails below some arbitrary speed/altitude? I would suggest that it is partly a hang over from the early days of light piston twins when it was fairly true and partly because pilots don't actually explore the FM but tend to allow well intentioned advice and old wives tales to dictate how they will fly and react to certain scenarios.
Early twins like the Commanche, Apache, Seminole etc certainly left you with few options but how many of those are still being used for commercial ops these days.
Barons, Islanders, Chieftains, C404s, Aerostars are the common aircraft piston types and Twin Otters, Kingairs, Conquests are the predominant turbine equivelents that, while turbine powered, are still FAR 23 and therefore don't have those reserves of performance that 'gaurantee' flying away from an engine cut at V1.
Flown properly they all will though!!
All that changes is the decison point...V1 in a FAR 25 type and, basically 'gear up' in FAR 23 type. Before those points you reject the takeoff...in the former you will (probably) stop within ASDA while in the later you takes what ya get!!!
I have had engine failures in the worst place, just airborne/gear up in the C402 and Aerostar...in the Cessna I was just under MTOW and in the Deathstar I was 'just'
over...both times I flew away, completed a circuit and landed 'uneventfully'. Mates have had engine failures in all manner of piston twin and done the same...one 'significanty' over MTOW on a C404...he got around the circuit and landed ok...shaking with adrenaline overdose but essentially OK.The common thread with all of us was a system of intial and recurrent training within a 'Supplemental' Airline/Reg 203 organisation...not so common these days...the piston twins have all been handed to barely viable charter outfits with less than impressive training...either initial or recurrent.
A Baron 58 will, according to it's performance graphs, be capable of a 'postive' rate of climb on one engine, with the other feathered, flap up and GEAR DOWN up to 1600' PA and 40deg C at MTOW. With the gear up it should climb at bettter than 2.5% at MTOW, MSL and 30DegC.
And I don't believe that holding the dead engine up with 5deg bank does all that much either....theory says you then need less rudder because you brought the drag line closer to the longitudinal axis but you have also reduced the verticle component of lift...I tend to think this is one of those things that has passed into folk lore and is perpetuated by the old wives network.
Certainly when sh1ts were trumps I never remembered to do that and it seemed to make no apprecable difference. Ball in the middle/wings level/full power/speed at blue line...if it climbs great..if not look for somewhere soft for a touchdown at Vmca +...I think you will be pleasantly surprised at how well they go on one.
In FAR 25 you are 'gauranteed' 2.4% minimum (twin engine) in the second segment provided you meet certain WAT limits...you would be amazed how often even airlines tend to assume more than is deemed acceptable by the pilots in order to do flights with viable commercial loads...various airlines that operate wide bodies in and out of Kathmandu is one example that I have personaly witnessed having had to design a special procedure for the Part 25, generally overpowered, Falcon I operated in and out of there.
So in Part 25 you are 'gauranteed' acceptable performance..in Part 23 you are not....but study your AFM and see what performance you can expect under various WAT scenarios...why throw away a perfectly good aeroplane for no reason other than "But I was told..."
Even a Duchess I flew recently on a IF renewal would climb at 2.5% (SE) with two fat bastards
and lotsa fuel...nice little aeroplane.Chuck.
Last edited by Chimbu chuckles; 21st Apr 2003 at 12:52.
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Lets not lose track here boys.... In the article they talk about a C90 (baby Kingair). I personally have never flown the C90 but have flown the B200. Everyone seems to be hung up on this magic blue line figure. Image what we would have done if no aircraft manufacture put a blue line on airspeed indicator.
Why do people die in aircraft when they suffer an EFATO???? I think the answer is because they lose control of the aircraft..... So therefore why the hell do pilots get so hung up on a performance speed like Vyse!!!!!!!!!
Why don't we debate Vxse....... When I design an aircraft I won't mark Vyse I mark VTOSS or V2 or V1 as a orange line.
Why do people die in aircraft when they suffer an EFATO???? I think the answer is because they lose control of the aircraft..... So therefore why the hell do pilots get so hung up on a performance speed like Vyse!!!!!!!!!
Why don't we debate Vxse....... When I design an aircraft I won't mark Vyse I mark VTOSS or V2 or V1 as a orange line.
That 5 percent
Hey again Chuck,
thought about what you have said re the 5 degrees bank. Just plugged the numbers, and I show less than a 0.4% reduction in the vertical lift component with the full 5 degrees bank applied.
Now as you are aware I am not able to calculate the extra performance drag through the 'extra' rudder drag, but it must be some, or any amount equivalent to the loss of said 4 percent. If not, then it would not be in the flight manual. After all performance data is shown in the best light possible!
The bottom line for me is that that it what the flight manual is calculated on, so that is what I shal strive to fly. I am not the greatest pilot ever born, so i shall attempt to stack everything in my favour. As such I shall fly with that 5% on climbout.
Throughout most of these thread there still lies the most important message for the new and not so new twin pilot - read the friggin flight manual and follow it. It is no Harry Potter.
thought about what you have said re the 5 degrees bank. Just plugged the numbers, and I show less than a 0.4% reduction in the vertical lift component with the full 5 degrees bank applied.
Now as you are aware I am not able to calculate the extra performance drag through the 'extra' rudder drag, but it must be some, or any amount equivalent to the loss of said 4 percent. If not, then it would not be in the flight manual. After all performance data is shown in the best light possible!
The bottom line for me is that that it what the flight manual is calculated on, so that is what I shal strive to fly. I am not the greatest pilot ever born, so i shall attempt to stack everything in my favour. As such I shall fly with that 5% on climbout.
Throughout most of these thread there still lies the most important message for the new and not so new twin pilot - read the friggin flight manual and follow it. It is no Harry Potter.
Grandpa Aerotart
Awww come on Bik...I put a smilie there
I accept your assertion that the model of IO520 in debate has such a limitation.
The point I make about reducing power on those engines is more to do with harming the engine, long term, than about performance at that specific point of time.
WAGIT
What's wrong with marking blue line, where only one such speed is appropriate for the aircraft and red line similarly?....seems simple to me...and is the accepted industry norm for smaller aircraft.
V1/V2/Vr etc are not appropriate terms for Part 23 aircraft and are not used, or should not be used, in non transport category aircraft.
I would agree that sometimes 'blue line' is relied on too much...the old C402As we had at Talair had a single blue radial speed at 103kts painted inside the ASI but in reality Vyse varied from about 97kts a light weights up to 103 at MTOW. I had one trainee go scooting out over the Bismarck Sea hardly climbing but perfecty under control at 103kts when just he and I were onboard and 97Kts was more appropriate. Amazing how much better we climbed at 97Kts
I find it very interesting that pilots, in general, expect a Baron/Chieftain/C402-4 to crash after an engine failure at say 50- 100' but expect better things from a B90/C441 etc when the certification basis, as far as I'm aware, is the same.
In general terms, for aircraft where the AFM suggests they will fly on one, get the wheels up quick and the likelhood is it will fly on one if you fly it properly...if it won't, for whatever reason, then I think you'll hurt yourself less putting the aircraft down on it's belly near Vmca than you will throwing it back on the ground on it's wheels. About the only places which are really long enough to reland and stop are major capital city airports...I don't think you'd get away with it at BK/JKT/AF etc...more likely to rip out the nosewheel at relatively high speed with all that that may entail.
Chuck.
Edit for Stallie's post.....0.4%, If it makes you feel better do it...if you remember in the heat of the moment, I didn't
BTW real engine failures are almost never the same as training ones...the one I had i the 402 was dead cut/full power/dead cut in rapid succesion- the deathstar was a fire warning and dramatic loss of power followed by shutdown...not at all like a prewarned or at least expected mixture cut at 400' on a renewal.
I accept your assertion that the model of IO520 in debate has such a limitation.
The point I make about reducing power on those engines is more to do with harming the engine, long term, than about performance at that specific point of time.
WAGIT
What's wrong with marking blue line, where only one such speed is appropriate for the aircraft and red line similarly?....seems simple to me...and is the accepted industry norm for smaller aircraft.
V1/V2/Vr etc are not appropriate terms for Part 23 aircraft and are not used, or should not be used, in non transport category aircraft.
I would agree that sometimes 'blue line' is relied on too much...the old C402As we had at Talair had a single blue radial speed at 103kts painted inside the ASI but in reality Vyse varied from about 97kts a light weights up to 103 at MTOW. I had one trainee go scooting out over the Bismarck Sea hardly climbing but perfecty under control at 103kts when just he and I were onboard and 97Kts was more appropriate. Amazing how much better we climbed at 97Kts
I find it very interesting that pilots, in general, expect a Baron/Chieftain/C402-4 to crash after an engine failure at say 50- 100' but expect better things from a B90/C441 etc when the certification basis, as far as I'm aware, is the same.
In general terms, for aircraft where the AFM suggests they will fly on one, get the wheels up quick and the likelhood is it will fly on one if you fly it properly...if it won't, for whatever reason, then I think you'll hurt yourself less putting the aircraft down on it's belly near Vmca than you will throwing it back on the ground on it's wheels. About the only places which are really long enough to reland and stop are major capital city airports...I don't think you'd get away with it at BK/JKT/AF etc...more likely to rip out the nosewheel at relatively high speed with all that that may entail.
Chuck.
Edit for Stallie's post.....0.4%, If it makes you feel better do it...if you remember in the heat of the moment, I didn't
BTW real engine failures are almost never the same as training ones...the one I had i the 402 was dead cut/full power/dead cut in rapid succesion- the deathstar was a fire warning and dramatic loss of power followed by shutdown...not at all like a prewarned or at least expected mixture cut at 400' on a renewal.
Last edited by Chimbu chuckles; 21st Apr 2003 at 20:16.
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Ahh!!!! Chimbu chuckles..... My only problem that I have with Blue line is people get fix sated on this speed.
What are you flying when you nail the blue line? The simple answer is Vyse.
But now instead of just having an airspeed indicator with blue line on it you also have an angle of attack indicator. What will you fly now 4 degrees angle of attack or the blue line??????
What are you flying when you nail the blue line? The simple answer is Vyse.
But now instead of just having an airspeed indicator with blue line on it you also have an angle of attack indicator. What will you fly now 4 degrees angle of attack or the blue line??????
Wagit,
Things might be better if there was better training! Throughout my training (and what I was subsequently taught to teach ) was blue line this and blue line that. It was not until I was out on my own did I start to think about things. I never had a C&T the same experience as say Chuck above, and to adhere to a speed other than blue line was something I worked out myself after reading and rereading that mysterious dog eared faded tome in the seat pocket.
Blue line (as you are well aware!) is a speed which should only ever be maintained in ONE condition - engine failure at MTOW sea level ISA day. Anything changes and so does the speed! But having said that it's a useful reference. If you are light or high (PNG?) knock a few knots off - refer the flight manual. Easier than trying to remember speeds given the sh!t fark factor.
I do not recall at any stage during my initial multi (or during my multi engine instructors rating ) having to understand and explain why for example Vyse varies with height.
Part of the problem could as well be so many new CPLs get their MECIR, taught to them by an snotty nosed instructor with all of 700 hours total and 50 hours multi and a 5 hour 'training' course (of which I was one). The students then go bush for 2 years before they get thrown a twin (me again) and only then when its thrown in their face do SOME of them start asking questions.
The old wives tales then start doing the rounds... To quote Gaunty..."dancing with somebody who danced with somebody who danced with the prince of Wales". Somebody told somebody that holding it on the runway is a good thing to past blue line as its safer. That somebody told the author of this article who in the absence of any other direction turned it into gospel, infecting a whole new generation of pilots.
What the industry needs is people with thousands of hours real flying (the likes of most of the posters above) to teach and check the new breed. But unfortunately people of such calibre are not lured into instructing for obvious reasons.
Instead people get taught by the sort of well intentioned, but naive 700 hour TT multi engine instructor like I was. I often think back to what I knew then, to what I know now, and what I have yet to learn. Only now with a still relatively low 2200 hours multi in charter and bush ops in piston and turbine do I feel that I have the depth of knowledge and experience to be a worthy multi engine instructor. (Also acknowledging that I have a lot more to learn - amongst other things how I will react when a fan stops!). :Hmm:
Maybe also IFR renewals should focus on these issues too..performance and procedures? I cannot recall being asked any FAR 23 performance based questions on an IFR renewal. Instead its been just the usual "do you need a clock or a watch for this op?"
Priorities! A second hand (or lack thereof) on a watch is not going to kill you - but holding it on till blue line will!
Then again how many MB or BK ATOs have experience with marginal performance on marginal length stips outside the circuit?
[/RANT]
CS
Edit as I got sidetracked - Wagit how susceptible to error would a commercially available AoA indicator be, and its relaibility in an airframe?
Things might be better if there was better training! Throughout my training (and what I was subsequently taught to teach
) was blue line this and blue line that. It was not until I was out on my own did I start to think about things. I never had a C&T the same experience as say Chuck above, and to adhere to a speed other than blue line was something I worked out myself after reading and rereading that mysterious dog eared faded tome in the seat pocket.Blue line (as you are well aware!) is a speed which should only ever be maintained in ONE condition - engine failure at MTOW sea level ISA day. Anything changes and so does the speed! But having said that it's a useful reference. If you are light or high (PNG?) knock a few knots off - refer the flight manual. Easier than trying to remember speeds given the sh!t fark factor.
I do not recall at any stage during my initial multi (or during my multi engine instructors rating
) having to understand and explain why for example Vyse varies with height.Part of the problem could as well be so many new CPLs get their MECIR, taught to them by an snotty nosed instructor with all of 700 hours total and 50 hours multi and a 5 hour 'training' course (of which I was one). The students then go bush for 2 years before they get thrown a twin (me again) and only then when its thrown in their face do SOME of them start asking questions.
The old wives tales then start doing the rounds... To quote Gaunty..."dancing with somebody who danced with somebody who danced with the prince of Wales". Somebody told somebody that holding it on the runway is a good thing to past blue line as its safer. That somebody told the author of this article who in the absence of any other direction turned it into gospel, infecting a whole new generation of pilots.
What the industry needs is people with thousands of hours real flying (the likes of most of the posters above) to teach and check the new breed. But unfortunately people of such calibre are not lured into instructing for obvious reasons.
Instead people get taught by the sort of well intentioned, but naive 700 hour TT multi engine instructor like I was. I often think back to what I knew then, to what I know now, and what I have yet to learn. Only now with a still relatively low 2200 hours multi in charter and bush ops in piston and turbine do I feel that I have the depth of knowledge and experience to be a worthy multi engine instructor. (Also acknowledging that I have a lot more to learn - amongst other things how I will react when a fan stops!). :Hmm:
Maybe also IFR renewals should focus on these issues too..performance and procedures? I cannot recall being asked any FAR 23 performance based questions on an IFR renewal. Instead its been just the usual "do you need a clock or a watch for this op?"
Priorities! A second hand (or lack thereof) on a watch is not going to kill you - but holding it on till blue line will! Then again how many MB or BK ATOs have experience with marginal performance on marginal length stips outside the circuit?
[/RANT]
CS
Edit as I got sidetracked - Wagit how susceptible to error would a commercially available AoA indicator be, and its relaibility in an airframe?
Last edited by compressor stall; 22nd Apr 2003 at 17:23.
Grandpa Aerotart
Wagit it would be wonderfull if more aircraft were fitted with AoA indicators AND people were taught there use...as it is I have flown three aircraft with said gadget - DHC7, F28 & DA200 (Falcon 200) and in none were we taught to use it properly. In the Falcon I played with it a bit and could see where they would be great...setting 1.3VS on the selector and flying the donut on final is kinda fun...but it's not taught outside the military, and they are not fitted to GA Light Twins...so discusion of same, within the terms of reference of this thread is, while interesting, counterproductive.
I reread that article and find it interesting that I essentially agree with much of what he initially said, if little of what he subsequently did, until I got to the last paragraph. His experience, or whatever input peers had later, has lead him to conclude that he's better off staying on the gound until blue line...I strongly disagree with that!!
It seems as if one experience of engine failure has caused him to forget the intelligent critique of the Baron driver's plan to reject from 400'
and come up with a not terribly well thought out opposite extreme.
What's really interesting- and unfortunately not surprising- is that his new 'policy' did not excite any response from the 'staff writers'...they seeming to be incapable of anything other than regurgitating from a C90 AFM they found somewhere, and dusted off. The only paragraph in the whole 'analysis' which warranted the term was that questioning whether, given the SE perf was adequate enough to steep turn around (no mention of the intermittant stall warning
) why didn't he just manouver visually clear of terrain and take his time to fly a less exciting circuit.
Chuck
I reread that article and find it interesting that I essentially agree with much of what he initially said, if little of what he subsequently did, until I got to the last paragraph. His experience, or whatever input peers had later, has lead him to conclude that he's better off staying on the gound until blue line...I strongly disagree with that!!
It seems as if one experience of engine failure has caused him to forget the intelligent critique of the Baron driver's plan to reject from 400'
and come up with a not terribly well thought out opposite extreme.What's really interesting- and unfortunately not surprising- is that his new 'policy' did not excite any response from the 'staff writers'...they seeming to be incapable of anything other than regurgitating from a C90 AFM they found somewhere, and dusted off. The only paragraph in the whole 'analysis' which warranted the term was that questioning whether, given the SE perf was adequate enough to steep turn around (no mention of the intermittant stall warning
) why didn't he just manouver visually clear of terrain and take his time to fly a less exciting circuit.Chuck
Wagit, the problem is that we DON'T have an AoA indicator. Wish we did. The ASI is the next best thing.
During training any reference to Blue Line should always be a qualified one, with an allowance for any change from the relevent conditions.
The next step is to have some idea of how Vyse changes & use that. An easy way is check the manual & see what it is at altitude. The change isn't linear but close enough so a rate of change with altitude can be found eg 2kts / 1000' or whatever.
During training any reference to Blue Line should always be a qualified one, with an allowance for any change from the relevent conditions.
The next step is to have some idea of how Vyse changes & use that. An easy way is check the manual & see what it is at altitude. The change isn't linear but close enough so a rate of change with altitude can be found eg 2kts / 1000' or whatever.
Grandpa Aerotart
Stallie...you can lay the blame for the poor level of multi engine training in Oz today directly at the feet of CASA.... you know the Civil Aviation SAFETY Authority.
I have had over the years C&T on Bn2, C402, C404, PA60, Twin Otter and Falcon 200...all bar the Falcon was in PNG where, for all their other faults, DCA took a very laudible, pragmatic view of who should do training. I passed DCA Checkrides for C&T on all except PA60, which was a 'over a beer at the Dero deal, + a DCA Checkride for initial Tailwheel Training approval on the C185. The fact that I had long expired Grade 3 IR helped.
Note all that training was done under the auspices of a Reg 203 airline licence except for the Aerostar/C185.
I passed some tough CASA testing on the Falcon for full C&T as well as I/R renewal/initial issue and Initial 1st/2nd class type endorsements...blah, blah.
But a recent enquiry to CASA about how I might go about getting endorsement approval for a certain FAR 23 turbine I'm flying met with a very definate negative response.
If I want to renew my Grade 3 Instructors rating, at great expence, with a ME Checkride I could, presumably, teach on any twin I'm endorsed on, under the umbrella of a Flying School...but no way will they do a Checkride on me and transfer (recent) previously held CASA approvals (Part 25 Internationa Ops) if I want to be a CP in a Part 23 Charter Operation.
How do I do recurrency on Pilots under my authority?
The answer is that's what ATOs are for!
Umm sorry but that doesn't work all that well.
Now I understand that they have a set of rules but when they are so inflexible one has to wonder whether they are counterproductive. Clearly this system protects the ATOs but, from what little I've seen of ATOs, SOME are not worth protecting.
As far as usefull questioning on performance is concerned you forget the first rule...never ask a question you don't know the answer to!
I have had a CASA approved ATO tell me during a groundcourse for a FAR 25 certified Corporate Jet, not the Falcon, that "To maintain directional control after an engine failure at V1 reduce power on the good engine"
This was because it had "very powerfull engines"
Searching questions on his understanding of V1 and it's relationship to Vmcg + V2 and it's relationship to Vmca were revealing...but had no effect because he told the same thing to someone else 6 months later.
Perhaps we were the first two ex airline guys he'd endorsed...and presumably it passed a CASA FOI without comment too! I wonder if he's still doing it!!
Wanna learn about performance? Join an airline!!!
Our answer?
"Nah sorry...won't be doing dat!!"
Chuck.
I have had over the years C&T on Bn2, C402, C404, PA60, Twin Otter and Falcon 200...all bar the Falcon was in PNG where, for all their other faults, DCA took a very laudible, pragmatic view of who should do training. I passed DCA Checkrides for C&T on all except PA60, which was a 'over a beer at the Dero deal, + a DCA Checkride for initial Tailwheel Training approval on the C185. The fact that I had long expired Grade 3 IR helped.
Note all that training was done under the auspices of a Reg 203 airline licence except for the Aerostar/C185.
I passed some tough CASA testing on the Falcon for full C&T as well as I/R renewal/initial issue and Initial 1st/2nd class type endorsements...blah, blah.
But a recent enquiry to CASA about how I might go about getting endorsement approval for a certain FAR 23 turbine I'm flying met with a very definate negative response.
If I want to renew my Grade 3 Instructors rating, at great expence, with a ME Checkride I could, presumably, teach on any twin I'm endorsed on, under the umbrella of a Flying School...but no way will they do a Checkride on me and transfer (recent) previously held CASA approvals (Part 25 Internationa Ops) if I want to be a CP in a Part 23 Charter Operation.
How do I do recurrency on Pilots under my authority?
The answer is that's what ATOs are for!
Umm sorry but that doesn't work all that well.
Now I understand that they have a set of rules but when they are so inflexible one has to wonder whether they are counterproductive. Clearly this system protects the ATOs but, from what little I've seen of ATOs, SOME are not worth protecting.
As far as usefull questioning on performance is concerned you forget the first rule...never ask a question you don't know the answer to!
I have had a CASA approved ATO tell me during a groundcourse for a FAR 25 certified Corporate Jet, not the Falcon, that "To maintain directional control after an engine failure at V1 reduce power on the good engine"
This was because it had "very powerfull engines"
Searching questions on his understanding of V1 and it's relationship to Vmcg + V2 and it's relationship to Vmca were revealing...but had no effect because he told the same thing to someone else 6 months later.
Perhaps we were the first two ex airline guys he'd endorsed...and presumably it passed a CASA FOI without comment too! I wonder if he's still doing it!!
Wanna learn about performance? Join an airline!!!
Our answer?
"Nah sorry...won't be doing dat!!"
Chuck.
Last edited by Chimbu chuckles; 22nd Apr 2003 at 21:52.
Hmmm,
Reminds me of a former chief pilot who told the room of young (and not so young) pilots that if you have an engine failure soon after take off when heavy in a P68 "You should be able to hoik it around and land on the runway (in the opposite direction) you just took off from". This from a person who had multi engine approval and a chief pilot of a then large organisation.
My concern was for the young aspiring pilots - who he looked after well and never really barstardised. They in turn revered him and hung on his every word. This was how he kept his power and respect. It is little wonder what myths these impressionable pilots took away with them. Hopefully most went on to airlines or an environment where further training was necessary.
Interestingly, anyone who knew what they were talking about and a threat to his knowledge and kingdom were belittled and isolated.
I never got to the point of asking about what speeds to fly - I was outta there....
Scary thing is that he's now moved elsewhere to perpetuate said myths in another organisation....
Reminds me of a former chief pilot who told the room of young (and not so young) pilots that if you have an engine failure soon after take off when heavy in a P68 "You should be able to hoik it around and land on the runway (in the opposite direction) you just took off from".
This from a person who had multi engine approval and a chief pilot of a then large organisation.My concern was for the young aspiring pilots - who he looked after well and never really barstardised. They in turn revered him and hung on his every word. This was how he kept his power and respect. It is little wonder what myths these impressionable pilots took away with them. Hopefully most went on to airlines or an environment where further training was necessary.
Interestingly, anyone who knew what they were talking about and a threat to his knowledge and kingdom were belittled and isolated.
I never got to the point of asking about what speeds to fly - I was outta there....
Scary thing is that he's now moved elsewhere to perpetuate said myths in another organisation....
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Fantastic
This thread has been both imensely interesting and thought provoking. It is great to have those that have an idea about such an important topic to discuss it freely on an open forum where others can learn, or at least read.
This thread has interested me as I am looking to getting my Twin Training Approval. What person or organsiation would be best to approach for this. I'm after someone who has a wealth of experience not a wealth of stories. Chimbu, Tinstaafl, Compressor and others, where would I find such a place.
Regards All
This thread has interested me as I am looking to getting my Twin Training Approval. What person or organsiation would be best to approach for this. I'm after someone who has a wealth of experience not a wealth of stories. Chimbu, Tinstaafl, Compressor and others, where would I find such a place.
Regards All