Piper Run Ups
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Piper Run Ups
Hi All
Just a query with run ups on a light twin (Seminole). I have seen a number of people insist that they perform their pre takeoff run ups with both engines set at the same RPM.
I have always be taught to run up one engine at a time. Is there a technical reason for running them up together or am I missing something
Ang
Just a query with run ups on a light twin (Seminole). I have seen a number of people insist that they perform their pre takeoff run ups with both engines set at the same RPM.
I have always be taught to run up one engine at a time. Is there a technical reason for running them up together or am I missing something
Ang
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Some twins (don't know if seminole) might call for some power, say 1500 rpm on the opposite engine being run as to avoid some static stress on to the nose gear system, I also suppose some people do it to "save time", as long as you can look at what you see during run-ups, shouldnt be a problem.
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Cheers thanks for that. I doubt that the stress on the nose wheel would be significant though considering what would happen if LAME's were doing run ups on twins with one engine completely removed. Are you saying that the stress on the nose wheel is sufficient enought to damage it.. ?
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Ang
It’s an ‘Airmanship’ thing so disregard the responses from the cowboys. Your instructor probably taught you the correct method. In doing so he has ‘risk managed’ a whole heap of ‘bad karma’ that has manifested itself through years of multi-engine operations. Here are some that I see:
Since engines are started independently then on a cold day the second engine may not have reached operating temperature in the run-up bay.
Running-up both engines at once doubles the risk of ‘brake-creep’ and leads to wiping out the expensive Learjet ahead of you – or the fuel truck. This normally happens when ‘head-down’ in the cockpit fumbling with switches and levers and looking at gauges!
The guy taxiing past in the tail-dragger is more likely to ‘ground-loop’ with double your propwash at run-up power!
Why not check your company operations manual, the AFM or ask the CFI if you are renting his twin. Procedures different from those published just make more loopholes for the insurance companies and the courts!
Discount all the convenient excuses for double run-ups put forth by the cowboys – after all, the time saving is just a few seconds but you might carry the consequences for life.
…I have always been taught to run up one engine at a time. Is there a technical reason for running them up together or am I missing something….
Since engines are started independently then on a cold day the second engine may not have reached operating temperature in the run-up bay.
Running-up both engines at once doubles the risk of ‘brake-creep’ and leads to wiping out the expensive Learjet ahead of you – or the fuel truck. This normally happens when ‘head-down’ in the cockpit fumbling with switches and levers and looking at gauges!
The guy taxiing past in the tail-dragger is more likely to ‘ground-loop’ with double your propwash at run-up power!
Why not check your company operations manual, the AFM or ask the CFI if you are renting his twin. Procedures different from those published just make more loopholes for the insurance companies and the courts!
Discount all the convenient excuses for double run-ups put forth by the cowboys – after all, the time saving is just a few seconds but you might carry the consequences for life.
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Any of you ever seen how much a T tail vibrates and flexes when one engine is at high power and the other isn't?? It's scary. Anyone remember the Nomad? Years ago I was shown 1500 on both for pitch/feather check, then one at a time to mag check rpm, leaving the other at 1500, to help even the load on the nose leg and the tail structure, especially T tail types. Dunno if it matters much, but it has always worked ok for me.......
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I prefer togetherness
I am no expert (at anything much) but I remember flying Nomads, where it had been demonstrated tragically that the tail plane accumulated fatigue much faster if ground running assymetrically rather than both together. Perhaps this is limited to STOL aircraft with large tails or with rudders not held in place by a nosewheel connection. I generally find that airframe and rudder buffeting, not to mention noise and vibration etc feels more "comfortable" when you run up together or at least somewhat together, rather than individually. As for checking the flight manual, yes, but also consider checking service manuals for ground running procedures, of course not for pilot action but perhaps a better understanding of the issues may result.
Regards,
Regards,
dragchute
I find your comment “ignore the Cowboys” totally offensive, ill-informed and totally unjustified. I have a considerable amount of experience in GA on light twins. I am a former Chief Pilot of a very large Charter Company with an impeccable safety record. I am also a former Chief Flying Instructor and I also have a considerable amount of experience in check and training and maintenance control. We had it explicitly written in our SOP’s that run-ups were to be done symmetrically. There were two reasons this was required:
1. The load that was imposed on the nose gear during an asymmetric run-up. The nose wheel assembly of a Cessna 400 series is exactly the same part as on a Cessna 310. Our engineering department always paid particular attention to this area, as it was the Achilles Heal of the 400 Series. Check all the AD’s on the nose wheel assembly.
2. The stress that is placed on the tail plane. Particularly on the 404 with its considerable dihedral.
Your assertion that symmetrical run ups is bad airmanship is misleading. Any run up with out a good lookout is bad airmanship. Like wise any pilot who blindly taxies behind any aircraft, particularly a twin in a run up bay is also showing a bad judgment in airmanship. You also talk about the likelihood of T’s & P’s not being at the proper level on the last engine to be started. What a load of BS. If it’s such a problem, wait another 30 seconds or maybe taxi a little slower. As for brake creep and hitting the expensive Lear in front of you. You shouldn’t be relying on your hand brake during a run up anyway. Keep your feet on the brake pedals as well and don’t do your run ups behind another aircraft. The whole idea of symmetrical run ups for us wasn’t to save time but to save unnecessary maintenance costs.
I find your comment “ignore the Cowboys” totally offensive, ill-informed and totally unjustified. I have a considerable amount of experience in GA on light twins. I am a former Chief Pilot of a very large Charter Company with an impeccable safety record. I am also a former Chief Flying Instructor and I also have a considerable amount of experience in check and training and maintenance control. We had it explicitly written in our SOP’s that run-ups were to be done symmetrically. There were two reasons this was required:
1. The load that was imposed on the nose gear during an asymmetric run-up. The nose wheel assembly of a Cessna 400 series is exactly the same part as on a Cessna 310. Our engineering department always paid particular attention to this area, as it was the Achilles Heal of the 400 Series. Check all the AD’s on the nose wheel assembly.
2. The stress that is placed on the tail plane. Particularly on the 404 with its considerable dihedral.
Your assertion that symmetrical run ups is bad airmanship is misleading. Any run up with out a good lookout is bad airmanship. Like wise any pilot who blindly taxies behind any aircraft, particularly a twin in a run up bay is also showing a bad judgment in airmanship. You also talk about the likelihood of T’s & P’s not being at the proper level on the last engine to be started. What a load of BS. If it’s such a problem, wait another 30 seconds or maybe taxi a little slower. As for brake creep and hitting the expensive Lear in front of you. You shouldn’t be relying on your hand brake during a run up anyway. Keep your feet on the brake pedals as well and don’t do your run ups behind another aircraft. The whole idea of symmetrical run ups for us wasn’t to save time but to save unnecessary maintenance costs.
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Titan 404
I don’t see any mention by Ang737 relating to C310/C404/NOMAD or any other type in the above question. The guy is probably kicking off in a light twin and some experts are jumping on the medium twin band-wagon. I’m sure any competent instructor would have enough sense to lead his student into more sophisticated types when demanded. Building block technique as I recall from my instructor course. Why cloud the issue?
Titan
My own extensive experience on C402 and Super King Airs never involved symmetric run-ups. If you justify the issue and include it in your operations manual then I don’t see a problem. Just out of interest the Super King Air checklist under ‘BEFORE TAKEOFF (RUNUP) states 11 d. Power Levers (Individually) – INCREASE UNTIL PROP…
I refer Ang737 back to my previous
No appologies!
… Just a query with run ups on a light twin (Seminole). …
Titan
My own extensive experience on C402 and Super King Airs never involved symmetric run-ups. If you justify the issue and include it in your operations manual then I don’t see a problem. Just out of interest the Super King Air checklist under ‘BEFORE TAKEOFF (RUNUP) states 11 d. Power Levers (Individually) – INCREASE UNTIL PROP…
I refer Ang737 back to my previous
… Why not check your company operations manual, the AFM or ask the CFI if you are renting his twin. …
dragchute
Don’t know anything about the King Air so can’t comment. Your advise to Ang737 is appropriate, do ask the CFI what they would prefer because frankly there is no right or wrong here. He should also ask what way they want run ups done on gravel strips because he probably hasn’t been taught how to do this either. Also speak with engineers as to what they think. They are a wealth of knowledge when it comes to these things.
What I found offensive, and you may not have meant it, is the inference that all pilots that do symmetrical run ups are Cowboys and that Ang should ignore them. People can make their own judgment as to whether someone is a Cowboy or not, but don’t paint everyone with the same brush.
Don’t know anything about the King Air so can’t comment. Your advise to Ang737 is appropriate, do ask the CFI what they would prefer because frankly there is no right or wrong here. He should also ask what way they want run ups done on gravel strips because he probably hasn’t been taught how to do this either. Also speak with engineers as to what they think. They are a wealth of knowledge when it comes to these things.
What I found offensive, and you may not have meant it, is the inference that all pilots that do symmetrical run ups are Cowboys and that Ang should ignore them. People can make their own judgment as to whether someone is a Cowboy or not, but don’t paint everyone with the same brush.
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One marvels at the rubbish that has appeared on these pages Such gems as: Don't run up one engine at a time because of
Static stress on the nose gear assembly - even the load on the nose wheel and tail structure - and how about the writer that boasts of his vast experience and his company's impeccable safety record? Jesus wept - spare us this legend in his own mind..
I am sure the manufacturers of the Pipers and Cessna and Beechcraft light twins would either be laughing their heads off at such myths of GA - or utterly dismayed at the nonsense that is peddled by GA instructors as fact when it comes to operation of their aircraft.
Any vital technical limitation on engine handling either on the ground or in the air would be promulgated in the AFM. A local directive on the subject published in a a flying school operations manual is usually someone's (the CFI) personal opinion and not necessarily based on the manufacturer's technical fact.
Single engine run up procedure as queried by Ang737 should be the norm - unless the manufacturer recommends otherwise. I have never seen such a limitation - have you?
Static stress on the nose gear assembly - even the load on the nose wheel and tail structure - and how about the writer that boasts of his vast experience and his company's impeccable safety record? Jesus wept - spare us this legend in his own mind..
I am sure the manufacturers of the Pipers and Cessna and Beechcraft light twins would either be laughing their heads off at such myths of GA - or utterly dismayed at the nonsense that is peddled by GA instructors as fact when it comes to operation of their aircraft.
Any vital technical limitation on engine handling either on the ground or in the air would be promulgated in the AFM. A local directive on the subject published in a a flying school operations manual is usually someone's (the CFI) personal opinion and not necessarily based on the manufacturer's technical fact.
Single engine run up procedure as queried by Ang737 should be the norm - unless the manufacturer recommends otherwise. I have never seen such a limitation - have you?
Menen
would either be laughing their heads off at such myths of GA - or utterly dismayed at the nonsense that is peddled by GA instructors
Apart from this stupid comment
Run them up together, you are flying a twin not two singles
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Danger Danger
Ibex.
Let me know where you are flying so I can stear clear. Call me pig headed but check the mags and pitch (I guess you mean feather check) on the early stage of the takeoff role is absurd. As for staying on the taxiway, I usually go to the run ups bay and with the park brake on do my run ups, assymetrically.
Please tell me your joking
Ang
Let me know where you are flying so I can stear clear. Call me pig headed but check the mags and pitch (I guess you mean feather check) on the early stage of the takeoff role is absurd. As for staying on the taxiway, I usually go to the run ups bay and with the park brake on do my run ups, assymetrically.
Please tell me your joking
Ang
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I agree following the AFM is the way to go, but also keep in mind that new experiences have evolved after the blueprints were made (evidence is the amount of SB's, SL's and AD's evolving over time). Some practices may emerge from experience (hangar or cockpit) and others from blindly following others. If in doubt, do what the book says!
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404 Titan
Spot on regardless of manufacturer.
Symetrical power and a maximum of whatever the manual says, 1500 RPM and gently generally does the trick.
I suspect some pilots see it as a badge of honour to sit in their twin in the holding bay surrounded by single revving the guts out of the engine with much flashing of hands around the quadrant and snarling and moaning from the engines......"hey look at me".
I mean I guess the manufacturer probably doesn't know anything about his product and only writes an AFM etc. for the fun of it and as a means of selling more aircraft.
Another thing that amazes me are the huge number of pilots and enginerds in this country, who, for one reason or another have managed to amass an enormous fund of knowledge and experience that renders the manufacturers advice and recommendations as the banging of drums and tinkling of bells.
But then I guess having built more than 250,000 aircraft means that you have only been practising and need to get out more to consult the local gurus down here.
The factory pays the warranty bills, they have thousands of aircraft owners reporting back, a thinking person would reckon it would be safe to assume that whatever they recommend will work and be the least expensive way to operate the aircraft.
And that includes operating the aircraft at the "high end" of the power settings recommended in the AFM.
Operating at the "granny power" often insisted on in the many versions of "operators" (viz aero club/owner) AFM, has exactly the opposite effect to that "imagined" by the operator to "saving" engines and fuel.
My Chief Pilot probably spent as much time unlearning the bullsh!t accumulated by new hires as he did getting them up to the company standard.
From one who wrote the checks.
Spot on regardless of manufacturer.
Symetrical power and a maximum of whatever the manual says, 1500 RPM and gently generally does the trick.
I suspect some pilots see it as a badge of honour to sit in their twin in the holding bay surrounded by single revving the guts out of the engine with much flashing of hands around the quadrant and snarling and moaning from the engines......"hey look at me".
I mean I guess the manufacturer probably doesn't know anything about his product and only writes an AFM etc. for the fun of it and as a means of selling more aircraft.
Another thing that amazes me are the huge number of pilots and enginerds in this country, who, for one reason or another have managed to amass an enormous fund of knowledge and experience that renders the manufacturers advice and recommendations as the banging of drums and tinkling of bells.
But then I guess having built more than 250,000 aircraft means that you have only been practising and need to get out more to consult the local gurus down here.
The factory pays the warranty bills, they have thousands of aircraft owners reporting back, a thinking person would reckon it would be safe to assume that whatever they recommend will work and be the least expensive way to operate the aircraft.
And that includes operating the aircraft at the "high end" of the power settings recommended in the AFM.
Operating at the "granny power" often insisted on in the many versions of "operators" (viz aero club/owner) AFM, has exactly the opposite effect to that "imagined" by the operator to "saving" engines and fuel.
My Chief Pilot probably spent as much time unlearning the bullsh!t accumulated by new hires as he did getting them up to the company standard.
From one who wrote the checks.
Menen
Your personal insults of me, I will ignore. I was only stating my background so people knew where I was coming from. If some take this the wrong way, then I will have to live with that. I am the first person to admit when I make a mistake and I can tell you I have made plenty. If you read my posts though, you will see that I said I have no problem with asymmetric run ups. That is the way I too was taught. I was only stating my old companies procedures based on advise given to us by engineers because of various AD’s on Cessna 400 series aircraft. Remember that aircraft flight manuals/Pilot’s Operating Hand Books were quite often written many years ago before many of these problems were know about or understood. Our SOP’s at the time were based on this advice and approved by the then CAA.
Your personal insults of me, I will ignore. I was only stating my background so people knew where I was coming from. If some take this the wrong way, then I will have to live with that. I am the first person to admit when I make a mistake and I can tell you I have made plenty. If you read my posts though, you will see that I said I have no problem with asymmetric run ups. That is the way I too was taught. I was only stating my old companies procedures based on advise given to us by engineers because of various AD’s on Cessna 400 series aircraft. Remember that aircraft flight manuals/Pilot’s Operating Hand Books were quite often written many years ago before many of these problems were know about or understood. Our SOP’s at the time were based on this advice and approved by the then CAA.
