Run-Ups: Where do you do them?
seaplanes do run ups while taxiing every time. I've done a run up while backtracking at Maree because the place was busy and congested, however I was the last person to use the aircraft and it was ok the night before and I had been using the aircraft continuously for a week so I thought I knew it's behavior reasonably well enough to spot any obvious deviation from normal.
the 210's all did their run ups about half an hour before loading pax.
the 210's all did their run ups about half an hour before loading pax.
Last edited by Sunfish; 6th Jul 2016 at 23:29.
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Who knew that a C172 or PA28 could be so complicated?
Better read your C172 POH again mate! Nowhere does it say T's & P's should be checked (let alone "closely scrutinised") during a run-up. I would suggest to you that "suction checked at idling" be done when the engine is actually idling and not during a run-up.
I'm not that special, but I could do all that by glancing inside at the appropriate time while keeping an eye out where I was going.
Please don't put words in my mouth. Show me where I suggested doing this in a twin or a constant speed prop.
So what? Like I said earlier, I was relating my experience. Yours is (obviously) different.
ROFL! The horror! Where's Helen Lovejoy when you need her?
As for brake wear and "hot brakes", sure if you spend 1-2 minutes doing a run-up but who does that? Like I (and plenty of others) have said, run-ups in something like a 172 should only take around 15 or so seconds. If the aircraft is flown every day, and operated correctly (i.e. as a typical charter aircraft would be) this is all it should take.
As I said earlier, a CPL is going to be required to use their judgement. If they judge that the circumstances and their competence can allow them to do run-ups while taxiing, I can't see a problem.
Not everyone shares that opinion, particularly as it's not a requirement.
DIVOSH!
Simple checks? These are run-up's where temps and pressures should be closely scrutinised and maximum rev drop between magnetos observed, suction checked at idling.
I'm not that special, but I could do all that by glancing inside at the appropriate time while keeping an eye out where I was going.
All the while using differential brake dragging if in a twin checking one engine at a time.
Have yet to see a flying school that teaches run ups while taxiing
To deliberately conduct engine run-ups while taxiing is sheer folly better known as cowboy antics, cutting corners, using the excuse to save the boss a few cents (never mind brake wear and possibility of hot brakes caused by brake dragging and costing the boss more money)
As for brake wear and "hot brakes", sure if you spend 1-2 minutes doing a run-up but who does that? Like I (and plenty of others) have said, run-ups in something like a 172 should only take around 15 or so seconds. If the aircraft is flown every day, and operated correctly (i.e. as a typical charter aircraft would be) this is all it should take.
As I said earlier, a CPL is going to be required to use their judgement. If they judge that the circumstances and their competence can allow them to do run-ups while taxiing, I can't see a problem.
I'm happy to pay for the small extra cost of doing an engine run-up, prior to every take off.
DIVOSH!
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Akro…..I have been holding back. There is a lot of good stuff posted already, some OWT's and stuff learned by rote. The problem is not enough folk appreciate science and learn the facts abut what works, why, and when.
I too was once a victim of the "just do what my instructor taught me" method of learning to fly. There will be many here who know what i mean. They too will have become advanced in their learning. Many are Advanced Pilots now by learning from various sources. (I went back and capitalised that….kind of tells you where the name came from :-) )
I will post some thoughts a little later when I can dedicate some time.…..end of year, another US trip to plan, farm stuff list as long your arm, shooting comp…..why am I even looking on pprune :-/
DiVosh, 15 seconds
you nailed it!
Back later
I too was once a victim of the "just do what my instructor taught me" method of learning to fly. There will be many here who know what i mean. They too will have become advanced in their learning. Many are Advanced Pilots now by learning from various sources. (I went back and capitalised that….kind of tells you where the name came from :-) )
I will post some thoughts a little later when I can dedicate some time.…..end of year, another US trip to plan, farm stuff list as long your arm, shooting comp…..why am I even looking on pprune :-/
DiVosh, 15 seconds
you nailed it!Back later
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One of the things I was taught in my first job where I regularly flew in and out of unsealed strips where there may not have been somewhere 'suitable' to do static run ups was that it's cheaper to replace brake pads then a prop that has been filed back to an inch of its life.
I'm seeing more and more airfields (particularly Council owned ones) installing small concrete pads which is good, particularly if they have a gravel strip.
To deliberately conduct engine run-ups while taxiing is sheer folly better known as cowboy antics,
I was going to write a more detailed reply and then I thought, "Nah, I can't be bothered"!
Dr
Last edited by ForkTailedDrKiller; 7th Jul 2016 at 05:26.
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A few of the regulars here know me well. And I am a bit under the pump, but I planned to write a good response, so here it is, with a little help from a friend .
Mag Checks. Most done the way the instructor teaches are almost pointless in terms of testing the ignition components. It does prove that one of the mags have not been stolen
. The best time to do a mag check is in flight, at high power and Lean of Peak. This is by far the most diagnostic and with an engine monitor the best way to define a problem. Period!
In order of diagnostic value it goes like this;
High Power in flight LOP looking for all EGT's to rise
High Power in flight ROP looking for all EGT's to rise
1700+/- a bit on ground LOP looking for all EGT's to rise
1700+/- a bit on ground ROP looking for all EGT's to rise
The way you were taught full rich and looking at RPM drop.
These can be done easily on the run or static when on the ground, as you gain experience. Newbies might be best to do it in a run up bay or holding point.
If you own the plane, the only one who flies it, and did a mag check on the way in last flight, then a 1000 RPM flick/EGT's all rise, flick same again….good to go. Of course an EMS is required
. High power prop damage is an issue so the less you do this the better.
After any maintenance do a serious 1700 or so RPM LOP mag check and study it on the EMS for about 10 seconds on each mag. I trust nobody or nothing if anyone has been under the cowl other than to check the oil.
As I am not keen on typing pages, the original poster could well learn a lot from reading this article written by my colleague and good friend John Deakin, who I am pleased to report is doing really well for an old fella when Leisa and I spent the day with him two weeks ago in sunny Camarillo.
Pelican's Perch #77: Startups & Runups - AVweb Features Article
magical flights I hope this helps you
.Mag Checks. Most done the way the instructor teaches are almost pointless in terms of testing the ignition components. It does prove that one of the mags have not been stolen
. The best time to do a mag check is in flight, at high power and Lean of Peak. This is by far the most diagnostic and with an engine monitor the best way to define a problem. Period!In order of diagnostic value it goes like this;
High Power in flight LOP looking for all EGT's to rise
High Power in flight ROP looking for all EGT's to rise
1700+/- a bit on ground LOP looking for all EGT's to rise
1700+/- a bit on ground ROP looking for all EGT's to rise
The way you were taught full rich and looking at RPM drop.
These can be done easily on the run or static when on the ground, as you gain experience. Newbies might be best to do it in a run up bay or holding point.
If you own the plane, the only one who flies it, and did a mag check on the way in last flight, then a 1000 RPM flick/EGT's all rise, flick same again….good to go. Of course an EMS is required
. High power prop damage is an issue so the less you do this the better.After any maintenance do a serious 1700 or so RPM LOP mag check and study it on the EMS for about 10 seconds on each mag. I trust nobody or nothing if anyone has been under the cowl other than to check the oil.
As I am not keen on typing pages, the original poster could well learn a lot from reading this article written by my colleague and good friend John Deakin, who I am pleased to report is doing really well for an old fella when Leisa and I spent the day with him two weeks ago in sunny Camarillo.
Pelican's Perch #77: Startups & Runups - AVweb Features Article
magical flights I hope this helps you
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Jaba W. As much as I admire John Deakin's "Pelican's Perch" engine handling series, I must say I am surprised when he said that run up procedures should be conducted with the park brake off and holding on the brakes by pedal pressure alone.
His article states:
Set the Brakes?
A very strong "No!" answers this question, for those airplanes with anything but power brakes.
............................................................ ............................................................ ....................................
If Deakin's technical argument for not using the park brake when stopped is valid, then it would suggest the aircraft certification process is flawed.
While I have often see pilots conduct run up's using brake pedal pressure only, it is an unwise policy in general; especially at night or in heavy rain where it is sometimes difficult to pick movement of the aircraft inching forward or on a rear sloping surface moving backward.
The most common reason for some pilots not using the park brake in general aviation aircraft is that from the beginning of their ab-initio training they are taught by their instructors not to trust the parking brake. This is negative teaching. It stems possibly from another fact in general aviation and that is many pilots are reluctant to write up defects in the maintenance release for fear of management or aircraft owner adverse reaction.
A pragmatic reader can understand why some pilots are wary of using the park brake for run up's. Good airmanship would dictate that until you are sure the park brake is holding correctly at high power, it is wise to be ready to apply prompt brake pedal pressure if the aircraft begins to move. But don't forget to promptly close the throttles.
If the park brake is inoperative or not holding, then legally you are bound to write it up in the maintenance release. If the defect is not cleared before the next flight, at least the next pilot is aware when he studies the maintenance release before flight. Too many pilots are happy to let the next pilot wear an unreported defect with the callous attitude of `not my problem mate`and let the next bloke carry the can.
In the POH for the venerable Cessna 172 the manufacturer's checklist states that before starting the engines "Brakes ---TEST and SET". The Securing Airplane checklist states "Parking Brake---SET".
During a run up, holding on the brake pedals rather than setting the parking brake, it only takes a momentary lapse of concentration to inadvertently relax one or both feet from the pedal pressure; particularly if heads down events are taking place in the cockpit such as writing down clearances or briefings. The parking brake is good insurance. In event of an incident involving the non-use of the park brake when it should have been on, the lawyers would have a field day citing the manufacturer's POH.
His article states:
Set the Brakes?
A very strong "No!" answers this question, for those airplanes with anything but power brakes.
............................................................ ............................................................ ....................................
If Deakin's technical argument for not using the park brake when stopped is valid, then it would suggest the aircraft certification process is flawed.
While I have often see pilots conduct run up's using brake pedal pressure only, it is an unwise policy in general; especially at night or in heavy rain where it is sometimes difficult to pick movement of the aircraft inching forward or on a rear sloping surface moving backward.
The most common reason for some pilots not using the park brake in general aviation aircraft is that from the beginning of their ab-initio training they are taught by their instructors not to trust the parking brake. This is negative teaching. It stems possibly from another fact in general aviation and that is many pilots are reluctant to write up defects in the maintenance release for fear of management or aircraft owner adverse reaction.
A pragmatic reader can understand why some pilots are wary of using the park brake for run up's. Good airmanship would dictate that until you are sure the park brake is holding correctly at high power, it is wise to be ready to apply prompt brake pedal pressure if the aircraft begins to move. But don't forget to promptly close the throttles.
If the park brake is inoperative or not holding, then legally you are bound to write it up in the maintenance release. If the defect is not cleared before the next flight, at least the next pilot is aware when he studies the maintenance release before flight. Too many pilots are happy to let the next pilot wear an unreported defect with the callous attitude of `not my problem mate`and let the next bloke carry the can.
In the POH for the venerable Cessna 172 the manufacturer's checklist states that before starting the engines "Brakes ---TEST and SET". The Securing Airplane checklist states "Parking Brake---SET".
During a run up, holding on the brake pedals rather than setting the parking brake, it only takes a momentary lapse of concentration to inadvertently relax one or both feet from the pedal pressure; particularly if heads down events are taking place in the cockpit such as writing down clearances or briefings. The parking brake is good insurance. In event of an incident involving the non-use of the park brake when it should have been on, the lawyers would have a field day citing the manufacturer's POH.
Last edited by Tee Emm; 8th Jul 2016 at 07:19.
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First point, Taildraggers, at no point would I want to do power runs with the park brake locked. If the tail starts to lift for whatever reason, or one brake slips the last thing you would want is a locked up park brake.
2nd. any high power A/C. A simple 172 isn't really an issue, but doing a full power run on a lot of high powered aircraft the brakes can barely hold, or the tyres skid. Much safer to have feet on the brakes, and if it does move have some controllability. (yes, you also pull the power but having directional control helps)
If your wondering what singles won't hold? Here is a few i've done runups in during the last few months.
- DHC2 Beaver (taildragger also applies)
- C182 with O550 - just drag the wheels if the brakes hold
c206/c207 - just drag the wheels if the brakes hold
Glastar with 180hp - drags the wheels
C172XP - Drags the wheels if not careful
and i've seen plenty of twin drivers drag the wheels when they get the bright idea to run up both at once....
The park brake is a PARK BRAKE. To be used when PARKING, or sitting idle.
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TM
I will disagree purely on the basis of even a perfectly functioning park brake might not be SET with enough brake pressure or uneven pressure, and during the run up you then jump on the pedals to find that no matter how hard you squeeze it makes not difference. Yes I know you can reduce power and it should stop moving…..but that is easy for some to overlook.
Personally I am far happier holding with my feet, after all they are used to applying brakes, and brake feel is something you acquire quickly. My other reason for this is you shall not be head down, even at night it should be less head down. An instrument scan is all you do, you may select one mag and let it sit there for 10 seconds "watching" the EGTs all rising, but in reality you glance at the EMS, not stare at it.
So while I understand your concern, if done properly it is really not a concern at all.
Lastly, just because it is written in the POH, does not make it the best or smartest way to do things, especially when they were written long before the EMS was developed. But if you feel compelled to use it, go right ahead! But teaching advanced or better methods is something we should be aspiring to. And if a particular aircraft for some really good reason should not be done that way then fine, don't do it. Know your aeroplane! Most GA's I would say it is better not to.
Does that make sense?
I will disagree purely on the basis of even a perfectly functioning park brake might not be SET with enough brake pressure or uneven pressure, and during the run up you then jump on the pedals to find that no matter how hard you squeeze it makes not difference. Yes I know you can reduce power and it should stop moving…..but that is easy for some to overlook.
Personally I am far happier holding with my feet, after all they are used to applying brakes, and brake feel is something you acquire quickly. My other reason for this is you shall not be head down, even at night it should be less head down. An instrument scan is all you do, you may select one mag and let it sit there for 10 seconds "watching" the EGTs all rising, but in reality you glance at the EMS, not stare at it.
So while I understand your concern, if done properly it is really not a concern at all.
Lastly, just because it is written in the POH, does not make it the best or smartest way to do things, especially when they were written long before the EMS was developed.
But if you feel compelled to use it, go right ahead! But teaching advanced or better methods is something we should be aspiring to. And if a particular aircraft for some really good reason should not be done that way then fine, don't do it. Know your aeroplane! Most GA's I would say it is better not to.Does that make sense?
I do mine during the take off roll and top of descent, unless I'm compelled to leave a sacrifice to the OWT Gods.
I might select the L and R mag during taxi to check whether a mag or plug is completely dead (or has been stolen - where do you live, Jabba?) if something doesn't feel right. But that's about it. Any problem found during a run up at e.g. 1700 or 1800 RPM can usually be found at idle RPM. Some problems at full power won't be found during a run up at e.g. 1700 or 1800 RPM.
You have to check all the numbers when you go balls to the wall anyway ...
And if the one-in-a-million happens and the prop governor won't move the blades off the fine pitch stops when you get to TOPC, take a deep breath and ...
Relax.
PS: I got me one o' them new fangled en-jine monitors. Yee har!
I might select the L and R mag during taxi to check whether a mag or plug is completely dead (or has been stolen - where do you live, Jabba?) if something doesn't feel right. But that's about it. Any problem found during a run up at e.g. 1700 or 1800 RPM can usually be found at idle RPM. Some problems at full power won't be found during a run up at e.g. 1700 or 1800 RPM.
You have to check all the numbers when you go balls to the wall anyway ...
And if the one-in-a-million happens and the prop governor won't move the blades off the fine pitch stops when you get to TOPC, take a deep breath and ...
Relax.
PS: I got me one o' them new fangled en-jine monitors. Yee har!
Last edited by Lead Balloon; 8th Jul 2016 at 10:18.
