[apkp777]

From the FAA's Airplane Flying Handbook Chapter 2-11. "BEFORE TAKEOFF CHECK - The before takeoff check is the systematic procedure for making a check of the engine, controls, systems, instruments, and avionics prior to flight. Normally, it is performed after taxiing to a position near the takeoff end of the runway. Taxiing to that position usually allows sufficient time for the engine to warm up to at least minimum operating temperatures. This ensures adequate lubrication and internal engine clearances before being operated at high power settings. Many engines require that the oil temperature reach a minimum value as stated in the AFM/POH before high
power is applied...Each airplane has different features and equipment, and the before takeoff checklist provided by the airplane manufacturer or operator should be used to perform the runup."

I have no problem with Bill's procedure, if I was doing a BFR with Bill and he skipped a runup, like Sig, I'd be a little leery, until Bill explained that his POH and installed equipment can diagnose problems that makes normal run-up redundant.

That said, I do a traditional pre-takeoff run-up. I am looking for the 3 things that can give me grief on take off, FUEL, AIR and FIRE. I want to make sure fuel is being delivered to the engine. At idle and a short taxi, you may not even empty the fuel in the bowl and lines. A run up may reveal a supply issue, If a bird go lodged in the intake (or a cowl plug) a run up should indicate that. Idle power may not. And finally, a mag problem (or more likely a spark plug problem) is identifiable at run-up power. The EICommander makes that part of the run-up unnecessary.

 

[TomVal]

....
Ill often do my 10-15 sec check prior to rolling...its an opportunity to notice a loose oil door, missing cowling hinge, bad EGT, CHT, or whatever might come loose or become noticable with more power. FWIW...i caught a partially blocked fuel injector with EGT/CHT on "run-up"....

Son-of-a-gun...it happened to me yesterday. As I ran up the power during a run-up check, my forward baggage compartment door lifted open. I did do a pre-flight walkaround and checked the door. Usually, with just light hand pressure if the door is not locked it will easily open. Next time, I'll stick the key in the door and use the key as a lift handle to check that the door is closed and locked.

I lucked out. The airport bums just installed two field cameras on top of a hangar wired to a 42 inch LCD TV located in our designated libation area. No one was there...it saved me from refrig re-stocking duties. Note: "Libation Area"....a designated area utilized for therapeutic treatment of arthritic elbows.

Also, where did I read that Lycoming (or Slick) now recommends 1800 rpm for a good mag check?

 

[pierre smith]

You're not alone, Tom.

I left my newly fabricated control locks in place and discovered that during my preflight check at the end of the runway!

It's not only a runup...but a pre-flight check,

 

[rvmills]

Bill,

Been following along on this...interesting thread. Please tell me if my interpretation is correct:

First, because you have P-Mags and an EI Commander, you want to eliminate the ignition system test from the runup...correct?

Second, because you have no vacuum system and you don't use carb heat, you want to eliminate the runup completely...correct?

To me that means you are just trying to eliminate the R in CIGAR, and you are still checking out all the other items on that list (if you use that acronym...could be any similar technique).

If the above assumptions are correct, then here's my input to your original query, as well as some of the discussion since. All FWIW, just one guy's thinkin'. Cliff Notes version: I would still do a quick runup, especially on the first flight of the day. "Why" takes longer to describe (fair warning ):

I get that you watch several parameters on start up and taxi (temps, pressures, volts, amps, etc) to make sure they are coming up to speed.
I get that the EI CDR gives you an instant assessment on the health of the ignition system during taxi/just prior to TO.
I get that you make a quick assessment of all parameters during the initiation of the takeoff roll, and make a go/no-go decision quickly.

I do much of the same, but I still want that operational pause a runup provides, to see the engine performing at something more than idle, before I cob the power for TO. Why? Here are my reasons:

I admit to not knowing much about the EI CDR, but my first question (as others have alluded to) is do the EI CDR's indications of ignition health at idle represent that the P-Mags performance will continue to be healthy as the power is advanced? Not sure how much the advance curves or other parameters in them change from 1000 RPM to 1800 RPM to full power, but I think I'd like to see it at run-up RPM, just to double check...before I take the runway.

As for the rest of the engine parameters: I'd kinda like to see them at something more than idle too, expecially on the first flight of the day. And I want to see that when not on the runway, because that first few hundred feet of my takeoff roll in an RV is when I'm managing directional control as the rudder becomes effective (you know that "funky" zone between 20-30 knots), easing the nose forward (or back if its an A...I do fly both), and I'm making the go-no go decision throughout the roll, based on how the airplane is performing in the "macro" sense (if you will). Run-up is when I look at the "micro" items, and perhaps push or stretch the engine just a bit to make sure all the connections are still made and the engine and its systems are all happy...takeoff is too busy, so its "no red or yellow lights, and no flashing on the engine monitor...fly the plane". To me its too busy to make sure my ignitions are looking good on a monitor, etc.

It has been mentioned that jets don't do run-ups. I was talking about this with a couple jet guys today. In our shared experience, multi-engine, multi-crew jets don't do runups. I don't do one at work. But we have multiple checklists being done as a crew, we have two sets of eyes on the airplane and its systems as we initiate the TO roll (where micro indications may cause a no-go), and a much longer TO roll (during which a transition takes place to using macro items as the only no-go items). All that happens so fast in a (usually) single pilot RV, that I just think you need to have your "micro" checks done before you take the runway...and to me that just means using a runup.

The guys I was with today also reminded me that in single engine jets (in my case an A-4, in their cases an F-16), we also did run-ups, just to make sure that the engine was behavin' at 80%. Heck, even in a multi-engine jet on a catapult, we ran it up, looked at all the guages, and checked all the controls...before we saluted and trusted our future to steam+Pratt & Whitney.

I do worry about rocks and my prop (I just bought a new one too...it's important to me!). I would worry about CHTs on a hot day, especially if its after one or more previous hops, so I don't advocate a long, drawn-out routine. Perhaps multiple back to back hops is where I may back down on a full run-up requirement...at the risk of sounding hypocritical...still mulling that one over. However, first flight of the day, or extended time between hops, or time away from the airplane between hops (to make sure nothin's stolen OZ )...I'm definitely staying old school.

New technology is great...I enthusiastically embrace it. Some of it eliminates tasks and relieves workloads...after much field testing and operational time in the field. Cross-checks, checks and balances, and task splitting (timing) to avoid task-saturation during a critical phase of flight are the tried and truisms that I'll stick with...even if I get dual P-Mags and an EI Commander...I just don't buy that it eliminates the need for a run-up Bill...at least not yet. I'd also want to get a read on what my engine manufacturer would recommend when running that set-up on my motor. Have you had any discussion with engine manufacturers or rebuilders on this topic?

Long 2 cents (sorry), but figured if I was saying I didn't agree with your premise, I could at least give you the rest of the (my) story.

I do think your EI CDR looks pretty cool though, FWIW!

Cheers,
Bob

 

[Sig600]

Every single and multi engine jet I've flown, we do/did a run up on the runway prior to take off. Usually to 80%, wipe out the controls, give the engine or engines a final once over, then go. Yes, I've aborted takeoffs before ever releasing the brakes based on the run up.

 

[N941WR]

Bill,

Been following along on this...interesting thread. Please tell me if my interpretation is correct:
...
Cheers,
Bob

You were right on with every comment and thanks for the input.

To answer your question, the EIC displays the current advance of each ignition. At low RPM (idle) it is acting like a standard mag and has the minimum advance. At WOT and high MAP, the timing is reduced to the minimum setting, so it acts like a magneto and it reduces the probability of damaging your engine. Only at lower power settings (lower MAP) does the P-mag allow the timing to advance. These numbers are displayed on the EIC for both ignitions.

(As a safety feature of the P-mags, if you have a vacuum leak, the P-mags will not allow the timing to advance and act like a fixed timing ignition.)

We recommend our EICommander customers still perform a run up as they would do with standard magnetos. In my case, I do a run up with every flight, not just the first flight of the day.

 

[az_gila]

...
Also, where did I read that Lycoming (or Slick) now recommends 1800 rpm for a good mag check?

My trusty Lycoming O-360 Operators manual says approx. 1800 rpm (2000 rpm maximum) for a Fixed Pitch prop mag. check.

For a Constant Speed prop it says to use the MP to set a power level of 50%-65% for the mag check.

EDIT - my typo - it is 65% not 60% as I first wrote...

 

[Vac]

Lycoming Service Instruction 1132B (Magneto Drop-off, dated 18 June 10) references the 1800 RPM run-up in paragraph E (1)(b) for fixed-pitch installations. As Gil said, the word "approximately" is used. Paragraph E(1)(a) specifies 50-65% for constant speed equipped aircraft.

A list of current Operator's Manuals is contained in Service Letter L114AT (Reciprocating Engine and Accessory maintenance Publications, dated 8 Feb 11).

These pubs are available on the Lycoming site.

Cheers,

Vac

 

[rvmills]

From Post 1:

This is not intended to be an ad but is a serious question I?ve been struggling with. <snip>

With the EICommander installed in my plane, I can look over and see exactly what the condition of the ignition is. <snip>

Since I have a fixed pitch prop, is there any legitimate reason to perform a run-up?

From Post 56:

<snip> We recommend our EICommander customers still perform a run up as they would do with standard magnetos. In my case, I do a run up with every flight, not just the first flight of the day.

Still struggling with it, or has a conclusion been reached? Just wunderin, Mr. Bill! (In a friendly sort of way, you pot-stirrer, you)

Cheers,
Bob

 

[airguy]

I left my newly fabricated control locks in place and discovered that during my preflight check at the end of the runway!

It's not only a runup...but a pre-flight check,

I was taught in my PPL instruction that just before crossing the hold-short line onto the runway, the last things you should do are a visual check of the runway and final, and control check. Easily becomes part of the mental checklist

Runway CLEAR
Final CLEAR
Controls FREE AND CLEAR

I do that everytime I take the runway. Haven't embarrassed myself yet, maybe this will prevent it!

 

[N941WR]

...Still struggling with it, or has a conclusion been reached? Just wunderin, Mr. Bill! (In a friendly sort of way, you pot-stirrer, you)

Cheers,
Bob

Just trying to get people to think about what they are doing and the reasons for doing "it", whatever "it" is.

I'm still strugggling with the run up issue and still doing them, only at 1400 RPM. (That should light another fire.) The reason for the reduced power runup is that any minor slip of the stick and the thing will nose over onto the prop.

 

[Ironflight]

I'm still strugggling with the run up issue and still doing them, only at 1400 RPM. (That should light another fire.) The reason for the reduced power runup is that any minor slip of the stick and the thing will nose over onto the prop.

I'll be the first to admit that I have never tried a tail-draggin' -9 Bill, and don't know where the CG normally resides, but is it really that light on the tail? In the RV-8, with no passenger, I can do a complete control check (stick all the way forward) at a run-up RPM of 1800 if I want to. (I don't do that, but I have checked to see how close I am to the tail coming up, and the answer is...not very).

Just curious - and maybe now we understand why you're asking the question!

Paul

 

[aerhed]

In my Emeraude, I can pick the tail up and move it left/right by squeaking the brakes a little. I think I could do a pirouette (haven't tried). It will lift at runup pretty good if the stick's not pinned.

 

[N941WR]

I'll be the first to admit that I have never tried a tail-draggin' -9 Bill, and don't know where the CG normally resides, but is it really that light on the tail? In the RV-8, with no passenger, I can do a complete control check (stick all the way forward) at a run-up RPM of 1800 if I want to. (I don't do that, but I have checked to see how close I am to the tail coming up, and the answer is...not very).

Just curious - and maybe now we understand why you're asking the question!

Paul

Paul, my -9 has about 54 lbs on the tail, pretty much in line with your -8, I would think. However, it has a much larger HS, which allows the tail to come up fairly easily. If you hold the stick back, as you are supposed to, then the tail will stay in place. Early in my Phase 1 the stick slipped while changing hands to test the ignition and I almost went over.

As for the reason for the original question, it goes back to being able to tell exactly what is going on with the ignitions by looking at the EIC rather than running the engine up to check the engine. I was simply trying to find out what is to be accomplished by running the engine up and doing a mag check.

From the very well thought out comments on this thread I have come to the conclusion is it 50% tradition and 50% checking for something out of sorts.

The idea of only doing a check on the first flight of the day doesn?t do it for me. The odds that something broke on subsequent flights is still there.

 

[alpinelakespilot2000]

Paul, my -9 has about 54 lbs on the tail, pretty much in line with your -8, I would think. However, it has a much larger HS, which allows the tail to come up fairly easily. If you hold the stick back, as you are supposed to, then the tail will stay in place. Early in my Phase 1 the stick slipped while changing hands to test the ignition and I almost went over.

I'm curious if any other -9's have this same tendency. I only have 48# on the tail so, if so, I'll have to pay attention to this.

 

[rvmills]

Bill,

Like Paul and the others, I'm surprised by the tendency of the tail to lift (well, the level of that tendency as you have described). I don't doubt ya, just surprised it is that sensitive. How is the feel with two people, or full bags...similar? Did this start or worsen with the new, larger motor?

I'm wondering if Greg's newly converted 9 out here is showing similar tendencies, and what his TW weight is. What say you Greg?

Certainly does add another dimension to your question, and though I remain in the same camp (as it sounds do you), I can empathize with the concern. Ya don't want to be giving any runup areas a buzz saw job with your new prop (and new engine)!

Cheers,
Bob

 

[N941WR]

... How is the feel with two people, or full bags...similar? Did this start or worsen with the new, larger motor?
...

Since people and bags shift the CG aft, the tendency is reduced. As for the new engine, I really don?t know has I haven?t given it a chance. Prior to the first flight, I did a full power run up and it took some strength to keep the tail pinned but I didn?t ?play? with it.

Like the Emeraude, you can pick the tail up while sitting in place and play with it and I would think you could also do this with the other taildragger RV?s, but I don?t really know. Again, the HS and elevators on the -9 are gigantic in comparison to what is on the short wing RV?s.

It would be good to hear from other RV-9 owners and get their input. Tony, Greg, Bruce, others?

 

[Greg Arehart]

My data point: I've never noticed any tendency for the tail to come up during runup (at ~18-1900 rpm). I have about 65 lbs on the tail (flight level) but that is closer to 100 lbs when it's sitting on the ground. I've always wondered about how you got the tail to come up, but must admit that I've not really tried to do this on purpose. And I'm usually at altitude (home field 5000 ft) so less air and less power. Maybe when I get back to flying in a few weeks I'll give it a try....

greg

 

[G3i Ignition]

I feel run-ups are important.

As far as ignition wise, most spark plugs and/or leads show possible break down at a higher cylinder pressures (under load) not at idle. This is one reason plugs are tested for potential problems with a pressurized test chamber.

Here?s a personal experience. I know you guys do not have a lexan floor like I do in my Super Acro. But one day I taxied out to the run up area and everything was in the green (good to go). As I pull forward to take the runway I saw a spot on the asphalt of fresh oil as I rolled forward. I aborted taking the active and taxied to a non-soiled area on the ramp and sat there for a bit. I didn?t see any new fresh spots. However, when I duplicated my run-up a fresh spot appeared. Taxied back to the hanger and discovered that the crank seal push out slightly and leaked excessively at the higher run up rpm.
Just food for thought.
Thomas S.

 

[Snowflake]

Hmm... Now I not only want to do runups, I want to install a glass floor!

 

[Loboflyer]

At higher altitude airports, the runup also allows us to set the mixture properly.