Run-Ups: Where do you do them?
 

Hi,

I have heard two different opinions on where you should do run ups for SEA at uncontrolled airports, assuming there are no run-up areas.

1) Do it on the runway threshold just before takeoff
Problem with this is that you hog the runway for about 5-7 minutes longer.

2) Do it on the taxiway just before entering the runway
Problem with this is that you are powering up to 1700-2000 RPM and there might be another aircraft lining up behind you.

Please advise. Thanks. I train out of a controlled airport, so I don't have as much experience with uncontrolled airports.

Magic, your instructor should advise you. I'm only a ppl, so I'm offering you my opinion, I'm sure others will have different ideas.
In option one, runups should be able to be completed in less than a minute. Don't know where you got the 5-7 minutes. However, in my opinion, it is important that you minimise your time on the runway. If you are delayed on the runway, I suggest that you hold crosswind. This makes you more visible for acft on final, and allows you to monitor the final approach for traffic.
Airfields octa generally require backtracking, it is unusual to have a taxiway to the threshold. In the case that you may be on a taxiway adjacent to the runway threshold, I was taught that your acft should be positioned into wind for the runups (better airflow into the engine, better cooling); this means, usually you will be roughly parallel with the runway, and hence, perpendicular to the taxiway. That means your thrust stream will be directed away from any acft directly behind you on the taxiway.
So, in general, runups before entering and backtracking. If you are delayed briefly on the runway, consider holding crosswind (or at least obliquely, for reasons mentioned). Prolonged delay on the runway should be avoided.
Regards, and happy landings

5-7 minutes for a run up in a single seems a bit long. That said if you are worried about other aircraft how about just using your radio and tell the other aircraft you'll be doing a run up at the holding point of wherever. It comes down to common sense and airmanship.

As you fly around the country you'll probably find out that the airports are very quiet compared to the controlled ones you're used to and you'll be the only one moving.

Where you may encounter traffic is if you attend an air show or fly in. Everyone wants to leave at the same time.

I would avoid the runway if at all possible.
Try to do it on a surface that doesn't damage the prop.
Don't direct your prop wash where is isn't welcome.
Do it where your engine noise doesn't disrupt others.
Try and do it into wind.

G'day,

I'll make an assumption that you're flying a 172, Warrior or similar. I'll put in a disclaimer that it's been many years since I've flown a single engine aircraft.

I can understand that while you're training, things like run-ups take a bit longer than once you're more experienced, but 5-7 minutes seems excessive. Run-ups are normally only required on the first flight of the day, NOT prior to every take-off, despite what some flying schools say.

I can't think of any valid reasons to do run-ups while on the threshold of a runway. Whoever gave you that opinion is wrong, IMHO!

In your other scenario, perhaps you've got a point, but any aircraft taxiing up behind you (presumably you've made some kind of broadcast that you're stopping on the taxiway to do run-ups) shouldn't come so close as to be affected by your prop-wash.

My Opinion:

Find somewhere on the apron that is appropriate and out of the way. That is, somewhere your prop-wash isn't going into a hangar, passenger movement area, parked aircraft, etc. Taxi there. Use your Situational awareness (e.g. looking over your shoulder) to check no-one's come up behind you, and do your run-ups.

Another opinion (once you're more experienced) do your run-ups while taxiing. Not an issue in a 172, Warrior or similar.

DIVOSH!

correction, my run up is approximately 1-2 minutes, not 5-7. 5-7 minutes is way too long for run-up, unless I have a triple cheeseburger in hand that I've got to finish.

5-7 minutes is total time from engine start, to taxi a looooong way to runup bay, and finish the run up.

I think I've gotten the answer I need.

1) Do it in a clear area in the apron (with situational awareness)

2) Right before takeoff (it's ok to hold for 1 minute on the runway to do the runup)

As for running up while taxiing, I'd prefer not to do it now, as I have quite a few items on my checklist at the moment, and I prefer not to miss out any crucial items.

I got it right?

So far, I'm in my hour building phase towards CPL, and therefore I'm doing quite a bit of flying into airfields octa, staying a night here and there, and flying out the next day. Hence, it's one of my first few trips where the first flight is octa, hence the need for runups.

Mayne not recommended until you're cpl, but try run ups while taxiing. Just make sure no ones behind you (and theres not an instructor next to you). Can also be done while back tracking...

The reason that doing it on the runway can be frowned upon is if you do have a issue, fouled mag or other, is that you are now going to either take longer on the runway until is rectified or possibly have to return to the apron.

Can't say I've never done it, but if there is traffic around I won't, there are usually more convenient places on the apron or before entering. Each aerodrome is different obviously and each would have areas more appropriate then others.

Also if it was a passenger carrying sector the run up would be completed before they arrived anyway.

As mentioned some (most?) aerodromes around the country are very, very quiet.

Another factor I'd contribute is that you don't want to get too far away before doing your runups, finding an issue and now having to vacate a runway. A lot of places OCTA you'll find the spot you're parked in will just as likely be perfectly suitable for doing runups. Not to mention the possibility of exacerbating an issue you've just found by having to taxi back to parking.

Most places OCTA you won't find heaps of aircraft parked up, they'll be a single line away from buildings a lot of the time, so just do it on the spot. Why waste time giving all your calls, taxiing out, doing your checklists, getting to the runway, running up there and then finding a fouled plug that needs a few minutes to clear when it could have all been done before taxiing.

Honestly as others have pointed out, it comes down to common sense, do it when necessary, do it away from others as much as practically possible and reasonably necessary, watch your prop wash and IMHO as soon as practical.

At country airports, you might find there isn't an obvious spot to do runups, so sometimes it's just easiest to do it where you're parked. If you do though,

1) Check what's behind you. If there is another aircraft, move to somewhere where your prop wash isn't going to kick stones up onto someones plane.

2) If there is a decent amount of wind, at least make some effort to point the nose into wind.

3) If you're going to do your runups where you're parked, during your walk around, have a quick look on the ground beneath the prop. If there are loose stones, kick them out of the way (or brush them out of the way of you're lucky enough to have a dustpan in the plane)

Every situation is different and you want to consider a few things when picking where to do it including:
Surface (ideally you want a somewhere sealed)
Surroundings (try not to blow crap into a hangar)
Traffic (try not to hold people up on taxi ways or even worse runways)
Warmth (you want your engine to be a little warm, so if you choose to do it at parking position you are sitting there for a long time. You could use the taxi to warm the engine but then you could be blocking someone)

There is no right answer to this, just better ones (there is probably wrong ones though).

Remember run ups and run up or pre take off checks are two different things. You can sit in your parking spot and do all of the checklist except the physical run up. Taxi to the holding point, do an idle check before stopping. Power up, mag check, carby if applicable, pull power back to 1,000 (shouldn't take much longer to do than say). Conduct line up checks. Go. If you detach the run up from the rest of the pre take off checks you make choosing a spot to do it much easier.

I can hear a checklist coming up ... just don't tell my (just now ex) CFI - presentations, standards, and checklists for anything/everything :ugh: I'll admit they have their place, but that place is not everywhere.

There's way too much formulaic, prescriptive stuff in aviation. Just understand what is important (AND WHY) and use common sense, please.

Why are you doing runups?

Runups are done for different reasons in different aircraft at different times of the day.

Frankly, runups are not very important for a fixed pitch C172. You can tell if the mags are working pretty much at idle and at 1600 static rpm (or whatever) the engine is not making much power, so its not testing the mags under load. Largely its a practice carried over from Tiger Moths. (come in Jaba)

On a cold day, runups in a turbocharged twin are a prolonged affair. I'm warming the oil, checking fuel pressure, vacuum, prop governors, feathering accumulators, alternators.

On difficult runways, in fixed pitch aircraft, I've done mag checks during the take-off run.

Do runups for a purpose you have thought about - not as a robot by rote.

Unbelievable that some pilots actually do that. Maybe "once you're more experienced" is just another way of saying the pilot is over-confident and exhibits very bad airmanship. It certainly is an "issue" in any aircraft including light singles such as a 172, Warrior or similar. It means dragging the brakes, head inside the cockpit while taxiing instead of outside the cockpit and leads to fast taxiing even while having the brakes on. :ugh:

Di_Vosh wrote:

"Run-ups are normally only required on the first flight of the day, NOT prior to every take-off, despite what some flying schools say."

I'm happy to pay for the small extra cost of doing an engine run-up, prior to every take off.

Just the way I was trained, saw others trained, and experienced throughout my time in GA. I only worked for four GA operators. All did run-ups on the run, and all expected their charter pilots to do so.

IME, most (not some) pilots in GA "do that".

And Maybe "once you're more experienced" means just that: A pilot has enough experience and can safely 1: run the rpm up to 1500; 2: check the carby heat (if fitted); and 3: drop each mag, before going back to idle.

If the aircraft is being operated daily and correctly it should take all of around 15 seconds to perform. If you've got to clear a mag or something more serious, then sure, stop and sort it out.

Disagree. It may do all those things, but doesn't have to, and shouldn't if the pilot uses their brain.

"head inside the cockpit while taxiing": There are other pre take-off checks that pilots do, and all of them require the head inside the cockpit for some of the time. Are you advocating that all these be done while stationary?

The OP is training for a CPL. If a CPL can't use their judgement as to whether it's safe to do simple checks while taxiing, then god help them if they're airborne and have to use their judgement in an abnormal or an emergency.


DIVOSH!

If you do run up while lined up on the runway, there is no need to reduce to idle after your checks. You already know that it idles OK so power up, check what you have to then go. I've just timed it - 30 seconds for a CS 0-360.

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. If a constant speed prop, exercising of the prop is done. All the while using differential brake dragging if in a twin checking one engine at a time. What is there to gain from all this? If it is good enough (i.e. safe) for CPL holders to conduct engine run ups while taxing including twins, then it is logical to train CPL candidates to do the same while under training. Practice makes perfect. Have yet to see a flying school that teaches run ups while taxiing and certainly never on a CPL flight test with an Examiner on board.

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)

The original question was about a Single Engine.

Moving or not I seem to recall the actual run up part of the check in a C172 took about 15 secs in total (assuming the engine was already warmed up and no issues found). Maybe less. It's been a number of years since I flew but on a long taxiway with no one around 15 seconds at 1700RPM from idle might require a tap or 2 on the brakes. I can't remember ever having to ride the brakes to keep the aircraft under control. If there were other aircraft around then it just wasn't done.

Its not even about riding the brakes. At taxi speed, the brakes are barely being working compared to when they are used during the landing roll from 60kts or more. Its just a non issue.

Being familiar enough with the cockpit to do the process safetly and being aware of your propwash are the considerations.