Engine Run Ups
 

Everyone knows when flying piston aircraft that run up checks are important, and back at flight school I was always taught it's something you do in between engine start and takeoff (of course!). But I've seen a few places doing runups first thing in the morning, then taxiing back and shutting down, getting passengers, starting up and going straight to the runway. Subsequent flights later in the day have no runups immediately before.


Am I the only person who sees this as being a bit strange? During that next shutdown or start sequence couldn't a problem arise and subsequently go unchecked, especially in outback Australia where aircraft engines get quite a battering with heat?

Cheers!

:eek: That sounds strange to me, and radically different to the way I was taught!

I was always taught the only thing you do before the first flight of the day, that you don't need to do subsequently, is check for water in the fuel tanks that may have accumulated over night.

My instructors have always told me to do a runup before every takeoff, even if you do a full stop landing and taxi straight back to the hold to takeoff again (e.g. when you're doing night rating circuits). As you say, the point of a runup check is to ensure the engine is operating correctly before the most critical phase of flight.

I have seen pilots at my club start up, taxi out and takeoff without a runup but certainly wouldn't be comfortable doing that myself (or even flying with a pilot who thought that was acceptable).

Well, if the runway is long enough, where's the real risk?
You do the runup on the first leg to verify both mags are working.
During a runup you'll only notice problems if they arise shortly after setting power - you'd have the same outcome on the take off run as well well before reaching Vr.

Wimps.

Runups on ordinary landing gear are a piece of cake - when you consider how it is done on skis or floats. You'll find your brake pedals pretty much -- ummm, useless.

:rolleyes:

I know there are some idiots out there but that takes the biscuit. I can only hope to God you're not a pilot with an attitude like that.

So just how long do you think is "long enough"? What if it's a 600m strip with houses at the end? What if you're taking friends or your girlfriend flying and the engine quits at 500 feet and you have nowhere to go? Imagine how you'll feel in the final seconds before impact, responsible for those lives!

Or do you think you know better than the guy that wrote the checklist?!

Run ups are done to ensure everything is working okay when you are about to depend on it the most, and they take all of 30 seconds to do! Coming on here and questioning that is pretty bloody stupid. You're checking for mags, t's and p's and no carb-icing. All pretty crucial in a SEP just before you firewall the throttle and put your life in the hands of that engine.

Flying is risky enough at the best of times, so anyone who doesn't try to minimise that risk deserves everything they get, in my view.

All I know is I'm glad I'll never be flying with you :ok:

I would call that statement into question. If you take on fuel, it is always a good idea to check the sumps/ low points, and that goes for jets too.

It helps avoid those unexpected moments of quiet contemplation.:eek:

Well, a run up is important first thing in the day. After you've already flown once, I normally just do very brief mag checks and prop checks on my taxi out for the next flight. On long cross country flights, I periodically check the mags in flight when I can remember to do so. Only time I redo the full run up if I've already flwon is if I've shut down and parked the aircraft and had it out of sight for a couple of hours and/or the engines have cooled down considerably.

@taxistaxing:

calm down. I agree with Adam. I never said that you should avoid runups, I'm just questioning the reason to do it when you have already flown a bit, the engine is warm and all indications have been normal. How high do you think the probability is going to be that the run-up is going to reveal something that won't show up during the first stages of the take off run?

And by long runways, I mean in excess of 3000ft / 1000m.

Well, on that basis why bother with checks at all. After all, it all went fine last time...

As this forum is called the Professional Pilots Rumour Network it seems a shame we have to suffer remarks like that. They belong elsewhere. Perhaps on the Jackanory website...

Well, let me ask you something else then, this time more related to professional aviation.

Say, on a 737 NG:
Do you perform an engine / APU / cargo fire test on every turn around?
Do you test the configuration warning before every take off?
Do both PF and PNF check the flight controls before every take off?
Do you perform the EGPWS / TCAS / STALL / Overspeed test on every turn around?
Do you do a light test on every turn around?

For every european operator I know, the answer is no to all above...
(And obviously, the answer is yes to all above for the first flight of the day)

Ka8. Nearly my friend. The following from Ryanair, the largest European operator.....



Say, on a 737 NG:
Do you perform an engine / APU / cargo fire test on every turn around? No.
Do you test the configuration warning before every take off? Yes, three separate times before EVERY flight.
Do both PF and PNF check the flight controls before every take off? Yes, absolutely!!
Do you perform the EGPWS / TCAS / STALL / Overspeed test on every turn around? No.
Do you do a light test on every turn around? No.

For every european operator I know, the answer is no to all above...
(And obviously, the answer is yes to all above for the first flight of the day)

I use to do run-ups Etc early at proper power to ensure no problems. Then with passengers on board a lower rev run-up to ensure mags OK.
Not so bad for nervous flyers. :ok:

an engine runup is something every jet airline passenger could recognise and they simply arent done anymore in australia.
your only runup is the taxi out to end of runway:ugh:

I never said jet aircraft, I said piston as per my first post. In regards to the daily/crew change tests stated above, of course they are daily/crew change - the aircraft types specify that and have the technology to show a failure.

But for piston, with no technology other than the runup to show a busted magneto, fouling, etc, I think you're mad to run up, shut down, come back a few hours later and fly with no further check. Older piston engines are ugly on startup, and I've had cases where thats messed with the mags (funnily enough after a mag check in the hangar). If I had just said I'd already flown it that day lets fly who knows what could have happened.

" take on fuel, it is always a good idea to check the sumps/ low points, and that goes for jets too.

You may care to review this statement.

If you do a water drain check, immediately after fueling it's an excercise in futility as the fuel entering the tanks, will still be happily sloshing around and with it any water.

Hence the reason, as an engineer, it was always done after as much down time as possible....... to allow any water to sink to the botton of the tank and thus with the fuel in a stable, rather than turbulent condition.

Eh? There is no run up for a jet. Anything a jet passenger thinks is a run up, isn't. Maybe you are getting confused by setting power on the brakes before take-off on a limiting runway?

Going back a few years I can remember that we only did a full run-up on the first flight of the day. For every subsequent flight we just made sure each mag was working. And, horror of horrors, I also remember having to lean the engine on hot days to get the required RPM/MP. As for jets (and turboprops), I've never done a water drain and runups are little more running at a high power setting just before departure to detect and/or shed ice.

PM

@ Ecam,

I deliberately mentioned the NG above because there are lot more automatics on the bus, such as the takeoff config memo on the ECAM. Regarding flight control checks, I guess everyone is going to be doing a full control check after the maintenance foul up at DLH where the sidestick roll axis got reversed.

@ Wally,

I'm surprised to read that. Is there a specific reason why you test the config warning 3 times? As to the flight controls, the outfits I'm familiar with will have only the PF test his/her controls when it's not the first flight.

@ All,

I just want to emphasize that what I'm questioning is the procedure of doing run-ups before every takeoff IF the PIC has been sitting in the aircraft the whole time. taxistaxing mentioned a required runup after a full stop landing and taxiing back to the runway for another take off. This would mean, a touch and go will be inherently 'much more dangerous' - or do you perform a runup in that case as well? :ok:

Trust me, I'm not a bold pilot and don't take unnecessary risks. Aviation is all about risk assessment and it's just my opinion, that there are cases where I don't think a runup is necessary. But that's all it is - my opinion.

Thanks for the clarification, K@8. In hindsight perhaps my first response was a bit strongly worded. Apologies if any offence was taken.

The reasoning behind the full run-up in the circumstances I mention is that the engine has been at low RPM for a few minutes during the taxi back, with carb-heat taken off as part of the post landing checks. Therefore it's sensible to at least check for carb-ice before applying full power. Since I fly a SEP and the "full" runup is only setting 1700rpm, T's and P's, carb heat and mags check, it makes sense to do the whole thing.

I'm also doing the night rating at the moment where the consequence of EFATO is certain death, which concentrates the mind !!! :sad:

As you say it would be difficult to do any kind of run-up check on a T&G :ok:. But then again during a T&G you go straight from idle throttle with carb-heat to full power so in theory there is no time for any carb icing to form. I suppose you could say a T&G is less dangerous than a full stop landing followed by another takeoff, on this basis.

My understanding is that if the SOPs call for something 3 times, the chances of it being done at least once are very very high. The big underlying fear is starting the take-off roll without flaps.