No more runups

Ron Levy said:
A run-up will not find:
  • Low oil quantity
  • Worn control surface bearings
  • Leaking hydraulic fluid
  • Cracked control surface mounting flange
  • Loose control surface connection
  • Loose fairing
  • Missing landing gear cotter pin
...and many other things which can really spoil your flying day.
Click to expand...

Ron, I'll find the low oil level in my preflight. If the aircraft is leaking fluids its really likely that I'll see it. Loose control connections and fairings I would hope to find in a preflight. I genuinely don't know where the gear cotter pin is, nor would I be able to pick out the control surface bearings in a surface inspection. I really don't know what they look like.

Besides, if a run up won't find all these horrible things, why do it? You make it sound far less useful than it is.
 
jesse said:
I fly a lot there. I was the last one to fly it. I confirm the fuel levels by checking the tanks. If it rains or if I add fuel I'll sump the fuel. Oil is checked every few hours. Everything else is checked on the first flight of the morning. I generally shut down, unload, grab some new passengers, and take to the sky again. Pretty much all weekend. I check the mags and all the systems on each flight.

There is a big difference between not doing something at all and spacing it out to reasonably time intervals based on your usage of the airplane.
Click to expand...

My idea of a reasonable spacing out is one a day versus one per flight.
 
Well, they say anal is better than no retentive at all.:thumbsup:
AdamZ said:
First off we have confused things a lot. Post are jumping back and forth between pre-flight and run ups. Two obviously different things.

I guess Michael my concern is that everything has its point of failure. and not all failures give us warning. a cracked muffler, a bad mag, birds nests in the srping that I have seen built in under 15 minutes.

Run ups take a minute so for me its worth it Then again Im the kind of guy who checks for wx NOTAMS etc and TFRs if I'm doing a repositioning flight 10 min away.
Click to expand...
 
whifferdill said:
Something to think about - How long does an airplane have to sit between flights to warrant a pre-flight before the next one? I'm pretty sure most people would preflight again before it flew again the next day. But do you think there is a significant difference between the airplane sitting for 15 minutes vs. 24 hours? If the airplane has developed a problem, it'll be there after you've shut down...whether it's for days or minutes. There aren't too many problems that will develop as a plane sits idle overnight - maybe birds nests, flat tires, frost, punks who stole your fuel, etc.
Click to expand...

It really depends on where the airplane sits. My own hangar? I'm less concerned and the preflight is the stuff that will kill me. Overnight on a ramp? I've been told (by an IA, no less), that it looks like I'm doing an annual.
 
Ron Levy said:
A run-up will not find:
  • Low oil quantity
  • Worn control surface bearings
  • Leaking hydraulic fluid
  • Cracked control surface mounting flange
  • Loose control surface connection
  • Loose fairing
  • Missing landing gear cotter pin
...and many other things which can really spoil your flying day.
Click to expand...

And a preflight without a runup will not find (based on my simple
cherokee 140):

Bad carb heat
Bad mag
Fouled plugs (of course, a REALLY thorough preflight might find that)
Inadequate Vac (I'd rather check that at 2000 rpm than on the roll)
Bad master - (found a failing master switch because of a bouncing
ammeter during runup)

any others?
 
steingar said:
Ron, I'll find the low oil level in my preflight. If the aircraft is leaking fluids its really likely that I'll see it. Loose control connections and fairings I would hope to find in a preflight. I genuinely don't know where the gear cotter pin is, nor would I be able to pick out the control surface bearings in a surface inspection. I really don't know what they look like.

Besides, if a run up won't find all these horrible things, why do it? You make it sound far less useful than it is.
Click to expand...
I give up. Do it your way. See ya.
 
Bob Noel said:
And a preflight without a runup will not find (based on my simple
cherokee 140):

Bad carb heat
Click to expand...

-that is very true, thought the possibility of the carb heat breaking between the morning and afternoon flights is quite slim. However, a concern, especially for the colder months.

Bob Noel said:
Bad mag
Click to expand...

-I flew my Cherokee 140 from Wisconsin to Ohio on a bad mag and didn't even realize it.

Bob Noel said:
Fouled plugs (of course, a REALLY thorough preflight might find that)
Click to expand...

-although a plug that bad might manifest itself on the takeoff roll. Might not.

Bob Noel said:
Inadequate Vac (I'd rather check that at 2000 rpm than on the roll)
Click to expand...

-I think there are one or two pilots on the board who fly aircraft with no vacuum system at all.

Bob Noel said:
Bad master - (found a failing master switch because of a bouncing
ammeter during runup)

any others?
Click to expand...

Depends on what you do in your run up. Maladjusted trim comes to mind, and of course you have to turn on the boost pump.
 
steingar said:
-that is very true, thought the possibility of the carb heat breaking between the morning and afternoon flights is quite slim. However, a concern, especially for the colder months.
Click to expand...

The probability of it breaking between a morning flight and
an afternoon flight is the same as the probability of it breaking
between the last flight of the day and the flight the next day.




steingar said:
-I think there are one or two pilots on the board who fly aircraft with no vacuum system at all.
Click to expand...

Well, I did say "based on my cherokee 140" - and I need the
vacuum system for IFR flight in IMC.


steingar said:
Depends on what you do in your run up. Maladjusted trim comes to mind, and of course you have to turn on the boost pump.
Click to expand...

With my 140, trim is something I do before the engine start, as well
as the fuel pump.
 
steingar said:
No one is going to rewire my flight controls between flights unless they want me dead, and if they do there are better ways to achieve it.
Click to expand...

Probably not rewire your controls, but if you think there is no point in checking your controls before launching then I guess you aren't familiar with the case of the well meaning lineguy who put a gust lock on while the pilot was making a head call.

Pilot found out about it when the FAA was interviewing him in the hospital.
 
Here's one reason I do pre-flights and run-ups.

If the guy flying the plane with the snipped picture below had actually done a pre-flight (I was flying in another plane's rear seat and saw very little evidence of any preflight whatsoever, was paying attention, and actually thought that to myself before the flight took place) he might have noticed a structural issue with the landing gear... I know, because I had previously flown this aircraft quite a bit and always checked the bungees right next to the bend as part of the pre-flight.

Ok, so I took this picture during a formation practice flight - the first flight of the day. I still think I would've grounded it if I had seen this prior to the flight.

IMG_5417.JPG


Also, this isn't the only photo I took showing it.

Anyway, they landed it like that with our formation, then turned around and took off again while we went to lunch. We came back to find this:

IMG_5486.JPG


The plane's nearly back up again, but I was quite annoyed. I personally would be surprised if the guy actually checked the oil much less the condition of the bungees and gear.

Ryan
 
Troska said:
Genuine question: Do your towpilots runup before every tow? What if they shut down for 5-10 minutes if the next glider isn't ready?

Tim
Click to expand...
And on a similar note, if you're doing a bunch of stop and goes, do you do a run-up before each takeoff? The sense I've gotten from this thread s that people are treating a takeoff as distinct from a flight.
 
Just to play devil's advocate, and because I'm in that sort of mood, I will list things I think I could neither find on a preflight OR a runup which could alter my upholstery or otherwise spoil my day :D

==

Internal engine damage (cracked crank, spinning bearing, or for my IO-550 -- alternator gear about to shear teeth and throw metal into my engine)

Undetected crack forming in a propeller blade or hub

Corroded control cables

Cracking or otherwise FUBAR control cables/pulleys

Landing gear nose-retract rod-ends about to break and render my nose-gear useless (sorry, more Bonanza specific stuff that I think about when flying)

Magneto "keeper" working loose, and about to shaft its timing.

Internal magneto damage.

wing attach fittings corroded (we found this while doing an annual on a piper cherokee -- LH wing held on by 4 of 12 rivets, RH by 7 of 12)

==

Was it Al Pacino who said.. "you can get killed walkin your doggie" ?
 
RyanShort1 said:
Here's one reason I do pre-flights and run-ups.

If the guy flying the plane with the snipped picture below had actually done a pre-flight (I was flying in another plane's rear seat and saw very little evidence of any preflight whatsoever, was paying attention, and actually thought that to myself before the flight took place) he might have noticed a structural issue with the landing gear... I know, because I had previously flown this aircraft quite a bit and always checked the bungees right next to the bend as part of the pre-flight...
Click to expand...

Apparently my stupid pills are working, because I'm not certain I see what's wrong other than that thing with the arrow is a different color.
 
Interesting to compare contemporaneous threads on different forums. Here we have the rote predilectations regarding the virtues of myopic and introspective routines of dubious tangible value, along with dire warnings of all the boogy-men that will eat the pilot who strays from the fold.

On the red board we have Art's ongoing posting of both preliminary and final NTSB reports, which are devoid of any evidence to support the near-certain-death admonitions and the finger-shaking assertations that "I always do yada because blah" prior to flying an airplane.

As the guy who was caught in a delicate situation asked his wife "Who are you going to believe, me or your lying eyes?"
 
Is it possible this debate is actually a debate between those who have served in the military and those who haven't? Military people understand why we are taught to do things a certain way, and that it is best to do things the way we were taught, even though it may seem mundane and repetitious.

John
 
John Baker said:
Is it possible this debate is actually a debate between those who have served in the military and those who haven't? Military people understand why we are taught to do things a certain way, and that it is best to do things the way we were taught, even though it may seem mundane and repetitious.

John
Click to expand...

I don't know about that. Military folks quickly learn about chicken, cow, bull, horse, and jack-%hi7, and quickly disregard bad-%hi7.
 
John Baker said:
Is it possible this debate is actually a debate between those who have served in the military and those who haven't? [snip]

John
Click to expand...

I doubt it. I have not served in the military. Yet I haven't read
a compelling reason to not perform a runup prior to every departure.
 
dmccormack said:
If the question is: "Perform a runup prior to every takeoff?" my answer is an unequivocal NO.
Click to expand...

I said "departure"... and to clarify, T&G's don't count, nor do
stop and go's.
 
John Baker said:
Is it possible this debate is actually a debate between those who have served in the military and those who haven't? Military people understand why we are taught to do things a certain way, and that it is best to do things the way we were taught, even though it may seem mundane and repetitious.

John
Click to expand...
I don't see any pattern between those who and served and their opinions in this thread.
 
dmccormack said:
Those items are why we do annuals, is it not?
Click to expand...

In theory. Assuming one doesn't opt for the drive-by annual in this economy. I see a lot of that going on here at our airport.

So which things do we expect to only find every year, vs those we expect to find every day, and those we expect to find every flight?

A lot of the "found it on preflight" problems being quoted here don't manifest themselves overnight.
 
schmookeeg said:
In theory. Assuming one doesn't opt for the drive-by annual in this economy. I see a lot of that going on here at our airport.

So which things do we expect to only find every year, vs those we expect to find every day, and those we expect to find every flight?

A lot of the "found it on preflight" problems being quoted here don't manifest themselves overnight.
Click to expand...


Yep -- which is why it's important to know the airplane and which items are critical to flight. In my old bird the tail brace wires are critical -- I doubt I would survive failure of one.

Oil level is critical as an indicator, but I don't remove the cowling each time, and if I had I might have identified the loose plug that gave me a bit of anxiety a couple of months ago.

I check the prop for cracks, but I live with less than perfect balance.

I check the tires for inflation, but will live with 12 PSI or 15.

And so on...
 
steingar said:
Apparently my stupid pills are working, because I'm not certain I see what's wrong other than that thing with the arrow is a different color.
Click to expand...
Um, yeah, like a 10-15 degree bend in the strut there just below the bungee where it apparently rusted through.

Ryan
 
schmookeeg said:
A lot of the "found it on preflight" problems being quoted here don't manifest themselves overnight.
Click to expand...

No, most don't, but anything dangerous caught on a preflight is something that won't kill you now that you fix it rather than fly it. Ignorance is not bliss. I read an article some years ago about a guy doing a quick preflight on a Beech 18, and noticed what looked like a crack in one prop blade. On closer examination, the crack extended two-thirds of the way through the blade and almost certainly would have failed in flight. That sort of imbalance tends to tear engines off mounts and screw up the airplane's C of G so much that it won't glide. A prop shop near here has a broken blade from a cropsprayer; the pilot flew the shaking machine all the way back to his strip but I don't imagine there were any tight rivets or uncracked welds left anywhere in the airplane.

Nicks in props. Don't tolerate them. They cause stress risers that will, given enough time, cause a crack.


Dan
 
Why hadn't it "almost certainly" failed before?
Dan Thomas said:
No, most don't, but anything dangerous caught on a preflight is something that won't kill you now that you fix it rather than fly it. Ignorance is not bliss. I read an article some years ago about a guy doing a quick preflight on a Beech 18, and noticed what looked like a crack in one prop blade. On closer examination, the crack extended two-thirds of the way through the blade and almost certainly would have failed in flight. That sort of imbalance tends to tear engines off mounts and screw up the airplane's C of G so much that it won't glide. A prop shop near here has a broken blade from a cropsprayer; the pilot flew the shaking machine all the way back to his strip but I don't imagine there were any tight rivets or uncracked welds left anywhere in the airplane.

Nicks in props. Don't tolerate them. They cause stress risers that will, given enough time, cause a crack.


Dan
Click to expand...
 
wabower said:
Why hadn't it "almost certainly" failed before?
Click to expand...

Because as the crack gets longer it progresses faster. Before the previous flight it might have been only an inch long, maybe less. As the blade--or any other metal part--flexes and cracks, there's less metal to take the loads as the crack lengthens and it will moves much faster.

I once had a crankshaft break in flight. The broken surfaces showed light rust over the first eighth or so of the area, much lighter rust over another eighth, and clean metal after that. The ripple effect across the break (metallurgists call it beach effect or something like that, for the appearance of sand ripples left by waves) showed a slow progression at first and the final break involved at least half of the section, indicating an almost instant failure.

A discussion of such failure:
http://home.hiwaay.net/~langford/corvair/flexplate/problem.html


Dan
 
Dan Thomas; said:
I once had a crankshaft break in flight. The broken surfaces showed light rust over the first eighth or so of the area, much lighter rust over another eighth, and clean metal after that. The ripple effect across the break (metallurgists call it beach effect or something like that, for the appearance of sand ripples left by waves) showed a slow progression at first and the final break involved at least half of the section, indicating an almost instant failure.



Dan
Click to expand...

And you didn't carch it on the preflight??:ihih:

Shame on you...:cornut:

Chris (who does a runup prior to taking the runway...everytime!)
 
Last edited by a moderator:
There may in fact be no rationale for preflighting after the first of the day. However itWAS one of those things just burned in by the law of primacy....and if I don't do it it just doesn't feel right.

...Kind of like riding in an auto w/o a seatbelt.
 
Killer items, then lights, camera, action.

Standard Takeoff briefing: Standard calls, ABC, don't let me f**k up.
 
I will abbreviate some things - depending on the circumstance. For instance, I flew the Cub three times today with students. There aren't a lot of systems I need to check on it. I can tell pretty easily that the flight control surfaces and leading edges are in good shape, and with the open cowling, can tell if something's dripping oil. On the other hand, I'm still going to give the landing gear a once over and make sure the oil level, fuel, etc... is good. I'm still doing a mag check before each flight.
I still think you need at least a partial check on critical stuff.

Ryan
 
Well! In most of the POHs I've checked a Pre Take Off Check List calls for a run up, mag carb heat etc. An airplane has to prove it is airworthy to me each time I fly it. In the Air Force we would launch out perfectly good jets. Some of them would start leaking something before it got to the EOR (end of runway) check.
I do sump the fuel after every fueling and run up after any engine shutdown.
There is no such thing as an emergency take off. (except maybe Tsunami coming)
 
Last edited:
steingar said:
nor would I be able to pick out the control surface bearings in a surface inspection. I really don't know what they look like.
Click to expand...

Depending on how the control surfaces are hinged, you may or may not have them. That you don't know anything about them makes me think that it doesn't really matter if you do a pre flight or run up. So I agree with you, "Why bother?" You won't find anything when you don't know what to look for where.
 
How much wear and time does the actual run up cost? It takes me about 15 seconds on any run up to cycle the mags and listen for a few seconds a side and then cycle the prop a couple of times to make sure it's getting oil and the cable is connected. And wear? Come on - the worse thing for your engine is to hardly ever fly it. Extra run ups might actually be helping it. Cost? My run up costs less than 0.1 gallon of gas.

I always move the controls as I'm rolling out. No one likely reconnected them between flights but you never know what's shifted or how a seat belt might have been routed or what's been placed in the floor at my passenger's feet.

On a separate note though, how many people do a thorough post-flight check and does it change the way you subsequently do a pre-flight? If you're the only operator of your plane and it lives in a secured hanger, would you consider a post flight walk-around of any value to speed up your next pre-flight?
 
I do post flight walk around, it doesn't save me any time on the next preflight, but occasionally catch something that would cause me a delay to fix next time I got to the plane.
 
None for me either, that I can tell. When taking the runway, I set power at 1.6k and check mags, prop, CHT, gages, CITGFRSS (seat stops) and LCA on the roll. An observer with a stopwatch couldn't find an extra second. If something breaks, an airplane must drive up the runway to a turnoff anyway, since we normally have a line and using the taxiway isn't possible

PittsDriver said:
How much wear and time does the actual run up cost? It takes me about 15 seconds on any run up to cycle the mags and listen for a few seconds a side and then cycle the prop a couple of times to make sure it's getting oil and the cable is connected. And wear? Come on - the worse thing for your engine is to hardly ever fly it. Extra run ups might actually be helping it. Cost? My run up costs less than 0.1 gallon of gas.

I always move the controls as I'm rolling out. No one likely reconnected them between flights but you never know what's shifted or how a seat belt might have been routed or what's been placed in the floor at my passenger's feet.

On a separate note though, how many people do a thorough post-flight check and does it change the way you subsequently do a pre-flight? If you're the only operator of your plane and it lives in a secured hanger, would you consider a post flight walk-around of any value to speed up your next pre-flight?
Click to expand...
 
You must log in or register to reply here.
Back
Top