On passenger flights, it seems to be policy that the pilot, or the first officer, or someone, walks around the big jet, sometimes with a flashlight, kicking tires and checking out the plane, before getting in and flying somewhere. I can’t for the life of me figure out why the pilot would be given that job instead of a trained mechanic, and what he might notice that would tell him/her anything meaningful, aside from streams of leaking oil or bolts falling to the tarmac. I watched a pilot yesterday do the walkaround thing and pat the nose, jiggle something tiny on the landing gear, and the whole thing looked totally useless. Clearly, that person couldn’t have noticed something truly significant, such as a loose rudder, so who’s kidding whom on this?
Don’t worry - trained mechanics check them before the pilots do. A pilot’s walkaround is mostly tradition - the idea being that if he’s gonna fly it he needs to be able to vouch for its airworthiness. Sometimes he might notice something the ground crew missed, most of the time he wont. Would’nt you rather have the pilot give one more shot at spotting an unnoticed hydraulic leak or loose bolt before firing her up and heading down the runway?
I think it’s just a case of one more set of eyes to check things out. The pilot isn’t checking things in place of a mechanic…he or she is checking in addition to a mechanic.
In the final analysis the plane and its passengers are a pilot’s responsibility. It’s only prudent to have a look around even if it is only a cursory check.
For a small plane, this is absolutely essential. You are checking for things such as condensation/rainwater in the gas, did any birds build a nest in your engine, do all the moving bits still move freely, stuff like that.
On a big airliner where you have a dedicated maintenance crew, I lean toward the “tradition” explanation.
Actually it’s a legal necessity.
The “Pilot In Command” is the final authority as to the safety of the proposed flight. Despite being checked by mechanics, final responsibility resides in the PIC.
Is the walkaround by the pilot actually mandated by some FAR?
True, the PIC has the final authority/responsibility, but the OP points out that his personal “inspection” is quite cursory. Responsibility or no, a pilot must place trust in the ground crew to a large extent, because his employer isn’t going to let him disassemble large parts of the plane to check on their welfare prior to every flight.
That said, I side with the tradition/comfort zone explanation. You can never have too many quick checks to see if something obvious is amiss, I personally would feel quite weird hopping behind the yoke and taxiing away without giving the bird at least the most basic “are the wings and tail attached?” check.
Well, I did the walkaround with a Canadian Airlines pilot once, and he looked at the control surfaces (exterior moving parts like the rudder and ailerons) the tail, and the overall craft for obvious problems. He also did a fairly extensive check inside the landing gear housing; he checked various lines and wires, and told me that some of them are designed so that they run through the gear housings for the sole purpose of being visible in a quick pre-flight check. The associated systems themselves are accessible to maintenance crews through panels and inspection ports elsewhere on the craft.
As well, the pilot is making the final check- just before the plane starts up and goes on it’s way. If something has changed since maintenance crews came by- foreign objects in the engine, a leak sprung in the hydraulics, (s)he’ll see it.
And, as a pilot, the preflight is very important. Sure, major flaws are better inspected and cared for by Maintenance, but you’d be surprised how much the pilot knows about his craft. If my students skip an item in the preflight checklist, boy oh boy…
Anyway, in the case of that CA 737, I’m sure everything had been verified by the maintenance crews. But if they missed something huge, or if one of them left a wrench in the wheel-well, the pilot could make his coming flight a lot more pleasant.
(Aside: You know, some real keener is probably going to tell me I should have abbreviated Canadian Airlines as ‘CP’)
I don’t believe a walkaround is specified in the FAR’s. But in the event of an accident, I’m told one of the first things the lawyers look at is preflight actions taken by the PIC. That’s what I meant by legal necessity. Also, I believe the airlines often require a walkaround by a crew member.
A jet pilot I know mentioned that when the planes are de-iced, a crew member must make a visual inspection before takeoff. Although I think this can be done from inside the cabin.
The only pilots I’m aware of who routinely skip their preflight checks are the US Air Force Thunderbirds - they stopped doing this at some point in the '60s to demonstrate the level of trust they have in their ground crews. So far no Thunderbird aircraft has been lost due to maintenance issues.
In the 1980s all five T-38 aircraft being flown by the USAF Thunderbirds crashed into the ground during a training flight. IIRC, an elevator actuator on the lead aircraft failed (would not operate the elevator upwards) and the aircraft was unable to complete a loop before hitting the ground. The other aircraft, which were in formation and whose pilots were concentrating on the lead aircraft, followed it in. I don’t know if an equipment failure is a “maintenance issue”, but I think it could be considered one.
The Thunderbirds switched to the F-16 after losing their T-38s.
I didn’t find a Federal Aviation Regulation (FAR) that specifically requires a preflight inspection of the aircraft, but I have read several excerpts from NTSB accident investigations that cite “pilot’s in adequate preflight inspection” of the aircraft as a cause of crashes. As Grok said, the pilot has the final responsibility for the safety of the aircraft and the flight. If a pilot tskes off (or tries to take off) with the towbar still attached, the pitot tube cover on, or with plugs in the cowl, you can bet they will blame the pilot for an inadequate inspection. I also noted in my google search references to “during the normal preflight inspection”. Clearly the FAA and NTSB intend that preflight inspections be a routine part of flying.
If I read the previous posts correctly, the reasons for the walkaround have to do with tradition, some legal beliefs, and the notion that it’s a pilots “responsiblity.” So, it seems that except for the mighty remote chance of finding a wrench in the landing gear, there really is no reason for performing this procedure. That’s really what I was asking in my OP. By the way, on Sunday, I watched my plane come in, get emptied of people and luggage and get refilled with that stuff, and at no time did any mechanic look at the outside of the plane. (American Airlines) So, the pilot was apparently not the last one to look. She was the only one to look. To me, it seems like an anachronism, retained for tradition’s sake. I guess that’s what I thought it was all along. Thanks.
It was my understanding that this accident was caused by a foreign object in the cockpit interfering with the pilot’s control stick - I dunno, maybe that counts as a maintenance issue. I’ve also found accounts that blame the equipment failure you mentioned as well as pilot error. Maybe more research is needed.
I think we need a re-count on those fatalities - it was a four-ship diamond that hit the ground, neither of the opposing solo pilots (#5 and #6) were involved.
Hmmm…looks like this was a slight hijack - sorry about that…
CC: I don’t think you quite get it. You seem to think that walkarounds are some vestigial function that serve no practical purpose today. Nothing could be further from the truth. Many, many lives have been saved when pilots caught problems during walkarounds, and many have been killed as a result of the pilot failing to do one.
I have personally saved my own bacon by doing a walkaround in a circumstance that you would probably think was ‘silly’. I had already done a walkaround (of a plane that had just landed - so it should have been in fine shape). The walkaround was fine, and then I forgot my logbook in the clubhouse. So I ran in and grabbed it, and the aircraft was out of my sight for maybe five minutes. I came back out, threw the logbook in the cabin, and started doing a walkaround again. My passenger said, “Why do it again? You just did it!” I was about to explain to him the importance of checking any aircraft that’s out of your sight for even a minute, when I found the towbar attached to the front wheel of the airplane. Apparently, when I ran inside somebody thought the airplane was done with and hooked up the towbar to push it back into position. Someone else probably told him that I was coming right back to go flying, so the guy just dropped the towbar and went away. If I hadn’t done a walkaround, I would have had an eventful runup and flight.
There was at least one jet crash in the last 20 years attributed to the pilot not checking the wings for frost, and just trusting that the lineman had checked the wings, which he hadn’t.
Aviation is very, very intolerant of mistakes. So we have devised a series of checks and double checks, and checklists for every procedure possible. We might do 1000 walkarounds without finding anything wrong, but if in our entire careers in aviation we find one wrong thing during a walkaround that could have killed us, they were worth it.
[fixed coding]
[Edited by bibliophage on 11-21-2001 at 11:00 PM]
Sorry about the bolding, guys. Preview is your friend.
I don’t have a cite. I was going from memory of the accident report I read when I was at Edwards AFB. I’ve never read anything about a foreign object in the cockpit. If there was something that interfered with the pilot’s operation of the control, then that would fall under the unbrella of “failure of the pilot to perform a satisfactory preflight check”. Making sure there are no foreign objects to interfere with the controls is part of the preflight check, and I can attest to the fact that it is in the preflight inspection checklists of the rotorcraft I fly.
Sam Stone: Funny you should mention that. This month’s “On the Record” in Flying magazine (Nov. 2001) reports on the crash of a Cessna 310: “Probable Cause: The pilot’s inadequate preflight inspection in which he failed to remove the towbar from the nose gear…” Another report on the crash of a Piper PA-46-350P Mirage states: Probable Cause: The pilot’s failure to ensure that the autopilot was off prior to takeoff…" Checking to make sure the instruments and avionics are correctly set can be considered part of the preflight inspection, although properly the check is performed during the pre-takeoff check.
I was employed by a contractor at Edwards AFB for data collection on the B-1B project. As we sat in Mission Control we learned that a mission was scrubbed because someone had left a wrench in one of the engine intakes. It was sucked in on startup and severely damaged the engine. It may be a “remote chance”, but it does happen.
Absolutely. Check and double check. Then check again if something seems in the least peculiar.
**
As long as we’re telling stories…
A friend of mine was pre-flighting a plane one day, but I noticed that she only took examined a drop of gas during the fuel sump check. It had rained the night before, and the plane was tied down outside.
I went over and suggested she examine a full tube’s worth. She drained the sump and showed me a tube of liquid. “Looks OK, no separation…” she said, and began to discard it.
I stopped her and examined the tube closely. I handed it back to her and said, “Smell it.” She went pale when she realized why there was no separation - it was ALL water.
We then pulled over a pint of water from that tank. Out of curiosity, we then looked in the cockpit and realized the fuel selector was set for that tank. Could have been interesting had she tried to take off that way.
I always preflight and welcome an extra pair of eyes. I hope the airlines feel the same way.
[fixed coding]
[Edited by bibliophage on 11-21-2001 at 11:02 PM]
You know, it’s funny that Sam Stone and I are here preaching our guts out about careful preflighting…
… and yet we both have posted without previewing.
hangs head sheepishly
Truckers and bus drivers do this (or should) too. And there is no reason an automobile driver should not give it a quick once over, how many people do you see driving obliviously around with a left side flat tire that is a danger to everyone on the road?