The hotel we stayed in has a really nice pool, so we go for a swim before I volunteer to drive back for the part. My coworker did all the driving for the previous trips, so I figure she should get to sit around a bit today.
I'm not actually picking up the part from the Fed Ex office: I'm picking it up from the part retailer who get it couriered to them, so what I collect is just the paperwork and the part, in its plastic baggie. Today's part is about the size of the last joint of my little finger. It's an electronic component. I don't know if it has a name or just a part number, but apparently it is responsible for the last two day's trouble. I drive back. They install it. They test it. It works.
We load our bags. We run up. We take off. I raise the gear. It starts goes up. The green lights go out and a red light goes on. The gear clunks into the belly and wings. The hydraulic cycle completes and the red light goes off. A glance in the mirror shows that the nosewheel is stowed.
I reduce the power from the take-off setting to the climb setting. I get distracted by a very odd indication on the panel and reduce the power too much. My coworker is reading the paper but this gets her attention and I show her that the flap indicator shows full down. They're not down even a little bit and the indication was correct on the ground. Flap indicators can be wonky. This one always indicates full down when electrical power is removed. Not all of them do that. Often cycling the flaps will fix an indication problem, but when selected down, they don't budge. I inspect the obvious culprit. Yep, the circuit breaker is popped. "I'll reset it once," I say and push on it, but it doesn't go in. She doesn't believe me and reaches over and tries it herself. I forgive her for thinking I'm too stupid to reset a CB, after my power setting stunt. It doesn't reset for her either.
We almost got out of there, too.
I'm in the U-turn, thinking about the short runway. I don't have flapless landing performance charts. There's still some wind, but not a whole lot. I consider going to the larger airport. That would allow a larger margin of safety, but it would introduce a lot of operational difficulties. A lot of people think that being a professional pilot is all about always making the safest decision. It's not. It's about making the decision that will come closest to achieving the operational objective while still remaining safe. Is it safe to land this airplane on this runway, at this weight, in only this much wind? In my judgement yes. And there's nothing to hit at the other end. Not even a fence.
I fly a long final to compensate for the fact that the flapless approach profile is less familiar. I want to land at the very beginning of the runway, and I want to do it with as little speed as is safe, so as to have less speed to kill by braking. Gear down and take a couple of extra inches of power off. Over the threshold, power idle, brakes ... and without jamming them on we almost make the centre taxiway.
My coworker has already texted the engineer about our issue. The popped circuit break is for the starter solenoid, flaps and right emergency fuel pump. Weird combination. Weirder are the combinations required to start it again. With the master off, the CB resets. They have me do various combinations of starting engines, operating the flaps and turning on the fuel pump. Sometimes it pops and sometimes it doesn't. The engineer and one of the apprentices work on the problem. We go inside and chat to the other apprentice, who is also a student pilot. We tell her that if we stay the night again, as it looks like we will, she can come to the excellent hotel pool as our guest. We aviatrices have to stick together.
So what do you think? Are we going to spend another night here? Will we go back to the parts distributor in the morning? Will they fix the airplane and see us on our way tonight? If it's of any help to your guess there is a ridge of high pressure over western Canada leaving it clear all the way to destination.
12 comments:
I'll take that bet. Given the wonderful weather forecast..
Are we going to spend another night here? ... If it's of any help to your guess there is a ridge of high pressure over western Canada leaving it clear all the way to destination.
... the weather is guaranteed to be crummy just as the last electrical problem is repaired (for now). You spent one more day there. But I'm glad there was a pool.
And I say the clean living is about to pay off. The fix will be complete in time to fly off into that beautiful Canadian high pressure...
Aviatrix wrote: The hotel we stayed in has a really nice pool, so we go for a swim
OK, we're going to need pics of this.
"A lot of people think that being a professional pilot is all about always making the safest decision. It's not. It's about making the decision that will come closest to achieving the operational objective while still remaining safe."
Yes. Exactly! I have tried to explain that concept to people many, many times - but I've never heard it put so well.
It's true for non-professional pilots, too. It doesn't really matter if your operational objective is "Get 300 people to Dallas by noon" or "Go have a $100 hamburger" or "Teach this person to fly"- the rule still holds.
I'm going to be quoting you a lot on the airport from now on, if you don't mind.
Interesting read as usual. I used to be of the school of thought to reset a popped circuit breaker.
After having smoke in the cockpit (unrelated), and doing some reading on the subject at here:
http://www.avcanada.ca/forums2/viewtopic.php?f=54&t=56651
I have changed my views, and now likely won't reset a circuit breaker unless it is something critical, like gear. Even then, however, most aircraft have a second method of lowering the gear.
I'm with Sarah. For your aircraft to feel like working just as the weather *improves* would violate Murphy's Law and could cause a freak accident somewhere else.
Dear Trix:
Echoing Jimmy Mack's comment, could I ask you to read this and favor us with your reaction?
Thanks,
Frank
@Jimmy Mack & Frank
I would like to read 'Trix's views as well, but as a CASO (and only a few moments to digest the content of the link) the following three things strike me.
1) I didn't see anything in that article to indicate that the accident crew reset the CB.
2) The failure mode describe by the previous pilot indicated that the radar was a fire hazard without tripping the CB. This indicates either a catastrophic failure in high current circuits in the radar, a faulty CB or both.
3) If the NTSB advice is valid, it indicates that wiring specifications are inadequate. The CB needs to be sized to provide adequate power to the equipment, but not more. The wire needs to be sized to carry all the power the CB will provide without suffering damage. If this is not the case, it is entirely possible that constant high loads that are just under the CB rating could cause dangerous wire damage resulting in a fire hazard regardless of any CB reset policy.
NT:
While we await Trix's input...
You will need to bear with me -- I'm a metal bender from way back and not much of a spark chaser. Anyway...
"1) I didn't see anything in that article to indicate that the accident crew reset the CB."
See the NTSB report page 10 et seq. On the previous flight the pilot was able to ID the radar as a problem and pull the breaker. It remained pulled and the a/c flew another 1 hr+. Maintenance neither collared the CB nor placarded the radar inop. The accident crew then came to grief minutes into the flight. NTSB infers that the PIC reset the radar CB in the course of a rote pre-flight. Could they have again broken the chain by pulling the breaker again? Not if the damage reached some "flashover" point, nor if the spread and intensity of the fire masked its origin or rendered it moot.
Re: your item (2), concur.
"3) If the NTSB advice is valid, it indicates that wiring specifications are inadequate. ..."
Here's where I need you to be patient with me. The CB is there to protect the wire. If the fault is in the radar itself (as you suggest supra) then the CB and the wire can be just fine but you die anyway because they continue to energize the catastrophic failure in the powered equipment. Salvation lies only in pulling (or NOT resetting) the CB, thus starving the beast. Thus, I am left very averse to resetting CB's in flight.
Is all that consistent with your informed judgement?
Regards,
Frank
@Frank
There is no doubt that a lot of things the NASCAR flight department and accident pilots did were ill advised and were bound to lead to an accident at some point. Re-energizing the Radar (if they did that) would be one of many.
While there are many lessons to be learned, nothing that I have read about this accident supports the one side of this issue, or the other. There are others that we can use to examine the "reset once" policy. A particularly tragic one took the life of Canadian singer/songwriter Stan Rogers. In this case, the cause of the tripping was well know and resetting was a common procedure. Points that, according to the NASCAR accident write up, would support resetting. Indeed it is also possible that the NASCAR plane, having one fire starter on board, had another waiting to flame up and the crew fell victim to something other than the Radar. I don't like basing safety policy on conjecture, even from the really super people at the NTSB. One can suppose that the NASCAR crew reset the breaker for some reason, rote checklist or otherwise.
The problem with conjecture is that it tends to compound. If you don't critically examine the basis of each conjecture, you can find yourself at the end of a long chain of them arriving at a decision that looks sound, but is in fact groundless.
Ultimately it comes down to the pilot knowing the systems, or having ready access to technicians that do; evaluating the need for the system and the safety of the flight.
NT:
Thanks for sharing your expertise.
It might be that with respect to this issue (i.e., resetting tripped CB's in flight) it would be well to apply the Precautionary Principle. I can't see where leaving a tripped CB alone could hurt you...whereas, it might be OK to reset it, but...
Yours, in (perhaps) an excess of caution,
Frank
@Frank
My apologies if I gave you the impression that the CB reset debate wasn't worth having or that I thought not resetting them was overly cautious. Neither was my intent. I simply want to point out that this accident does not provide any grist for that particular mill. There are certainly some breakers that once popped should probably be left alone, and the associated equipment turned off as well. Other systems may warrant one or multiple resets but no one answer will serve all cases, which I think is what the NTSB was trying to say. Pilots need education and operational directives.
However, after 24 hours of rattling around in my head I decided that the question of cumulative damage to wiring during CB trips is best answered by electrical engineers in labs, not by accident investigators poking wreckage. Either the damage can/is being done and the wire should be replace, or the CB is protecting the wire and resetting it is a systems criticality/operations safety decision.
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