As I mentioned in my last post, some captain upgrades and new hires are finally appearing at Dynamic.
For the past year and a half, things had been completely static. I was one of the last people to upgrade to the left seat, and those who were stuck as first officers eventually started to get discouraged. It’s hard to blame them. They work extremely hard for $11 an hour (yeah, you read that right) day in and day out. Thankfully, for those who stuck around, their patience has begun to pay off. And for those who haven’t upgraded yet, at least they see some light at the end of the tunnel.
The down side to this is that I have lost some of my favorite first officers. I’m glad they’ve upgraded, but today I started to realize how much I’d come to rely on their experience, not to mention the fun factor of flying with them. Then again, I get to play a part in the training of some upcoming pilots, and that’s pretty neat too.
Today I was flying with one of the “new guys”. It was an atypical day because I clocked in at 6:00 a.m. I normally get an early start, but not THAT early. We were cranking at that hour because a ceremony would be taking place later in the day to honor a soldier whose body was being returned home from Afghanistan. During the ceremony, which was to occur in the middle of our work day, the base would be on “quiet hours”, meaning no aircraft operations were permitted.
My first officer and I had taxied out to the runway for our second flight. We lined up, completed our final checks, set power, and released the brakes. Everything was normal for a few seconds. Then, as we accelerated down the runway, a very large hawk came into view. He was sitting in the middle of the runway with his back to us, wings folded majestically. He didn’t seem to be doing anything special, just sitting there.
My FO (who has only a few flights under his belt in the BE90) asked if he should abort. I said no. My feeling about birds is that they generally get out of the way. Those that don’t are not going to be avoided by maneuvering, especially in something the size of a King Air. It’s akin to a scuba diver trying to out-swim a sea lion under water. We move at a comparatively glacial pace, and if they want to avoid us, they can jink and jank in ways we can only dream of.
And in this case, I don’t think we could have stopped in time anyway, even with full reverse and hard braking. I’d rather hit the bird than try and steer around it in a 10,000 lb. King Air and end up veering off the runway.
We seem to hit birds fairly frequently at Los Alamitos. The base — along with the adjacent Seal Beach Naval Weapons Station — is some of the last open space in the area, and it attracts a lot of wildlife. Now as to why the wildlife that flies seems to enjoy hanging out around the runway, you got me.
So as I mentioned, the hawk was sitting on the runway centerline with his back to us. I’m sure he knew we were coming. A King Air with the props turning at 2200 RPM is pretty loud. Plus we have two alternating flashing landing lights on each wingtip and another one on the nose gear. In fact, I know the bird saw us coming, because he actually turned his head 90 degrees and looked at us as we approached!
By now you’ve probably guessed the hawk elected to make a stand against the five-ton turboprop, and in the words of the Knight Templar, he chose… poorly. We heard a distinctive thump as the half of the hawk which wasn’t left on the runway hit the right main landing gear leg.
We rotated, the FO called for gear retraction, and I selected… nothing. The gear handle wouldn’t move. So I pushed the downlock override, selected gear up, and was rewarded with red lights, warning horn, and no gear movement. Mmm-hmmm. I lowered the gear handle and immediately got three green lights. Down and locked.
Remembering rule #1 (always fly the plane), I elected to monitor the FO as he flew and ignore the gear until we could get to a higher altitude. Once off the coast, I briefed the FO: he would focus on flying the airplane and look for traffic; I would troubleshoot the gear and handle the radios.
There were no indications of blown circuit breakers or other failures. No reason to pump the gear manually, it was already down. There is a checklist for failure to extend, but nothing for a failure to retract. I suspected that the bird strike had done something to the squat switch, because the aircraft was reacting like I had raised the landing gear lever with the plane sitting on the ground.
I called our maintenance shop and after a few queries, they said that if it was definitely down and locked, leave it that way and return. So that’s what we did. I elected to make a fly-by of the tower just to have them look at that right gear leg and see if there was any obvious sign of damage, flat tire, or other abnormality. They didn’t see anything amiss, so we returned and landed uneventfully. Well, aside from the trail of emergency vehicles which followed us to the ramp.
We moved our load to another aircraft and had an uneventful flight. At the end of the day, I got with the mechanic who put our broken bird up on jacks, and what they found was that the hawk had bent part of the squat switch — a device which detects when the airplane’s weight comes off the wheels — in such a way that it was locked in place and always thought the plane was on the ground. An easy fix. And they also found the hawk on the runway. Or should I say, half of it. Apparently our prop cut the bird cleanly in half.
What I learned today (or should I say, re-learned) is that rule #1 really works. Fly the airplane, no matter what. When something goes wrong, there’s often an irresistible urge to do something, fix something, check for that breaker, try the gear retraction juuuuust one more time. In a busy terminal area when you’re low to the ground with the extra drag of the landing gear reducing your climb rate and a brand new low-time first officer flying the airplane, the best course of action is frequently to ignore the problem and just fly.
Sounds like you guys couldn’t have done it any better. I’m sure the FO was glad to be with an “old hand” like yourself and not some other short-timer.
I agree with MJG; sounds like you handled it very professionally. And for the FO, it made for a “teachable moment”. I can’t help but feel sorry for the hawk, but sh** happens. I watched your flyby from my front yard, and made my own assessment of your gear with my binoculars (LOL).
BTW, as for why the hawks hang out there, I think it might have something to do with all the gophers in the fields. There’s probably mice, too.
I forgot to add that when I got back to the maintenance shop, there was a note on the white board for me. It said, “Ron, PETA called — you’ve been warned.” 🙂
So, why didn’t you abort? There is an object on the runway, you are well below V1, and instead of aborting you chose to hit the object; why? You trusted the safety of your airplane to a decision made by a hawk. Why not take the safer option and abort? This brings your whole approach to flying into question.
Your FO had the right idea. Instead of heeding his advice you ignored him and endangered your airplane. This also had the affect of shutting him down. It seems you had too much pride to accept the advice of your FO.
So, you hit the hawk, at what speed? If you were still below V1 you still had the option to abort. But now we find you airborne with possible structural damage. With airframe damage suspected, the procedure is to not change, or attempt to change, the airplanes’ configuration and land. Trying to change configuration might result is a situation that is much worse.
Once airborne it seems you chose a more complicated and potentially dangerous course of action instead of simply returning for a landing. While I understand that the normal procedure is to raise the landing gear, what comes to mind in this case is, “Why?” If you knew the bird hit the main gear, why did you attempt to raise the gear? It’s good the gear didn’t come up; a much worse situation would have any other configuration. What if the gear would have come up, but not down? Or what if only one main had retracted?
In this case you attempted to override the downlock solenoid; again, “Why?” With the gear down and locked, why risk losing the most desirable configuration for the landing gear for any other configuration? Overriding the downlock solenoid, if it had been successful, could just as easily resulted in a partial gear retraction.
I am also dismayed that you tried to troubleshoot the gear problem. Let’s say you pulled a circuit breaker and when you reset it there was just enough electrical energy to briefly power the mechanism that controls the squat switch, but not enough time to complete the signal before it popped again. You might have been left with a different configuration; one gear up and the other down, for example. Leave the troubleshooting for the mechanics when the airplane is on the ground.
Was there an obstacle departure procedure? Did you comply with it? What instructions did you provide your FO other than ‘fly’? At what altitude did you start troubleshooting the gear problem? While it is not stated, the impression is that your attention was focused on the gear problem beginning right after takeoff. It seems to this reader that you focused more on the gear problem than on flying the airplane.
In your article you referred to your FO’s lack of experience, but it was your poor decisions and lack of leadership that got the airplane into this situation, not his lack of experience. He had the right idea to abort the takeoff and then quickly understood that you didn’t want any input. So now we have him flying and looking out for traffic and you on the radios, overriding the solenoid, and checking circuit breakers. What did you hope to accomplish? Why not just turn the airplane around and land?
The Captain’s arrogance was the problem here, not the FO’s lack of experience.
Kevin, thanks for your input. Good questions. Clearly we don’t see eye-to-eye on what happened, but you are certainly entitled to your opinion.
We did not abort because there was insufficient space remaining to do so. For what it’s worth, I did not “choose to hit the object”. To say there was an object on the runway is incomplete. Most objects don’t have the ability to fly. The object in question was a bird. Birds are a fact of life out there, and they always try to fly away. There are hawks all over the place.
I’m certainly no ornithologist, but I’d never seen or hear of this kind of behavior from a bird. It saw us coming and just chose to sit there. I would have put the change of a bird strike at virtually zero.
As for the first officer, he was low time and new to the airplane, that’s just a fact. I don’t believe I “shut him down”. Quite the contrary. Prior to departure at the start of the day, when we did the takeoff briefing, I made it a point to say that if he ever saw me doing anything dumb in the airplane, he should not hesitate to speak up. I told him I’m human and I do make mistakes. FOs have helped me out on many occasions, and I’m thankful for it. He did an excellent job.
As for structural damage, I had no reason to suspect that. As I mentioned, bird strikes are not that uncommon at Los Al, and when you consider the fact that all the ones I’ve heard of were at much higher speeds and resulted in no damage, I wasn’t overly concerned about structural damage. On the other hand, I figured it wouldn’t hurt to have the tower take a look at the airplane as we flew by, either.
Once we were airborne, raising the gear was imperative because if, for example, the left engine were to have chosen that moment to fail, the airplane would not have been able to climb much, if at all, with the gear extended. I’d completed recurrent training recently (we do it in the actual airplane) and had seen that scenario first-hand.
Perhaps I gave the wrong impression about the troubleshooting. It did not take place at low altitude. After rotation, the gear was selected up, etc. It wouldn’t move, so I lowered the gear handle, reminded the FO to focus on just flying, and I simply monitored the aircraft’s condition. Airspeed, climb rate, etc. We added some power (we use a reduced t/o setting normally) to account for the extra drag. I monitored the engine gauges to ensure the ITT remained below limits at the higher setting, and I was dealing with radio communication. Once we were handed off to Socal, they assumed we were headed to a region to work. I advised that we had a gear issue and would like to head south and circle off the coast at a sufficient altitude to allow troubleshooting and talking to company maintenance. It wasn’t until we got out there that I talked with the FO about the best way to divide the work load. He would fly and look for traffic, I’d handle interior tasks like the radios.
Regarding the troubleshooting, I did not pull any circuit breakers. I simply scanned the panels to see if any were blown, because that could have provided a clue as to the cause of the problem. And I didn’t know that the bird had hit the main gear leg until later.
There was no obstacle DP. We were VFR. It’s funny that you say “why didn’t you turn the airplane around and land?”, because that’s what we did. I simply chose not to do anything rapidly, to take my time, and not deal with any non-critical issues until we were away from the field and up at altitude.
I don’t know what you fly, but your idea of “altitude” might differ from mine. We operate below 1000′ AGL for extended periods. The company has operations (in other divisions) which involve flying overwater as low as 50′ AGL in King Airs for extended periods. This is not a passenger operation, it’s a Restricted category airplane doing some unique things.
Anyway, as I said, I do value the questions and comments, even if I don’t agree with them. Thanks for contributing to the discussion.
LOL! Yeah, I heard the controller saying something about a fine for hitting a hawk!
Wonder if that calls for a prop inspection or replacement?
That’s more of a maintenance question. I’m not an A&P, but I left it to those guys and they had the appropriate inspections completed.
Someone else asked that, and I got to thinking about it. The PT-6A engine doesn’t have the same sort of complex parts train that a piston engine does. In fact, the gas generator and power sections of the engine are not even physically connected. There is no crankshaft. Probably the part most likely to be damaged in a prop strike would be the two-stage planetary gear box. But that’s just a guess.
Ron is thinking down the right lines on possible damage to the engine from a sudden stoppage, but this is not a sudden stoppage incident. Pratt is very clear on what procedures are required and recommended for prop strikes and bird strikes. With birds they are most concerned with a bird going through the engine. If parts of the birds are on the first stage compressor blades they recommend a hot section inspection but also give procedures to clean and check the engine if it remains in service. In the case or Ron’s bird, it did not go through the engine, just the prop. If there is a sudden stoppage from hitting a solid object and stopping, or there is major propeller damage from a strike, the power section (including those gears Ron mentioned) is to be overhauled along with other general inspection items. Minor prop damage from a strike is defined as delamination (for composite blades), indentation, slight bending of tips, etc.) and only requires recurring checks for metal contamination in the oil. Since there was no damage to the prop in this case, none of these precautions are necessary. A few years ago, Lycoming added that if the prop speed decreases due to going through water or high grass, that is considered a prop strike on their engines.
Sorry, but I cannot give you too many brownie points on this incident. I agree mostly with what Kevin said and he brought up some very good points & questions. I think this is a great opportunity to learn from this event and develop some SOP.
PPPPPP: Proper Planning Prevents Piss Poor Performance.
See and Avoid: You have not really given us enough information on your airspeed, distance, weather conditions, pavement conditions, length of field … so we do not know rather you had enough time to stop. And since you were ‘VFR’ I assume you did not calculate Accelerated Stop Distance before you put the petal to the metal. There should always be plan ‘A’ and ‘B’ before your toes leave the brakes and it doesn’t sound like you went down that road. Especially if this is an airport that you regularly operate out of, there should be a ‘visual’ go/no go decision point that takes into account max weight, worse case condition.
Land: You had an airport that had a Control Tower. Why would you leave that airspace to be handed off to another controller? I don’t believe your explanation about needing altitude out in your playground, yada, yada. At 1000′ agl, you have enough altitude to fly a decent, safe pattern and land the aircraft. Why take the precious time to dicker around? And your attempt in explaining ‘why’ you needed to get the gear up ‘if’ the other engine were to fail is just a bunch to BS. You did not have an engine failure, you had a gear failure in the down position. The King Air C-90 can climb just fine with it down and locked, even at gross weight! You will still get, at worse, 400’/m climb, which can fly you out of just about any situation. I know you were not thinking of ‘what if my engine fails’ during this. You were thinking ‘how do I get my gear up and continue on?’
Reflect: One of the best classroom learning opportunities is being able to reflect on a past experience and admitting how ‘I’ could have done better, handled things more effectively, made better use of my precious time. ‘Hanger Flying’ is what we need to more of. We learn much from listening to other pilot’s experience and file it away for a rainy day.
Decision Time: I am not sure where you went for your annual training, but you did not learn those techniques at Flight Safety! When you KNOW you have hit an object, in this case a large bird (hawk), you KNOW it hit your landing gear, you KNOW it is large enough to case damage, you KNOW that you now came out of normal operations into abnormal procedures … you DON’T mess with the configuration of the aircraft when it is in the perfect configuration for the most important part of your flying – the landing. You need to throw your planned mission out the window, make your boss late, upset the apple cart, and limp on home with a white flag. At best, you can land, make an evaluation of the condition of your aircraft, clean off the bird shit, and then restart your days plans a little late. Leave the fixing to the mechanics.
This was not a good example to set for your FO or Co-Pilot. Yeah, you disregarded her/his advice and placed your safety at risk. You had a really bad idea of overriding the downlock solenoid system. You need to play the ‘what if’ game and see the flip side of the coin.
Doing a fly-by was good and calling out the emergency equipment. Not sure why you decided that was necessary after flying around your playground for a while … you had 3 green, your engines were humming perfectly, the tower reported gear looked down, I am sure you pulled your power lever back to check for any gear horn to double check gear down … you were VFR, no passengers, FAR Part 91. Calling out the calvery is never a bad thing. I am just wondering what, after flying around with your Co-Pilot, made you decide to roll the equipment?
Learn: Have you sat down with your Chief Pilot and talked about this incident? You got lucky! Very lucky! You could have made this situation into a ‘real’ emergency. This is a great opportunity to learn from your mistake(s) and build your decision making skills. Even though you may have x amount of hours under your belt, that doesn’t mean that you have been given the opportunity to make all the decision, especially during abnormal situations.
You are still green and growing. We want you to grow old with some rust under that belt.
That’s quite all right, Sher — I’m not looking for brownie points. My goal was simply to share my experience.
The aircraft in question is not a C-90, it’s a non-pressurized military variant of the King Air which has smaller engines (PT-6A-20) called a U-21A.
We use reduced power settings for standard takeoffs out of this airport. This makes it hard to come up with a precise number for accel-stop, but it isn’t normally an issue. One of my tasks after the gear wouldn’t come up was to assess the ITTs, power setting, climb rate, and make the appropriate adjustment.
I believe the primary issue you and Kevin have with my performance is that I did not abort the takeoff. Fair enough. Part of our takeoff briefing is that the Pilot Flying will abort the takeoff for an engine failure or abnormality prior to 95 knots.
What is not included in that briefing is that the FO was very new, had very little training on the aircraft, and that I made the decision after the bird hit the plane that the engines were operating normally and it was safer to take off than to a) have him abort, b) take control myself and abort, or c) try and talk him through an abort.
What is also not included in that briefing is an exact definition of “abnormality”. An engine abnormality? Fine, anything I don’t like on the gauges and I’m aborting. But it’s impossible to take into account every possible scenario. What if there’s a bird on the runway? What if it’s near the runway? What if it’s flying over the runway? What if…
Well some of those decisions get made while you’re hurtling down the runway. Add in a brand new guy in the right seat who’s at the controls, and some surprise that the bird did not at least try to move out of the way (as I mentioned, I had never seen or heard of that behavior before) and things become a little less clear.
I’m sure it’s very clear to someone sitting in a chair at a computer, but as you know, in the cockpit, it’s not always like that.
The company I fly for is the largest operator of King Airs in the world, as far as I know. We do all our training, recurrent and otherwise, in the actual airplane. That may change in the future, but that’s the way it has been done up to now. There are advantages and disadvantages to this approach, of course, but one of the negatives is that first officers don’t have nearly as much training in the aircraft before they start as they might if sim training were utilized.
On the other hand, this is a single-pilot aircraft, so we can (and do) fly them with only one pilot at times.
What mystifies me most about your comment is this “land NOW” mentality. I don’t get it. Pilots frequently make things worse by rushing around. I see this constantly as a CFI. While there are certainly times when immediate action is called for (engine failure, fire), have you ever heard of the “wind the clock” concept?
In this case, the gear won’t go up, but the plane is otherwise operating fine. Just keep the speed below Vle and leave it alone for a minute. The thinking was never “how can I get the gear up and continue on?”. It was “let’s focus on getting the aircraft safely to a place where this can be analyzed”.
The thing that came to mind were all the accidents that have happened while the flight crew was distracted by something completely superfluous.
No advice was ignored. The FO asked a question, he didn’t make a recommendation.
I do agree with you on one point: playing the what-if game and looking at one’s performance after the fact is not a bad idea. And when I look back on it, I feel I used the resources at my disposal — that includes the FO, controllers, company maintenance, airport equipment, and so on — as well as could be expected.
We are all green and growing. One of the things I love about aviation is that it’s never boring. Every flight is different, and while most of them are not as exciting as this one, each offers the opportunity to learn something.
I have to add my two cents to counter Kevin and Sher saying “you did that wrong” from the comfort of their computer.
Sounds like you had an interesting day and you gained experience.
Part of being a good pilot is rapidly adapting to what’s being thrown at us. In the grand scheme of things a hawk on the runway vs a U21 is fairly minor. I think the most dangerous part of your day was probably using the 405 to get to/from work.
Maybe you should have aborted, sure. But the only people truly qualified to critique your decisions closely would be your FO and and any other first hand observers.
Ron, you’ll always be second-guessed when you publish these sorts of accounts. I deal with that on message boards from time to time.
I hope you don’t take the following as direct criticism of your actions — just my personal reaction to the tale you recounted on your site. Also note that I only do so in a public forum because you have invited comment on the matter. If this were a private incident (and maybe it should have been left that way) I’d just keep my mouth shut. You are a professional and it’s your judgement, not anyone else’s, that matters. It was your call, and you did as you saw fit. I respect that completely.
My armchair weigh-in based on the not-so-detailed account (airspeed, length of runway, etc. are omitted, not that the lack of those details really detracted from your story) is that an abort would have been more appropriate. You were flying a light turboprop, you saw the hazard, you had time to stop, and thus you could have taken the flight controls and come to a stop, new FO or no. Birds do generally get out of the way, but “big” birds are a bit of a different story — more mass to get moving, and in my experience, more unpredictable.
The second comment I have is that, as an industry, I think we’ve generally learned that any sort of collision that occurs on the runway, theoretically at or above V1 such that we take the emergency to the air, should predicate that the crew make minimum configuration changes, if possible. In particular, choosing to attempt to retract the gear after striking the bird seems like a very odd choice to me. I’m reminded of a video I watched in Hawker recurrent once in which a tire blew out on takeoff — above V1 — and after rotation the crew retracted the gear. The tire was in the process of coming apart as it spun down from 130 knot speeds in the wheel wells and it did a great deal of damage in the process. The flying rubber severed several critical hydraulic lines. The net result was that the crew was unable to deploy flaps or gear after that, and was forced land gear up on the runway. Thankfully, everyone survived with no injuries, but the airplane caught on fire briefly from the heat of the friction on the belly and was nearly destroyed by rescue efforts (fire retardent foam spray, etc.)
If the airplane gets bigger — jet, etc. — maybe the decision process changes a bit. I certainly wouldn’t initiate a high-speed abort in a jet due to a bird sitting on the runway. However, in my King Air experience, the airplane handles more or less like a big piston twin. Not too hard to speed up or slow down. Been awhile since I’ve flown one, though.
Glad everything worked out okay!
Thanks for the notes. I like to hear about as many scenarios as possible. Every bit of knowledge is helpful when the next eventuality presents itself, you know?
I elected to retract the gear because the King Air variant we fly has small engines (the -20 variant), and in my experience, at our typical departure weight, with the drag of the landing gear the airplane is not going to be a stellar performer on one engine. I know this because we do all our training in the actual airplane — no simulators — and I’ve seen that situation in training. The odds of an engine failure after takeoff? Minimal, of course. But everything we do is predicated on being ready for that moment should it happen.
If that is something which should have been discounted after that takeoff, it was not covered by our training.
Ron, thanks for your courteous reply. I appreciate having a professional dialog about this.
I understand your rationale for why you felt it was important to clean up the airplane. But I think your urge to do so was a holdover from your piston flying experience. The chance of a ‘stacked’ failure (multiple, independent failures occurring simultaneously or in short intervals) is exceedingly low; almost nonexistent.
I’ve never had a turbojet or turbine engine fail on me, ever. I don’t personally know anyone who has — and most of my friends work in this business. We all know that, thankfully, failures of these wonderfully reliable engines are so rare that we are likely to complete our careers without dealing with one.
In short, I don’t think there’s any published or loosely-organized ‘groupthink’ on this subject that would ever support forcing the gear up after striking an object on the runway. Choosing to retract at all would generally be discouraged unless you’re IMC out of Aspen, in which case you’ll need the climb performance. But only an insane pilot would attempt that in a King Air (the only aircraft which can safely do it in the corporate world are Falcons and G-IVs and up). Even my beloved Hawker can’t come close to meeting the the required climb gradient with one engine inoperative and it’s blowing out almost 5,000 lbs. of thrust per side. As a result, we’re VFR-only into Aspen — as part 91 operators, it’s by choice.
Regarding gear override scenarios, they’re generally not ‘practiced’ in the sim or other training environments. It only takes a brief discussion to understand why overriding a set of gear that are reluctant to get sucked into the wells is a very bad idea. In short, there’s a reason why they don’t want to come up; most of them are bad. The _only_ reason you’re granted the power to override that is because the manufacturer wants you to have an option to clean up the airplane in the event you need all the climb performance you can get. It’s an option of last resort.
Leaving aside the discussion of whether it was better to abort or continue: if you strike an object on the runway, and you’re confident your landing gear struck the object (which it more or less had to unless the bird was the size of an ostrich), the appropriate action is leave the airplane configured in the takeoff configuration (flaps T/O, gear down), circle back to the runway and land immediately, assuming you have the necessary runway length to support your landing weight. Choosing to continue the flight is a difficult decision to support. Imagine that, due to the strike, perhaps you began leaking hydraulic fluid or brake fluid and in the course of your flight to your destination. Again, a minor incident turns into, potentially, a full-blown emergency.
Thanks again for having an open discussion on this topic!
I just noticed you attempted to use the downlock override. I didn’t catch that the first time.
Unfortunately, that’s simply a bad deal, my man. I wish there was a way to sugar coat it, but your decision to do that, when you did it, effectively took a very minor incident and ratcheted the possible outcome up to full-blown emergency. You and your FO were quite fortunate that the cause of the malfunction was nothing more than a bent WOW switch. I can’t even begin to list all the reasons why this was a really, really bad idea, but I suggest you bring it up with your FSI gurus or a trusted friend/member within your company.
The only time you should even _consider_ using the downlock override is if you feel you absolutely require the climb performance you’ll enjoy with the gear in the wells. And when I say ‘absolutely require’, I mean it. Very last option on a very bad day.
This is a great learning opportunity!
Downlock override scenarios were not covered in our training. We learn what it is and how it works, but the kind of situation I encountered was not covered.