Dip stick malfunction
 

I recently was hired to fly jumpers in a place that's sunny all year. Flying a lot of hours and planning to stay here for a few months. So first week on the job this happens:

I dip my tanks before the last load of the day and I have about 10 gallons in the right tank (plus 10 in the left that we only use as a reserve) which is plenty to turn a load to full altitude in this particular airplane. I had been averaging about a 6-7 gallon burn per load before this but it was the first time i had taken off with under 15 gallons in the right tank. So I start up, taxi, take off, then at about 500 ft AGL I hear for the first time what it sounds like to run out of gas. I was able to flip the aux fuel pump and switch tanks before it completely quit but it freaked out all the skydivers. I finished the load on the left tank.

When the owner found out he was not pleased... he fired me on the spot. Before leaving, even though I was no longer an employee at that point I went to re fuel the plane. Just for the hell of it I dipped the right dry tank... it was bone dry, and so was the left tank. Apparently I was only seconds away from dead sticking it in. I couldn't believe it, I knew there was no way I could have burned up that much gas, so with the tanks dry I checked the wooden dip stick I had been using the last two weeks against the fuel counter on the pump. At 10 gallons on the fuel counter I checked the dipstick... dipstick read close to 20 gallons. Turns out the dipstick was way off. The owner was the one who gave me this dipstick and told me it was for this airplane. When I showed him the mismarkings he re-hired me. Moral of the story is don't trust anyone else's dipstick. Well, you can but I never will again.

Sounds like a nice lesson learned.

A homemade wooden dipstick is certainly not the method I would trust my certificate or life with.

Two dipstick malfunctions - the mechanical one and the owner (who fired you "on the spot"). Three if you count his calibration skills. I'm glad you re-fueled the airplane when you didn't have to.

You saved the owner's ass too (figuratively), not to mention possibly a pilot and jumpers; eventually somebody would have run out of fuel.

Hang in there - but be careful, though. This sounds like an all too typical jump operation. A violation or accident will put a dent in your career hopes as well as possibly your body. :)

Well, I used one on light helicopters quite a bit - but I calibrated it myself. :)

Once they're accurately calibrated, the biggest danger is dropping the damned thing into the tank. The stick needs to be really long or have an oversized tennis ball attached.

So you appeared to run through 10 gallons in the first minute or two, then continued a flight on what you thought was the same amount of fuel in the other tank? I don't know that I would be calling someone else a dipstick.

Still not worse than my diver-driving experience... I won't go into it here but it was a serious eye-opening experience. "Engine failures, runaway props, and dead-sticks oh my".

I was only calling the dipstick a dipstick, but anyway you're right, I should have landed the plane right after that. The reason I didn't was I thought right away that I must have screwed up somehow... glanced at the 5 gallon mark and thought it was the 10, or thought I flew one less load than I actually did or something like that (my immediate assumption was pilot error)... the possibility that my dipstick was off did not occur to me so I continued on thinking I did have 10 gallons in the other tank. If I had known there was in reality much less than that there is no way I would have kept going. I also thought if I just finished the flight as usual then I could come back, fuel up and the owner would never find out where as if I went back to land right after take off than it would have been obvious something went wrong. That didn't matter since one of the jumpers in the plane brought it up later anyway.

All I can say is at least you didn't experience a "wardrobe malfunction.". :D

I always topped off after a certain number of runs was performed, and used the number of runs to determine how much fuel (runs) were left. Start with full fuel, do the set number of runs, top it off. Fool-proof system and you can keep track of the number of hops using the OBS dial on a typical VOR head. Start at 0 (360), 1 run is 10 degrees, 2 runs are 20 degrees, etc. There is no excuse for a fuel starvation event. You do not need fuel gages and should not depend on them. I had one freeze at a half tank one time, even bobbing a little bit. The tank was bone dry.

Glad you are ok. Be rather anal about safety in this job, always bear in mind the drop zone is about making money and YOU are about safety. They will screw you in a heartbeat and think nothing of it, seen it many times. Take care of your tickets, just say no if safety is in doubt.

Another good tip is, on a sheet of paper work out your fuel load in detail.

x gal reserve
x gals per 10k run
x gal capacity
x gal unusable
x gal per 5k run

Keep this sheet in the plane and look at it at the start of each day to remind yourself what the game plan is.

The only jump school I went to traded fuel for pax (C182). Is this common? One of the jump pilots said you had to be careful descending (steep turns) as you may unport the fuel flow.

I can't say how common partial fuel loading in order to increase pax load is nowadays in the industry, but it is a great way to set up a fuel starvation event.

If I were being pushed to do partial fuel loads to add a couple more pax, I would give the DZ two options, neither of which they are going to like-

1. Provide a calibrated fuel hock (dipper) certified in writing by a mechanic with gallon increments. You may be able to buy one already made somewhere. The mechanic will obviously charge to make one, because he will have to drain out all the fuel and refuel the airplane to calibrate the stick, which is a big chore.

2. De-fuel as necessary pound for pound in order to accommodate each added passenger over a normal pax load starting with a topped off fuel load. This is a bigger pain than getting a calibrated dipper made. No DZ in their right mind will go for it, but you should offer this option to show them you are serious about not having a fuel starvation event on your watch.

Using the fuel gauges or any other method is a gamble against the luck of the pilot. I discourage any new DZ pilot to gamble with the fuel load using home made dippers, fuel gauges, and guesswork. You'll really regret it if you have a fuel starvation event. It will haunt you for life as a pilot.

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On the steep spiral question, you absolutely can unport the fuel taps doing steep spirals on the descent. You need to keep the fuel loads balanced left to right by alternating direction of turn on the hops. Do not get past your allowable load/ hop count, and I discourage playing with the fuel selector to balance tanks because you will forget to select it to "both" sooner or later. The gauges are not trustworthy on old 182s either, so do not use that to do it.

Unfortunately we usually have a classic time-building situation; "if you won't do this, sonny, there are ten others waiting in line behind you".

It was a common practice when I was diver-driving. We only filled up one side of the ole 182 about half way and left the other side dry. I never noticed any serious performance issues but you damn sure had to keep track of your fuel burn. Usually re-fill after about 3 loads.

How is this happening if flight is coordinated?

I've flown me lots of C182, and something I've noticed is that certain older ones are notorious for not burning out of tanks equally during all flight maneuvers and especially S&L when on "both", even leading to fuel starvation issues as at least one was not taking fuel out of one side reliably, even when selected, but other than that, how would a steep spiral cause one side to be uncovered, unless you are yawing the whole way in a slip?, which wouldn't be the best way to drop altitude as far as stresses on the aircraft in any case.

Who said it is coordinated. I used to do a "knife edge" slip all the way down, purposefully uncoordinated. Let me see if I can find the pictures of that. See my post no. 4 on the thread below for an explanation of the knife edge steep spiral. If done correctly it is the fastest way down and was/is used for decades by various drop zones. Structural issues arise when pilot technique is shoddy, and I would not recommend doing this maneuver without a g meter even with a decent pilot. You want to push 3 g's and no more, but poor pilot technique can lead to over g'ing the airplane.

Knife edge thread

I'd trust it as long as it was homemade by me :D

Well, you can do a steep spiral and come down very fast without being uncoordinated at 60 degrees of bank, not to mention that I think most people assume coordinated flight unless specified otherwise. The FAA recently put out some stuff on using more than one control surface to input full deflections and Va, although I'd assume this is done slow enough where it's no problem. It's more than just pilot technique, it's knowledge and sometimes misunderstandings as to what the aircraft was really rated/intended for. I just don't see any major reason to do this uncoordinated. I've done plenty of high bank angle "knife edge" slips, but if I was taking people up flight after flight, I'd think equal fuel is a more important consideration.

While this knife edge steep spiral is very hard on a 182 if not done correctly, many limit of the performance envelope maneuvers are done for many reasons in training and operations, and it is not a valid argument in itself that simply because it is risky we do not do it. Where the advantages outweigh the disadvantages, like in student training, air shows, and in skydiving ops we do high risk maneuvers. And do them carefully. Like any high risk action, we manage the risk carefully to reduce it and control it.

Knife edge steep spiral is only done in smooth air. You need to knock it off and quickly slow to Va if not, and in this case you would never speed past Va if you knew there was rough air around. We are talking about a drop zone where you fly the same profile 20-30 times a day. You know what the winds are.

However, the fastest way down in this airplane is this maneuver, which explains why it is used. If you do not believe me then call some drop zone who use it and ask why. They do not do other types of rapid descents because they simply take longer and time is money. It's a question of rate of wasted of potential energy in physical terms. The uncoordinated steep turn wastes a large amount of energy height.

Like said, I have done thousands of turns of this maneuver, never a single fuel issue. This is due to my careful risk management- I carry enough fuel not to unport anything.

I actually agree with this statement. Drop zones will not allow their pilots to do serious steep turns or other edge of flight envelope tasks if they cannot train them well enough to do it safely. If there is a high pilot turnover and/or poor pilot training they will stick to easier maneuvers. That's why we see the other kinds of descents being used.

I know technically its rated for it but 3 g descents all day every day would sure be rough on the air frame after a while wouldn't it? In most cases these 182's and other piston airplanes at most drop zones are half a century old. I'd say it's more cost effective in the long run to save the frame, gyros etc. and come down nice and easy. I'm getting 2000-25000 ft per minute descent with a wings level nose down attitude.

A correctly done steep spiral knife edge maneuver in a 182 can push 5,000 fpm in the descent. Maybe that sheds some light on why it is so useful. I have obtained that descent rate many times, two minutes from door shut to touchdown. Like I said several times it takes some skill, and it is not something you want newbies doing. On the other hand, you get so much practice at a busy drop zone there is no reason anyone cannot work it up over a period of days or weeks which is what I did.

As for loading the wings to 3 g's, it works fine all day every day. In material science there is something called the elastic limit of a material, which is the stress limit where complete recovery of the strength of the material occurs without permanent damage. Drop zone experience has it that 182s can go to the mid +3g range for decades without exceeding this limit. Above that to the certified limit of +3.58 works fine too, but you have no margin for error going that high in normal operations. Beyond that up to about 4.5 you will not fold a wing right away, but you will start popping rivets on top of the wing. If you do that enough times you will pop a lot of rivets, and beyond that you may fold a wing. Go right to 5+ and you may fold a wing without warning. There is a company that has tested 182 wings to this level (and was not Cessna). I'll see if I can dig up that reference.

Another relevant question is, what is the life cycle load limit- it does decrease with time, but it is such a high number that no drop zone with any vintage 182 has ever found any change (reduction in limit) as far as I know. And I have asked if there are any. of the data I have examined, there is no evidence that load limits have come down within 50 years of normal operations over which data was collected.

Sorry, there are just too many red flags here. Usually the DZ pilots are low time and not the most experienced (and yes, you can "learn fast", but that doesn't mean they learn the full envelope as if you'd been flying for thousands of hours). There's the issue of if you hit a little bump and get too many Gs, the issue of multiple excessive control forces (related to above, depends on if you understand them), and the issue of fuel imbalance due to flying wildly uncoordinated. It seems like the context here is lost. We're not talking about an aerobatic or high time stick-n-rudder pilot in this thread according to the information so far, and I think we have a responsibility as high time pilots to not make flying more dangerous than it needs to be. To say it again, I agree that a high bank angle slip will come down like you describe. I've done it and yep, it works, but in relation to this thread and the fuel issue, it just doesn't seem appropriate. Even if you're a great pilot, it starts to add up risk factors pretty fast. I would want the DZ pilots to exercise some control and maneuvering that is not commonly done in other piloting areas. At 110 or so and 60 degrees of bank, a 182 drops like a rock (especially with the gear down). I seem to remember that 3 turns took 4+K without being super agressive.

Well just repeating my earlier points.. but agreed, high-g maneuvers are not for novices. Don't forget however the average drop zone pilot does anywhere from one to four dozen of the exact same profile in a given day and indeed can get very good at the job. You may see red flags, but with that much practice you could probably swallow swords and juggle burning tennis balls. It's 12 straight hours of practice many days. Same for entering full beta in a King Air on the decent, another "red flag" technique that is done all the time. One can develop a very fine sense of what is safe and what isn't with enough repetition of just about anything, and decades of accumulated experience is also there to draw on.

True enough.