There’s no understating the importance of being able to safely and efficiently get rid of a load should the need arise. It’s something every ag pilot must train for on a regular basis. Knowing the proper time and technique to jettison a load is just as important as knowing when to make a go-around on landing. In fact, dumping a load is often part and parcel to any emergency procedure. Waiting until you need a skill, is not the time to try to gain that skill.
Young or old, experienced, or a boot pilot, every pilot needs to be well versed in the dynamics of the rapidly shifting CG envelope that can occur when jettisoning a load. He also needs to be conscious of when is the right time to do it. Recognizing a failing take-off, for example, is something a guy needs to be ready for and have the decisiveness to hit the dump handle well before the airplane hits the ditch at the end of the runway. There is a brief time just before all your options run out when you have to act without hesitation in order to minimize damage to the airplane and yourself.
Any airplane you fly will have different tendencies. Different make and models fly differently. At the same time, every airplane, even if they came off the assembly line together, has their own personalities. A pilot needs to know his airplane intimately. He needs to know every aspect of how it will fly and react under any circumstance. Especially austere circumstances when the usual becomes unusual and reaction times are measured in heartbeats. Knowing how the airplane will react when jettisoning a load, whether intentionally or inadvertently is something a pilot needs to be familiar with and always ready for. It’s something he needs to practice often. When strapping into a new airplane, a guy ought to take it up and try it out. See how it flies empty and loaded. Familiarize himself with its characteristics in all phases of flight and operation. That includes emergency procedures.
Don’t be hesitant to ask the boss if you can make a practice flight in his airplane. Any operator worth his insurance premium should be willing to let a pilot take a familiarization flight or two before working one of his airplanes. It just makes sense.
Having your dump handle rigged correctly should be added to your preflight checklist. If your dump handle is set too tight, you’re flying with something that will cause more harm than good when you need it the most; possibly aggravating an already bad situation.
Straining to open the dump handle means you won’t be able to control the gate once it pops open. Everything will leave the hopper in a hurry and you’ll find yourself riding an angry bronc when the airplane violently pitches up. If on take-off, the airplane will likely be screaming at full power, but you won’t be able to do anything about it because your left hand will be all the way forward trying to grab the dump handle. Your right arm will be extended to its limit attempting to stuff the stick into the instrument panel to try and get the nose down. Your shoulder straps and seat belt will be doing their best to try to keep you in some sort of proximity to the seat. Hopefully they’ll be snug enough to do so. You’ll be contorted and off center in the cockpit, feet floating off the rudder pedals, scrambling to gather everything back up into the middle.
It’s a bad place to be and could very well lead to those actions becoming your last if you’re not trained and prepared for it.
Dumping a heavy load all at once will make your airplane jump like a gut shot cat. You’d better be ready when it happens. A stall is coming at you at a dead run at that point, so you’d better be able to react quickly and appropriately. It happens damn fast and there ain’t much in the way of mercy from the forces of nature when it does. Being able to control the gate is the absolute key to a successful jettisoning evolution.
Our airplanes often get configured from wet to dry applications and back again. That is when the dump gate gets adjusted the most. It’s also when a pilot needs to pay close attention to how his gate is set. The hopper needs to be checked for leaks of course, but the gate needs to be adjusted correctly so that it doesn’t inadvertently pop open when a little ‘G’ force is added to the load. I’ve had that happen and let me tell you my friend, that will get your attention.
When transitioning from dry to wet applications, the pilot needs to make a conscientious shift from the dump handle to the spray handle. There’s been several pilots who’ve spent all day putting out fertilizer and dumped their first load of spray because muscle memory went to the wrong handle. I’ve known pilots who’ve placed an object on their dump handles as a physical reminder. Tennis balls, gloves, even a squeaky toy. Not a bad idea. Some operators have extra gate sets for their airplanes. One rigged for dry, one for wet that can be swapped out as required. It’s a good system.
Practice makes perfect. If you are uneasy about practicing dumping a load, take time to practice jettisoning a load of different sizes. Start with a hundred gallons and work your way up in quantity, one hundred gallons at a time. Even dumping what we consider a light load causes the airplane to react substantially. We have to remember that fifty gallons is a heck of a lot of weight.
To a professional ag pilot, dumping a load of any size should be a non-event. It should be no more than a required action taken to achieve a desired result. It’s not something taken lightly or without serious consideration, but it shouldn’t be something that causes a hazardous situation. Training and preparation are vital. Most ag airplanes have published parameters in their POHs describing the flight envelope required to safely jettison a load. Read up on them and keep them in mind.
Fly well and Stay safe!