jsfBoat

I'm finishing my commercial/instrument, and am bitting at the bit to start working as a pilot. I'm going to start working on my CFI. I am thinking of flying jumpers at Crosskeys here in NJ while working on my CFI, so I can start making back some of the $$$ i put into my training. What should I know about doing this? Am I wrong for wanting to start working? Thanks, -JSFboat

Ewfflyer

Not wrong for wanting to get paid. Good experience, teach you how to fly a plane @ MGTW 99% of the time. I haven't done it, but I wouldn't mind taking a stab at it one of these days.

Twin Wasp

Not wrong for wanting to make money, remember as PIC you are responsible for what happens. There's no worse feeling than coming back and finding an ambulance and group of people in the middle of the drop zone. Ask to see the packing slip on a couple of reserve chutes every once in a while. If no one wants to show you, I'd stay away. Of course, you've got to learn what the time limit is, used to be 90 or 120 days depending on the chute, they may have up'ed it some.

Rama

Flying jumpers is really fun some days and blows on others. Be familiar with far 105-you are responsible for everything. Be careful about marginal days, jumpers punching through clouds is a no no and can get the pilot violated. Also the zero feet to 10,000 feet and back down is hard on piston engines-guard against shock cooling. All in all good experience. Make sure your operator is not shady-as posted the reserves must be repacked every 120 days, if they are not doing this you don't want to be involved with them

rickair7777

Make sure that YOU know how to jump, and wear a chute. And pack it yourself.

WmuGrad07

I have flown for a dropzone before and it's pretty cool. The place I went the DZ makes sure that everyone who jumps has a current pack job, and are sober. A few of the other pilots who worked there checked me out, we'd go up and I'd show them I can fly and then they would jump out. It was fun, kinda weird getting checked out with them jumping out of the plane.

The DZ I worked for was very particular about how you operated their plane. I would take just as long to get down as I did to get up because they didn't want to damage the engine. Their procedure had you leave power at 15" mp and 2100 rpm on the decent. Start the decent at 120 mph then up to 140 provided you're not getting a CHT drop of more than 2* per 5 seconds or something along those lines.

You've just got to hang out at the DZ see how things work. Talk with the owners and make sure your plane is legal. Talk with the other pilots too.

meeko031

I heard they only put enough gas for the climb and idle the plane down to land. I guess it makes sense to put only enough gas for the climb to allow more jumpers in the plane. I guess you can perfect your 180 accuracy landing!

Kdub

There is no such thing as shock cooling. Its an OWT that began in the 70's decades after the 1000+ HP aircraft did power off dive bombing runs and power off 'overhead' approaches, over and over again - never having problems with this fictitious condition. Why does this myth persist? There is no evidence for it.

rickair7777

The metallurgy is pretty straight-forward. Doing it occasionally is not likely to have a big effect, but doing it all the time will definately have an impact. You are effectively "shock cooling" an engine everytime you reduce power, but the magnitude and speed of the power reduction determines the metalurgical effect. The largest impact is on the top-end.

Trainers are lucky to reach TBO, and will often need a top-end prior to that.

A cruiser can easily go beyond TBO.

The OEM's didn't give us cowl flaps just for fun.

Rama

Shock Cooling
An aircraft engine spends much more time developing near full power than does an automobile engine. The wear on an aircraft engine is made shorter through negligent operation, non-operation, corrosion, and the shocking effect of hot and cold cycles. Shock heating cycles the metals of an engine just as much as does shock cooling.

Heat shock can be reduced by starting the engine at idle leaning to reduce oil dilution by excess fuel and then allowing the oil pressure to rise before aggressive leaning. The start of an engine its most damaging cycle of operation. A sudden reduction of engine power after a period of increased power causes a rapid reduction of engine heat being generated. This heat change inside the cylinders is reflected in the heat released by the cooling fins and increased cooling airflow through the engine plenum. The result is called shock cooling. Lycoming says that shock cooling results in worn piston grooves, broken rings, warped exhaust valves, bent pushrods, and plug fouling. Recommended cooling rate is no greater than 50-degrees per minute.

Shock cooling occurs when the pilot reduces power to off and goes into a descent. The effect of this is to suddenly reduce the internal heat of the engine and greatly increasing the cooling effect of the air over the cooling fins of the engine. This may be a damaging shock to the bimetallic cylinder blocks. The principal effects of shock cooling are cylinder-head cracking, valve seat to valve seat, plug to plug. Anywhere inside the engine where tool marks, sharp edges and other stress points are liable to damage. Any engine operation that makes it possible for the valve guide to shrink faster than the valve will cause sticking. Valves stick open and the pushrod bends. A raised valve hits the piston dome, breaks and is redistributed throughout the engine and turbo if any. This situation often occurs when poor navigational planning causes the pilot to arrive over his destination at several thousand feet too high. Never make descents that will shock cool the engine. It may not fail on your but it will on some pilot down the road.

To prevent all these bad things from happening to your engine keep some power on the engine, re-lean during altitude changes to keep the EGT near cruise values. If you have CHT on all cylinders maintain a controlled (slow) decrease rate. Use of factory CHT on one cylinder is a very poor second. Regardless, always reduce power in increments so that engine temperature changes will be gradual. Retard the throttle during descents. Do not enter a descent that will both give a throttle reduction and an increase in engine cooling air. Use landing gear and flaps to keep the speed down. control the thermal changes of the engine to limit temperature and cooling related damage.