The Cessna 182 has to be hands down the workhorse of the skydiving community. It has been in production for a long time and has excellent support from Cessna. It can carry a pilot, four jumpers and enough fuel typically for two loads to 10,000 feet, and is a “high-performance” aircraft with the reliable O-470 engine. It is a non-complex aircraft with “spring steel” landing gear. Very early 182s (1956-1958) have very tall landing gear and sit high off the ground with a long nose strut. The tall gear also allows four jumpers to be out on the step with plenty of room under the wing. Later years saw a shorter, more “squat” landing gear and a wider body by four inches.
Weight and Balance
Check your weight and balance carefully for every load even if you hear “that’s how we’ve been doing it for years.” Well, “they” may have been doing it wrong for years. Get the book out and do some sample balance problems. Figure exactly how much useful load you have after you have put yourself and two loads of fuel PLUS reserve fuel of 30 minutes during the day and 45 minutes at night. Remember, it is YOUR certificate that gets affected if something happens.
Seating arrangements can really affect your balance. Usually you have one jumper sitting with his back to dashboard. Make sure his reserve and main pin flaps don’t get caught on anything under the dash. Many DZs have put up back boards from the floor to the panel to prevent this from happening. Also make sure that the area around the fuel selector and flap handle stay clear. Early model 182s have a “parking brake” type of manual flap extension handle. Loose leg straps and handles have found their way around or under these handles and have been snagged.
The next jumper can sit on his knees in between the legs of the front jumper or can sit facing aft. It always makes me chuckle when someone insists on sitting on their knees facing forward and then leans forward for the takeoff roll for the “balance problem.” In an accident this person will flop around inside the cabin as they will have a pretty loose strap tying them down. I prefer people to sit facing aft in between the forward jumper’s legs as this provides the best tight restraint in case of a forced landing or crash.
Another jumper sits back to pilot with his legs stretched straight back to the tail, and the last jumper sits with his back to the back bulkhead facing forward (with his legs in between the the other two aft facing jumpers’ legs). Go and measure the actual “arm” from the zero point on your aircraft (typically the firewall) and then compute their “moment.” Tally up the weights and moments and compute the final center of gravity (CG). I believe you find that the CG is much further forward than you might first think. It surprised a couple of FAA inspectors when I did it for them during a ramp check. They had been sure that I was running over max gross weight and aft CG because I had five people in there when typically with seats you would only have four. For grins, you can compute the CG for four people (pilot plus three) with seats and the CG will probably be further aft than a typical jump setup.
But most importantly, do the math for yourself! Don’t go on just what someone told you would be acceptable. Know for yourself that you are running legally.
Jump Run
Plan to be at altitude at least two miles prior to drop. Power for level flight at that altitude and keep the mixture on the rich side. This will help cool the engine slowly without shock cooling. Your cylinder head temperature (CHT) should be around 300 degrees or thereabouts. I fly jump run at about 75-80 knots with NO CUT! If you power back to idle this will certainly start the shock cooling process and the cylinder heads will shrink on the still hot pistons inside. OUCH!! Typically this power setting will be about 15 inches of manifold pressure and the prop speed at the maximum. Make sure you have good communication as to when the door can be opened. Most in-flight doors have a speed limitation on them of 100 kts. If for some reason you were above that speed and a jumper let loose the door, it could do damage to the hinge and eventually you may have the door leave the aircraft altogether. This would be bad.
During climbout monitor your airspeed. DO NOT GET SLOW!! The more people that climb out on the step, the more airflow is being blocked from going over your elevator. If you stall on jump run, you will have a good chance of a jumper hitting your horizontal stabilizer. It’s an extreme case, but you don’t want to go there.
Be ready for the increased load leaning to the right. Make sure you fly ball centered and aren’t slipping the aircraft. If you feel the aircraft buffeting into a stall, ADD POWER. Try to be smooth with it but just don’t sit there and let the aircraft stall. Remember, it would be bad. Also, you can trade altitude for airspeed. The commercial ticket ride does not include having four fat boys with 20-pound rigs riding in the slip stream hanging off your wing strut. This is a different type of flying.
Be ready to use hard right rudder if you see a premature deployment. This may be your only shot at avoiding structural damage to the horizontal stabilizer and elevator. It has to be an almost instantaneous response.
Descent
After everyone is gone, let’s go down. Using left rudder you can get the door closed and then trim for about 140 kts. with cowl flaps (if installed) closed. Set power at a minimum of 15 inches (bottom of the green arc). As you descend the manifold pressure will rise. Let it rise to about 17″ and then reduce to 15 again. CHT should not drop below 200 degrees (bottom of the green). Realistically, I always had the CHT at 300 degrees or just under during the entire decent. If this is not happening with your aircraft then investigate why. If you are beating the jumpers to the ground you may be pushing the aircraft too hard. Be careful. The small damage you do to the engine on each flight will catch up to you later down the road or may catch up to your buddy who didn’t know what you were doing to the aircraft. Going just a little beyond the rules won’t pop cylinders this flight or maybe not even the next. But it will wear on it over time.
Addition 11/3/2014: These CHT numbers may be a bit dated at this point. Many operators are running different types of engine monitoring equipment and the displayed numbers will not resemble what I have put here. Do not take my numbers in stone. Investigate your own aircraft’s engine manufacturer and numerous articles now available around the internet on proper CHTs in climb, cruise and descent.
General Points of Consideration
added 12-19-2008
Some points about 182s I’d like to add after years of exchanging information about 182s with different operators:
Some of the oldest models of 182 (circa 1958) have very high unusable fuel limitations during manuevering flight which is most of the time while flying skydivers. It can be as high as 5 gallons per tank! Make sure when you calculate your fuel load you account for this higher unusable fuel level. I have seen many accidents where the engine quit and everyone was surprised to learn this limitation. Get into your Pilot Operating Handbook and know your aircraft. I can’t stress it enough.
I have also had conversations with operators who inexplicably had partial or intermitent engine failures on descent. First thing to check obviously was fuel amounts. Next was to check for wrinkled fuel tank bladders in some 182s. When that wasn’t the cause we looked at airbox, carburator and intake manifold. Nothing was found wrong. And the problem persisted. But a good mechanic stayed on the job and it was found that the cross-vent (the one that goes between the two tanks through the headliner) had become blocked. During ascent the pressure would go out of the tanks and then on the subsequent rapid descent a vacuum would be created limiting the fuel flow.