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Skyvan
Just like the Twin Otter, the Shorts Skyvan is a very purpose built aircraft! Ruggedly built to haul bulky loads out of short unimproved strips.
Affectionally called "the shed" by pilots and crew the Skyvan is a strut braced high wing aircraft with a fixed landing gear. It features a 18ft 7in long and 6ft 6in high by 6ft 6in wide cargo hold with an
equal size in-flight opening cargo door.
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OE-FDE The PINK Skyvan rests after a day at
work. Photo by www.pinkskyvan.com
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Most Skyvans are SC7 3 Variant 100 Aircraft with a MTOW of 12.500lbs, other Variants like the 3M sport up to 13.700lbs MTOW.
There is also 2 different versions of Engines on the Skyvan. The original engine is the single shaft Garret TPE 331-2-201A. Some Skydiving Skyvans have the -201A Super or -6 Engines that
feature a larger Compressor which greatly enhance hot-and-high performance of the A/C, as well as climb rate.
The Weight and stability of the A/C, as well as the incredible low speed performance (Stallspeed@8500lbs and Flaps 50 is as low as
49Kts) make it a pretty easy to fly aircraft. However to fly the Skyvan efficiently there are a few things that differ from other skydiving aircraft.
Without cargo the Skyvans C of G is very far forward! This means the less jumpers that are on the plane the closer to the door you
want them, to ensure that the C/G is not too far forward and thus your climb performance suffers. In a no seats/sidewallbench configuration, seating 3 abreast looking aft you will not be able to
physically put too many people too far aft (unless they sit on top of eachother) so there is no need to worry exceeding the aft C/G limit. The Step into the cockpit is a favorit seat for a lot of
skydivers, but remember it's a two man cockpit and you really don't want anybody sitting there. Aside from the lack of a seatbelt, a person sitting there can reduce your rate of climb by 200ft/min!
The Engines have very nice handling qualities being single shaft. But you have to take extra caution not to exceed EGT limits on
takeoff due to the lag in indication. As a rule of thumb above 15°C OAT you will most likely be limited by EGT and not MAX Torque.
Climb
Speed Speed Speed! Like any big aircraft it takes a while for a Skyvan to accelerate from unstick speed which should be never
lower than Vmca, to take-off safety speed. Depending on Weight and flap setting on departure KNOW YOUR SPEEDS ! We have made a placard that fits into the recess of the instrument panel just
forward of the control collumn that contains all the necessary speeds at 8, 10 and 12.500lbs. At MTOW your performance margins are pretty slim when you loose an engine.
Another area where pilots mess up is that they climb at the wrong airspeed for Best Rate Vy. Not too fast and not too slow.
Coordinated flying is extremely important as the huge sidearea of the "Shed" will produce tremendous ammounts of drag with any slip or skid. Climb performance is better if you keep your bank angles
low, apart from making it a more comfortable ride for your passengers. If you can stay away from built up areas as much as possible, because a Skyvan with 100% RPM produces quite some noise.
Jump Run
Depending on Weight the jump run can be flown at an indicated airspeed of 95-75knots. Normally i fly at 85Kts clean. Slower than
that i usually go to Flaps 18. I also prefer Flaps 18 for jumpruns that involve any kind of manouvering, like a circling jumprun.
Also if You arrive a bit low at your spot, you can get some 500ft
extra by popping flaps to Takeoff, but be carefull, as you will have the jumpers standing up in the airplane and sudden decceleration can easily topple them.
Now that the jumpers are standing up in the airplane you need to worry again about your C/G! Maximum number of people in the door
should be 11 Jumpers! This number is already pretty uncomfortable as you will be very close to the forward stop of control collumn travel. Generally you can say as many people as in the door should
be behind the mid cabin for ballance reason. This requires a bit of briefing for larger RW exits. To get anything bigger than a 10 way out of the door at once you need the ones further back in the
plane start towards teh door at SET, so that they all leave the plane at GO, without making the plane uncontrollable.
And that is what happens if you put more than 11 poeple into the door, you will hit the forward stop on the elevator, with the
airplane continuing to pitch up. Eventually the jumpers will exit/fall out but by that time you're most likely fully stalled and part of their formation.
Jump run power settings are typically around 30 lbs. Tq. I usually reduce RPM to 90% thus cutting drag when you gradually reduce
Turque when the plane gets lighter as well as for noise abatement.
If you do any manouvering during your jumprun be gentle on the controls and remember that coordination is esential! 25° bank does
not bother when you are standing up in the back of a skyvan, a skid makes you want to have handles to keep upright.
Descent
Descend at Flight Idle, 90% RPM and Vmo of 173Kts. you will find yourselfe in a 25° Nose down attitude with 5500fpm rate of
descend with your elevator trim in neutral (That's how heavy that nose is). You can get even better rate of descend with a higher RPM setting but anything more than 90% will make folks on the
ground go berserk (at least in Europe), i even go to as low as 85% RPM which is the minimum in flight setting.
Be carefull tho when you come in for landing with reduced RPM,
you will have less drag so you need to plan a bit further ahead to get your speed down for flaps extension. Also coming in light for landing 90% RPM is quite sufficient for a go around, at 85% you will
not have enough power to go around and when you increase RPM you will momentarily increase drag quite a bit, so take care if you reconfigure.
If you think you are way too high for landing just go full flaps, 80Kts and 100%RPM. The result is spectacular but beware you will
need most likely power to arrest descend rate and the A/C will not flare with 100%RPM but rather you only rotate to touch down attitude.
The Flaps of the Skyvan are a bit of a weak spot, so i would not recomend depolying flaps at the limiting speeds but rather use slower speeds.
Lastly, PROCEDURES, PROCEDURES, PROCEDURES!! Know your procedures for all emergencies and malfunctions.
Our Operation is based on a "flow" where you basically start at the ceiling on startup and end up having all systems switched on and
ready for engine start. After shutdown go the same way back. The A/C is extremely simple to operate and during normal flight ops you will only need the column, power levers, rpm levers, flap lever and
the nose wheel tiller. However any abnormals should be handled with a checklist and the essential tasks of Emergency and Abnormal Checklist have to be memorized! Learn your airplanes
systems with special attention to the electrical system. It's the most complicated and failure prone system on the Skyvan but also when you understand its operation it gives you incredible redundancy.
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