Super Skyvan Performance Specs

[WillScudRun4Food]

Hey all,

I've been flying a short body Caravan (600) for a few months and my drop zone is considering upgrading to a heavier twin...I'm familiar with the Twin Otter, but I have very basic knowledge of the Skyvan and no flying experience on airframe.  The conditions I routinely face are takeoffs from a 2,600 foot strip with small obstacles at either end and 70 foot trees displaced some 1,600 feet from the runway on the departure slope going in one direction.  I'm looking for realistic ideas on the kind of performance offered by a Super Skyvan (-6 powered) in these conditions.  My DZOs have indicated that it should rival Super Otters flying in the same conditions...I'm looking for a more experienced pilot's expertise.

-What kind of gross weights can be flown to safely depart a 2,600' strip?

-What kind of obstacle clearance capability does the Skyvan provide at these gross weights?

-The DiverDriver description of the Skyvan and many other texts cite the airplane as being

Ruggedly built to haul bulky loads out of short unimproved strips

...This may be true, but any "short" strip is only short relative to the size of the aircraft using it.  Does my runway meet the accelerate stop/go requirements of the Skyvan at gross in standard day conditions?

-Any other tips/ideas/points?  Having no experience on airframe yet, I'm looking for real anecdotes on flying the thing.

Thanks in advance.

[Administrator]

I have not checked out in a skyvan but I have some points to make.

Make sure the door is ALWAYS closed for takeoff. 

Just because it climbs as well as an otter doesn't mean it can takeoff like an otter.

At the 2000 record attempts in Ottawa, IL the skyvan pilot forgot to get the props of the start locks.  He applied power and ran off the side of the runway a tad and pulled it back onto the pavement.  Only one engine was really producing power as the blades on one engine would not "bite" (still on start locks).  He did not abort the takeoff.  Got to rotation speed and had nothing.  Made the decision to abort and ran off the end of the runway snapping the nose gear off.  No injuries.  Ottawa's runway is 4,500 feet long.  He may have departed from the intersection which would give him roughly 3,500.  Still much longer than your 2,600.  With 2,600 you better be perfect or you have to abort immediately.

Be aware that Garrett engine can be finiky.  This is how it have been described to me by pilots with lots of time in them.  But they do also nice things about Garrett engines in that power is more readily available since it is direct drive as opposed to PT-6 free turbine.

Hope this helps and I hope others can chime in here.  A pilot with the Pink Skyvan used to frequent the forum quite a bit years ago.  Don't know if he still lurks here.

[outtamymind]

With the Garrett engine..... if you aren't off the start locks and apply TO power you will notice little or no torque and a slightly higher EGT on that engine.... the engine itself is very finicky and prone to getting back onto the start locks even after being taken off.... at least the metro's I flew were like that. I would say that maintenance on aircraft with garretts needs to be a bit better than other airframes because of problems like this.... but that is just my two cents.

[Artweger Phillip]

Well i have ot been on the forum for a long while but i'd like to comment on this one.

it is a technical impossibility to get a TPE331 -2 or -6 as used on Skyvans on the startlocks while engines are running... The prop RPM has to decrease below 30% for teh startlocks to reengage, above this the centrifugal force prevents startlock engageent.

A pilot who doesn`t recognize one engine not of teh startlocks and performing a basically single engine takeoff run can hardly be a comment on a/c performance.. i'm actually amazed one would not recognize having 1 ton of thrust on one side and not on the other side too, as well as having really low torque and enfgine speed pegged at 103%..

Next a Superskyvan per se doesn't exist. The stronger engine only keeps engine temperature lower enabling you to hold max torque at higher OAT and or higher altitude. For all performance calculations tho only standard skyvan performance tables exist.

Performance is very strongly depending on pressure altitude and outside air temperature wind and runway slope of your 2600ft field... at 2000ft elevation and normal temperatures no wind and no slope you will be able to fly a max gross weight takeoff out of that field.

Example Short field Technique Flaps 30 Takeoff @ 20°C OAT and 2000ft elevation with  will give a takeoff distance (ground run and crossing of a 30ft(!) screen hight) at 1900ft distance from start of takeoff roll... the ground run in that example is  1500ft as per teh performance tables in the AFM.

regards

[outtamymind]

Well i have ot been on the forum for a long while but i'd like to comment on this one.

it is a technical impossibility to get a TPE331 -2 or -6 as used on Skyvans on the startlocks while engines are running... The prop RPM has to decrease below 30% for teh startlocks to reengage, above this the centrifugal force prevents startlock engageent.

A pilot who doesn`t recognize one engine not of teh startlocks and performing a basically single engine takeoff run can hardly be a comment on a/c performance.. i'm actually amazed one would not recognize having 1 ton of thrust on one side and not on the other side too, as well as having really low torque and enfgine speed pegged at 103%..

Next a Superskyvan per se doesn't exist. The stronger engine only keeps engine temperature lower enabling you to hold max torque at higher OAT and or higher altitude. For all performance calculations tho only standard skyvan performance tables exist.

Performance is very strongly depending on pressure altitude and outside air temperature wind and runway slope of your 2600ft field... at 2000ft elevation and normal temperatures no wind and no slope you will be able to fly a max gross weight takeoff out of that field.

Example Short field Technique Flaps 30 Takeoff @ 20°C OAT and 2000ft elevation with  will give a takeoff distance (ground run and crossing of a 30ft(!) screen hight) at 1900ft distance from start of takeoff roll... the ground run in that example is  1500ft as per teh performance tables in the AFM.

regards

Ok.... cool beans... so the -2/6 cant be put back on the start locks if the engine is running... the -10 can slip back on if you use  beta on the ground and the speed levers are in the low position. Plus the systems between a Skyvan and Metro might simply be different. Thanks for correcting me!