Does your jump pilot put down/extend flaps on jumprun?

[dorkitup 1]

Hello All,
So the other month I was visiting a DZ that flies a super otter. At this dz, the pilot refused to extend/put down the flaps on jump run. I know there were several requests from jumpers to put the flaps down for jump run, but the pilot still refused. I didn't talk to the pilot myself or ask why he refused, as many people said he was really moody/grumpy and not to bother him. Obviously, with the increased air speed, climbing out was a little more challenging than usual for me when I jumped, but not that big a deal.

I've been jumping for 10+ years and have never had a jump pilot NOT put the flaps down on jump run. I'm wondering if this is a common practice and what the safety issues are -- for and against putting flaps down. As a jumper, my concern would be increased likelihood of a tail strike. I have talked to a few other pilots since then (who I consider skilled) and they all put the flaps down and have said its no problem, so I'm just not sure what the issue was.

Thoughts?

[JackC1 0]

Of the places I've jumped, most pilots will put the flaps down but a few like to run in a little faster. But then I've also been in a Twin Beech trying to stay with a slow flying Caravan on jump run when the Beech stalled with half a dozen 200# gorillas hanging on the outside of it. Of the two scenarios, I'd rather take the fast run in.

[JohnMitchell 16]

dorkitup

At this dz, the pilot refused to extend/put down the flaps on jump run. I know there were several requests from jumpers to put the flaps down for jump run, but the pilot still refused. I didn't talk to the pilot myself or ask why he refused, as many people said he was really moody/grumpy and not to bother him.

The guy sounds like he shouldn't be flying jumpers. I'd like to hear his reason why no flaps. I can't think of any.

[JohnMitchell 16]

JackC1

Of the places I've jumped, most pilots will put the flaps down but a few like to run in a little faster.

It's not about what they like, it's about what the jumpers need and the safety margin flaps give you.

Quote

But then I've also been in a Twin Beech trying to stay with a slow flying Caravan on jump run when the Beech stalled with half a dozen 200# gorillas hanging on the outside of it. Of the two scenarios, I'd rather take the fast run in.

Wow, sounds like poor planning from the start. Either the Beech should have been lead or the Caravan should have nailed a speed the Beech could fly at. That $hit is super dangerous. Glad we didn't read about it in the paper.

[riggerrob 643]

Varies with the type of airplane.
The primary determinant is the height of the horizontal tail above the door.

The Twin Otter's horizontal tail is so high that you have to be a total dumb-ass to hit it. I have front-floated on plenty of Twin Otters and I can remember lots of Twin Otter pilots adding one or two notches of flaps, but cannot remember any Twotter pilot applying full flaps on jump run.

OTOH, early King Airs have horizontal tails below the top of the door, making it too easy to hit, so flaps down are mandatory on jump run.

When I flew piston-pounding Cessnas, I never lowered flaps - during jump run - because that made little difference in airspeeds, but vastly increased the risk of helmet-shaped dents on the flaps.

[EatSleepFly 0]

JohnMitchell

***At this dz, the pilot refused to extend/put down the flaps on jump run. I know there were several requests from jumpers to put the flaps down for jump run, but the pilot still refused. I didn't talk to the pilot myself or ask why he refused, as many people said he was really moody/grumpy and not to bother him.

I'd like to hear his reason why no flaps. I can't think of any.

Purely a guess, but I can: operator thinking that they're saving wear and tear (and thus $$) on the flap system.

Disclaimer- I know nothing (mechanically speaking) about Twin Otters, so I don't know if the flaps are a weak point at all, but regardless, fewer cycles = less potential for problems.

[JohnMitchell 16]

EatSleepFly

ing wear and tear (and thus $$) on the flap system.

Could be. Sounds like a pretty false economy to me if that's it.

Any other ideas, anyone?

[fencebuster 7]

I have 110 hours flying jumpers in the Super Twin Ottter. Never put flaps down. You can fly 80 kts with 4 people outside and maintain control and altitude with the left engine pulled back. High tail, no issue. I also started a DZ where we are running a Navajo (PA-31-310) and we fly jump run with full flaps to get the tail out of the way.

Charlie Gittins, 540-327-2208
AFF-I, Sigma TI, IAD-I
MEI, CFI-I, Senior Rigger
Former DZO, Blue Ridge Skydiving Adventures

[totter 2]

I've never known any pilot who put flaps in on jump run in a Twin Otter, except one, and he actually stalled the plane.
This was the first and only time that this pilot used flaps on jump run. He had a big group exiting, think it was a 16-18 way, and he knew the door was going to be loaded, so he thought that adding flaps would help. He only put in 10 degrees. Weight shifted aft faster than he could compensate, nose came up and airplane stalled. He never used flaps after that and never had anymore issues. Even with big ways.
When you start adding flaps you change the angle of attack that the plane flys at. And the angle of attack change is significant compared to a vast majority of aircraft out there. This is the reason why if you look at the LH wing of a Twin Otter you'll notice that it has two Stall Warning vanes. One slightly lower than the other.
The lower one is active continuously and the upper when only works after 12 degrees of flaps have been added.

[pchapman 279]

totter

I've never known any pilot who put flaps in on jump run

That's actually an awkward phrasing, as it could be taken both ways -- "flaps are IN not OUT" vs "put in some flaps".
To be clear, you are used to pilots NOT using flaps on jump run.

[topdocker 0]

I know some pilots won't put the flaps down because floaters like to use them for handles in spite of the large "Do not grab!" signs on them. It seems 200lbs of stupid hanging on a flap is bad for it....

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[totter 2]

Correct, I've never known a pilot who has used (added) flaps on jump run. Except that one, once.

[Zlew 0]

After this thread, I went back to look at pics from this weekend. My home DZ had flaps down on all the pics I could find. We had a visiting Otter as well, and at least in this pic, flaps were clean. https://www.facebook.com/photo.php?fbid=10152244625189220&set=a.10152244530114220.1073741839.622434219&type=3&theater

Their plane is configured a little differently than ours. Both have -34's but they have the 4 blade prop. Not sure if that matters for prop blast or not, but I did notice a few climb outs seemed a little bit more brisk than I was used to (nothing too bad though). I'm sure there are many more variables to what I feel out there and how it relates to actual airspeed over the wing...but in this pic anyway, no flaps.

[cpoxon 0]

DiverDriver makes no mention of flaps on jump run on his website for Twin Otters, but does for (at least some) of the others. I jump at the only Otter dz in the UK and both pilots add flaps on jump run. I think it's in the SOPs. I shall ask at the weekend.

Skydiving Fatalities - Cease not to learn 'til thou cease to live

[diverdriver 5]

dorkitup

Hello All,
So the other month I was visiting a DZ that flies a super otter. At this dz, the pilot refused to extend/put down the flaps on jump run. I know there were several requests from jumpers to put the flaps down for jump run, but the pilot still refused. I didn't talk to the pilot myself or ask why he refused, as many people said he was really moody/grumpy and not to bother him. Obviously, with the increased air speed, climbing out was a little more challenging than usual for me when I jumped, but not that big a deal.

I've been jumping for 10+ years and have never had a jump pilot NOT put the flaps down on jump run. I'm wondering if this is a common practice and what the safety issues are -- for and against putting flaps down. As a jumper, my concern would be increased likelihood of a tail strike. I have talked to a few other pilots since then (who I consider skilled) and they all put the flaps down and have said its no problem, so I'm just not sure what the issue was.

Thoughts?

In 2,000 hours of flying the Twin Otter I have never, ever extended flaps for jumprun. It's not necessary. And I've only flown static liners and world records.

King Airs, yes use flaps on jumprun. Twin Otters? Why?

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[diverdriver 5]

JohnMitchell

***At this dz, the pilot refused to extend/put down the flaps on jump run. I know there were several requests from jumpers to put the flaps down for jump run, but the pilot still refused. I didn't talk to the pilot myself or ask why he refused, as many people said he was really moody/grumpy and not to bother him.

The guy sounds like he shouldn't be flying jumpers. I'd like to hear his reason why no flaps. I can't think of any.

I'd like to hear a reason why you WOULD extend flaps on a Twin Otter. I can't think of any.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[JohnMitchell 16]

diverdriver

I'd like to hear a reason why you WOULD extend flaps on a Twin Otter. I can't think of any.

Glad to have a Twin Otter pilot chime in.

So. . . I know every Cessna I've jumped from uses them, Caravans included. If I remember correctly, the DH2 even uses a notch of flaps for climbing. Are you saying the Otter won't fly slower with flaps? You don't use them on jump run? I have to admit I watch the flaps on Cessnas but not on the Otter (bench seats in that plane make it difficult to look out the windows easily).

[diablopilot 2]

Pilot, and company policies can vary as can policies between different types of aircraft. In general low tailed turbines use flaps on jump run to produce a flatter deck angle and keep the tail higher relative to the door to avoid jumper strikes. 182's generally don't use flaps because of jumper proximity to them. Twin Otters don't use flaps because of the high tail and low risk of jumper strikes weighed agains the increased risk of using flaps.

A Twin otter can be flown at a safe no flap jumprun speed of 85-90 knots, getting slower as the aircraft becomes lighter, in fact airspeeds of 75 and slower are common on the last few jumpers exits. Flaps can add danger for a few reasons. With flaps down the stall speed does get slower, but the air flowing over the control surfaces becomes less as well, and once the center of gravity moves aft of limits (jumpers stacking up in the door) the only thing keeping that aircraft in a flying attitude are those control surfaces. With reduced airflow the amount of control movement to produce the same effect becomes greater which increases drag, and further slows the aircraft continuing the cycle till stall.

Flaps are not particularly strong structures on most aircraft and therefore have maximum operating speeds. On a Twin Otter, the maximum speed for flap operation between 0 and 20 degrees is about 100 knots, and more than 20 is 85 knots. While a pilot should try to remain within these limits, some maneuvers such as a stall recovery can push these limits. Damaging the flaps to the point where they will not extend/retract is very possible and bad enough, but added to that risk the flaps on a Twin Otter are interconnected with the control surfaces (elevator AND ailerons) and therefore damage to the flaps can easily render the aircraft uncontrollable.

Economics play a factor as well. Besides the added cycles placed upon the systems causing premature wear (remember these are 50 year old aircraft) the time spent retracting the flaps before beginning the high speed descent adds up. The average Twin Otter costs a DZ between $15 and $20 a minute to fly.

In well over 5000 jumps from Twin Otters I personally have never felt any need to ask a pilot for flaps on jump run. I can not think of any regular skydiving activity that requires their use.

----------------------------------------------
You're not as good as you think you are. Seriously.

[hokierower 0]

I can't recall any of the otters I've flown in putting down flaps on jump run. That said, a PAC or King Air without flaps down scares me a bit.

[JohnMitchell 16]

Thanks for that. See, every day I learn something.

[diverdriver 5]

JohnMitchell

***

I'd like to hear a reason why you WOULD extend flaps on a Twin Otter. I can't think of any.

Glad to have a Twin Otter pilot chime in.

So. . . I know every Cessna I've jumped from uses them, Caravans included. If I remember correctly, the DH2 even uses a notch of flaps for climbing. Are you saying the Otter won't fly slower with flaps? You don't use them on jump run? I have to admit I watch the flaps on Cessnas but not on the Otter (bench seats in that plane make it difficult to look out the windows easily).

The reasoning for extending flaps can be different on different aircraft even if the action is the same (extending flaps).

King Air? Fly slower.
Cessna 182? Raise the tail.
Twin Otter? The tail is already above the level of the door if jumprun is flown correctly. If you add flaps you add drag which requires more power for level flight. More power means more prop blast. So, fly slower but get more prop blast. It's just not making sense to me.

IF...big if you were still trying to raise the horizontal stabilizer during exit I would suggest a power idle descending jumprun.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[kawisixer01 0]

In hundreds of Cessna 182 jumps at a few drop zones with multiple pilots I've never seen flaps engaged. In fact I asked our very experienced jump plane pilot who has also flown turbine DZ's if he uses flaps on jump run and he said he never has and has no reason to.

[stayhigh 2]

I've done both extremes side on T-Otter.

One time, both engines almost turned to idle, for super slow exit. stall horn was going off and pilot was screaming for us to get the fuck out. that one felt like a ballon jump.

seeing prop barely turning and not hearing engine noise at altitude was creepy for sure.

and muiltple times both cranked to full blast, for super fast exit.

freeflying becomes so much better when the pilot cranks it up. It goes somewhere over 120 kts no? at max speed?? wasn't sure how fast but you start turning points sideways right out the door.

feels like jumping into a tunnel at topped out speed.

Bernie Sanders for President 2016

[theplummeter 15]

I fly jumpers roughly 3 times a month and have never used flaps on jump run in a 182. I use them with left rudder to shut the door after everyone exits. I have never jumped out of a King Air without flaps to the approach setting, last week I jumped out of a PAC several times and they lowered flaps for each jump run, and I have seen Twin Otters use either a little flaps or none.

[julius 0]

I much prefer the no flap exits from a Twin Otter as this gives an exit speed of at least 90kts. This airspeed makes it easier to start flying immediately upon exit. I have exited an Otter with full flaps and its like a balloon jump, needless to say, many more funneled exits. There is safety in airspeed for the pilot and the for jumpers.