Twin Otter Beta Use in Flight

[C.W.E.]

Losing your pilot license is not as much pain as having an accident and they can prove you were not flying within the airplanes limitations and thus invalidating the C of A.

It will be the insurance company who you need to worry about.

[SuperchargedRS]

Normally 500 to 1000 under gross

Ahh

[golden hawk]

There is no need to select beta in flight for that approach with that 2100 foot runway in a Twin Otter. To need to do so it just poor approach planning and speed control.

You are ALREADY IN beta range on approach as soon as you control propeller RPM with the power levers, as opposed to the propeller levers. The latter is constant speed range.

I agree that you should not twist the grips and retard the power levers in flight.

[rolly117]

back in the day DH a couple of twins for the Brits DHC 310 with aileron spoilers and beta approach a Green light indicated your angle of prop 9 degree i recall
the DH Buffalo DHC 5A the military Buff MTOW is 43000 and has a PCU prop control unit that is highly sophisticated with a approach beta selection also and it is what makes this aircraft a legend
My god i have sat in the Fe seat in a civilian buff on a steep approach and never saw the sky for a minute, only when we landed i looked up thru the crazed overhead windows Wow what a machine
the 5 civilian model has flaps restricted to 30 and is heavier
and does not have the PCU that the military version has with flaps 40 but it is impressive for a 49900 pound machine
Arctic sunwest has a few adventures i was on check out youtube

[SuperchargedRS]

Also I am a professional... ,l I'll still protect the skin, tin and ticket

If you are a professionnal then you ought to have integrity. Having integrity is doing the right thing even when the bosses aren't looking. This includes following rules and limitations.

If you really want to keep your ticket, you really should follow AFM limitations. The CofA of the aircraft you fly definitively has which AFM and AFM Supps you have to follow. If you don't follow the AFM and its limitations, you are operating outside the CofA and you can kiss your ticket goodbye if you get caught.

I don't do things like put it into beta, but the thing is I'm not a rote level guy, just because a law says so isn't good enough, I demand reasoning and logic, in the case of not using beta range in the air the logic is pretty clear lol

[NWONT]

Wish my memory was better on this one, but....somewhere in South America a very experienced Twin Otter pilot was taking off from an airport about 8000 ft asl. He had a prop reversal immediately after take-off. He didn't follow standard procedures and because of it lived another day. Anyone know the details on this one?

[AuxBatOn]

If you break the law or your CofA, you better have some really good reasons. " 'Cause I couldn't make it in the cleared flight enveloppe" won't cut it.

Emergency situation? This is one case where you could do it. Normal conditions? Nope.

Again, apply judgement in deviating from SOPs. Don't disregard the law, in normal situation, because you judged it was better. Some really smart people cleared the operating enveloppe of your aircraft. If you want it changes, make a changed proposal to the owner of the AFM (likely the OEM). Heads up: it'll be expensive.

[PilotDAR]

If you want it changes, make a changed proposal to the owner of the AFM

The type certificate holder (and TC's) first question is going to be "why?". " 'Cause I want to" won't cut it. I occasionally get such inquiries, and the "why?" sorts out the pros from the wannabes pretty quickly. After detailed consideration, and understanding some historic accident reports, I seldom find myself thinking to change a limitation in isolation from other major design changes to an aircraft. They're really carefully thought out.

[shimmydampner]

Pc12 we had to do it sometimes on the short strips wasn't really a big deal yeah the afm says not do it but when the alternative is going off the runway. I know what I'll pick

I find it highly doubtful (to the point of being a virtual impossibility) that if the pertinent performance charts indicate that a strip is of suitable length and an approach is flown properly, that it would also require the use of a technique explicitly prohibited by the AFM. I find it far more likely that either the performance charts were not consulted and the aircraft was being landed somewhere that it shouldn't have, or a poor approach was flown and "salvaged."
Now, I don't know anything about the PC-12, but I have some experience with strips significantly shorter than 1000'. I found that STOL work at the edge of the aircraft's envelope does not require made-up, self-invented techniques. It requires good understanding of and familiarity with the aircraft's handling characteristics and the ability to control the aircraft precisely on the razor's edge. Do that, and operating at the edge of the envelope is exciting to be sure, but in a fun way that is a relative non-event. The further you deviate from a perfectly flown STOL approach, the more "exciting" things will get in a much less fun way.

[CpnCrunch]

Pc12 we had to do it sometimes on the short strips wasn't really a big deal yeah the afm says not do it but when the alternative is going off the runway. I know what I'll pick

I think I'd pick an aircraft that can actually do that safely.

[SuperchargedRS]

Pc12 we had to do it sometimes on the short strips wasn't really a big deal yeah the afm says not do it but when the alternative is going off the runway. I know what I'll pick

I find it highly doubtful (to the point of being a virtual impossibility) that if the pertinent performance charts indicate that a strip is of suitable length and an approach is flown properly, that it would also require the use of a technique explicitly prohibited by the AFM. I find it far more likely that either the performance charts were not consulted and the aircraft was being landed somewhere that it shouldn't have, or a poor approach was flown and "salvaged."
Now, I don't know anything about the PC-12, but I have some experience with strips significantly shorter than 1000'. I found that STOL work at the edge of the aircraft's envelope does not require made-up, self-invented techniques. It requires good understanding of and familiarity with the aircraft's handling characteristics and the ability to control the aircraft precisely on the razor's edge. Do that, and operating at the edge of the envelope is exciting to be sure, but in a fun way that is a relative non-event. The further you deviate from a perfectly flown STOL approach, the more "exciting" things will get in a much less fun way.

Nah, I'll go a step further and just call him out right now as BS, and I do fly the PC12

Check the numbers out, at 1k shy of gross, which is his most... "optimistic" weight mentioned, shot field takeoff, he couldn't make it out of that 1,000' strip, and these numbers are for PAVED strips, so it would even be worse for his "unprepared mine camp" strip.

[StudentPilot]

Nah, I'll go a step further and just call him out right now as BS, and I do fly the PC12

Check the numbers out, at 1k shy of gross, which is his most... "optimistic" weight mentioned, shot field takeoff, he couldn't make it out of that 1,000' strip, and these numbers are for PAVED strips, so it would even be worse for his "unprepared mine camp" strip.

1000foot unprepared mine camp strips

What was your weight on landing?

Normally 500 to 1000 under gross

Perhaps you should look at landing distance? Nowhere did he say he took off at 1000 lbs under gross, nor did you ask...

[SuperchargedRS]

Nah, I'll go a step further and just call him out right now as BS, and I do fly the PC12

Check the numbers out, at 1k shy of gross, which is his most... "optimistic" weight mentioned, shot field takeoff, he couldn't make it out of that 1,000' strip, and these numbers are for PAVED strips, so it would even be worse for his "unprepared mine camp" strip.

1000foot unprepared mine camp strips

What was your weight on landing?

Normally 500 to 1000 under gross

Perhaps you should look at landing distance? Nowhere did he say he took off at 1000 lbs under gross, nor did you ask...

How much time do you have as PIC in the PC-12??

Sorry, but even if he left damn near empty and super light on fuel, 1k worth of dirt is most likely BS at best, and very reckless at worst.

[dogfood]

In with supplies out empty wasn't that bad.. one way strips so the wind would have to be just right anyone thats flown a pc12 knows that it likes to float so when going around is not an option sometimes beta has to get used.

[PilotDAR]

anyone thats flown a pc12 knows that it likes to float so when going around is not an option sometimes beta has to get used.

?? I've never flown a PC-12. So a pilot might choose to apply a bit of beta/reverse while the aircraft is floating just prior to touchdown? Wow, that idea really scares me, as the effect could be to really change the airflow over the tail, probably at the very worst phase of flight for that to occur. But.... I've never flown a PC-12.

While in the landing flare in the SM1019, I accidentally selected reverse (finger trouble between the flap selector and reverse lock out - my fault). Happily, for me, when the aircraft just about stopped in the air, it settled (well, thumped) onto the main wheels at an attitude I could recover without nosing over - but it sure got my attention!

[SuperchargedRS]

In with supplies out empty wasn't that bad.. one way strips so the wind would have to be just right anyone thats flown a pc12 knows that it likes to float so when going around is not an option sometimes beta has to get used.

Heres to hoping you're just a BSer.

And they don't float if you use the AOAs and those nice trailing link gear, those numbers I posted were for a dry hard surface, going in and out of 1k of dirt, I'd think someone smart enough to afford a PC-12 would also be smart enough to not permit their pilots to do something that stupid.

If anything goes wrong operating that pilatus out of a 1k dirt strip, between TC, the insurance company and the lawyers, you'll be eviscerated

[StudentPilot]

How much time do you have as PIC in the PC-12??

Sorry, but even if he left damn near empty and super light on fuel, 1k worth of dirt is most likely BS at best, and very reckless at worst.

I have no time in PC12s.

I don't need any time on type to consult an app or performance charts.

I have not disputed your argument, I merely called you out on bringing an irrelevant 1000 lb under gross weight take off into a discussion about landing at that weight.

Coming out empty at 7,000 lbs has a slightly lower ground roll than landing at 9,000 lbs work according to the AFM Google found. A lot was left out: elevation, temperature, slope, surface, etc that was not mentioned - and how much better maximum braking is over 'average braking technique' that the landing charts use. If it was -20°C the numbers are quite reasonable with a 15% addition for not behind asphalt. If it was 20°C the numbers do not look good.

As for beta in flight, no thanks.

[SuperchargedRS]

How much time do you have as PIC in the PC-12??

Sorry, but even if he left damn near empty and super light on fuel, 1k worth of dirt is most likely BS at best, and very reckless at worst.

I have no time in PC12s.

I don't need any time on type to consult an app or performance charts.

I have not disputed your argument, I merely called you out on bringing an irrelevant 1000 lb under gross weight take off into a discussion about landing at that weight.

Coming out empty at 7,000 lbs has a slightly lower ground roll than landing at 9,000 lbs work according to the AFM Google found. A lot was left out: elevation, temperature, slope, surface, etc that was not mentioned - and how much better maximum braking is over 'average braking technique' that the landing charts use. If it was -20°C the numbers are quite reasonable with a 15% addition for not behind asphalt. If it was 20°C the numbers do not look good.

As for beta in flight, no thanks.

You're right, who need experience or facts lol

Dude are you even a pilot?


Also how far is that 7,000lb PC12 going to fly?

Our is pretty light, only has two seats in the back, and it's not even 7000lbs with Z E R O fuel.

Maybe you should have some experience or training on type before you start trying to correct people who have time in type.





Also, EVEN if you somehow got that plane to take off at 7,000lbs you have just enough ground roll, but your total takeoff distance and also accelerate/stop distance is well over 1,000' and that's on dry pavement.

So again, taking a PC-12 into a 1000' dirt mining strip is stupid all day long and twice on Sunday's.

[StudentPilot]

You're right, who need experience or facts lol

"Facts" like saying it is BS because there is no way he could depart a 1,000' strip at 8900 lbs, which was never stated in the first place?

I would definitely want some experience and to be comfortable in type before making a go/no-go decision, as well as having all of the details, but you broke out the AFM performance data and, in some situations, it does work.

Also how far is that 7,000lb PC12 going to fly?

Our is pretty light, only has two seats in the back, and it's not even 7000lbs with Z E R O fuel.

That may well be. I saw a BEW of 6250 lbs on the preview screenshots for the PC12 digital AFM. I weigh 150. This site says a PC12 burns 26% more than a Caravan. We block a hair under 350 lbs/hr reliably, so 441 pounds for a PC12 approximately. 500 pounds will be ~0.6 hours plus 0.5 hours reserve, I doubt there is an IFR approach so no need for IFR reserves. Not far, although a PC12 does come and go in my neck of the woods flying legs that short regularly.

6250+150+500=6,900 lbs

Close enough for me, for these purposes.

Also, EVEN if you somehow got that plane to take off at 7,000lbs you have just enough ground roll, but your total takeoff distance and also accelerate/stop distance is well over 1,000' and that's on dry pavement.

Total takeoff distance may or may not matter. Perhaps there are 100' trees at the far end of the strip, in which case you may not want to go even if the total takeoff distance is long enough. Perhaps it is a cliff 100' above the ocean and you just need to be airborne by the end of the strip.

As a 703 aircraft there is no requirement for accelerate/stop distance. From my experience, if you can meet the accelerate/stop distance for a given type it isn't a short strip to begin with. No, that does not make it reckless or stupid, merely a short field.

[SuperchargedRS]

That AFM isn't really set all the way up on my phone the pilatus app is great for somethings, but W&Bs ain't one of them, however our plane, which only has two rear seats and a stretcher, is just shy of 6900lbs with zero fuel and zero people.

As for fuel burn, below 10k we plan on 500lbs hr at 240kts.




Now here's the kicker, it's not just legal, that hardly gets you on the bus, it's what's safe and prudent.

Going taking that PCL aft of the gate while in the air, that's not legal, it's not very safe and it's sure as heck not prudent, thus no bueno

I fly this plane all over, we get called to go to airports I've never heard of at times, and the PC-12 is a champ, most anything on a chart and many backcountry strips are no problem for this very capabible airframe.

That said, though I don't legally need accelerate and stop distance, I would be a damn fool not to have it, especially in something like the PC-12 where's it's both a large and fast plane, and also a plane where it's really not asking much realestate to get you that accelerate/stop distance.

Now I'm not flying rich folks, or chips and pop, I do some rather emergent flying, our company also has some pretty high mins to fly here, well beyond ATP, and I don't know a single pilot in the company who would take one of our PC12s into a 1000' dirt strip.

Even if you follow the letter of the law, if you knowingly do something that's not safe or prudent, you will find no shelter from the fall out if things go sideways, and that's only presuming you survive to deal with it.

[Noo]

I remember when I flew a PC-12 for my first job and thought it was a large and fast plane too.

[SuperchargedRS]

I remember when I flew a PC-12 for my first job and thought it was a large and fast plane too.

Far from a first job lol, but for where a PC-12 can land, it's quite quick and quite large

[napoleandynamite]

1000foot unprepared mine camp strips

That's impressive!!!! Did the the phonebook you sit on to see over the dash slide out from under you stopping that quickly?

[shimmydampner]

In with supplies out empty wasn't that bad.. one way strips so the wind would have to be just right anyone thats flown a pc12 knows that it likes to float so when going around is not an option sometimes beta has to get used.

I've heard people say it before, about types that I've flown, but I don't really buy that aircraft "like to float" because of the type they are. I think floating happens when an approach is flown too fast and the aircraft is carrying too much kinetic energy. However, I'm unfamiliar with the PC-12. I believe that it is a very capable aircraft. Regardless, it definitely doesn't seem like the type that would be wise to take in to a one-way in/one-way out 1000' strip. Then again, I've probably done similarly unwise things in aircraft that might not have been best suited for the job, so who am I to say. Where was this strip at, out of curiosity?

Edited to add:
Isn't there a stick shaker/pusher in the PC-12? Would you turn it off for these approaches? Seems like a bad bit of technology to have when doing serious STOL work. I'm very intrigued about this operation now.

[SuperchargedRS]

In with supplies out empty wasn't that bad.. one way strips so the wind would have to be just right anyone thats flown a pc12 knows that it likes to float so when going around is not an option sometimes beta has to get used.

I've heard people say it before, about types that I've flown, but I don't really buy that aircraft "like to float" because of the type they are. I think floating happens when an approach is flown too fast and the aircraft is carrying too much kinetic energy. However, I'm unfamiliar with the PC-12. I believe that it is a very capable aircraft. Regardless, it definitely doesn't seem like the type that would be wise to take in to a one-way in/one-way out 1000' strip. Then again, I've probably done similarly unwise things in aircraft that might not have been best suited for the job, so who am I to say. Where was this strip at, out of curiosity?

Edited to add:
Isn't there a stick shaker/pusher in the PC-12? Would you turn it off for these approaches? Seems like a bad bit of technology to have when doing serious STOL work. I'm very intrigued about this operation now.

That's why I said too fast and too large for that type of strip, though it's not a 747, it's also sure as heck not a PA18.

The PC-12 has a shaker and pusher, there is a button by the pilots left thumb, that if depressed will deactivate the shaker and pusher while the button is held down, this however was NOT designed to be used as an aid to short field work, the plane has quite a nasty stall with full flaps, looks almost like a wing over.

https://m.youtube.com/watch?v=VNRK2aUmWWI