Granny Gas

[Doc]

It's not ILLEGAL to use unapproved flap settings. Sometimes it may not be wise....and sometimes it may save your bacon, but there is nothing "illegal" about it.

[Just another canuck]

It's not ILLEGAL to use unapproved flap settings. Sometimes it may not be wise....and sometimes it may save your bacon, but there is nothing "illegal" about it.

Well, what does this mean then:

"We know some pilots have been taking off on floats with 30 degrees. This is not permitted. We remind you that the -100 series can take off with 30 degrees on wheels, but is prohibited from doing this on floats. The -300 series is not allowed to take off with 30 degrees on wheels or floats."

and I'm quite sure it's prohibited to use Flaps 2 on takeoff on the 228 as well. If it's not illegal, what is it? It's more than just a recommendation.

And furthermore, if you go off the end with one of these flap settings, what do you think the outcome will be? Do you think the insurance company would pay up?

[iflyforpie]

It's not ILLEGAL to use unapproved flap settings. Sometimes it may not be wise....and sometimes it may save your bacon, but there is nothing "illegal" about it.

Well, what does this mean then:

"We know some pilots have been taking off on floats with 30 degrees. This is not permitted. We remind you that the -100 series can take off with 30 degrees on wheels, but is prohibited from doing this on floats. The -300 series is not allowed to take off with 30 degrees on wheels or floats."

and I'm quite sure it's prohibited to use Flaps 2 on takeoff on the 228 as well. If it's not illegal, what is it? It's more than just a recommendation.

And furthermore, if you go off the end with one of these flap settings, what do you think the outcome will be? Do you think the insurance company would pay up?

Those sound like limitations in the AFM. So in these cases, the use of more flap than specified is illegal.

But for the 180/185/206, a maximum flap setting for takeoff isn't in the limitations. The flap settings are recommended in the operating procedures sections, usually for wheels only. The only limitations for flaps are maximum operating speeds and G loadings.

To me, it is like climbing at a slower speed than Vx. There is nothing saying that I can't--even though in most circumstances it is not wise. But if I have a lightly loaded aircraft, the actual Vx will be lower than the Vx is in the book anyways.

[Aviatard]

Once again my comments were specific to the Cessna 180/185/206.
Can you post the exact wording from the AOH that prohibits selecting 20 degrees of flap to break free of the water?

The 180 manual that I have says:

Other Limitations
Flap Limitations
Approved takeoff range 0 to 20 degrees.

Therefore I would conclude that 20 degrees of flap is not prohibited. In fact the normal procedures section specifies 20 degrees for takeoff. I don't have manuals for those other types.

[Cat Driver]

Thanks Aviatard:

If you used more than 20 degrees briefly to get unstuck from glassy water or to get off real rough water would that be " ILLEGAL " ?

[Aviatard]

If you used more than 20 degrees briefly to get unstuck from glassy water or to get off real rough water would that be " ILLEGAL " ?

I believe it would be illegal, according to 602.07. You would be operating the aircraft not in accordance with the limitations in the manual. Would it be sensible in some circumstances? Probably. Do people do it? I'm sure they do. However, that's my opinion. It's worth exactly what you paid for it. I've been wrong before.

[Siddley Hawker]

There's something in the FAA regs about it being illegal to change the configuration of the aircraft once you are on the take-off roll. Adding or subtracting flap could concieveably be construed as changing the aircraft configuration, I suppose. The only reason I know that is because on the F-27 at pretty well anything other than standard day at sea level, you were WAT limited with dry power. We used to use 0 flap for take off, up to 42,000 lbs MTOW, without using water methanol if the dry take off figures could be met. Our procedure was to start the take off roll with 16 flaps and raise the flaps to 0 at the 'airspeeds alive' call. The reason for that was on the power up with 0 flaps, it shook the shit out of the horizontal stab, the attach fittings of which were a weak point on the aircraft, so much so that there was a periodic x-ray inspection that had to be performed on them. One year on refresher one of us happened to mention that to the recurrent instructor and he quoted us the FAA reg chapter and verse.

Another example of adding flap to avoid pounding the piss out of an airplane was the DC-3 on skis. Cat do you remember what Austin's procedure was for the DC-3 in rough ski conditions? At Northern Wings we used to get the tail up as soon as we could, then at around 60 - 65 knots add 1/4 flap and horse the airplane into the air. It meant you were airborne well below Vmca, but if one quit the thinking was you were no worse off than with an Otter if the engine quit. Simply throttle the other engine back and land straight ahead. That procedure was far from kosher and not one to be used under normal conditions, but I preferred it to pounding along in the drifts.

[square]

However, I don't remember ever seeing this listed in the limitation section. It's usually just a comment in the normal procedures, something like "Use of flap settings more than 20 degrees is not approved."

Once again my comments were specific to the Cessna 180/185/206.

Can you post the exact wording from the AOH that prohibits selecting 20 degrees of flap to break free of the water?

So, does that qualify as an operating limitation?

You tell me.

I don't know about the 180's or 85's but for the 206, the procedure in the AFM says "Flaps 0 - 20 degrees" for takeoff. I always thought using more than that would just slow you down, heard a rule of thumb from a number of people that basically up to 15 or 20 degrees of flaps gives you more lift and after that it's just drag. Now I know that's not exactly scientifically true cause more flaps will give you a better coefficient of lift but I figured it was accurate in how to best clear the trees at the end of a soft field.

So.. it's still not clear to me why people would use more flaps to get out of a short strip, seems like excessive flaps would just keep you under your climbout speed for even longer than the recommended flap setting. Though, I do have a friend who tells me he used to dump sixty degrees flap in an L19 just before liftoff to get out of 600 foot strips.

[Just another canuck]

So.. it's still not clear to me why people would use more flaps to get out of a short strip,

What I did in the Caravan on really short strips was accelerate with flaps set 20, then extend to 30 if I thought I may not get airborne in time or cut it close. As soon as I was in ground effect I could raise them back to 20. It all happened really fast, but the idea was just to get flying.

As well, the 228 was the same sort of the thing SH was talking about with the DC-3... set "Flaps 2" and make the plane go flying at 65 or 70, well below V2... it was just to get out of the rough stuff and into ground effect.

[Cat Driver]

Another example of adding flap to avoid pounding the piss out of an airplane was the DC-3 on skis. Cat do you remember what Austin's procedure was for the DC-3 in rough ski conditions? At Northern Wings we used to get the tail up as soon as we could, then at around 60 - 65 knots add 1/4 flap and horse the airplane into the air. It meant you were airborne well below Vmca, but if one quit the thinking was you were no worse off than with an Otter if the engine quit. Simply throttle the other engine back and land straight ahead. That procedure was far from kosher and not one to be used under normal conditions, but I preferred it to pounding along in the drifts.

Yup we did the same when needed, one of our biggest problems was breaking hydraulic lines on the skis due to pounding the snot out of them on rough hard surfaces.......at least half wheels helped but there was a trade off due to drag if the surface was soft in places.

Way I figured it was do whatever got the thing in the air in ground effect to save pounding the snot out of the airplane.

I have a few thousand hours on skis on the DC3 and that method always worked for me and I never lost control of one.

Theory is great, but reality and practicality sometimes requires a little extra touch to get the job done and still have an airplane that has not been beat all to hell.

By the way Siddley H.. Moose Murdoc taught me how to fly both the DC3 and the PBY

[Siddley Hawker]

Yeah Cat, I met Moose a few times. The guy I flew the DC-3 on skis most with what little time I do have on skis with it, about 200 hours, was Frank Burney. Frank introduced me to Moose, he was flying the Canso hauling fuel between Gagnon and Mile 191 on the QCM railroad. I can't remember the Canso he had, it may have been CRR. It had a full clipper nose. I knew his son Leigh well. Leigh worked for years for Wabush Mines, here in Sept-Iles.

[beaverbob]

[quote
I don't know about the 180's or 85's but for the 206, the procedure in the AFM says "Flaps 0 - 20 degrees" for takeoff. I always thought using more than that would just slow you down, heard a rule of thumb from a number of people that basically up to 15 or 20 degrees of flaps gives you more lift and after that it's just drag. Now I know that's not exactly scientifically true cause more flaps will give you a better coefficient of lift but I figured it was accurate in how to best clear the trees at the end of a soft field.

So.. it's still not clear to me why people would use more flaps to get out of a short strip, seems like excessive flaps would just keep you under your climbout speed for even longer than the recommended flap setting. Though, I do have a friend who tells me he used to dump sixty degrees flap in an L19 just before liftoff to get out of 600 foot strips.[/quote]


You are correct to a point. Lift is increased with an increased over 20 degrees of flap in greater proportion than drag is increased up to a certain speed. I don't know that number off hand.
So at low speeds greater flap extensions beyond 20 degrees will increase the take off performance at a slow speed. After that extra flap will decrease performance. The whole idea is to use the extra flap to shorten the take off distance only and then they are retracted to the normal climb setting immediately after lift off and then its climb, climb,climb.

Bob

[square]

You retract flaps in ground effect then? I thought that'd be kind of nuts cause of the sudden loss of energy

[Cat Driver]

You retract flaps in ground effect then? I thought that'd be kind of nuts cause of the sudden loss of energy

When required I retract the flaps in ground effect to the recommended climb flap to allow the airplane to better accelerate to the climb speed I want for the departure.

Every time I did that I got an increase in energy, not a sudden decrease of energy.

There are two things that I can think of that will produce a loss of energy in ground effect.....allowing the airplane to hit the ground or reducing power.

Hitting the ground may produce a sudden loss of energy so if you are unsure of your ability to change flap settings in ground effect by all means do not do it.

[beaverbob]

You retract flaps in ground effect then? I thought that'd be kind of nuts cause of the sudden loss of energy

When required I retract the flaps in ground effect to the recommended climb flap to allow the airplane to better accelerate to the climb speed I want for the departure.

Every time I did that I got an increase in energy, not a sudden decrease of energy.

There are two things that I can think of that will produce a loss of energy in ground effect.....allowing the airplane to hit the ground or reducing power.

Hitting the ground may produce a sudden loss of energy so if you are unsure of your ability to change flap settings in ground effect by all means do not do it.

That's exactly what I meant, thanks Cat

Now that's enough for today, I'm off to work
Bob

[square]

You know what I mean, when you retract flaps the airplane wants to dip a little bit cause of the loss of lift.

[Cat Driver]

You know what I mean, when you retract flaps the airplane wants to dip a little bit cause of the loss of lift.

I do not wish to sound condescending square but when discussing how to fly airplanes we should try and remember that for every action and or change of attitude/ velocity / height, there is a corresponding action that can adjust any change that is not desired.....in this case " dip " can be corrected by the use of the elevators.

O.K. ? are we in agreement?

I left the flight training forum because I was unable to express my thoughts without ending up in a pissing match with the experts there, I sure do not want to get into it here.

Then again I just an asshole anyhow according to some of the " Experts "

[square]

Yeah exactly.. you lose lift so you have to pull up and you slow down a little bit. That's what I meant by a sudden loss of energy. Which sounds a little crazy for a land plane trying to clear trees on a little bush strip. Anyway I'll just keep using the approved procedures, if I go someplace that's so wet or short that I'd need to act like a test pilot.. I'd rather just take the load out in two trips.

[Cat Driver]

I'm a real bear for punishment so I will ask another question.

I assume you are a relatively low time pilot square by your responses......soooo here is another question this time with regard to a land plane.

The following was from a high time pilot asking me a question.

Another example of adding flap to avoid pounding the piss out of an airplane was the DC-3 on skis. Cat do you remember what Austin's procedure was for the DC-3 in rough ski conditions? At Northern Wings we used to get the tail up as soon as we could, then at around 60 - 65 knots add 1/4 flap and horse the airplane into the air. It meant you were airborne well below Vmca, but if one quit the thinking was you were no worse off than with an Otter if the engine quit. Simply throttle the other engine back and land straight ahead. That procedure was far from kosher and not one to be used under normal conditions, but I preferred it to pounding along in the drifts.

My response was I used the same procedure.

Now here is the question:

What would do in the same circumstances?

Use a procedure that gets you in the air as quick as possible.

Or:

Keep pounding the hell out of it until you reached the normal rotate speed?

By the way I did not consider myself a test pilot as I was taught that procedure by many high time pilots.

[Just another canuck]

What would do in the same circumstances?

Use a procedure that gets you in the air as quick as possible.

Cat, I think you know I respect your advice and opinions... but I gotta raise an eyebrow and ask you a question? You DO NOT condone flying overweight because it's illegal just as an example. Why do you condone this procedure? I'm not saying it's illegal on the DC-3, but what about the Twotter, Caravan or Dornier 228? I know you've flown at least one of these types. Are you saying it's okay to break the law and use a procedure to get you in the air quicker and out of a rough strip even though it is not authorized in the AOM?

I always thought you condemned anything deemed ILLEGAL... by the way, I've done it countless times on the Caravan... go 30 flap, then back to 20 once airborne. I felt safe doing it. I'm just curious why you think this one procedure is okay? or do you not think there is anything illegal about it?

[square]

Kind of puzzling to me why my following SOPs would indicate I'm inexperienced, I haven't flown a DC3, but in your example I would follow the company SOPs as I was trained to do. I like to keep things simple.

[Cat Driver]

I'm just curious why you think this one procedure is okay? or do you not think there is anything illegal about it?

Flying airplanes can not always be Black or White, there are sometimes when a departure from the norm or from that matter from the AOH can mean the difference between a sucessful take off and wrecking the airplane because you did not use a known technique to get it in the air.\

I do not council pilots to do anything " illegal " none of the techniques I have described and have done were " illegal " they were actions I took to prevent possible damage to the airplane caused by operating off unprepared surfaces like snow in the high Arctic flying an airplane that was on skis.

If any pilot feels that a technique to get out of an unusual situation is " illegal " by all means don't use it.

Like I said there were times when one has choices, like using whatever flap works best to break ground under minimum single engine air speed and once in ground effect reconfiguring the flaps and airspeed for the climb.

Or:

Flying by strict conformance to a set SOP and adhering to the accelerate speed using normal flaps and risk driving a landing gear up through the wing and for sure you are not going to get far then.

I have not flown the airplanes you mentioned Just Another Canuck, but if I were faced with having to use any technique that would mean getting into the air or risk smashing the airplane all to pieces I would opt for flying it home rather than bringing it back in pieces.

We could get into the discussion of landing in zero zero weather to, after all why just discuss a take off technique that works lets do the whole what is " illegal " thing.

Jesus I sure do step in front of the firing squad sometimes...but then what the hell I'm still alive and never lost control of an aircraft yet.

And no employer or regulator ever said to me " . how did you get that airplane here without a scratch on it? "

[Cat Driver]

Kind of puzzling to me why my following SOPs would indicate I'm inexperienced, I haven't flown a DC3, but in your example I would follow the company SOPs as I was trained to do. I like to keep things simple.

Exactly:

Like I said, I followed the standard company procedure for getting a DC3 on wheel/ skis off rough snow/ice.

[Cat Driver]

Square, do you fly single pilot or multi pilot crews?

And regardless of whether you fly single pilot or multi pilot crewing, do you practice landing the airplane simulating zero/zero using the ILS with a safety pilot to take over if you are screwing up?

Because I was taught that procedure many years ago and on several occasions being able to do it allowed me to fly another day...not to mention my crew and passengers.

In fact I just got another cheque from " Todays Pilot " to finish writing a story about having to do exactly that many years ago in a Tri Gear Beech 18 with passengers sitting in the back.

[Just another canuck]

Okay, okay, fair enough, Cat... I was just curious is all.

By the way, I agree with all you are saying... sometimes deviation from normal... or even abnormal procedures or SOP's may be required... at least in the bush/float environment. 'Tis better to bring the airplane home healthy and in one piece, right?