Needless steep climbouts

[rookiepilot]

I don't fly floats, know absolutely nothing about flying them, but I read on a cereal box they (probably) aren't the class leaders in glide ratios.......

[rxl]

I don't fly floats, know absolutely nothing about flying them, but I read on a cereal box they (probably) aren't the class leaders in glide ratios.......

One of THE best learning experiences that I ever had while training in an airplane occurred while training for my float endorsement in a 172. The instructor pulled the power just after takeoff at a fairly low altitude. It was a long time ago but I remember my response and the result like it was yesterday - push, carb heat on then pull and SPLASH back on the water ... and we weren’t doing a Vx climb out. Airspeed heads south in a big hurry at climb pitch and idle power. Dead engine and the drag of a windmilling propeller would make things even worse.
Here’s an interesting related video ...
https://m.youtube.com/watch?v=m_tKShlf_gU

[rookiepilot]

They don't glide well: 3:35 on this video.

https://m.youtube.com/watch?v=fC5yscm9dsI

[photofly]

A part of PilotDAR’s post that nobody has mentioned is that a draggy airframe needs to finish its approach going faster than its best glide speed in order to make a successful landing. Which is interesting.

[Scuderia]

Are you interested in the "immediately lowering the nose" part, or the "tiny bit below cruise attitude" part?

I'm interested in the part where the nose only needs to be lowered a "tiny bit below cruise attitude".

Moral: fly the pitch, don't dive for airspeed.

Fly the angle of attack, not the pitch.
After an EFATO, especially after a steep climb, a "tiny bit below cruise attitude" will not produce the required angle of attack for best glide. As the pilot reacts, the airplane will start to significantly decelerate forwards and vertically resulting in the angle of attack increasing for the same pitch. While setting the glide pitch will eventually cause the airplane to accelerate, the airplane may mush to the ground in the process.

Like a stall recovery, altitude loss can be minimized by first lowering the nose below the glide attitude.

[photofly]

Don't wait until you're stalled, and don't dive for airspeed. Place the nose at the correct attitude. Soft hands. Retrim, nose up. Very straightforward. You can teach this to a student in their second or third lesson. It's when pilots read on online forums how difficult things are that they panic and @#$! up.

[northernpilot2]

Please northernpilot2, explain this to me.

I was talking about my observations with some of the guys I flew with. I was told occasionally that I should climb "steeper" after takeoff in case I needed to turn back and land. The single engine flying used to freak out some people, so sometimes they would get crazy for no reason. And the same folks would have no problem flying a few hundred feet off the ground in the bushes, as if the engine will never fail then. Obviously, I would use Vx for obstacle and Vy to get to altitude fast, that's not the discussion here. I was just saying, the engine can fail anytime, and you just gotta deal with it when it happens. No need to get crazy for no reason.

[PilotDAR]

If you have established the powerless plane in a stable glide, ideally at the recommended glide speed, you have set yourself up for a more positive outcome. But no matter what your next thing to do will be, it'll involve you changing that path. At the very least, you will choose to change your glide path upward, so as to reduce your descent rate momentarily to flare. You may also, prior to that, choose to change direction, so you'll turn (and then still want to flare to touch down). Each time you change direction, you have to accelerate away from the path you were just gliding. To accelerate, you'll have to add a little energy (which you have as airspeed and altitude). If you're having to accelerate to glide speed, you only have altitude to trade to get there.

So a gliding turn (like back toward your takeoff area) will use up a lot of energy in speed to get you around. If you have the altitude to trade it, that's fine, but practice would be a good idea before you need to figure this out.

If you're flying an amphibious floatplane version of your favourite wheelplane, do you know the recommended glide speed in that configuration ('cause it's going to be faster!)? Some floatplanes are accompanied with a floatplane flight manual supplement, which should provide that speed, some seem to have missed that step in certification. If your favourite floatplane, also has a STOL kit, wing extensions, a gross weight increase, and a different prop, it's possible that there is no recommended glide speed for that configuration. So if you cannot refer to an authoritative speed, you'd better figure it out before you really need to know!

For example: The Cessna 182Q, as a 2950 pound wheel plane has a POH recommended glide speed of 70 knots. By the time I approved a 182Q with the combination of wing extensions, STOL kit, Aerocet 3500 amphibs, three blade MT prop, Gomolzig exhaust, and gross weight of 3350 pounds, the glide speed which I had approved in the flight manual supplement for that configuration was 82 knots. The testing to determine that speed was not relaxing. The original Cessna flight manual for the 182 states Vx of 57, and Vy of 70. A Vy speed stated in the FMS for one of those mods (not considering the others) is 65 knots. All of those speeds are much slower than you'd want to be flying if you needed to enter a glide from low altitude, and finish with a suitable flare at the bottom. If you even have FMS' for mullti mods on an amphibious floatplane, have you figured out their relationship to each other, and what the "best" speeds will be? When I flew that plane, I avoided needing to clear obstacles (take the longer arm of the lake) and looked for 82 knots as soon as practical after liftoff.

From my experience, airplane manufactures have tended toward stating Vy as being close or equal to the recommended glide speed. There are aerodynamic reasons for this, which can be found on the drag curve, but more simply, if you're already climbing the plane at the recommended glide speed, and it quits, you simply lower the nose, and maintain the speed, while you figure things out. It make the airplane manufacturer's lawyers job easier.

[Blowin' In The Wind]

Next time I’m up in an amphib with a student and we’re practicing losing an engine, I’ll tell them to put the nose “a tiny bit below cruise attitude” and see how that works out

[Big Pistons Forever]

It doesn’t have to be an amphib. In a C 172 or equivalent try it at altitude. Establish a stable Vx climb, close the throttle, count 2 potatoes for reaction time and then set a “tiny bit below cruise attitude” and see what happens.

I think pilots will be surprised at how long it takes for the airplane to reestablish a normal glide ROD at best glide speed and how much altitude is lost.

[photofly]

One absolutely can not fault the suggestion simply to go and try it.

[co-joe]

I would suggest that if the Snowbirds did steeper climbs after takeoff we might have one more of them around.

[fish4life]

Has anyone ever seen gliders do winch launches? They are probably 40ish degrees nose up with frequent rope breaks

[pelmet]

I have found myself doing Vx climbs on occasion when it was not necessary to use it for clearing obstacles. This was at airports with very poor landing options off the end of the runway. My reasoning was that I not only want to get to an altitude where I can turn around quickly in the event of an engine failure but I also want to be close enough to the airport so that I can make it back once turned around. My reasoning was that Vy might get me to a turnaround altitude a bit more quickly but the forward speed might put me too far off the runway, especially when the winds are light.

[digits_]

A part of PilotDAR’s post that nobody has mentioned is that a draggy airframe needs to finish its approach going faster than its best glide speed in order to make a successful landing. Which is interesting.

It sounds very interesting. It sounds like a reasonable statement, but I don't fully understand why.

Is that documented somewhere? The 172 on floats I flew just mentioned a best glide speed. It also mentions approach speeds.

The problem with transitioning from a best glide speed to a landing speed, is a problem of arresting a descend. The best glide is usually (always?) higher than your final approach speed, so logically, getting to that approach and touchdown speed should not be a problem. The question is: can you arrest your descend enough in time to flare and "pre flare" if you wish.

If you want to minimize your descend rate, you'd be flying your "minimum sink speed", which would be the speed at which your descend rate is the lowest. This speed is slower than your best glide speed. While not a mathematically air tight proof, would this not strongly indicate, that if you are approaching at best glide, you would then have enough energy to transition into the minimum sink speed, and thus start your flare from there?

Or, to rephrase, are there airplanes in which you are unable to land once you are stabilised at your approach speed in a power off situation?
The more speed, the more margin of error you have, and the more you can drag out the flare. But assuming average skills, which planes would crash in such a situation?

Drag in itself doesn't prevent you from levelling out, you'll lose a lot of speed while doing it, but that should be taken into account in the defined approach speed. If the original statement was talking about comparing a light and a heavy airplane, I would understand, as you have to fight the extra intertia, but that's not a factor if we're merely talking about draggy airplanes.

[pelmet]

A part of PilotDAR’s post that nobody has mentioned is that a draggy airframe needs to finish its approach going faster than its best glide speed in order to make a successful landing. Which is interesting.

Correct. Unlike on wheel aircraft, I would maintain at least an extra ten knots if possible on the best glide speed to allow for a nice flare and landing. That being said, I don't have a lot of float experience compared to many on this forum and have only done a few engine failure scenarios. So others may have better information.

[Jungle Jim]

The Tiger Moth at Edenvale was pranged when the engine quite on a very steep climb out. ( $100,000.00 damage) The pilot was not able to get the nose down in time to get a decent glide. Not sure why it also did not crash on the runway. A draggy plane like that will lose airspeed very quickly in a nose up attitude.

Jim

[AuxBatOn]

The Tiger Moth at Edenvale was pranged when the engine quite on a very steep climb out. ( $100,000.00 damage) The pilot was not able to get the nose down in time to get a decent glide. Not sure why it also did not crash on the runway. A draggy plane like that will lose airspeed very quickly in a nose up attitude.

Jim

Drag, whether the aircraft is in a 5 degrees or 45 degrees climb is roughly the same for a given speed (in fact, it will be less in a 45 deg climb but let’s consider them to be roughly the same). What slows you down faster is gravity.

[pelmet]

The Tiger Moth at Edenvale was pranged when the engine quite on a very steep climb out. ( $100,000.00 damage) The pilot was not able to get the nose down in time to get a decent glide. Not sure why it also did not crash on the runway. A draggy plane like that will lose airspeed very quickly in a nose up attitude.

Jim

Tiger Moth aircraft types have massive amounts of drag with all those wires out there among other things such as wind-driven generators on some and even drag from the wing-mounted airspeed indicator. I am not sure why a pilot would do a 'very steep' climbout on a Tiger Moth under any circumstances(or similar light biplane) as getting a reasonable airspeed in a normal climb seems somewhat challenging.

[photofly]

It doesn’t have to be an amphib. In a C 172 or equivalent try it at altitude. Establish a stable Vx climb, close the throttle, count 2 potatoes for reaction time and then set a “tiny bit below cruise attitude” and see what happens.

I think pilots will be surprised at how long it takes for the airplane to reestablish a normal glide ROD at best glide speed and how much altitude is lost.

I tried this a Cherokee 140 today, and it worked well. There was less "snooze time" than the same exercise from a regular climb, but I can report that commencing from a Vx climb, closing the throttle exactly on passing three thousand feet, maintaining Vx pitch while counting to three, then lowering the nose smoothly to the glide attitude (but no further) resulted in a stable glide before the altitude had descended even back to 3000'.

I will try it in some other types when I get the chance.

[RedAndWhiteBaron]

This may sound like a relatively elementary question...

Are engine failures at takeoff more likely than otherwise?

I can see there may be some cooling issues due to the high AoA, and you're at full power with a recently started engine which may not yet quite be "warm". Is it more likely for an engine to fail during a takeoff climb than it is during a cruise climb?

I'm wondering what the actual statistics are, in terms of how often it happens, and how often it gets real ugly, compared to engine failures elsewhere.

(If this would be a long discussion I can start a new thread)

[photofly]

This may sound like a relatively elementary question...

Are engine failures at takeoff more likely than otherwise?

I can throw some ideas into the ring.

Compared to the immediately preceeding ground operations, you have a suddenly increased fuel flow, and a changed pitch attitude. So fuel blockages can worsen, small fuel header tanks can find themselves emptied and not able to be refilled fast enough, and water that was peacefully nestling at the bottom of a wrinkled fuel bladder can find itself suddenly ingested into the induction system.

I'm wondering what the actual statistics are, in terms of how often it happens, and how often it gets real ugly, compared to engine failures elsewhere.

Most statistics come from the FAA, and engine failure stats are complicated by the fact that only ones that have very bad endings get counted. Loss of power in a small piston single that ends without damage or injury is not reportable. Same in Canada.

[PilotDAR]

resulted in a stable glide before the altitude had descended even back to 3000'.

Which is half the objective. Did the airplane, as flown to establish that glide, have enough reserve energy (speed) to be flared prior to 3000 feet, to arrest the rate of descent at 3000 feet momentarily?

This is why I have never been satisfied with a practice forced approach, when the instructor calls for addition of power, and an overshoot at 100 feet up on final, the candidate would not really know if a successful forced landing could have been accomplished. Yes, the plane is gliding, but if you were slow, you might have pulled, or flared early, and run out of energy before landing. A part of this is how precise your flare is. If you do it really well, you can do it later and lower, and thus not need so much speed reserve. But the configuration of the plane (different from others) could really affect how it slows and can be flared. Even changing from a thin blade two blade prop, to a wide blade three blade can make a vital difference! Following my change to a three blade MT, my amphibian glided very differently, and I had to develop new techniques and skills - in the plane I knew well from having 500 hours in it on the two blade Hartzell.

[rxl]

Drag, whether the aircraft is in a 5 degrees or 45 degrees climb is roughly the same for a given speed (in fact, it will be less in a 45 deg climb but let’s consider them to be roughly the same). What slows you down faster is gravity.

AuxBatOn, let’s say an aircraft is in a STEADY STATE climb that produces a 45 degree climb angle. (6,000’/nm a 100% climb gradient which is far beyond the capabilities of any airplane most of us have flown) Is it correct to assume that the total drag is reduced in this situation because engine thrust is producing a very large share of the lift required thereby reducing the amount of lift needed from the wing? This, in turn will reduce the amount of induced drag produced. In other words, thrust is taking the load off of the wing. Carried to the extreme your CF-18 in a steady state vertical climb, induced drag would be negligible.

[PilotDAR]

Are engine failures at takeoff more likely than otherwise?

As many factors have already been offered, I'll add one more to consider:

A Cessna 180 may be modified by STC to have a carburetted 520 or 550 engine - 'works great. Other than to note, obviously, it burns more fuel. Sure, when the STC applicant did the testing, they demonstrated compliance with the requirement, and positioned the plane in the attitude least favourable for continued flight (way nose up), and showed the fuel flow was adequate. But, when they selected that (unfavourable) pitch attitude, was that for the regular wing 180? Or the 180 with a STOL kit, wing extensions, and VG's. With all of those wing mods, the nose can be head a lot higher than the factory winged 180, does the fuel still flow? Hint: you can fly with the carb higher than the sumps of the wing tanks, and there is no header tank, nor fuel pump - just what's in the carb float bowl.

Each of the STC's I've mentioned has the following phrase at the bottom (my bold):

Conditions: This approval is only applicable to the type/model of aeronautical product specified therein. Prior to incorporating this modification, the installer shall establish that the interrelationship between this change and any other modification(s) incorporated will not adversely affect the airworthiness of the modified product.

How many installers are confirming the fuel flow is adequate for more than the float bowl contents, in a steep climb? How many installers are even considering this when they're signing on the STC's? I did this test on a 180A amphibian last weekend, 'cause I'll be issuing the STC which says that all those mods are safe together, so I did the test. That plane is fine.

Yes, having the nose pointed way up for an extended time is a more likely occasion for an engine failure, and much more critical when it happens. The first time it happened to me (carburetted 520 in a C 185, during flight testing in 1989, it was a surprise, since then, I'm testing for it). That's why 185's left the factory with a header tank over the fuel pump!

The fact that a plane is able to do something, does not make it a good idea. When you read between the lines in the flight manual, while following the recommended procedures, you'll find some things which are not a good idea....