Turbo 210 forced landing at Bankstown
A windmilling prop at full fine pitch produces drag nearly equivalent to a flat disc the diameter of the prop.
Checkboard: Do you think it’s more? Or less?
You’re probably making the usual mistake of not taking into account the reason why the propeller on a failed piston engine is rotating and the drag caused by the work necessary to make that happen.
You’re probably making the usual mistake of not taking into account the reason why the propeller on a failed piston engine is rotating and the drag caused by the work necessary to make that happen.
Not sure about the Bonanza, but the Lance just drops out if hydraulics fail, no pumping, no uplocks, nothing but gravity, it will just do it by itself, hence why they had the simple annoying automatic system that dropped the gear if you flew below a certain speed, disabled in most now. The C210 is definitely more complicated and failure prone than the Piper system in it's light singles. The only gear failures I've heard of in those simple Piper types has been more pilot induced than aircraft related.
1. A windmilling prop at full fine pitch produces drag nearly equivalent to a flat disc the diameter of the prop.
2. Hmm. I don't think that's anywhare near correct
Doing formation in a T-28B and on join up after take off found I was over running lead at a great rate of knots, not wanting to pop the speedbrake, which would immediately catch the eye of the instrutor flying trail, I closed the throttle and put the pitch up to fine, like hitting a brick wall so to speak when the pitch hit the fine stops, of course if the instructor was really paying attention he would have seen the doppler change of my prop RPM through the arc of his own prop, if he was so positioned, fortunately he was non the wiser.
The least ammont of prop drag is when it is stopped (feathering aside).
Not sure about the Bonanza, but the Lance just drops out if hydraulics fail, no pumping, no uplocks, nothing but gravity, it will just do it by itself, hence why they had the simple annoying automatic system that dropped the gear if you flew below a certain speed, disabled in most now. The C210 is definitely more complicated and failure prone than the Piper system in it's light singles. The only gear failures I've heard of in those simple Piper types has been more pilot induced than aircraft related.
If that’s true, my bad. My “nearly equivalent to” 3/3rds could reasonably be construed as more than 2/3rds.
Bottom line, either way, in the real world is the same: Full fine equals ‘much more’ drag than full coarse on a windmilling piston engine.
We still haven’t solved the mystery as to why Cessna seems not to mention full coarse in any emergency procedure, in contrast to other manufacturers who use the same engines and propellers.
Bottom line, either way, in the real world is the same: Full fine equals ‘much more’ drag than full coarse on a windmilling piston engine.
We still haven’t solved the mystery as to why Cessna seems not to mention full coarse in any emergency procedure, in contrast to other manufacturers who use the same engines and propellers.
Very informative archived thread, here, including this post:
Checkboard
26th Jun 2010, 19:57
In a single (no feather) you move the pitch control to full coarse in order to reduce drag and give you the best glide distance.
It used to be a demonstration as part of the Constant Speed Unit endorsement (it's a separate endorsement in Australia) to set up a glide, and then pull the pitch control back to point out the surge of extra speed.
Lack of fuel flow, assuming a flow gauge is fitted, would be the major indictaor.
Only if the engine has failed because you have run out of fuel.
26th Jun 2010, 19:57
In a single (no feather) you move the pitch control to full coarse in order to reduce drag and give you the best glide distance.
It used to be a demonstration as part of the Constant Speed Unit endorsement (it's a separate endorsement in Australia) to set up a glide, and then pull the pitch control back to point out the surge of extra speed.
Lack of fuel flow, assuming a flow gauge is fitted, would be the major indictaor.
Only if the engine has failed because you have run out of fuel.
Very informative archived thread, here, including this post:
It seems crazy to me if they aren't still doing this. It's a very low risk exercise: Go up to a few thousand feet, pull back to idle, trim for best glide and then bring the prop back and forward to feel the effect.
Worth doing if you are flying a single with a CSU and never experienced it before.
The following 2 users liked this post by JustJoinedToSearch:
The least ammont of prop drag is when it is stopped (feathering aside).
The following 2 users liked this post by Checkboard:
It is much, much less. You're probably making the usual mistake that a rotating propellor looks like a disc to your mark one eyeball, when it is still simply a propellor of the same size. It doesn't magically become a solid disc.
No, a rotating fixed-pitch propellor has less drag than a stopped one. On a stopped propellor the airflow is hitting the prop at 90º to the plane of rotation, when it's rotating that rotation means the relative airflow is at a lessor angle of attack (so less drag).
No, a rotating fixed-pitch propellor has less drag than a stopped one. On a stopped propellor the airflow is hitting the prop at 90º to the plane of rotation, when it's rotating that rotation means the relative airflow is at a lessor angle of attack (so less drag).
It is not just the form drag you are competing with when a propeller is windmilling. It is also creating negative load/thrust from the blades, that's why it continues to turn even against the compression load.
Spot on… I know from my real engine failure (and practicing) that my aircraft with fixed pitch prop glides much further than with the engine running.
Its a bit of a trap as you end up cooking your speed and over-shooting the landing area because it glides much further before running out of puff.
Its a bit of a trap as you end up cooking your speed and over-shooting the landing area because it glides much further before running out of puff.
Best to add that a CSU just becomes a fixed pitch prop when it gets to the stops, so there's no real difference when the engine has failed to a fixed pitch. So if you set high rpm, it will just move to the fine pitch stop and rpm will adjust to forward speed, at normal gliding speeds that is. If you wanted to you could accelerate to a point that the CSU will govern the pitch coarser to maintain maximum RPM until you reach the coarse pitch stop, and then exceed maximum RPM, but why.
The following users liked this post:
The pilot DID NOT do an amazing job ...
THIS incident is a classic example of WHAT NOT TO DO when you have an engine out in the circuit at Bankstown. The guy is flying a Cessna T210M, which, as far as single engined Cessnas go, requires a decent level of skill and comptetence to fly. First of all - his inbound call from Prospect was poor, and his reponse to the tower required a few prompts to correct his readback (was he really competent in D class airspace procedures?). He was at 1500' on downwind when his engine failed - with a glide ratio of (lets say) 10:1, this gave him more than ample distance (at best glide speed for a 210 of say 75 knots-ish) to position himself somewhere over the field with 500' to spare to line up on a runway. Instead, either due to the nose dropping due to loss of engine power, or him purposely pushing the nose down, he ends up at very low level at a high speed 500m from the airport perimeter (where the video starts). All you pilots out there know the drag curve - flying at a speed higher than best L/D speed incurs higher drag, and hence a waste of potential energy. He was VERY lucky to not hit the hangar, take out other people and aircraft on the ground, and kill himself and his wife. A perfect scenario would have been, when the engine failed, for him to turn immediately towards the runways and set best glide speed, positioning himself for one of the runways, getting the flaps out and finally gear down - THAT would have been a real hero scenario ... prove me wrong ...
A perfect scenario would have been, when the engine failed, for him to turn immediately towards the runways and set best glide speed, positioning himself for one of the runways, getting the flaps out and finally gear down - THAT would have been a real hero scenario ... prove me wrong ...
He should have managed his energy better so as to touchdown with gear down and with enough speed to roll off at the appropriate taxiway and continue rolling up to the front door of the maintenance hangar and gently coming to a stop,
Extra points for not using brakes.
Or, we could just accept that any landing you can walk away from is a good one because that, at the end of the day, is all we should aspire to after a catastrophic emergency.,
The following 11 users liked this post by lucille:
He should have managed his energy better so as to touchdown with gear down and with enough speed to roll off at the appropriate taxiway and continue rolling up to the front door of the maintenance hangar and gently coming to a stop,
Extra points for not using brakes.
Funny you say that, I managed to do exactly that at Ballina 30 years-ish ago, though didn't quite make it to the hangar ...
Extra points for not using brakes.
Funny you say that, I managed to do exactly that at Ballina 30 years-ish ago, though didn't quite make it to the hangar ...
Last edited by nreese; 31st May 2024 at 20:41.
The following users liked this post:
Looks like it had a few horses left on landing as the prop blades all appear to be bent like some power was being delivered rather than windmilling.