Non-towered airport. Single engine airplane. Un-hospitable terrain below most of the pattern area.
It’s a PAPI equipped runway and you’re VMC.
Do you fly the PAPIs or ignore them.
VFR, in the pattern at an uncotrolled, field: always fly at an altitude to be able to make the runway if you lose power.
I assume when you ask about flying the PAPIs you are asking should you be higher? I also assume that you are suggesting that I am unfamiliar with the field?
In that case, my answer stands. I would note the PAPIs and fly my airplane safely. I would not like to be below the PAPIs if I am unfamiliar with the field. If for some reason I was very familiar with the field and was comfortable being lower and wanted to be lower (wanted to land at the very end) then I would.
Jerry,
Without more information I can’t answer. What do you mean by inhospitable terrain? How long is the runway? What’s the weather (especially the wind in reference to the runway)?
As a general answer I would NEVER completely ignore a PAPI. Whether I would use a 3 degree glidepath or a steeper one depends on some of the above questions.
I can virtually assure you though that regardless of the terrain I never use a glidepath under 3 degrees. With the PAPI system that’s two whites and two reds.
For day VFR conditions I’m virtually always above the VASI/PAPI in the Cirrus until very close to the ground (in other words, my standard approach angle is greater than three degrees.) Note this does not mean that the approach isn’t “stabilized,” nor does it mean that I’m flying the approach faster than necessary; it simply means that I’m flying the approach with less power than would be necessary to maintain a three degree slope (which is a fair amount in a Cirrus with the flaps out.) This allows a much tighter pattern, which is advantageous at a number of levels.
I’ve ranted around this before, but the “always fly the PAPI” approach means that you are less likely to widen your comfort zone in handling the aircraft; there will be times when you simply cannot fly such an approach for whatever reason, and being flexible and comfortable will help a lot.
So long as it doesn’t cause other problems in the pattern, I like to go power idle and full flaps downwind abeam and deadstick it in, (though this will be a bit steep for non-pilot passengers; I shallow it out in that case.) On top of being fun, this will hopefully prepare me for the day when I need to deadstick it in for real.
Having a firm, consistent set of procedures and sticking to them makes absolute sense while you’re getting used to a new aircraft (you’ve got enough else going on that it is good to stay away from the edges.) However, once you have some time under your belt, I think it’s important to widen the envelope to the extent possible consistent with safety (this is, of course, the great irony in aviation–in order to stay safe you have to push the edges the right amount.) Things like circling approaches in relatively low conditions are times when those skills will come in handy (yes, such approaches are best avoided, but there are times when they may be unavoidable.)
Grab a more adventuresome CFI and find out more about what you and your aircraft are capable of.
I was reviving a debate I had with a CFI who says that you should always fly the PAPIs, since it helps to set you up for a stabilized approach.
The scenario I set up was to show that, if you fly PAPIs in single engine aircraft, if you lose your engine, you will not likely make it to the runway. I’ve done many, many simulated engine outs (with CFIs on board) and never made it to the runway with the power pulled even in planes with 9:1 glide ratios
In my opinion PAPIs are for twins and instrument approaches only and should be ignored in singles.
I wanted to see if anyone had any insight that would change my mind
Jerry,
Perhaps your CFI actually knows something.
The purpose of the PAPI or VASI or electronic glideslope for that matter is to set the plane up for a normal landing and providing obstacle clearance on the approach path. If a glidepath indicator is provided it is mandatory in class D airspace not to go below it (see FAR 91.129 e 3).
I gather from the last thread you started about using raising of flaps as your touchdown technique that you probably make rather steep and somewhat fast approaches. In the Cirrus, and indeed in any airplane, it is best to approach at the correct speed (usually 1.3x Vso) and at an angle of about 3 degrees. This sets you up for a nice easy flare or roundout and a gentle touchdown without using lots of runway. If you come in way above the recommended glide path you will use significantly more runway to stop. I would suggest that far more accidents occur from undershoots and overshoots during landing than from an engine failure on final. In fact I would be willing to bet that most engine failures on final result from fuel exhaustion or starvation - something that you as a careful pilot would never suffer. Use of the PAPI will minimize the chance of undershoots and overshoots.
The other advantage to using a consistent glide angle is just that - consistency. If all your approaches are at the correct speed and at about the same angle, your landings will be consistently better without using personal and unorthodox techniques like raising the flaps when in ground effect.
If you really don’t want to use a 3 degree path use one slightly higher - three whites and one red. Just be consistent.
Thanks for your reply. Yes, I do tend to fly them higher, rather than lower, which would be genuinely unsafe.
I’m also starting to think, from the posts I’ve read here, that I’m going to find drastic differences between the SR20 and the C172. It may just be that the C172 is more forgiving than the SR20.
I’m accustomed to high approaches (to maintain engine out glide distance) and higher than POH approach speeds (not usually more than 5 kts or so) yet I have no trouble landing on short fields (2000 ft or so) or in a short distance on longer fields.
Sure, I probably use more brake pads than most, but I find these techniques to be extremely easy and feel very safe doing them after hundreds of repetitions.
Like I said, maybe I’ll find enough differences in the Cirrus to change my attitude. I promise to let you know if I do.
Thanks again for taking the time to write your thoughts
In reply to:
The other advantage to using a consistent glide angle is just that - consistency. If all your approaches are at the correct speed and at about the same angle, your landings will be consistently better without using personal and unorthodox techniques like raising the flaps when in ground effect.
If you really don’t want to use a 3 degree path use one slightly higher - three whites and one red. Just be consistent.
I agree completely, Jerry. Well said. It’s the old saying - a good approach sets up a good landing. The more locked in you are on understanding that sight picture and how to achieve it with good airspeed and glidepath control, the better the resulting landings.
Jerry: I don’t think it is as simple as the 172 being more forgiving than the Cirrus. The 172 with it’s high wing has a separate set of difficulties with crosswind approaches and ground handling. The high wing is also a hazard to visibility, witness the number of midairs involving the 172 and similar aircraft. Finally, it is just not the way to get speed out of horsepower as any comparison of performance tables will show.
However, when it comes to approach speeds and approach angle the Cirrus is definitely different than the 172. I think the range of approach speeds and approach angles is greater with the 172 than with the Cirrus. That being the case, the speed and approach angle control has to be better with the Cirrus.
There are a number of practices which have some shaky if not downright wrong premises.
There is the idea that a steep approach close to the airport will get you in if you have an engine failure. That may have been true decades ago, but true engine failures (as opposed to fuel exhaustion) are very rare and are way outnumbered by landing accidents by a too steep or too fast (or both) approach and landing.
There is the idea that a somewhat faster approach speed is a safer approach due to gusting winds, possible downdrafts, etc. Again, the accident statistics show way more accidents due to fast approach speeds than to any loss of control on final. What accidents you do see in the approach phase are more likely due to too steep or uncoordinated turns than to a true loss of control due to wind gusts, etc.
The other thing to keep in mind is that there is a very significant difference in wing loading between the Cirrus and the 172. I don’t have the specific numbers but the effect is that the Cirrus is much less easily perturbed by wind gusts on final.
The higher wing loading and lower wing also means that if it is not ready to stop flying about the time you get near to the ground that you are going to have trouble.
I don’t think anything like dumping the flaps near the ground is a good idea. The solution is to have the speed down to near the stall about the time you near the ground, not to make changes in aircraft configuration close to the ground. The fact that this has worked in the 172 does not mean it is a good idea, and it is even a less good idea in the Cirrus.
I don’t think the C172 is more forgiving than an SR20, it’s just slower, that’s all, so you have more time to set up the correct landing attitude. Having said that, I rarely see a 172 landed with the nosewheel more than a few inches off the runway. They tend to be nose-heavy in the flare as well as having poor visibility over the nose. And a gusty crosswind will get your attention really quickly!
The SR20 is quite different to land compared to a 172, so you can expect to have somewhat of a learning curve adapting.
You are certainly right about wing loading. The Cirrus is nearly twice that of the C172, which was a determinining factor in my decision to buy it. I fly quite alot of IMC and need a good stable platform.
I thank you for your input. I look forward to flying my new plane to see if I’ve got to eat some crow in this chat room…
I think the COPA forum is a good one. I am always pleased to read the well informed comments provided by Shirley, Sir Mike, Gordon, et. al.