“POH is supposed to be credible.” “Technically outside the POH.” I’m a little confused.
POH takeoff distance (50’) approximately 2450’; POH climb (2000’ AGL) about 625’ per minute. All of course with professional pilot, optimal conditions. Actual experience doesn’t surprise me at all, especially with pilot’s low time in plane.
What does surprise me is that pilot was surprised. I’d love to have his self-confidence.
Andy
“Clearly I agree now that the SR20 is best avoided if you
want to go much above shoulder height. I would certainly
not dispute this point. My return LAS-PAO is already
planned initially SW and over the Tehachapi pass at 10500’
if possible and otherwise at 8500’”
Huh… I just returned from a tour of the west in our SR20 that crossed the Rockies and Cascades several times - sometimes at max gross (3000), sometimes not, all at ISA+20-30 days, and all above 11,500. I routinely filed for 12,000-13,000 IFR, and had no problem getting there - I peg Vy as it decreases with altitude (and never stray below Vx), lean slightly as I go, and motor up. Oil T and CHT all in the green. 15,500 VFR Eastbound out of Everett over the cascades (trying to catch that mythical monster Westerly) was an experiment and a bit of a struggle, requiring a pause at 13,500 to cool down and speed up. This was near the published ceiling at the ambient -3 C and about 2700 lbs; the performance was poor (TAS down to 140) and it was not worth the effort, but it was still obtainable. I’m sure it takes longer to get up there than with a “real airplane”, and I plan for departing high density altitude airports early in the morning before they become excessively high density altitude airports, but with some experience in the 20 (I have about 175 hours now) you can safely and efficiently cruise in the 12-13,500 range even on hot days with acceptable performance, and higher if necessary. FWIW
Phil
In reply to:
" However my takeoff from LAS was firmly within the POH and it was this which caused the problem."
Actually, you WERE NOT within the published operating limitations of the aircraft when you took off from LAS. There is no entry in the SR20 POH Takeoff Distance charts for 2200 ft. press alt. and 43C temp. Although you may interpolate between press. alt. entries, you may not EXTRAPOLATE beyond the max. charted temp in the table. {See the AIM, Chapter 7, Section 5}. In fact, according to the POH (page 5-3. Performance Data) “If ambient temperature is above the chart value, use extreme caution as performance degrades rapidly at higher temperatures.”
Be very happy I don’t work for the FAA. In my opinion, you were in violation of both 91.103 and 91.13.[:@]
BTW, I assume your climb rates listed in your original post are meant to be expressed as FPM, not FPS. If truly you meant FPS, I’d be gloating about the performance, not complaining!
You’re right of course that it’s not fair to compare the SR20
with the 182. At equivalent equipment levels, a 182 is only
$10K below an SR22. And it is also 65 HP below it, so an
SR22 should indeed substantially outperform it. It also
seems that the SR20 I’ve been flying is for some reason a
poor example, performance wise.
In fact it’s not entirely my choice what I buy - my family
was a lot more bothered by what happened than I was.
I enjoyed flying the Cirrus but indeed I don’t think it will
be for me, for that reason. Which is probably a shame,
because everything everyone says, supports the fact
that the SR22 is a great plane.
Oh well.
JohnPhil, it’s good to hear that your SR20 does so well. I am struck by the wide variation in SR20 owners’ reports of altitude performance and especially oil cooling issues. Some report little or no difficulty, others–a small but significant number, it seems–are highly vexed especially by engine/oil cooling in hot weather. What gives here? Again, none of this appears to apply to the SR22.
So this kind of convinces me that while the SR20 may not be
the greatest hot & high airplane in the world, the problem is
really more with this particular example - as someone pointed
out a while back. This morning’s flight was LAS-PAO
planned via HEC and PMD (and in reality shortened because
R2505 over Edwards was cold). Two people (my kids
on Southwest), 40 lbs baggage, full fuel - around 120 lbs under gross. 2200’, 37 C at LAS. Reasonable climb rate
at 95-100 KIAS, but even so the oil light came on. Having
seen this before, I just kept a careful eye on the gauges
(which were in the green, just) and pushed the nose down
when this happened. (I knew about “constant airspeed”
and “constant VS” climbs, but nobody told me about
“constant oil temperature” climbs…)
The rest of the flight was fine although at 2600 rpm I was
seeing around 143 KTAS at 10500’, way below the book.
JohnThe rest of the flight was fine although at 2600 rpm I was
seeing around 143 KTAS at 10500’, way below the book.
If the temperature at 2200 was 37 than the temperature at 10500 would have been 21. That gives a density altitude of 13,000 feet. According to my tables and depending on how you lean that should produce between 139 and 149 KTAS. 143 would seem to be in the middle.
If you weren’t getting climb or cruise performance as per the book, there seems a decent chance there’s something wrong, don’t you think? Maybe the engine should be checked. At least run the engine through a few compressions by hand to see if there’s anything obvious. An engine that’s overheating when it should be performing adequately seems to indicate a potential problem.
Also, with regard to your comparison between the 182 and the SR-20: there really isn’t any. The 182 is really between a SR-20 and SR-22 in terms of engine size and is comparable to an SR-22 in terms of purchase price.
IIRC the OAT was 17C. According to my book (a generic
POH, not the one in the plane), and interpolating,
this should give 157 KTAS at best power (which I was)
and 2600 rpm. I’m referring to something that says
P/N 11934-001 Change A3.
JohnAccording to my book (a generic
POH, not the one in the plane), and interpolating,
this should give 157 KTAS at best power
You are right that their tables are screwed up. Every other set of performance tables I have seen true air speed decreases as temperature increases. It is the opposite for the Cirrus tables. I would recommend you calculate the density altitude and then look up in the performance table using the density altitude and standard temperature column. You come much closer to actual performance.
In reply to:
I say this in friendly tone, but also hoping you will notice that everyone who has flown the airplane on more than one mission has reached a different conclusion from what you did on your trip.I don’t think that’s fair to say. I’m sure the guy that killed himself flying out of Angel Fire would agree with John.
In friendly fashion , au contraire. The point of discussion in these posts was whether all Cirrus airplanes had been discredited by a full-gross, high-and-hot, over-the-Sierra expedition, as the poster announced in his “so much for Cirrus” declaration. (He used his troubles with the 20 as a reason not even to consider the 22.) Or whether, on the contrary, the SR20 had been discredited for that mission. The latter is what “everyone who has flown the airplane on more than one mission” was asserting. Everyone with first-hand experience with the two planes emphasized that the SR20 could have trouble in this scenario – but that the SR22 would not. Unfortunately the Angel Fire disaster confirms the point all the responders were making. If it’s very hot, and very high, and your plane is full, and you need to outclimb mountains to survive, then you either want to rethink that mission or get a 22.
Jim:
You and Mr. Birge are in the same business; journalism. I thought his comments above concerning the Cirrus had a significant tone of bias against the airplane but am not quite sure why. I thought you guys were unbiased and unprejudiced when writing your stories. What gives here?
I think there is more than enough pro and con discussion on this website to suggest that we are not all "brainwashed by Cirrus>’ Quite the contrary, I think we are pretty hard on them at times.
But facts are facts. When you fly the Cirrus and compare it to other models of the SAME PRICE AND PERFORMANCE , the plane speaks for itself. It does not need us to praise it.
Brian
then you either want to rethink that mission or get a 22.
Based upon the departure procedure and the SR22 POH, taking off in an SR22 under the conditions of the Angle Fire accident would have been unwise. The only safe advice would be rethink the mission.
Hi Brian –
In reply to:
You and Mr. Birge are in the same business; journalism.
I don’t know this to be true. I had heard from friends in Colorado that a Jonathan Birge was a Libertarian-party politician there, but I don’t know if this is the same one – and I don’t know of anyone in normal journalism with this name.
As for this:
In reply to:
I thought you guys were unbiased and unprejudiced when writing your stories.
Ohhhhh, of course! In case there is not a healthy tongue-in-cheek component to your comment, I’ll shamelessly refer Cirrusites to my previous book, Breaking the News: How the Media Undermine American Democracy.
Also bear in mind that J Birge hasn’t paid the member fee so doesn’t see the detailed pro-and-con discussion in the “real” forum. For instance, the long recent thread, “Is There a Worse Instrument?” about the problems people have had with the Century HSI. Jim
The problem is that there ARE NO other models of the “SAME PRICE AND PERFORMANCE”. Of the Cessna line, the SR20 falls between the C172 and the C182 (we won’t consider the Cessna RGs since the Cirrus is fixed gear), while the SR22 falls well beyond the C182 in performance. Granted, the SR20 typically falls below expectations (However, mine - N508JS - usually performs within 5% of POH #s unless its dirty), but its the best thing out there for the price point and included std features!
On a pet peeve note, the pilot of the original flight that started this thread did, in my opinion, a classic PILOT ERROR SCENARIO. Luckily, he got away with it. Unfortunately, he then chose to berate the plane instead of his own lack of judgement in conducting the flight. From the data I gathered out of his original post, the flight conditions were outside the performance envelope of the aircraft, and he then proceeded to operate the aircraft contrary to POH recommendations. Add to that the fact that most of us UNDERESTIMATE the actual weight of the plane, pax, and stuff loaded, yet OVERESTIMATE the performance of the plane, and we could easily have been reading yet another NTSB report instead of having this conversation. THEN, when the airplane warned him, through poor performance, redlined temps, and out-of-limits annunciators, he elected to continue the flight to the original destination instead of going to his then-declared alternate and having the plane checked for possible mechanical problems! Can anyone say “Part 91.13 violation”?
My instructor at Duluth told me, as he was trying to cure me of “Cessna-itis” during my transition training, “…the performance #s for a Cirrus are much closer to absolute limits (=less conservative) than for Cessnas. Exceed them by much and you’re begging to become the next big smoking hole in the ground.”
I’m sure I’ll get flamed for this post. Go right ahead. Maybe the next time, someone will re-read the POH before trying a marginal flight and my insurance won’t go up because of yet another CFIT Cirrus accident.
You and Mr. Birge are in the same business; journalism. I thought his comments above concerning the Cirrus had a significant tone of bias against the airplane but am not quite sure why.
There’s nothing wrong with bias when you’re writing an editorial. And I do have a bias against Cirrus at this point, though it’s an honest one (i.e. I have no financial or personal ties to anything related). As a member of the GA community, I’m a little disturbed by Cirrus. They strike me as a glib marketing company, with a lot less substance behind them as engineers than people here think. The airplanes they build aren’t that well designed, if you ask me. If Cirrus is the last hope of GA, frankly I’m scared, because they can’t even design a flap system that isn’t prone to RF interference (as a EE, I have no idea how you would do that even if you wanted to), an autopilot system that is stable, a chute that works (nevermind the specious logic behind its very presence), an airframe that doesn’t flutter, etc. And what really bothers me is the lack of honest consideration of these problems by the company. Klapmeier staunchly defends everything and keeps the spin machine rolling. I mean, if they can’t design a cable that pulls reliably, you have to wonder what other problems are lurking in the design, waiting to be discovered as the fleet ages. My honest belief is that the used market will get flooded with early Cirri after some horrible design flaw is uncovered. I mean, they’ve only been around for a few years and look at all the problems that have already come up. You think they’ve found them all?
In the end I came here to do final research on what I thought was the airplane for me. After all I’ve learned (both here and elsewhere) I’m not getting near a Cirrus until they’ve been around for a while and learn how to build airplanes. (I’m looking at used 172RGs and 182RGs, which I can actually pay cash for.) As for those that excuse Cirrus because they’re building some revolutionary plane, I must point out that there are a few other companies making new composite planes that are doing much better in the reliability/safety department (most notable is Diamond). Cirrus just strikes me as a bunch of guys who really don’t have the required experience to be an aircraft manufacturer. But trust me, I hope I’m wrong.
You sure do express yourself well. It is a pleasure to read your posts. Clark Jernigan
Bill, don’t expect me to flame you - I think you’re absolutely right!
He’s lucky he didn’t have a terrible mishap - this is the type of pilot that Aviation Consumer was referring to when they discussed Cirrus’s accident rate.
I, for one, am glad this guy isn’t buying a Cirrus.
Now it’s my turn to be flamed.
Andy
No flame, I too agree with the concern for pilot judgement in the original posting. So I wondered what the SR20 POH says about the conditions described. (I’m sharing this as part of a personal learning effort to get better at flight planning in challenging conditions, mostly because what I found surprised me! John Harper, I sympathize with your dilema in making this trip under such conditions.)
In reply to:
The final 2000 ft to 13500 was done at 100-200 ft/sec holding the plane between the stall horn at 75 KIAS and zero VSI at 80.
SR20 POH, page 5-22, Enroute Climb Gradient:
At 2900 lbs, 12,000 feet, 0C, climb at 88 kts is 139 ft/nm or 203 ft/min
At 12,000 feet with temps higher than 0C, the POH entries are gray.
The POH contains the recommendation above this table “For operation in air warmer than this table provides, use extreme caution.”
SR20 POH, page 5-23, Enroute Rate of Climb:
At 2900 lbs, 12,000 feet, 0C, cimb at 88 kts is 251 ft/min (curious why this differs from page 5-23; leaves me to use the more conservative number from above)
At 12,000 feet with temps higher than 0C, the POH entries are gray.
The POH contains the recommendation above this table “For operation in air warmer than this table provides, use extreme caution.”
SR20 POH, page 5-24, Time, Fuel, Distance to Climb:
At 2900 lbs, 12,000 feet, -9C, speed in climb is 80 kts and rate of climb is 282 ft/min.
For temps above ISA, add 10% to computed values for each 10C above ISA. (Hmmm… if temp was +10C, then 20% addition would reduce speed and climb rate, eh?)
In reply to:
Two days in Vegas then off to GCN. Now we really were at gross, a bare 30 gals of fuel. 43 degrees and 2200 ft, so density altitude high but still well within the POH limits. … our best climb rate, … maybe 400-500 ft/sec (sic!)
SR20 POH, page 5-21, Takeoff Rate of Climb:
At 2900 lbs, 2000 ft, 40C, takeoff speed is 84 kts and rate of climb 737 ft/min.
The POH contains the recommendation above the table “For operation in air warmer than this table provides, use extreme caution.”
In reply to:
I’m worrying seriously about departure from GCN at 6600’ and Bryce at 7700’.
SR20 POH, page 5-21, Takeoff Rate of Climb:
At 2900 lbs, 6000 ft, 20C, takeoff speed is 82 kts and rate of climb 582 ft/min
At 6000 ft with temps higher than 20C, the POH entries are gray.
The POH contains the recommendation above the table “For operation in air warmer than this table provides, use extreme caution.”
So . . .
From my reading of the SR20 POH, all of the flight conditions stated in the original posting are NOT within the POH. In fact, the final climb to 13,000 feet is just about right but probably hot enough to be outside the POH, the Las Vegas temp is above 40C and outside the POH, and the speculation about Grand Canyon and Bryce are at elevations and temps outside the POH.
Now, since John compares the Cessna 182 in his posting, I went looking (but didn’t find) performance info for the 182. What I did find was an AOPA safety document Cessna 182 Skylane Safety Highlights. The document is quite complimentary about the 182. However, when discussing similar scenarios to John’s, it contains these paragraphs:
In reply to:
For example, a short-field takeoff in a C-182 at sea level, standard temperature (15 degrees C), and zero wind requires 1,518 feet to clear a 50-foot obstacle. If the field?s elevation is 3,750 feet with a temperature of 95 degrees, a common occurrence on a summer day, the density altitude equates to 7,000 feet. The 182?s takeoff distance will more than double to 3,185 feet. The maximum rate of climb at sea level is 865 fpm and decreases to 505 fpm at 7,000 feet. Add in terrain or obstacles and the possibility of downdrafts to negate the already anemic climb, and it becomes obvious why states with high real estate have much higher accident rates than the flatlands.
Remember that POH performance numbers are based on new aircraft under standard weather conditions with a test pilot. Most of us will not achieve the published numbers on a normal basis. ASF recommends adding 50 percent to all published takeoff and landing numbers, to allow a safety margin. Therefore, the takeoff distance from the same 7,000-foot density altitude airport becomes 4,778 feet.
Note the takeoff distance of 4,778 feet and the comment “ASF recommends adding 50 percent … to allow a safety margin”
That sealed the deal for me. I’m feeling a bit more focused now on my flight planning to Wyoming tomorrow.
Cheers
Rick
It’s true that there are no current-production Cessna aircraft that are strictly comparable with the SR20. However, it is interesting to compare the SR20 with the 1979 Cessna Hawk XP (model R172K).
Like the SR20, the Hawk XP had a Continental IO-360 (albeit developing 195 hp rather than 200 hp as in the SR20), a constant-speed prop, and fixed gear. Here’s a comparison of some POH numbers:
[B]
Aircraft[/B]
[B]
2002 Cirrus SR20
[/B]
[B]
1979 Cessna R172K (Hawk XP)
[/B]
Engine
Continental IO-360-ES, 200 hp
Continental IO-360-KB, 195 hp
Wing area
132.5 square feet
174 square feet
Gross weight
3000 lb
2550 lb
Typical empty weight
2100 lb
1600 lb
Useful load
900 lb
950 lb
Power loading
15.0 lb/hp
13.1 lb/hp
Wing loading
22.6 lbs/ft2
14.7 lbs/ft2
Fuel capacity
56 gallons usable
49 gallons
Payload with full fuel
564 lb
656 lb
Takeoff distance, gross weight, sea level, 20 degrees C
1497 ft (ground roll)
2132 ft (over 50-foot obstacle)
830 ft (ground roll)
1410 ft (over 50-foot obstacle)
Takeoff distance, gross weight, 6000 feet, 30 degrees C
2845 ft (ground roll)
3959 ft (over 50-foot obstacle)
1565 ft (ground roll)
2765 ft (over 50-foot obstacle)
Rate of climb at vy, sea level, 20 degrees C
866 fpm at 96 KIAS
845 fpm at 81 KIAS
Rate of climb at vy, 12,000 feet, 0 degrees C
218 fpm at 90 KIAS
295 fpm at 75 KIAS
Cruise speed at 75% power, 6000 feet, +3 degrees C (standard day)
156 KTAS at 11.5 gallons/hour
127 KTAS at 10.8 gallons/hour
Range at 75% power, 6000 feet, standard day, including 45 minutes reserve
629 nm in 3.7 hours
495 nm in 4.0 hours
Landing distance, sea level, 20 degrees C
1032 ft (ground roll)
2063 ft (over 50-foot obstacle)
630 ft (ground roll)
1285 ft (over 50-foot obstacle)
Landing distance, 6000 feet, 30 degrees C
1332 ft (ground roll)
2471 ft (over 50-foot obstacle)
815 ft (ground roll)
1560 ft (over 50-foot obstacle)
Maneuvering speed
131 KIAS
105 KIAS
Stall speed, flaps up
65 KIAS
49 KIAS
Stall speed, full flaps
56 KIAS
44 KIAS
Maximum demonstrated parachute deployment speed
135 KIAS
Depends on your speed when you jump out
I have several hundred hours in a Hawk XP. It’s a great airplane. Am I giving up our SR20? No way.
Cheers,
Roger