C152 preferred trainer. Why?
Who's talking accelerated stalls (apart from turning flight of course)? No more than 1kt/sec was always quite adequate. You only need be in a turn (left or right for different responses) or in various flap configurations or power setting up to high cruise and the like compared to power off S&L to effect a noticeable change in stall characteristics.
According to my reading of FAR23 those are all within the testing envelope.
According to my reading of FAR23 those are all within the testing envelope.
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Tinny .. not having a go at you at all, good sir.. the problem is Industry wide and endemic.
Our concern merely is to draw it to the attention of the folks in PPRuNe .. what they might do with the knowledge is another matter, I guess ..
According to my reading of FAR23 those are all within the testing envelope.
.. and this is where we would like the discussion to go in due course.
However, before that, how about a few people list their thoughts on how to
(a) approach the stall
(b) recover from the stall
It would be best if this could be done in boring bullet point detail.
After that it might be quite useful to have a look at
(a) the regs
(b) a few AFM/POH to see what the OEM suggests
and then see to what extent reality matches the airworthiness certification presumption.
So far as being adventurously boring in aircraft handling matters, the earlier reference to an inverted spin was related by a TP (but one who is well up the TP ladder) who had an airforce TP student in one particular well known light twin simply hold the aircraft into the stall, rather than recovering per the OEM procedure at the onset of stall indications ... onto its back and around it went to the amusement/surprise of both ....
The concern is that the instructing industry, aided and coerced by the flying side of the regulatory processes, encourages protocols which are potentially dangerous and certainly outside the intent of the certification process .. no problem, I guess, if the exercise, knowingly, is intentional between consenting adults .. but, if in ignorance - especially with an impressionable newbie student who knows no better, that may be a different matter and worthy of discussion here ?
Our concern merely is to draw it to the attention of the folks in PPRuNe .. what they might do with the knowledge is another matter, I guess ..
According to my reading of FAR23 those are all within the testing envelope.
.. and this is where we would like the discussion to go in due course.
However, before that, how about a few people list their thoughts on how to
(a) approach the stall
(b) recover from the stall
It would be best if this could be done in boring bullet point detail.
After that it might be quite useful to have a look at
(a) the regs
(b) a few AFM/POH to see what the OEM suggests
and then see to what extent reality matches the airworthiness certification presumption.
So far as being adventurously boring in aircraft handling matters, the earlier reference to an inverted spin was related by a TP (but one who is well up the TP ladder) who had an airforce TP student in one particular well known light twin simply hold the aircraft into the stall, rather than recovering per the OEM procedure at the onset of stall indications ... onto its back and around it went to the amusement/surprise of both ....
The concern is that the instructing industry, aided and coerced by the flying side of the regulatory processes, encourages protocols which are potentially dangerous and certainly outside the intent of the certification process .. no problem, I guess, if the exercise, knowingly, is intentional between consenting adults .. but, if in ignorance - especially with an impressionable newbie student who knows no better, that may be a different matter and worthy of discussion here ?
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My small contribution on the ‘stall’ topic, based on 7+ years of engineering flight testing on Part 23/25 aircraft.
First of all, it is not only the Regulation (FAR/Part 23 or FAR/Part 25) which determines the ways in which a stall should be investigated : the basic guide for the authority is the Advisory Circular AC23-8 or 25-8 (and the equivalent for the EASA side). Here you can see how many types or stall stall entries etc should be investigated for the handling quality side. Having cleared the handling, normally you proceed with the performance side To demonstrate good handling , you need to investigate very slow entries (<< 1 kts/sec), 1 g entries (close to 1 kts/sec) and fast entries (3-5 kts/sec) . it is interesting to note that the fast entries do not normally correspond to an accelerated entry (>> 1 g), as the manoeuvrability of whatever a/c at those low starting speeds (trimmed at 1.3 stall speed) do not allow to load many g’s.
The different entry decelerations allows also to interpolate the nominal 1 kts/sec entry speed, which is normally the ‘performance’ stall speed. It is interesting to note that , contrary to common sense, very often the ‘fast deceleration’ entry is more predictable and more straightforward than the 1 kts/s entry, with less wing drop, etc. Low deceleration stalls at 35000+ ft are often more strange, with hard wing drop and less clean nose pitching.
Power-on stall can sometimes results in very, very high deck angles, with an usual marked wing drop at the break.
For multiengine, the OEI stall with the other at 75% power is… frightening (at least, I always was frightened), because , though the VMC should have been already investigated and cleared, stall speed and VMC are often too close to allow to remain … relaxed . For FAR /Part 25 a/c , the performance determination of the stall speed is even more complicated (use of trailing cones, precision pitot tubes, etc to measure the exact static / total pressure). This is due to the fact that all runway speeds( and, as consequence, take-off and landing performance) are factored over the stall speed in TO configuration ( plus other speeds as VMCG, etc) .
For what refers to the post stall spin, I am pretty confident that, even 50 years ago during the C150 certification, being AC 23-8 already in use in its primitive form, quite all types of spins have been investigated ( at least those with the W & CG inside the promulgated envelope), and for the C152 Aerobat also those with a negative AoA ( being that aircraft certificated in the acrobatic category).
Note also that , for single engine aircraft, the spin, and its different spin entries, should be investigated anyway , which implies a matrix of many configurations (power/flaps/landing gear/weight/CG) . Recently Cessna lost two prototypes of their new trainer aircraft in spin investigation/certification, though not intending to certify it in the acrobatic category.
In the ’70, I learned to fly on a C150 with floats ; my AUW was 82 kg, hopefully the instructor was , and still is, smaller than me. Training lessons were 00:50 each, and after two lessons we needed to refuel. Waves / OAT affected veeeery much the take off run, sometimes in summer we counted 80 seconds between power application and take-off ! But I still think that, for basic training (also for learning seaplane technique) is one of the best aircraft .
Having learned take-off and landings on a 50 km long / 3 km wide runway (=lake) , I had lot of difficulties , when I transitioned on land planes, to align during landing with the runway, which was now very narrow and short compared to that on which I learned to fly……
First of all, it is not only the Regulation (FAR/Part 23 or FAR/Part 25) which determines the ways in which a stall should be investigated : the basic guide for the authority is the Advisory Circular AC23-8 or 25-8 (and the equivalent for the EASA side). Here you can see how many types or stall stall entries etc should be investigated for the handling quality side. Having cleared the handling, normally you proceed with the performance side To demonstrate good handling , you need to investigate very slow entries (<< 1 kts/sec), 1 g entries (close to 1 kts/sec) and fast entries (3-5 kts/sec) . it is interesting to note that the fast entries do not normally correspond to an accelerated entry (>> 1 g), as the manoeuvrability of whatever a/c at those low starting speeds (trimmed at 1.3 stall speed) do not allow to load many g’s.
The different entry decelerations allows also to interpolate the nominal 1 kts/sec entry speed, which is normally the ‘performance’ stall speed. It is interesting to note that , contrary to common sense, very often the ‘fast deceleration’ entry is more predictable and more straightforward than the 1 kts/s entry, with less wing drop, etc. Low deceleration stalls at 35000+ ft are often more strange, with hard wing drop and less clean nose pitching.
Power-on stall can sometimes results in very, very high deck angles, with an usual marked wing drop at the break.
For multiengine, the OEI stall with the other at 75% power is… frightening (at least, I always was frightened), because , though the VMC should have been already investigated and cleared, stall speed and VMC are often too close to allow to remain … relaxed . For FAR /Part 25 a/c , the performance determination of the stall speed is even more complicated (use of trailing cones, precision pitot tubes, etc to measure the exact static / total pressure). This is due to the fact that all runway speeds( and, as consequence, take-off and landing performance) are factored over the stall speed in TO configuration ( plus other speeds as VMCG, etc) .
For what refers to the post stall spin, I am pretty confident that, even 50 years ago during the C150 certification, being AC 23-8 already in use in its primitive form, quite all types of spins have been investigated ( at least those with the W & CG inside the promulgated envelope), and for the C152 Aerobat also those with a negative AoA ( being that aircraft certificated in the acrobatic category).
Note also that , for single engine aircraft, the spin, and its different spin entries, should be investigated anyway , which implies a matrix of many configurations (power/flaps/landing gear/weight/CG) . Recently Cessna lost two prototypes of their new trainer aircraft in spin investigation/certification, though not intending to certify it in the acrobatic category.
In the ’70, I learned to fly on a C150 with floats ; my AUW was 82 kg, hopefully the instructor was , and still is, smaller than me. Training lessons were 00:50 each, and after two lessons we needed to refuel. Waves / OAT affected veeeery much the take off run, sometimes in summer we counted 80 seconds between power application and take-off ! But I still think that, for basic training (also for learning seaplane technique) is one of the best aircraft .
Having learned take-off and landings on a 50 km long / 3 km wide runway (=lake) , I had lot of difficulties , when I transitioned on land planes, to align during landing with the runway, which was now very narrow and short compared to that on which I learned to fly……
