Spin Testing
Horst Philip presented a paper on this at this year's Dresden SETP conference, although there's no sign of conference proceedings as yet.
I don't have any documents or contacts, but there were a couple of Bulldog successful abandonments in the 1980s; it may be worth asking the RAF flight safety organisation if they have copies of reports on file.
G
I don't have any documents or contacts, but there were a couple of Bulldog successful abandonments in the 1980s; it may be worth asking the RAF flight safety organisation if they have copies of reports on file.
G
Moderator
Spin testing
Hello aviators,
I have read many of the contributions, and they have made me think. That's always good. Among the topics of great interest to me, is that of spin testing. In my capacity as a Transport Canada Design Approval Representative, I am asked to flight test aircraft to assure their continued compliance with the applicable design requirements following modification. In all cases, these aircraft are light single and multi engine, land or seaplanes. They have design approval under FAA part 23, or the earlier CAR 3. One of the design requirements which prevails for all of these aircraft is spinning. Whether "approved" for spins (aerobatic or utility category), or not "approved" (normal category), they all still must demonstrate spin and recovery.
I recently was asked to fight test a Cessna 185 with a 10' long survey boom fitted to the aft fuselage. Included in the flight test plan required by Transport Canada Flight Test staff, was spinning. I questioned this, as the aircraft is placarded "spins not approved" ("not approved" having a different meaning to "prohibited", I'll come back to this later). I was told that compliance had to be shown, so spins had to be demonstrated. I was also told that there was no distinction between a spin and an incipient spin for the purposes of flight testing.
So I spun, and the world stopped turning with the appropriate application of rudder, and all was fine. I recommended the approval (STC) of the modification be issued, and it was. The plane left on wheels to its operation base in northern Canada, to have floats installed there.
The installation of the floats constitutes a configuration change, so the flight test had to be re-flown. I again asked if spins had to be done (as the aircraft owner was not at all keen to have his floatplane spun at gross weight). Spins still required.
The world did stop turning again, though not quite as quickly as on wheels, and from a much more vertical attitude. This was not a relaxing excercise, so it was not done more than necessary. It is noteworthy that a full control input spin recovery was required to recover in a reasonable time, and the aircraft is equipped with a STOL kit. STOL kit installation on most other single Cessnas makes them very difficult to hold in a spin, and they'll nearly always recover to a spiral dive quickly upon the relaxation of the controls.
So what have I learned from this? First; all FAA part 23/CAR 3 aircraft have demonstrated spinning and safe recovery within their approved operating limitations (even on floats!). It should therefore be expected that a properly prepared pilot can accomplish this with adequate safety. Next; spinning aircraft which were not manufactured with spins as an intended maneuver may not be as much fun as it sounds, and is best avoided. The airframe can withstand it, but it's hard on engines (lubrication and cooling), instruments (gyros hitting stops), and increases the chances of bad things happening. And finally; "not approved" has a different meaning from "prohibited", read the flight manual carefully. "Prohibited" means thou shalt not. "Not approved" means just that; the regulatory authority has not approved that maneuver in that plane, perhaps because the applicant did not seek approval. That does not mean that it cannot be done (safely, and legally), it just has not been presented for approval. BUT.... perfoming a maneuver which is known to be "not approved" and having a problem as a result, would certainly put the pilot in a very weak position with the authorities and insurance companies - who needs that?
Oh, and by the way, upon arriving at the dock following my fourth, and final test flight, I was met by a different branch of Transport Canada - Enforcement. I was asked what I was doing, and under what authority. The flight permit, approved flight test plan, and all other documentation were in order, and I was left with a handshake and a pleasent goodby. My first "ramp check" in 30 years of flying!
So, after all of that, I shall conclude by expressing my appreciation for the efforts of the moderator, the wisdom and oversight are of great value. I would also like to offer to everyone, that we are in this industry together, doing our best to support each other is the best way for us to all get ahead safely.
Cheers everyone...
I have read many of the contributions, and they have made me think. That's always good. Among the topics of great interest to me, is that of spin testing. In my capacity as a Transport Canada Design Approval Representative, I am asked to flight test aircraft to assure their continued compliance with the applicable design requirements following modification. In all cases, these aircraft are light single and multi engine, land or seaplanes. They have design approval under FAA part 23, or the earlier CAR 3. One of the design requirements which prevails for all of these aircraft is spinning. Whether "approved" for spins (aerobatic or utility category), or not "approved" (normal category), they all still must demonstrate spin and recovery.
I recently was asked to fight test a Cessna 185 with a 10' long survey boom fitted to the aft fuselage. Included in the flight test plan required by Transport Canada Flight Test staff, was spinning. I questioned this, as the aircraft is placarded "spins not approved" ("not approved" having a different meaning to "prohibited", I'll come back to this later). I was told that compliance had to be shown, so spins had to be demonstrated. I was also told that there was no distinction between a spin and an incipient spin for the purposes of flight testing.
So I spun, and the world stopped turning with the appropriate application of rudder, and all was fine. I recommended the approval (STC) of the modification be issued, and it was. The plane left on wheels to its operation base in northern Canada, to have floats installed there.
The installation of the floats constitutes a configuration change, so the flight test had to be re-flown. I again asked if spins had to be done (as the aircraft owner was not at all keen to have his floatplane spun at gross weight). Spins still required.
The world did stop turning again, though not quite as quickly as on wheels, and from a much more vertical attitude. This was not a relaxing excercise, so it was not done more than necessary. It is noteworthy that a full control input spin recovery was required to recover in a reasonable time, and the aircraft is equipped with a STOL kit. STOL kit installation on most other single Cessnas makes them very difficult to hold in a spin, and they'll nearly always recover to a spiral dive quickly upon the relaxation of the controls.
So what have I learned from this? First; all FAA part 23/CAR 3 aircraft have demonstrated spinning and safe recovery within their approved operating limitations (even on floats!). It should therefore be expected that a properly prepared pilot can accomplish this with adequate safety. Next; spinning aircraft which were not manufactured with spins as an intended maneuver may not be as much fun as it sounds, and is best avoided. The airframe can withstand it, but it's hard on engines (lubrication and cooling), instruments (gyros hitting stops), and increases the chances of bad things happening. And finally; "not approved" has a different meaning from "prohibited", read the flight manual carefully. "Prohibited" means thou shalt not. "Not approved" means just that; the regulatory authority has not approved that maneuver in that plane, perhaps because the applicant did not seek approval. That does not mean that it cannot be done (safely, and legally), it just has not been presented for approval. BUT.... perfoming a maneuver which is known to be "not approved" and having a problem as a result, would certainly put the pilot in a very weak position with the authorities and insurance companies - who needs that?
Oh, and by the way, upon arriving at the dock following my fourth, and final test flight, I was met by a different branch of Transport Canada - Enforcement. I was asked what I was doing, and under what authority. The flight permit, approved flight test plan, and all other documentation were in order, and I was left with a handshake and a pleasent goodby. My first "ramp check" in 30 years of flying!
So, after all of that, I shall conclude by expressing my appreciation for the efforts of the moderator, the wisdom and oversight are of great value. I would also like to offer to everyone, that we are in this industry together, doing our best to support each other is the best way for us to all get ahead safely.
Cheers everyone...
Join Date: Apr 2006
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There was an interesting presesntation by Sean Roberts about spinning the GA-8 Airvan. It was presented at the SETP Flight test safety workshop in 2000. It described the preparation for the spin tests and the accident. The airplane entered an unrecoverable spin, the recovery systems failed and the pilot had to jump out. A lot of things had gone not as planned including the pilot falling through the prop plane but he made it because the prop had stopped turning by that time.
Do a Hover - it avoids G
Join Date: Oct 1999
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The topic of which is the better side to use for succesful escape from a single piston aircraft is very well covered in a book about RAE research
Always a Challenge.
Tom Kerr
ISBN 0-9543436-0-3
Always a Challenge.
Tom Kerr
ISBN 0-9543436-0-3
