Gordon Misch
MEMBER
Toledo, Wa (KTDO)
Speed and AOA are unrelated.
Oops, darn it...
- Thread starter Anne
- Start date
Speed and AOA are unrelated.
stid2677
SPONSOR
This one is a makes you wonder, anyone seen this? How the heck did he fall out?
https://aviation-safety.net/wikibase/300307
https://aviation-safety.net/wikibase/300307
BC12D-4-85
SPONSOR
Fairbanks, AK.
He jumped but forgot his parachute wasn't on? "The forward pilot’s seat was equipped with a lap belt and shoulder harnesses, which were intact, unlatched, and undamaged."
Gary
Gary
skywagon8a
MEMBER
SE Mass MA6
The earliest 150 hp Cessna 177 Cardinal had tail stall issues during landings which caused a lot of nose gear failures. Cessna solved the issue by installing a slot just behind the leading edge of the stabilator. I never flew one, but apparently the stabilator would stall during landings causing the nose to drop onto the runway with extreme force.
frequent_flyer
Registered User
Arizona, USA
Yes, agree. Thanks for that correction.
Steve Pierce
BENEFACTOR
Graham, TX
I was told the tail VGs came out because of the tail strake on the Boundry Layer Research VGs for the PA18.
After reading the report it appears the altitude this pilot was doing stalls at was 400 feet?
After reading the report it appears the altitude this pilot was doing stalls at was 400 feet?
courierguy
MEMBER
Inkom, Idaho
stid2677
SPONSOR
Our camp is near the crash sight,, I have a couple hundred hours flying in that area,, Mr Gary is correct about the winds,, even when Fairbanks is calm, there is most often an easterly wind at 10 mph or so, usually a burble too coming from a couple high spots to the east and south. His GPS flight track shows an average of 1500 ft AGL and the terrain elevation near the crash sight is 400 ft ish, so to me it looks like he was doing his airwork at 900 to 1000 ft AGL. Lower than I would do so,, any thoughts on the skis maybe contributing to the airflow over the tail in a high AOA???
skywagon8a
MEMBER
SE Mass MA6
Definitely a possibility. Chances are good the flight testing for approval of the VGs did not include flights with skis installed. Thus ....... low altitude initial testing would not be a very wise decision.
stid2677
SPONSOR
Farmboy
MEMBER
Middlebury, VT
This crash was a tragic incident, like all, but this borders on bizarre.
Facts : Ron Snyder and Mike Bowen, both pilots from Farmers Pride in PA had been flying that day. They left Wyoming Valley (PA) to go home, and a few minutes later in a stable cruise attitude there was a sudden pitch down and 400’ drop in altitude. Ron departed the aircraft, and all parts fell nearly vertical. Both men passed.
Witnessed events: witness reports seeing geese near flight path but not seeing contact. A witness reported seeing the sudden pitch change and Ron leaving the aircraft.
Knowns : Ron had a reported weird yaw when he banked into a turn, and another pilot flew and noted what Ron was describing but neither could pinpoint a cause, nor did either feel it was an unsafe condition, just an anomaly compared to others. Otherwise Ron had quite a number of hours flying it after completing the build and all seemed fine.
The investigation narrowed down to the tail area.
- Left stabilizer and elevator largely intact and bent 90* around the tail, to a trailing position over the tail wheel. Trim tab intact.
- Right Stab has impact damage in leading edge, and was folded down and aft, ripping out the front bolt from the attachment angle at the fuselage. Right Trim tab ripped off elevator but still attached by control arm.
- Vertical stabilizer was essentially destroyed, but pieced together shows breaks in leading edge; breaks, kinks and bends on internal braces and tubes; and tailpost broken in 2 locations.
Conjecture:
While a goose strike was expected, no evidence of any bird strike could be found.
Other evidence gives them reasons to believe that Ron may have been ejected vertically through the skylight, where he then impacted the tail surfaces, rendering the airplane uncontrollable.
It is a complete mystery as to why, or when, Ron unbuckled his lap belt and shoulder harness. He was visibly seen latching it at Wyoming Valley airport prior to taxiing. The harness was a Crow assembly.
There is no historical evidence nor does it seem likely but IF the right trim tab had developed a flutter or had some condition that ripped it from its hinge, during the time it was ripping off would be an extremely wild ride in the front seat. With no belt fastened it would easily toss a pilot out.
I truly hope that more meaningful evidence points to a greater smoking gun than theory, but without in flight cameras it may be a hard one to ever understand.
Transmitted from my FlightPhone on fingers… [emoji849]
RaisedByWolves
FRIEND
Tx
https://aviation-safety.net/wikibase/wiki.php?id=191909
Sounds like he started at 1000ft descended to 469 agl.
Seems to me if I was going on a test flight I’d start a little higher.
Sent from my iPhone using Tapatalk
mvivion
SPONSOR
Bozeman,MT
There is significant guidance related to recommended minimum altitudes for stall practice.
From the Airplane Flying Handbook: “ It is recommended that stalls be practiced at an altitude that allows recovery no lower than 1,500 feet AGL for single-engine airplanes, or higher if recommended by the AFM/POH. Losing altitude during recovery from a stall is to be expected”
From Private Pilot ACS: “The applicant demonstrates the ability to:Clear the area.Select an entry altitude that will allow the Task to be completed no lower than 1,500 feet AGL (ASEL, ASES) or 3,000 feet AGL (AMEL, AMES)”
Note that this guidance states that RECOVERY must be complete by no less than 1500 feet agl. Further, while this recommendation is not regulatory, if one were to violate that guidance during a Private Pilot Practical Test, the pilot would fail the checkride, and be required to retest.
Now, add to that the fact that this was not a routine flight training operation, but in fact a post maintenance flight test, specifically testing the flight characteristics of the addition of an aerodynamic modification which was specifically designed and installed to alter the stall characteristics of the subject airplane. Added to this, the aircraft was operated in a configuration not flight tested by the manufacturer of the VG kit.
While I see nothing in this scenario to suggest any ugliness in the proposed flight, the argument to maintain significantly HIGHER flight test altitudes than are recommended for routine stall practice certainly seems compelling.
I’ve conducted a lot of post maintenance flight tests, and those ALWAYS start above 3000 agl if stalls are to be demonstrated. To me that is a common sense safety precaution.
In this case, it seems the Pilots choice of an exceptionally low height to demonstrate stalls was the cause of the accident.
I’ve flown 7GCBC aircraft both with and without VGs, including considerable stall practice. I’ve never seen anything I would consider “unusual” in the stall characteristics of that aircraft. In an accelerated stall (steep bank with pull) the airplane exhibits an abrupt departure, but is fully recoverable using normal recovery techniques. Altitude loss can be significant in this regime. But the subject accident didn’t suggest any turning prior to the stall.
i can’t imagine practicing full on stalls at the altitudes this pilot conducted them.
MTV
From the Airplane Flying Handbook: “ It is recommended that stalls be practiced at an altitude that allows recovery no lower than 1,500 feet AGL for single-engine airplanes, or higher if recommended by the AFM/POH. Losing altitude during recovery from a stall is to be expected”
From Private Pilot ACS: “The applicant demonstrates the ability to:Clear the area.Select an entry altitude that will allow the Task to be completed no lower than 1,500 feet AGL (ASEL, ASES) or 3,000 feet AGL (AMEL, AMES)”
Note that this guidance states that RECOVERY must be complete by no less than 1500 feet agl. Further, while this recommendation is not regulatory, if one were to violate that guidance during a Private Pilot Practical Test, the pilot would fail the checkride, and be required to retest.
Now, add to that the fact that this was not a routine flight training operation, but in fact a post maintenance flight test, specifically testing the flight characteristics of the addition of an aerodynamic modification which was specifically designed and installed to alter the stall characteristics of the subject airplane. Added to this, the aircraft was operated in a configuration not flight tested by the manufacturer of the VG kit.
While I see nothing in this scenario to suggest any ugliness in the proposed flight, the argument to maintain significantly HIGHER flight test altitudes than are recommended for routine stall practice certainly seems compelling.
I’ve conducted a lot of post maintenance flight tests, and those ALWAYS start above 3000 agl if stalls are to be demonstrated. To me that is a common sense safety precaution.
In this case, it seems the Pilots choice of an exceptionally low height to demonstrate stalls was the cause of the accident.
I’ve flown 7GCBC aircraft both with and without VGs, including considerable stall practice. I’ve never seen anything I would consider “unusual” in the stall characteristics of that aircraft. In an accelerated stall (steep bank with pull) the airplane exhibits an abrupt departure, but is fully recoverable using normal recovery techniques. Altitude loss can be significant in this regime. But the subject accident didn’t suggest any turning prior to the stall.
i can’t imagine practicing full on stalls at the altitudes this pilot conducted them.
MTV
hotrod180
FRIEND
Port Townsend, WA
A Caravan crashed in the Seattle area yesterday, both occupants killed.
Original conjecture was that it was a skydiving jump plane out of Harvey Field S43, which is just west of the crash site, however this was not the case.
It was apparently owned or at least operated by Lake and Pen Air out of Alaska, and had been doing flights out of Renton KRTN all week.
This flight involved a lot of maneuvering over the eventual crash site.
N2069B
2 dead after plane crashes, catches fire in field near Snohomish – KIRO 7 News Seattle
Original conjecture was that it was a skydiving jump plane out of Harvey Field S43, which is just west of the crash site, however this was not the case.
It was apparently owned or at least operated by Lake and Pen Air out of Alaska, and had been doing flights out of Renton KRTN all week.
This flight involved a lot of maneuvering over the eventual crash site.
N2069B
2 dead after plane crashes, catches fire in field near Snohomish – KIRO 7 News Seattle
BC12D-4-85
SPONSOR
Fairbanks, AK.
One comment on the 7GCBC. I flew mine for 10 yrs in winter on Landis 2500 fixed skis (his were smaller 2000's), I tested and did lots slow flight running a trapline with a STOL kit, and never had what I'd call a hard to recover deep stall or tail stall. Maybe the VG's allow that. The elevator always worked reliably for me except at way forward CG. He was calculated 3" behind the front limit and 2" forward of the aft datum during the accident in the Final Report.
During slow level flight forward visibility of lower flat terrain for me at 5'9" was lost under the cowl. This pilot was taller, but someone had modified his seat mount to allow further rear extension for presumably more leg room. That may have limited his forward view of the ground. Being too low to recover seems right.
Gary
During slow level flight forward visibility of lower flat terrain for me at 5'9" was lost under the cowl. This pilot was taller, but someone had modified his seat mount to allow further rear extension for presumably more leg room. That may have limited his forward view of the ground. Being too low to recover seems right.
Gary
skywagon8a
MEMBER
SE Mass MA6
Do you suppose this restricted the forward movement of the rear stick which limited down elevator for stall recovery?
BC12D-4-85
SPONSOR
Fairbanks, AK.
It's very likely but only if the rear control stick was installed. The Report doesn't mention its presence or absence. Bellanca offered control sticks that S-curved away from the rear of the front seat or forward panel area. I had more issues with the aft stick hitting the rear seat padding (or occupant's body) than the front seat, so flew with it removed and the exposed stub covered with a raised cover approved for their Scout model. I doubt he had it installed because of potential clearance issues but don't know.
The left side seat bracket that was modified for more rear travel broke allowing those two support legs to detach from the airframe mounts.
Gary
stid2677
SPONSOR
I saw an inview on this one,, they were doing flight test for a cargo pod STC,, something about modification to the current pod design.
stid2677
SPONSOR
Any thoughts on the modified seat bracket possibly failing in flight?? At a high AOA more weight would be on the back of the seat, if it let go while almost at a stall, seems one would naturally pull back more on the stick since it would be your only point of contact.
BC12D-4-85
SPONSOR
Fairbanks, AK.
My thoughts are tempered by Cessna's known seat rail wear issues and initially a lack of adequate seat stops. Back went a C-185 seat for me only once on takeoff...grabbing the seaplane V-brace above the panel prevented a control problem. Pics (#9) of the broken seat brace can be viewed in the Public Docket available below.
From Post #3240: It can be found in the accident Docket report under #11 Photo Array by going to CAROL basic search below and entering the NTSB number ANC17FA009:
https://data.ntsb.gov/carol-main-public/basic-search
I linked this flight test of VG's on a Beech earlier. Take the time to read it and note the engineer's process of evaluation. Quite different than the low and slow approach here:
https://www.nar-associates.com/technical-flying/vortex/Vgs_stall_wide_screen.pdf
Gary
From Post #3240: It can be found in the accident Docket report under #11 Photo Array by going to CAROL basic search below and entering the NTSB number ANC17FA009:
https://data.ntsb.gov/carol-main-public/basic-search
I linked this flight test of VG's on a Beech earlier. Take the time to read it and note the engineer's process of evaluation. Quite different than the low and slow approach here:
https://www.nar-associates.com/technical-flying/vortex/Vgs_stall_wide_screen.pdf
Gary
algonquin
MEMBER
Seldovia,Ak
Pete, also the Cardinals also had a lot higher angle of incidence and people would flair to a level picture and the wing would start loosing lift and it would slam down, nose low. Taught in them when they first came out.
The Short 360 would get interesting when you got a bunch of ice, it would porpoise big when the tail loaded up.
The Short 360 would get interesting when you got a bunch of ice, it would porpoise big when the tail loaded up.
BC12D-4-85
SPONSOR
Fairbanks, AK.
Route of the last flight for N2069B. Several prior tests as well. Might have included stalls according to one Alaskan news source:
https://www.flightradar24.com/data/aircraft/n2069b#2e41b36c
Edit: Speculation> https://www.pilotsofamerica.com/community/threads/caravan-down-outside-of-seattle.140639/
Gary
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skywagon8a
MEMBER
SE Mass MA6
Flight testing can be dangerous, since something no one else has done is being learned about while operating the airplane at or beyond the limits of it's anticipated envelope. Sometimes something happens which is totally unrelated to that which you are investigating. The average airplane pilot/owner has no clues as to what paces any particular type of airplane has been put through in order for it to be operated safely by the average pilot.
Steve Pierce
BENEFACTOR
Graham, TX
Thanks, I just read the NTSB report and somehow came up with that 400'.
hotrod180
FRIEND
Port Townsend, WA
stid2677
SPONSOR
This is a video about the Caravan.
https://www.youtube.com/watch?v=C2jihx6knFI&ab_channel=blancolirio
https://www.youtube.com/watch?v=C2jihx6knFI&ab_channel=blancolirio
BC12D-4-85
SPONSOR
Fairbanks, AK.
Here's an update: https://www.seattletimes.com/seattl...hed-in-snohomish-county-was-on-a-test-flight/
And here's type of work Raisbeck Engineeering undertakes: https://raisbeck.com/raisbeck_product/epic-caravan/
Gary
And here's type of work Raisbeck Engineeering undertakes: https://raisbeck.com/raisbeck_product/epic-caravan/
Gary
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stid2677
SPONSOR
I misunderstood the purpose of this thread,, I deleted my comments and will not participate any further.
