1 / 63

Cessna Model 162 (Skycatcher) Spin Compliance/Safety Lessons Learned

Delve into the safety measures and compliance strategies for Cessna Model 162 (Skycatcher) through an in-depth examination of ASTM guidelines, spin testing, and key lessons learned from the spin program. Explore the history, prototype flights, and safety systems overview while understanding the spin testing process post-event analysis and risk mitigation. Enhance your knowledge of Cessna's flight test procedures and safety protocols for optimal risk management.

jharland
Download Presentation

Cessna Model 162 (Skycatcher) Spin Compliance/Safety Lessons Learned

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cessna Model 162 (Skycatcher)Spin Compliance/Safety Lessons Learned C. Dale Bleakney (M) Cessna Engineering Flight Test

  2. Introduction – What is an LSA? • ASTM 2245-xx: • Max gross TO weight: 1320lbs • Min useful load - 430lbs • Vs min - 45KCAS • Vh max - 120KCAS • SE, fixed gear, fixed pitch prop

  3. Cessna LSA History Program Launch – Friday, January 13, 2006 Proof of Concept 1st Flight: Friday, October 13, 2006 Prototype 1st Flight: March 7, 2008 Wichita Built P1* 1st Flight: April 30, 2008 *P1 = Production No. 1

  4. Model 162: Final Configuration

  5. Instrument Panel

  6. Spin Program Overview In 1980, the US Supreme Court concluded that "Safe" is not the equivalent of "risk-free." LSA Spin Testing Goal: Safe, Thorough, Efficient ASTM 4.5.9: • ….(4) For the flaps-extended condition, the flaps may be retracted during recovery. 14 CFR 23.221 • ….. For the flaps-extended condition, the flaps may be retracted during the recovery but not before rotation has ceased. The rules are technically identical, Therefore: • Spin matrix was defined using FAA Advisory Circular 23-8B: • 352 spin conditions

  7. Safety Equipment/Process • First flight • Chute & Helmet • Chase aircraft w/video • Special Inspection • First Flight Readiness Review (FFRR) • Envelope expansion • Chute & Helmet • Chase aircraft • Stalls • Chute, Helmet, BRS (Aft cg) • Spins • BRS, Chute, Helmet • Chase aircraft w/video • Spin FFRR

  8. Spin Program Weather/Test Constraints**Before 1st Spin Event Weather Ceiling – MIN 10,000 feet Surface Winds – MAX 10 knots with 5 knot gusts (chute limits) Spins per sortie No MAX - BUTfatigue will be watched Crew Rest MAX - 5 flying days per week NOwork or flights on Sunday

  9. Spin Matrix and Buildup Program Before 1st Spin Event • Spin Matrix – Buildups (¼ , ½, 1 turn) • Fwd cg, idle power • Normal - flaps - up / down • Turning - flaps -up / down • Abused - flaps up / down • Repeat with power on - Buildup to MCP • Repeat at aft cg - Idle, then buildup to MCP

  10. Safety Systems Overview Crew Entry/Egress • Removable Door – 2 action • Procedure practiced before 1st flight Spin Chute (Options) • BRS Whole Airplane Chute –CHOSEN • Tail mounted airplane spin chute – NOT CHOSEN

  11. Spin Event No. 1 – September 18, 2008 • BUILDUP • Spins Successfully Completed: • Fwd cg Idle/MCP • Fwd cg MCP abused (ailerons with) • Event SPIN: MCP, ailerons against:3+ turns • KEY FACTS • 143 Successful spins completed • Key spin characteristics identified: • All spins were ASTM and 23.221 compliant • Redundant safety systems and safety discipline - ALL important

  12. Spin Event No. 1 - Lessons Learned • Safety Systems • BRS Spin Chute - Did not deploy • Rotation rates and spin attitude contributed to improper rocket trajectory and failure • Changed BRS parachute installation design • Door Jettison - Dual action door delayed bailout • Other • Buildups - Did not forecast event

  13. Risk Mitigation/Event analysis – Post Event No.1 • Internal Review • Flight Test • Project / Advanced Design • Outside Assistance • Former Cessna Test Pilots • Retired Cessna Aero / Advanced Design • BIHRLE • NTPS

  14. Post Spin Event No. 1BRS Design Changes OLDCanister Type Installation NEW Bed Mount Installation Parachute Actuation Handle • Soft Pack Design – No Canister • Parachute Bag - Oriented horizontally and near window • Rocket aft of parachute - Close proximity to window. No way it will catch on anything on the way out. • Cessna designed truss • Supports both parachute and rocket • Built in deflectors/guides Rocket

  15. Removable hinge pins Single Emergency Release Handle Post Event No. 1 - Door Release Changes

  16. Post-Event No. 1 - Bihrle Spin Tunnel testing • Power model updated • Predicted delayed spin recovery • Now matched event No. 1 spin • New vertical stabilizer w/ ventral • Spin tunnel data - No unrecoverable spin modes

  17. Safety Equipment/Process • Spin Briefings (Before and after 1st Event) • Include standard test card items • FTE monitors air-to-air frequency • Standard debrief, data review, and characteristics review • Missing elements(Lessons learned after 1st Event) • Telemetry • Ground crew at spin sight • Instrumentation • Control positions • Body angle of attack • Real-time pilot feedback

  18. Revised Spin Matrix – Post Event No. 1 Buildup redefined (look at aft cg earlier) • Idle –fwd cg, then aft cg • then, • MCP –fwd cg, then aft cg Note: 2000 rpm to MCP (100 rpm at a time) 28 to 33% MAC (1% at a time)

  19. Spin Videos – Mod 1 Configuration • Idle, Flaps Up, Right • Idle, Flaps 10, Left

  20. Risk Mitigation – Post Event No. 1 • SAME • Chase Aircraft • Spin Chute – BRS • Personal safety equipment • Brief and debrief • NEW • Fly the spin aero simulator before each new configuration • Go/No go as part of pre-flight brief • Post spin discussion of characteristics-to-simulator correlation • Detailed characteristics discussions with Flight, Aero, Safety • NO-GO decision is okay – Proceed with caution • Same as before but with increased emphasis • High definition video for post-spin analysis • Detailed flight reports to the Chief Pilot, Safety to independently assess positive and negative characteristics of each spin before we proceed.

  21. Spin/Stall Progress Chart We are now here

  22. Spin Event No. 2 - 3/19/2009 • COMM antenna damaged during BRS deployment • No communication with chase airplane • Rotation would not stop until engine shutdown • Pilot Door Jettison – Failed • (Door opened but would not jettison) • BRS saved the Pilot – Impact still substantial • (approx. 1600 fpm)

  23. Tail Change No. 2 Original design • Original tail (Mar 08) • Rev 1 tail (Sep 08) • 20% larger vertical tail • 10º less rudder sweep • Removed dorsal fin • Shielded rudder horn (directional stability) • Added ventral fin (not shown) • Rev 2 tail (V4) (Mar 09) • Increased rudder span • Ventral moved further aft • Maximum UP elevator changed from 30° to 22° Rev 1 Design Rev 2 (V4) Design

  24. Spin Compliance Completion Plan • Check Stability and Control/Stalls • Look for max AOA change: • Reduced max elevator travel (from 30° to 22°) • Power-on stall checked – lower AOA/better characteristics • Power-off stall speed checked - still ASTM compliant • Spin Compliance • New spin chute –Aft cg testingonly (due to aft truss/chute mount) • New spin matrix (with buildup) • Redo critical case spins without spin chute/with BRS

  25. Post Event No. 2 Safety/Flight Procedure Changes • Check Door Release, then re-attach before every spin flight • Maximum of 12spins per sortie. • Maximum of 2 sorties per day • 1 spin pilot – Pick up on subtle cues between spins • Early morning flights only – reduce pilot fatigue • Real time feedback from telemetry room on entry/recovery on every spin

  26. Spin Compliance Matrix (Post No. 2) • Original Spin Matrix • 352 Total Spins • Fwd then aft cg • Idle then MCP Power • Turning – over-the-top/under-the-bottom • Abused – ailerons with/against • Remaining untested spins (with spin chute) • 92 Total Spins • Aft cg – Normal • Aft cg – Turning • Aft cg – Abused (ailerons with, ailerons against, Idle/MCP) • Final Spins (without spin chute, with BRS) • Aft cg – Normal (IDLE), Normal (MCP) • MCP Abused (ailerons against) (Problem Spin)

  27. Spin Video – Final (Flaps 10, MCP, abused , Left , Ail Against) • With spin chute • Without spin chute

  28. Spin/Stall Progress Chart FINISHED 7/17/2009

  29. Spin Event Summary • September 18, 2008 (28% MAC) (Event No. 1) • BRS failure, Pilot bailed out • March 12, 2009 (30% MAC) (3 turn recovery) • Analyzed and thought to be caused by distributed ballast • March 19, 2009 (32% MAC) (Event No. 2) • (28%, 30%, 31% MAC successfully completed with new ballast configuration) • 32% MAC – recovery not seen after approx 3 turns • BRS deployed • Communication antenna lost • Jettison malfunctioned • Door release malfunctioned • Pilot rode airplane to ground • minor injuries to pilot • damage to airplane – most damage was after impact • July 17, 2009 (32% MAC) Spins successfully completed (with and without spin chute) • Stall and spin characteristics significantly improved • Final spin completed - 1 turn recovery. Meets ASTM and FAR 23

  30. Summary of Lessons Learned • Get recent spin practice in a similar airplane • Spin Tests should be done last - Final aero configuration • Look for excess flight control travels and limit them as necessary • Watch for subtle clues. Stall characteristics were a big clue. • NO two airplanes and NO two spins are identical (snowflake effect) • Safety systems mustbe robust. (Video) • TM data with experienced pilot feedback was very helpful • ¼ and ½ turn spin buildup did not predict 1 turn behavior However, it does acclimate and tune the pilot

  31. 162 Program - Interesting Statistics • Are you superstitious ??? • LSA Program go: Friday, Jan 13, 2006 • POC First flight: Friday, October 13, 2006 • First POC cross-country: AOPA, Palm Springs, CA • Flight 13, 1300 NM, took 13 hours • Spins • First Proto spin event, Spin 13, Thur, 9/18/08 • Second P1 spin event, Spin 13, Thur, 3/19/09 • Final P1 spin flight, Flight 169 (13 squared) • No more than 12 spins a day were done with the version 2 tail. • Don’t give the big guy a free shot – superstition or not

  32. Questions? Fun at Mach 0.162

  33. Post Event No. 1AerodynamicConfiguration Changes Original Proto configuration Post Event No. 1 configuration • Dorsal removed • Ventral added • Vertical stabilizer chord increased • Vertical stabilizer sweep angle decreased

  34. Spin Video – MCP Abused (Final –W/O Spin Chute) • Flaps 10, MCP, Left Spin, Ailerons Against – w/o chute

  35. Post Spin Event No. 1 - BRS Design Changes(Details on Next Slide) OLDCanister Type Installation NEW Soft pack Installation

  36. Bihrle Testing - Post-Event No. 2 • Bihrle Test Matrix • Baseline with flaps 10 • Baseline plus dorsal (Event configuration) • Three new vertical stabilizers (+20% area) • Baseline vertical + 5-in chord extension (V1) • New vertical with 10-deg sweep reduction (V4) • New vertical with zero sweep (V5) • Vented elevator • Horizontal stabilizer moved aft • Additional aileron deflections • Additional down elevator deflection • Conclusion • Selected V4 with/without ventral for simulation (see next slide)

  37. Post Event No. 1Aerodynamic Configuration Changes Vertical Stabilizer Changes V1 V4 Thorough!!

  38. Spin Video – Normal Spin • Rev 1 Configuration: Flaps Up, Idle, Left Spin

  39. Spin Video:Idle, Normal Spin Mod 1 Configuration: Flaps Up, Left Turn (Note Entry)

  40. Spin Event No. 2 - 3/19/2009 • Potential Causes • Change in perceived AOA at stall/spin entry –Too much elevator?? • BRS Spin Chute – Deployed but would not jettison • Rotation rate, spin attitude, inability to jettison BRS • High rotation rate caused risers to twist and increased friction in release pin attachment • Friction forces caused cable stretch – pilot unable to generate enough force to pull the release pin

  41. Stall/Spin Progress Chart Over 600 stalls completed before the first spin We are here

  42. Spin/Stall Progress Chart We are here

  43. Spin Video:MCP – Abused Spin • Mod 1 Configuration: Flaps Up, Left, MCP Ailerons Against

  44. FWD BRS Installation (Before 1st Event) Actuation Handle Safe

  45. Spin Program Schedule –Before 1st Spin Event • Efficient • Test Team (Pilot’s share spin sorties approx. 50/50) • Dale Bleakney – Project Pilot • Bob Newsome – Contract Pilot (former T-6A Test Pilot, and spin pilot) • Bob Rice – Assistance flying spins after first event • Andrew Thorson – FTE (in chase airplane) • Ahmed Mohamed – FTE (ground data analysis) • Sortie Generation Rate • 2 – 3 sorties per day • Spin Pilot/Chase Pilot alternate - Reduce fatigue

  46. 162 Configuration Change Summary September 2008 Original Configuration March 2009 Rev 1 Configuration Post Event No. 1 • Dorsal removed • Ventral fin added • Vertical stab chord increased • Vertical sweep angle decreased June 2009 Rev 2 Configuration Post Event No. 2 • Rudder extended • Ventral fin move aft • Ailerons geared (reduce adverse yaw) • Up elevator reduced from 30° to 22° (Significant)

  47. Aileron Change – Reduced Adverse Yaw Pre 3-19-2009aileronconfiguration 20° up/ 15° down Post 3-19-2009 aileron configuration 20° up/ 5° down (less adverse yaw)

  48. Summary – Lessons Learned - 2 • Safety • Spin chutes are proven technology.Design them in at the beginning • Spin tests should be donelastin a program after all aero data are gathered. Otherwise, you may end up repeating the spin tests. • Get recent spin practice in a similar airplane • NO two airplanes and NO two spins are identical (snowflake effect) • NO covenants with past programs.There may not be a correlation. • Watch for subtle clues. Stall characteristics were abigclue. • Reluctant to reduce up elevator due to stall speed impact - BIG • Safety systems MUST be robust. • TM data - essential. • Experienced pilot feedback from TM - invaluable.

  49. Model 162 Configurations Pre-September 2008 (Original) Post-September 2008 (Event No. 1) Increased vertical, added ventral Post-March 2009 (Event No. 2) (Final) Ventral Moved Aft, Rudder Extended Elevator UP Reduced, Aft cg limit Reduced, Ailerons re-geared

  50. Compliance Spin Test Status • Completed • Power Off – • Fwd/aft cg wings level • Fwd/Aft cg turning • Fwd/aft cg abused controls • Power On – • Fwd/aft cg wings level • Incomplete Conditions • Power On – Abused (Aft cg) • Power On – Turning (Aft cg)

More Related