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Capt. Brad Alberts MD11 Captain Precision Vertical Navigation on the MD11/MD10 : PROFILE V/S PROF IDLE HOLD.

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Presentation on theme: "Capt. Brad Alberts MD11 Captain Precision Vertical Navigation on the MD11/MD10 : PROFILE V/S PROF IDLE HOLD."— Presentation transcript:

1 Capt. Brad Alberts MD11 Captain Precision Vertical Navigation on the MD11/MD10 : PROFILE V/S PROF IDLE HOLD

2 Jan 2008 Disclaimer This slide show is an attempt to more adequately explain precision vertical navigation on the MD11/MD10, know as PROFILE. It is a work-in-progress at this point in time. Please confirm all information herein against CFM or other official FedEx/Boeing/Honeywell documents. Make the aircraft do what you want it to do and fly safe! I can be reached for questions at: This slide show is an attempt to more adequately explain precision vertical navigation on the MD11/MD10, know as PROFILE. It is a work-in-progress at this point in time. Please confirm all information herein against CFM or other official FedEx/Boeing/Honeywell documents. Make the aircraft do what you want it to do and fly safe! I can be reached for questions at:

3 V/S PROF IDLE HOLD Jan 2008 : Controlled Flight Into Terrain CFIT: Controlled Flight Into Terrain Leading cause of hull loss around the planet Most preventable through solid procedures Requires all levels of protection to breakdown Precision Vertical Navigation Systems (PROF) can assist in preventing it if used properly in the approach environment! Leading cause of hull loss around the planet Most preventable through solid procedures Requires all levels of protection to breakdown Precision Vertical Navigation Systems (PROF) can assist in preventing it if used properly in the approach environment!

4 V/S PROF IDLE HOLD Jan 2008 Review: Flying Tiger Flt 66 Arrival KUL Non-Precision/Automated Non-VNAV aircraft ATC Cleared descent to 2,400 Descend two four zero zero Crew heard, read-back & entered 400! Descend to four zero zero Min segment altitude 2,400 Aircraft descended and crashed into side of mountain descending to 400 Non-Precision/Automated Non-VNAV aircraft ATC Cleared descent to 2,400 Descend two four zero zero Crew heard, read-back & entered 400! Descend to four zero zero Min segment altitude 2,400 Aircraft descended and crashed into side of mountain descending to 400

5 V/S PROF IDLE HOLD Jan 2008 CFIT Levels of Prevention 1.Crew Situational Awareness (S/A) Where are we & whats below us? 2.PROFILE/VNAV (V/S PROF IDLE HOLD ) Using Vertical Navigation (VNAV or PROF) 3.ATC Terrain Warning System Most 1st World Countries only! 4.EGPWS Activation & Escape Bottom layer of protection 1.Crew Situational Awareness (S/A) Where are we & whats below us? 2.PROFILE/VNAV (V/S PROF IDLE HOLD ) Using Vertical Navigation (VNAV or PROF) 3.ATC Terrain Warning System Most 1st World Countries only! 4.EGPWS Activation & Escape Bottom layer of protection

6 V/S PROF IDLE HOLD Jan 2008 Definitions Calculated Vertical Descent Path (CVDP): The FMS calculated descent path that optimizes speed, fuel & DOC saving with path angle stabilization in compliance with MCDU distance, constraints & winds. Touching PROF enters autoflight into management of this profile. It is calculated without regard to how descent is actually flown. Top of Descent Point (TOD): FMS calculated Top of Descent point based on mileage (magenta line), speed & altitude constraints &winds aloft entry in PERF page PROF: FMA display when aircraft is operating ON the CVDP path (when profile management is activated after touching the PROF tile) V/S: FMA display when aircraft is below the CVDP or the pilot has started descent prior to calculated TOD using Vertical Speed (V/S) followed by pushing PROF IDLE: FMA display when aircraft is above the CVDP HOLD: FMA display when aircraft is in level altitude capture mode Calculated Vertical Descent Path (CVDP): The FMS calculated descent path that optimizes speed, fuel & DOC saving with path angle stabilization in compliance with MCDU distance, constraints & winds. Touching PROF enters autoflight into management of this profile. It is calculated without regard to how descent is actually flown. Top of Descent Point (TOD): FMS calculated Top of Descent point based on mileage (magenta line), speed & altitude constraints &winds aloft entry in PERF page PROF: FMA display when aircraft is operating ON the CVDP path (when profile management is activated after touching the PROF tile) V/S: FMA display when aircraft is below the CVDP or the pilot has started descent prior to calculated TOD using Vertical Speed (V/S) followed by pushing PROF IDLE: FMA display when aircraft is above the CVDP HOLD: FMA display when aircraft is in level altitude capture mode

7 V/S PROF IDLE HOLD Jan 2008 PROF System Architecture Series of IF > THEN logic-flow statements Next thing to do is conditional on something occurring and triggering it New altitude, airspeed, config change Change limited to programmed options Limited pilot knowledge of how automation works leads to the airplane is all up! & using LVL CHG instead when PROF doesn't go as anticipated due to limited knowledge Series of IF > THEN logic-flow statements Next thing to do is conditional on something occurring and triggering it New altitude, airspeed, config change Change limited to programmed options Limited pilot knowledge of how automation works leads to the airplane is all up! & using LVL CHG instead when PROF doesn't go as anticipated due to limited knowledge

8 V/S PROF IDLE HOLD Jan 2008 PROF Design Considerations FAA Violations: 93 to 1 93 Altitude violations for each Speed violation Aircraft alerts you to altitude errors as follows: Altitude errors are annunciated on MCDU scratch pad Arrows on ND also display altitude reached past required fix High & long information displayed on the PERF page System designed to comply with the crossing altitude restriction before speed compliance System advises pilot of inability to maintain speed Flashing FMA above at selected Speed +10 KIAS ADD DRAG advisory in ND FAA Violations: 93 to 1 93 Altitude violations for each Speed violation Aircraft alerts you to altitude errors as follows: Altitude errors are annunciated on MCDU scratch pad Arrows on ND also display altitude reached past required fix High & long information displayed on the PERF page System designed to comply with the crossing altitude restriction before speed compliance System advises pilot of inability to maintain speed Flashing FMA above at selected Speed +10 KIAS ADD DRAG advisory in ND

9 V/S PROF IDLE HOLD Jan 2008 Design of PROF: IF>THEN Conditional Statements NADP AGL- PROF Speed MaintainsV2- V2+10 Flex/Max PWR 1,000 AGL Climb Power 3,000 AGL Accel KIAS V FR & V SR prompts 10,000 MSL Accel to 330 KIAS/.84 At Anytime: Confirm E/O? Speed MaintainsV2- V2+10 Flex/Max PWR Accelerate to 250 KIAS Climb to FCP Altitude Await further pilot inputs Reaching EO Accel Alt Reaching FCP Speed- 250 A different logic-flow tree PRE-PROGRAMMED TO: CONDITION TO MEET: PRE-PROGRAMMED TO: Push PROF to begin sequence: Reaching FCP Altitude

10 V/S PROF IDLE HOLD Jan 2008 Unintended Consequences of Level Change & V/S (Non-PROF/White FMA Indication) Dive & Drive mentality of the non VNAV aircraft Thinking that PROF does not work Descends to FCP Altitude or hits the ground … whichever come FIRST! Dive & Drive mentality of the non VNAV aircraft Thinking that PROF does not work Descends to FCP Altitude or hits the ground … whichever come FIRST! t IDLE CLAMP 400NAV 1 THRUST 250 FMA Indication

11 V/S PROF IDLE HOLD Jan 2008 Creating Accurate TOD Point (Top of Descent) Loading accurate Magenta Line miles Look for un-needed fixes in STARs SIDs IAPs Use local knowledge of ATC procedures (FOM Compliance) Loading SID/STAR Constraints Crossing altitudes & speed limits Loading TOD & Airport Winds/Temp PERF pg 2: DESCENT FORECAST Anti-Ice does nothing in MD10 No FADEC to increase N1 when Anti-ice is ON like the MD11 Loading accurate Magenta Line miles Look for un-needed fixes in STARs SIDs IAPs Use local knowledge of ATC procedures (FOM Compliance) Loading SID/STAR Constraints Crossing altitudes & speed limits Loading TOD & Airport Winds/Temp PERF pg 2: DESCENT FORECAST Anti-Ice does nothing in MD10 No FADEC to increase N1 when Anti-ice is ON like the MD11

12 V/S PROF IDLE HOLD Jan 2008 Using PROF in Descent Only three possible relationships relative to the calculated profile (CVDP): 1.Above profile angle Profile FMA: IDLE Past TOD point-IDLE power (Speed on Pitch) when lower altitude entered in FCP 2.On profile angle Profile FMA: PROF When started down at TOD point-power is THRUST (Speed on Thrust) 3.Below profile angle Profile FMA: V/S Descend prior to TOD requires pilot applied V/S-power is THRUST (Speed on Thrust) 1.Above profile angle Profile FMA: IDLE Past TOD point-IDLE power (Speed on Pitch) when lower altitude entered in FCP 2.On profile angle Profile FMA: PROF When started down at TOD point-power is THRUST (Speed on Thrust) 3.Below profile angle Profile FMA: V/S Descend prior to TOD requires pilot applied V/S-power is THRUST (Speed on Thrust)

13 V/S PROF IDLE HOLD Jan 2008 Vertical Deviation Indicator (VDI) in relation to CDA Profile angle Aircraft is On Profile Autothrottles: Speed on Thrust FMA: PROF Aircraft is Above Profile (high) Autothrottles: Speed on Pitch FMA: IDLE 1, Diamond represents aircraft location relative to the Profile/ CVDA path Mid-point bar indicates center of CVDA path- On Profile Aircraft is Below profile (low) Autothrottles: Speed on Thrust FMA: V/S

14 V/S PROF IDLE HOLD Jan 2008 Starting the Descent in relationship to the Top of Descent point If started PRIOR to calculated TOD: enter new alt in FCP- Select an appropriate V/S then press PROF or Enter the newly assigned altitude in MCDU INIT page - 750fpm Magenta V/S is PROF Armed condition-if CVDA profile is re-intercepted it reverts to & captures the profile: PROF If started AT calculated TOD Descend in PROF ATC offers Pilot discretion descent If started PAST calculated TOD Dial in new altitude in FCP Aircraft will descend in IDLE Magenta IDLE in PROF Armed condition-if calculated profile re-intercepted it captures the profile: PROF If started PRIOR to calculated TOD: enter new alt in FCP- Select an appropriate V/S then press PROF or Enter the newly assigned altitude in MCDU INIT page - 750fpm Magenta V/S is PROF Armed condition-if CVDA profile is re-intercepted it reverts to & captures the profile: PROF If started AT calculated TOD Descend in PROF ATC offers Pilot discretion descent If started PAST calculated TOD Dial in new altitude in FCP Aircraft will descend in IDLE Magenta IDLE in PROF Armed condition-if calculated profile re-intercepted it captures the profile: PROF VDI

15 V/S PROF IDLE HOLD Jan 2008 Using the VDI to determine CVDP location A/T power V/S *Requires PROF be touched after V/S initiated IDLE PROF FL330 or 10,000 or VDI 8,000 3,000 TOD Autothrottles: IDLE=idle PROF=thrust V/S=thrust Calculated descent profile (CDA)

16 V/S PROF IDLE HOLD Jan 2008 How the MD11 tells you it knows its above profile… The VDI shows diamond below center mark Intercept Icons start to appear on magenta line PERF page shows how high & long FLTPL page shows * DECEL in 1R When you see these signs & enter a lower altitude in PROFILE the throttles can only go to one setting: IDLE The VDI shows diamond below center mark Intercept Icons start to appear on magenta line PERF page shows how high & long FLTPL page shows * DECEL in 1R When you see these signs & enter a lower altitude in PROFILE the throttles can only go to one setting: IDLE IDLE FL330 10,000 VDI Intercept with 2/3 Speed Brakes (white) Re-intercept on its own-clean wing! (magenta) TOD ECON DES PATH ERROR PRED TO 5320HI 12LONG ECON UTC DIST Where aircraft will level at new altitude

17 V/S PROF IDLE HOLD What causes an ALT ERROR AT…? Aircraft above the CVDP Alert always shown in the scratch pad. When the magenta intercept ball goes past the upcoming constraint the ALT ERROR alert occurs in the scratch pad. If the white IP is still prior to the constraint speed brakes could salvage the crossing restriction. When the magenta IP move back prior to the constraint the error message will disappear. Aircraft above the CVDP Alert always shown in the scratch pad. When the magenta intercept ball goes past the upcoming constraint the ALT ERROR alert occurs in the scratch pad. If the white IP is still prior to the constraint speed brakes could salvage the crossing restriction. When the magenta IP move back prior to the constraint the error message will disappear. Jan 2008

18 V/S PROF IDLE HOLD Jan 2008 Where will the aircraft descend to in PROF? Whichever is higher: MCDU: Line 2 R –LARGE font altitude (Here HAYDN at 4,000) SMALL font altitudes & 1R are never honored FMS calculated or actual crossing altitudes FCP Altitude (where would it descend now if in PROF?) Whichever is higher: MCDU: Line 2 R –LARGE font altitude (Here HAYDN at 4,000) SMALL font altitudes & 1R are never honored FMS calculated or actual crossing altitudes FCP Altitude (where would it descend now if in PROF?) T-P 6230 HAYDN 4000 MCGEE L V/S

19 V/S PROF IDLE HOLD Jan 2008 Advantages of flying the PROF Profile/CDA (vs. dive & drive-LVL CHG/ IDLE CLAMP) Less fuel used Less VFR traffic conflicts Less noise for our neighbors Reduced bird strike chances Operating on a stabilized descent Farther away from CFIT! Less fuel used Less VFR traffic conflicts Less noise for our neighbors Reduced bird strike chances Operating on a stabilized descent Farther away from CFIT!

20 V/S PROF IDLE HOLD Jan 2008 Alternate Way to Utilize Level Change (& V/S for that matter!) If Level Change is necessary – pull Level Change Verify VDI diamond is not in the PROF capture zone Touch PROF – Altitude FMA is now IDLE (magenta) Aircraft now has big font MCDU altitude protection If Level Change is necessary – pull Level Change Verify VDI diamond is not in the PROF capture zone Touch PROF – Altitude FMA is now IDLE (magenta) Aircraft now has big font MCDU altitude protection t IDLE 400 NAV THRUST

21 V/S PROF IDLE HOLD Jan 2008 V/S to IDLE Issue Scenario: you initiate a V/S descent and hit PROF. The FMA changes to IDLE unexpectedly It may be a function of the margin between the FMS derived cruise speed vs. high-speed foot V/S is Speed on Thrust. If the magenta ball is too close to high-speed foot there is insufficient speed margin to control a speed-on-thrust command Aircraft defaults to IDLE as a result. This has been seen less on the MD11 due to higher margins between the magenta ball and high-speed foot. Treat Profile software like dealing with Crew Scheduling: Trust but Verify! Scenario: you initiate a V/S descent and hit PROF. The FMA changes to IDLE unexpectedly It may be a function of the margin between the FMS derived cruise speed vs. high-speed foot V/S is Speed on Thrust. If the magenta ball is too close to high-speed foot there is insufficient speed margin to control a speed-on-thrust command Aircraft defaults to IDLE as a result. This has been seen less on the MD11 due to higher margins between the magenta ball and high-speed foot. Treat Profile software like dealing with Crew Scheduling: Trust but Verify! MD10-10 MD11

22 V/S PROF IDLE HOLD Jan 2008 Technique for Complying with an Early Descent to a Lower Intermediate Cruise Altitude Scenario: you are cleared to descend from FL360 to FL320 prior to TOD then Pilot's Discretion to FL240: Enter FL320 in the FCP (aircraft remains level FL360 due to fact that TOD is some miles ahead of aircraft) Select INIT page on MCDU and enter 320 in line 5L as new cruise altitude Aircraft will then begin a descent in magenta V/S at 750 fpm until reaching FL320 and will capture/HOLD Leveling at FL320 (Magenta HOLD on the FMA) select FL240 in FCP (do not change INIT page). Aircraft will stay at FL320 until newly calculated TOD then start down to FL240 on Profile Scenario: you are cleared to descend from FL360 to FL320 prior to TOD then Pilot's Discretion to FL240: Enter FL320 in the FCP (aircraft remains level FL360 due to fact that TOD is some miles ahead of aircraft) Select INIT page on MCDU and enter 320 in line 5L as new cruise altitude Aircraft will then begin a descent in magenta V/S at 750 fpm until reaching FL320 and will capture/HOLD Leveling at FL320 (Magenta HOLD on the FMA) select FL240 in FCP (do not change INIT page). Aircraft will stay at FL320 until newly calculated TOD then start down to FL240 on Profile

23 V/S PROF IDLE HOLD Arrival Technique Jan 2008 JSICA SQIDD 36L Approaching this side of the airport: use DIRECT/INBD COURSE (1R in DIRECT TO page). NOTE: being on magenta line not required for accurate profile information NOTE: Wait until rolling out of turn before executing 1R-magenta line is drawn on ground track, not heading Approaching from this area: Go DIRECT to HAYDN /inbound course – 270° and a magenta line (for PROF purposes) mimics a downwind-to-base pattern < 270° JSICA/180° JSICA/270° Aircraft on a 330° heading Aircraft on a 090° heading SQIDD/270° Aircraft on a 300° heading

24 V/S PROF IDLE HOLD PROFILE Misc. Issues When at an altitude that is many miles from the next FP point (30 mile final in to MEM) and ATC gives a clearance to descent, this system does not manage very low rate–of-descent vertical speeds well. Use V/S or Level Change to get the VDI diamond out of the PROF capture zone (2-3 diamond heights from center) then select PROF for CFIT protection. Comply with the AIM recommended 500 fpm ROD or ATC request. The last appr fix (usually the FAF) is a big font altitude. If the G/S capture/Land does not capture prior to approx 100 above that fixs altitude, the aircraft will go into altitude hold and consequently go above glideslope. When at an altitude that is many miles from the next FP point (30 mile final in to MEM) and ATC gives a clearance to descent, this system does not manage very low rate–of-descent vertical speeds well. Use V/S or Level Change to get the VDI diamond out of the PROF capture zone (2-3 diamond heights from center) then select PROF for CFIT protection. Comply with the AIM recommended 500 fpm ROD or ATC request. The last appr fix (usually the FAF) is a big font altitude. If the G/S capture/Land does not capture prior to approx 100 above that fixs altitude, the aircraft will go into altitude hold and consequently go above glideslope. Jan 2008

25 V/S PROF IDLE HOLD Instances When PROF Will Not Work Switching to HOLD Mode prior to entering a holding fix Within :03 mins of entering holding the aircraft will stop operating in PROF and switch to HOLDING mode Greater than ~150nm from destination (full descent buffer memory issue) If the aircraft is greater than this distance from destination a PROF decent will not be honored as the memory available to manage PROF are limited – ie: coast-in after Atlantic crossing enroute to CDG Switching to HOLD Mode prior to entering a holding fix Within :03 mins of entering holding the aircraft will stop operating in PROF and switch to HOLDING mode Greater than ~150nm from destination (full descent buffer memory issue) If the aircraft is greater than this distance from destination a PROF decent will not be honored as the memory available to manage PROF are limited – ie: coast-in after Atlantic crossing enroute to CDG Jan 2008

26 V/S PROF IDLE HOLD Jan 2008 The Bottom Line: Use PROF whenever possible/appropriate in the terminal environment as another tool to prevent CFIT Make the aircraft complies with ATC instructions: fly the aircraft Lower automation level whenever ambiguity arises as to what HAL is doing Use the highest level appropriate to conditions and pilot knowledge Use PROF whenever possible/appropriate in the terminal environment as another tool to prevent CFIT Make the aircraft complies with ATC instructions: fly the aircraft Lower automation level whenever ambiguity arises as to what HAL is doing Use the highest level appropriate to conditions and pilot knowledge

27 V/S PROF IDLE HOLD Jan 2008 Operating in PROFILE V/S PROF IDLE Your key to added CFIT protection in the approach environment Safe Legal Professional Your key to added CFIT protection in the approach environment Safe Legal Professional


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