Capt. Brad AlbertsMD11 Captain

Precision Vertical Navigation on the

MD11/MD10 :

PROFILEV/S • PROF • IDLE •

HOLD

V/S • PROF • IDLE • HOLD

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: jbalberts13@yahoo.com

V/S • PROF • IDLE • HOLD

Jan 2008

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!

V/S • PROF • IDLE • HOLD

Jan 2008

Review: Flying Tiger Flt 66Arrival 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’

V/S • PROF • IDLE • HOLD

Jan 2008

CFIT Levels of Prevention

1. Crew Situational Awareness (S/A)• Where are we & what’s 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

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

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

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

V/S • PROF • IDLE • HOLD

Jan 2008

Design of PROF: “IF>THEN” Conditional Statements • NADP 1

400’ AGL- PROF

Speed MaintainsV2-

V2+10 Flex/Max PWR

1,000’ AGL

Climb Power

3,000’ AGL Accel - 250

KIASVFR & VSR 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:

CONDITION TO MEET:

PRE-PROGRAMMED TO:

Push PROF to begin sequence:

Reaching FCP Altitude

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!

t IDLE CLAMP 400’NAV 1THRUST 250

FMA Indication

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 STAR’s • SID’s • IAP’s

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 ONlike the MD11

V/S • PROF • IDLE • HOLD

Jan 2008

Using PROF in DescentOnly three possible relationshipsrelative 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)

V/S • PROF • IDLE • HOLD

Jan 2008

Vertical Deviation Indicator (VDI) in relation to CDA Profile angle

Aircraft is On ProfileAutothrottles: Speed on ThrustFMA: PROF

Aircraft is Above Profile (high)Autothrottles: Speed on PitchFMA: IDLE

1,000’

100’

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 ThrustFMA: V/S

V/S • PROF • IDLE • HOLD

Jan 2008

Starting the Descentin 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 -

750’fpm 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

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)

V/S • PROF • IDLE • HOLD

Jan 2008

How the MD11 tells youit knows it’s 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 1RWhen you see these signs & enter a lower

altitudein 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 it’s own-clean

wing! (magenta)

TOD

ECON DESPATH ERROR PRED TO 5320HI 12LONG 10000

ECON UTC DIST

Where aircraft will levelat new altitude

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.

Jan 2008

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?)   

T-P 6230HAYDN 4000MCGEE 197036L 470

400 V/S

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!

V/S • PROF • IDLE • HOLD

Jan 2008

Alternate Way to UtilizeLevel 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

t IDLE 400’NAV 1250 THRUST

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!

MD10-10

MD11

V/S • PROF • IDLE • HOLD

Jan 2008

Technique for Complying with anEarly 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

V/S • PROF • IDLE • HOLD

Arrival Technique

Jan 2008Jan 2008

JSICA

SQIDD36L

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 informationNOTE: 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 ona 330° heading

Aircraft ona 090° heading

SQIDD/270°

Aircraft ona 300° heading

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 fix’s altitude, the aircraft will go into altitude hold and consequently go above glideslope.

Jan 2008

V/S • PROF • IDLE • HOLDInstances 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 CDGJan 2008

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

V/S • PROF • IDLE • HOLD

Jan 2008

Operating in PROFILEV/S • PROF • IDLE

Your key to added CFIT protection

in the approach environment

Safe • Legal • Professional