Late Nav Failure Condition

MMDAC VISTAS Scenario

Late Nav Failure Condition

Briefing:

Experimenter reads: You will be flying an ILS approach to a desert landing site. The ILS is approximately 7 NM long and will lead you to a hover at 250 feet MSL (250 feet HAT) above the landing site. From here, you will descend vertically to land. You must have visual contact with the ground at 100 feet MSL (100 feet HAT) in order to complete the landing. If you do not have visual contact with the ground at this altitude, you must execute a go-around. At the beginning of the scenario, all checklists have been completed, but you have not yet received landing clearance.

Initial conditions:

[Information only]

Time: 0 min

Bearing and distance to landing site: 100True/6.9 DME (on localizer and glideslope)

Altitude: 2460 MSL/1680 AGL

A/S: 250 KIAS

V/S: -1327 fpm

Wx: IMC, visibility 0

Experimenter reads: You are 6.9 NM from the landing site at 2460 feet MSL. You are on the localizer course of 100 degrees and on glideslope. Your airspeed is 250 KIAS and you are in a 1327 fpm descent. The weather is IMC with a ceiling of 500 feet AGL. Take whatever time you would like to brief the approach and landing and coordinate with your copilot before we start the simulator (after first trial, only changes need to be briefed). Your display configuration for this approach is: (tell pilot which features are active for this trial). Let us know when you are ready to begin the simulation.

[Start the simulator when the pilot indicates that he/she is ready to begin.]

Expected pilot actions:

Pilot manipulates sidestick left and right to maintain localizer course.

Pilot manipulates hat-switch to adjust descent rate and to maintain glideslope.

Pilot manipulates sidestick fore and aft to control deceleration to match target airspeed with commanded value displayed on speed tape.

Event 1:

Time: Approximately 10 seconds

Bearing and distance from landing site: 100T/6.3DME (on localizer and glideslope)

Altitude: 2425 MSL/2425 HAT

A/S: 230 kts

V/S: -1300 fpm

Wx: IMC, visibility 0

Experimenter reads: NASA 113, wind calm, cleared to land.

You will be flying an ILS approach to a desert landing site. The ILS is approximately 7 NM long and will lead you to a hover at feet 250 MSL (250 feet HAT) above the landing site. From here, you will descend vertically to land. You must have visual contact with the ground at 100 feet MSL (100 feet HAT) in order to complete the landing. If you do not have visual contact with the ground at this altitude, you must execute a go-around. At the beginning of the scenario, all checklists have been completed, but you have not yet received landing clearance.

Initial conditions:

Time: 0 min

Bearing and distance from landing site: 280True/6.9 DME (on localizer and glideslope)

Altitude: 2460 MSL/1680 AGL

A/S: 250 KIAS

V/S: -1327 fpm

Wx: IMC, visibility 0

Experimenter reads: You are 6.9 NM from the landing site at 2460 feet MSL. You are on the localizer course of 100 degrees and on glideslope. Your airspeed is 250 KIAS and you are in a 1327 fpm descent. The weather is IMC with a ceiling of 500 feet AGL. Take whatever time you would like to brief the approach and landing and coordinate with your copilot before we start the simulator. Let us know when you are ready to begin the simulation.

[Start the simulator when the pilot indicates that he/she is ready to begin.]

Expected pilot actions:

Pilot manipulates sidestick left and right to maintain localizer course.

Pilot manipulates hat-switch to adjust descent rate and to maintain glideslope.

Pilot manipulates sidestick fore and aft to control deceleration to match target airspeed with commanded value displayed on speed tape.

Event 1:

Time: Approximately 10 seconds

Bearing and distance from landing site: 280T/6.3DME (on localizer and glideslope)

Altitude: 2425 MSL (2425 HAT)

A/S: 230 kts

V/S: -1300 fpm

Wx: IMC, visibility 0

Experimenter reads: NASA 113, wind calm, cleared to land.

Expected pilot actions:

Pilot recognizes that landing clearance has been received and directs copilot to respond to ATC.

Co-pilot acknowledges landing clearance to ATC.

Pilot continues to manipulate sidestick left and right to maintain localizer course.

Pilot manipulates hat-switch to adjust descent rate and to maintain glideslope. Pilot manipulates sidestick fore and aft to control deceleration to match target airspeed with commanded value displayed on speed tape.

Event 2:

Time: 3 minutes

Bearing and distance from to landing site: 280T100T/0.90 DME (on localizer and glideslope)

Altitude: 510 MSL (510 HAT)

A/S: 62 kts

V/S: -380 fpm

WX: IMC, visibility 0

Begin navigation system drift. Tunnel or navigation indicator on ND begins drift at rate 0.972 dots / 2386 ft of travel (6.5613.2 ft lateral error / 2386 ft of travel) to yield 1 2 dot width difference between the navigation guidance and localizer after 1 minute of drift.

[These should be different values – the dots on the localizer show degrees off course, so linear distance will be much smaller this close to the landing site to give the same needle deflection]

Expected pilot actions:

Pilot continues to manipulate sidestick left and right to maintain localizer course.

Event 3

Time: 3.2 minutes

Bearing and distance from to landing site: 280T100T/0.87 DME (on localizer and glideslope)

Altitude: 500 MSL/500 AGL

A/S: 60 kts

V/S: -375 fpm

WX: VMC, clear visibility, below cloud deck

Aircraft breaks out of clouds and ground features become visible.

Expected pilot actions:

Pilot notes change in visibility, announces intention to continue approach.

Co-pilot confirms that surface is visible.

Pilot continues to manipulate sidestick left and right to maintain localizer course.

Event 4

Time: 4 minutes or when pilot notes navigation system drift, whichever occurs first

Bearing and distance from to landing site: 280T100T/0.06 2 DME (on localizer and glideslope)

Altitude: 270 315 MSL (270 315 HAT)

A/S: 10 23 kts

V/S: -50 121 fpm

WX: IMC, visibility 0Clear below clouds

Expected pilot actions:

Pilot continues to manipulate sidestick left and right to maintain localizer course.

Pilot should note deviation of navigation system indications (tunnel, if present, and ND indication) from localizer display.

[Pause simulation when pilot notes deviation.

If pilot does not note deviation, continue until navigation system reaches 1 dot deviation from localizer course (should occur 1 minute after onset of drift), then pause simulation.]

[Have pilot complete clutter questionnaire while simulator is paused. Navigation system error should be removed.]

Event 45

Time: 4 minutes flight time or when pilot notes navigation system drift, whichever occurs first

Bearing and distance from to landing site: 280T100T/0.06 2 DME (on localizer and glideslope)

Altitude: 270 315 MSL (270 315 HAT)

A/S: 10 23 kts

V/S: -50 121 fpm

WX: IMC, visibility 0Clear below clouds

Experimenter reads: We will be restarting the approach at .2 DME, with the aircraft on course and on glideslope. Your altitude at this point is now 315 feet MSL/315 feet HAT your airspeed is 23 knots, your rate of descent is 121 feet per minute, and you are below the cloud deck. Let us know when you are ready to begin.

[Resume simulation at point at which Event 3 4 occurred, with navigation system deviation corrected for the rest of the trial.]

Expected pilot actions:

Pilot continues to manipulate sidestick left and right to maintain localizer course.

Event 56

Time: 5 minutes

Bearing and distance from to landing site: 280T100T/0 NM

Altitude: 250 MSL/250 AGL

A/S: 0 – 10 kts forward

V/S: 0

WX: VMC, clear visibility, below cloud deck

Transition to hover as aircraft reaches landing site at 250 AGL. Guidance cue (white circle) appears on the ND portion of the flight display.

Expected pilot actions

Pilot should reach the landing site in a stable state at 205 feet AGL, with 0 – 10 knots forward airspeed, 0 vertical speed, and no lateral movement.

Pilot should command a descent from hover with the hat-switch not to exceed 200 fpm downward.

[If the V/S exceeds 200 fpm, the simulator should be reset and the trial should be considered as a missed approach.]

The pilot should maintain 0-10 kts forward airspeed, and no lateral movement, through fore and aft and left and right movements of the sidestick.

Event 7

Time: 7 minutes

Bearing and distance from to landing site: 280T100T/0 NM

Altitude: 100 MSL/100 AGL

A/S: 0

V/S: no more than 200 fpm descent

WX: Below cloud deck, with dust from surface obscuring visibility

Aircraft reaches decision height at 100 feet AGL.

In landable condition 50% brownout is present, with landing site visible out the window.

In non-landable condition 100% brownout is present, with landing site not visible out the window.

Expected pilot actions

Pilot should be descending at 200 fpm or less, with airspeed 10 kts forward or less and no lateral movement. Copilot provides requested altitude callouts.

At 100 feet AGL in the landable condition, the pilot should announce that he/she will be landing the aircraft.

In the non-landable condition, the pilot should announce that he/she will be executing a go-around.

[Once the pilot announces whether or not the aircraft will be landed, terminate the simulation and administer the second clutter questionnaire.]