“DISRESPECTING” THE V1 SPEED - IMPLICATIONS OF NOT RESPECTING V1

 

Sources:

AIRBUS 
Getting to grips with aircraft performance. Jan 2002.
Michel PALOMEQUE
A320 Flight Safety Director & Chief Engineer Advisor A320 Program
Safety first #06 July 2008
LORRAINE DE BAUDUS
Flight Operations Standards & Safety management
PHILIPPE CASTAIGNS
Experimental Test Pilot
Stéphane PUIG
Project Leader, Safety Initiatives
Engineering
 24th Flight Safety Conference
19-22 March 2018
Vienna, Republic of Austria
Safety first - Special Edition - February 2018

“disrespecting” the V1 speed - implications of not respecting V1

 

a)     The crew decides to continue take-off while an engine failure occurred before V1.

The aircraft can potentially exit the runway laterally, or be unable to take-off before the end of the runway.

b)     An RTO is initiated above V1.

GO/ NO GO decision prior to the aircraft reaching V1.

 After V1, the crew must continue take-off and consider using TOGA thrust except if a derated take-off was performed.

 What speeds exactly should be monitored?

What do these speeds mean and where do they come from?

What happens if such speeds are exceeded?

V1: Decision speed

V1 is the maximum speed at which a rejected take-off can be initiated in the event of an emergency.

V1 is also the minimum speed at which a pilot can continue take-off following an engine failure.

VMBE = Maximum Brake Energy speed.

The ground speed at which maximum energy is put into the brakes, when a RTO is performed at MTOW.

V1 must be lower than VMBE.

This speed is entered by the crew in the MCDU during flight preparation, and it is represented by a “1” on the speed scale of the PFD during take-off acceleration.

If take-off is aborted at V1, the aircraft must be able to come stopped before the end of the runway, without exceeding the maximum energy the brakes can absorb.

If an engine failure occurs after V1, then the aircraft must be able to achieve a safe take-off with TOGA or derated power (enough lateral control).

The minimum speed during take-off roll at which the aircraft can still be controlled after a sudden failure of one engine (be it a two or four-engine airplane).

If the take-off is continued, only the rudder will be able to counteract the yaw moment that is generated by asymmetric engine(s) thrust.

VMCG = Minimum Control Speed on the Ground

It is the limit speed determined during Airbus flight tests.

If a failure occurs before reaching this minimum speed, the takeoff must be interrupted to maintain control of the aircraft.

V1 must be greater than VMCG.

VEF = Engine Failure Speed

The maximum aircraft speed at which the most critical engine can fail without compromising the safe completion of take-off after failure recognition.

V1 must be greater than VEF.

Considering that it is generally assumed humans have a reaction time to an unexpected event (such as a failure) of 1 second.

VEF must be greater than VMCG.

If an engine failure happens at VEF, then it must be possible to continue and achieve the safe take-off speed with TOGA power triggered.

Minimum Control Speed on the Ground: VMCG

In the determination of VMCG, assuming that the path of the airplane accelerating

with all engines operating is along the centerline of the runway, its path from the point

at which the critical engine is made inoperative to the point at which recovery to a

direction parallel to the centerline is completed, may not deviate more than 30 ft

laterally from the centerline at any point.”

V2: Take-off safety speed

 V2 is the minimum take-off speed that the aircraft must attain by 35 feet above the runway surface with one engine failed at VEF and maintain during the second segment of the take-off.

This speed must be entered by the crew during flight preparation and is represented by a magenta triangle on the PFD speed scale.

V2 is always greater than VMCA and facilitates control of the aircraft in flight.

What are the operational implications of not respecting V2?

Supposedly, there are two different ways of “disrespecting” the V2 speed criteria:

1. Flying below V2 in case of an engine failure.

The drag increase below V2 may lead to a situation where the only way to recover speed is to descend.

If the speed further decreases and V2 is not recovered, then the high angle of attack protection may be reached, and the aircraft may ultimately enter into an unrecoverable descend trend. In particular, if the speed decreases below VMCA, the aircraft might not be recoverable due to lack of lateral control.

2. Flying above V2 in case of an engine failure.

In case of excessive speed, the required climb performance may not be reached, thus increasing the chance to trespass the obstacle clearance.

 Minimum Control Speed in the Air: VMCA

VMC[A] may not exceed 1.2 VS with

• Maximum available take-off power or thrust on the engines;

• The most unfavorable center of gravity;

• The airplane trimmed for take-off;

• The maximum sea-level take-off weight

• The airplane in the most critical take-off configuration existing along the flight path after the airplane becomes airborne, except with the landing gear retracted; and

• The airplane airborne and the ground effect negligible

 Minimum Control Speed during Approach and Landing: VMCL

The minimum control speed during approach and landing with all engines operating, is the calibrated airspeed at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the airplane with that engine still inoperative, and maintain straight flight with an angle of bank of not more than 5º.

VMCL must be established with:

• The airplane in the most critical configuration (or, at the option of the applicant, each configuration) for approach and landing with all engines operating;

• The most unfavorable center of gravity;

• The airplane trimmed for approach with all engines operating;

• The most unfavorable weight, or, at the option of the applicant, as a function of weight.

• Go-around thrust setting on the operating engines

Minimum Unstick Speed: VMU

It is the calibrated airspeed at and above which the airplane can safely lift off

the ground, and continue the take-off…”

During the flight test demonstration, at a low speed (80 - 100 kt), the pilot pulls

the control stick to the limit of the aerodynamic efficiency of the control surfaces. The

aircraft accomplishes a slow rotation to an angle of attack at which the maximum lift

coefficient is reached, or, for geometrically-limited aircraft, until the tail strikes the

runway (the tail is protected by a dragging device). Afterwards, the pitch is

maintained until lift-off.

Two minimum unstick speeds must be determined and validated by flight tests:

- with all engines operatives : VMU (N)

- with one engine inoperative : VMU (N-1)

In the one-engine inoperative case, VMU (N-1) must ensure a safe lateral control

to prevent the engine from striking the ground.

 Typical tailstrike scenario

Most of the tailstrikes on A320 family aircraft occur during landing in manual mode (Auto Pilot OFF), when the sidestick is maintained in the aft position after touch down.

Additional alerts to impeding tailstrike

• A pitch limit indicator on the Primary Flight Display, which is displayed at landing (below 400 feet AGL in both manual and automatic modes) when the thrust levers are below the FLEX/MCT setting.

• A “PITCH, PITCH” call out, activated when the pitch is greater than a certain threshold and if TOGA is not selected.

(The call out is available on the following standards : FWC H2F3 or H2F3P and FAC 618 or 619).

Managed Descent 

The managed descent mode guides the aircraft along the FMS computed vertical flight path. The  mode is preferred when conditions permit since it ensures the management of altitude constraints and reduces the operating cost when flying at ECON DES speed. The  mode is only available when the aircraft flies on the FMS lateral flight plan, i.e. when the aircraft uses the  horizontal guidance mode.

MANAGING SPEED DURING APPROACH AND LANDING

In a decelerated approach, the aircraft is decelerating during its final approach segment to be stabilized at VAPP at 1000ft above the airport elevation. In most cases, it reaches the Final Descent Point

(FDP) in CONF1 at S speed. However, in some cases, when the deceleration capabilities are low (e.g. heavy aircraft, a high elevation airport or tailwind), or for particular approaches with a deceleration segment located at low height, the flight crew should select CONF 2 before the FDP. The FCOM recommends selecting CONF 2 before the FDP when the interception of the final approach segment is below 2000ft AGL (A320) or 2500ft AGL (A330/A340, A350 and A380). In this case, for ILS, MLS or GLS approaches, or when using FLS guidance, it is good practice to select FLAPS 2 when one dot below the glideslope on the PFD deviation scale.

The take-off preparation by the pilots entails the computation of the aircraft weights (Zero Fuel Weight, Take-Off Weight) and respective CG positions, as well as the calculation of the different Take-Off speeds (V1, VR, V2) and thrust rating.

These data may be obtained either by using load sheets and take-off charts, or by means of non-aircraft software applications (i.e. flight operations laptops).

 Three types of errors may be performed during this process:

• Parameters entered into the tables or into the programs may be wrong (carried load, outside temperature, runway length etc…)

• Computations may be inaccurate (wrong interpretation of charts, bug in the software etc…)

• The data entry process into the Flight Management System (FMS) may be incorrect (distraction, stress etc…).

 Each of these types of errors may have consequences on the Take-Off speeds:

• A too low VR inserted through the Multipurpose Control & Display Unit (MCDU), may lead to a tail strike.

• A too low V2 may lead to the flight path not clearing the obstacles in an one engine out condition.

• A set of too high Take-Off speeds may lead to a runway overrun or too high energy rejected take-off (RTO).

 Other possible consequences:

• An error on the A/C configuration at take-off (CONF/TRIM setting) may lead to an “auto rotation” or a nose heavy condition

• A take-off from a different runway from the intended one, or even from a taxiway, may lead to:

- A collision on ground with another aircraft, vehicle or obstacle

- A collision in the air with an obstacle

- An overrun if no lift-off before the end of the runway (even more so if combined with a high temperature FLEX take-off)

- A low or high energy runaway overrun (in case of RTO)

• A wrong thrust rating may result in a tailstrike, a runway overrun or a shift of the climb path.

Take-Off Securing function (TOS)

The TOS has been developed to detect, to the best extend possible, wrong data entered into the

FMS.

The Thales system checks:

• The Zero Fuel Weight (ZFW) range

• The Take-Off speeds consistency.

 The Honeywell system checks:

• The Zero Fuel Weight (ZFW) range

• The Take-Off speeds consistency

• The Take-Off speeds limitations.

MH370 A NEW STUDY

 

MH370 Flight Path Analysis

Case Study

by Richard Godfrey, Dr. Hannes Coetzee (ZS6BZP) and Prof. Simon Maskell

30th August 2023

At 17:19:26 UTC Malaysian Air Traffic Control (ATC) at the Lumpur Radar station contacted

MH370 with a routine message: “Malaysian Three Seven Zero contact Ho Chi Minh one two zero

decimal niner good night.” Captain Zaharie Shah responded at 17:19:30 UTC: “Good night

Malaysian Three Seven Zero.” At 17:20:36 UTC, just 66 seconds later, the Mode S transponder

symbol of MH370 dropped off the Malaysian ATC radar display. MH370 had gone ‘dark’ and

disappeared into the night sky diverting back over Malaysia to the Malacca Strait according to

primary civilian and military radar data.

This case study examines the use of radio waves from the Weak Signal Propagation Reporter

(WSPR) and the historic database called WSPRnet. WSPR data can be used as a multi-static

passive radar system to detect and track aircraft, where WSPR links between radio transmitters

and receivers align with the aircraft position along a great circle path. Signal level and signal

frequency modulations can result, when an aircraft flight path intersects with the propagation path

of a WSPR link. Together with the Boeing aircraft performance data, the MAS Operations fuel and

engineering data, the weather data enroute, the Inmarsat satellite data and the drift analysis of the

41 items of possible MH370 floating debris that have been recovered from around the Indian

Ocean, a comprehensive picture of the final hours of flight MH370 can be collated.

The purpose of detecting and tracking MH370 across the Indian Ocean is to ensure the reliability

of the flight path analysis during the 7 hours 46 minutes the aircraft was in the air and therefore

the accuracy of the end point position, where MH370 ran out of fuel after 7 hours 35 minutes and

then subsequently crashed around 11 minutes later. The alignment of the WSPR analysis with the

analyses from Boeing, Inmarsat and the drift analysis from the University of Western Australia is a

significant multi-disciplinary outcome, which all point to the same crash area. There have been 41

items of confirmed or possible MH370 floating debris recovered from round the Indian Ocean.

Flight MH370 was diverted to the Indian Ocean, where it crashed after fuel exhaustion on 8th

March 2014 at some point after the last satellite signal was received at 00:19:37 UTC. At the time

of writing of this case study, MH370 still has not been found despite extensive surface and

underwater searches. Around 10 million commercial passengers fly every day and the safety of

the airline industry relies on finding the cause of every aircraft accident.

APPROACH OPERATIONS IN REDUCED VISIBILITY

 

HUD With a Velocity (Flight-Path)

Vector Reduces Lateral Error During

Landing in Restricted Visibility

Örjan Goteman

Scandinavian Airlines

Stockholm, Sweden

Kip Smith and Sidney Dekker

Department of Industrial Ergonomics

Linköping Institute of Technology

The majority of approaches (the segment of flight immediately before touchdown) performed in U.S. and European civil air transport operation are conducted as Category I instrument landing system (ILS) approaches. For a Category I approach the two critical factors when making the decision of whether to

land are the decision height and the RVR. Decision height refers to the aircraft’s vertical distance above the runway threshold where the pilot must make the decision to land or make a go-around. The pilot must be able to see at least some of the approach or runway lights at the decision height. The approach lights will then guide the pilot to the runway.

The RVR is a measure of horizontal visibility defined by the length of visible approach and runway lights in the ambient atmospheric conditions. If the RVR is too low the pilot will not be able to see any of the approach lights at the decision height and must make a go-around.

This RVR is expected to allow the pilot to see a visual segment of the ground that contains enough of the runway approach lights to judge the aircraft’s lateral position, cross-track velocity, and position in roll when the aircraft is at decision height.

EXPERIMENT 1

Method

Forty-eight pilots from a major European airline volunteered to participate. All were qualified to fly the B–737–700 aircraft and had completed their HUD training for the operator. The HUD training sessions consisted of 1 day of theory and two simulator sessions of 4 hr duration each. Experience on the B–737–700 varied from 50 hr to more than 1,000 hr. There is every reason to believe that these participants are representative of the population of commercial pilots to whom regulators need the data to generalize. Apparatus. We used a CAE B–737–700 training simulator with aircraft aerodynamics and visual angles valid for B–737–700 to collect data. This six-axis full-motion simulator is approved for low-visibility operations down to an RVR of 200 m. The simulator’s visual system had a field of vision of 180°/40° with a focal distance greater than 10 m.

The head-down instrumentation was a B–737–700 instrument panel in primary flight display (PFD) configuration with flight director guidance. This instrumentation was available in both the with-HUD and the no-HUD conditions.

The HUD installed in the simulator was a Rockwell-Collins Flight Dynamics HGS–4000® (Head-up Guidance System), certified for low-visibility operations down to and including an RVR of 200 m. The HUD symbology and functionality used in the experiment met the production-line standard specification for the instrument meterological conditions (IMC) mode used when conducting Category I ILS and non-precision approaches (see Figure 6). This mode was deliberately chosen to improve the external validity on the form of operational usability of the study. In normal operations, the vast majority of ILSs are only approved for Category I operations. The HUD provided conformal display of flight path (velocity) and flight-path guidance. The flight path was displayed as a circle with slanted wings. Flight-path guidance was displayed in the form of a ring inside the flight-path symbol. Flight-path guidance was not available in the conventional head-down instrumentation.

The radio navigation facilities simulated in the study conformed to the ICAO (1996) standard for ILS radio navigation aids for Category I approaches transmitting a radio beam for both vertical and lateral reference. The integrity of the transmitted beam is guaranteed to keep the aircraft within allowable airspace, safe from

Gulfstream GVII-G500 in level flight at 40,000 feet, Mach 0.90. 

obstacles down to 200 ft height, corresponding to lowest allowable decision height. Approaches in Experiment 1 were flown to a simulated runway with a system of approach lights 900 m in length. This length falls within the full facilities system category of European aviation regulation (JAA, 2004b).

Procedure. Each pilot manually flew two approaches using standard operating procedures of the airline. The scenarios started as a 6 nm final to the runway in lower than standard or standard RVR in a simulated 10 kt left crosswind. In the with-HUD condition, the pilots kept the aircraft on lateral and vertical by following the flight-path guidance ring with the flight-path symbol on the HUD. At 50 ft above the runway threshold, the guidance cue was automatically removed and the pilots performed the landing flare using external visual cues in conjunction with the HUD flight-path symbol. The HGS–4000® IMC mode incorporating automatic removal of the guidance cue was deliberately chosen to ensure that the pilots could not attend solely to the HUD symbology in the with-HUD conditions.

In the no-HUD condition the pilots kept the aircraft on lateral and vertical track by following the flight director bar guidance. At decision height they continued the approach and landing using the external cues only.

All approaches were recorded to determine approach success. Approach and landing plots for approaches ending with a landing were printed using the aircraft’s center of gravity as the reference to determine the size of the touchdown footprint.

Results

Approach success rate. Each of the 48 pilots attempted two approaches.

Thirty-seven made two successful landings, one with HUD and one without. Three made go-arounds in both conditions. Two pilots landed with the HUD and made go-arounds without the HUD; six landed without the HUD and made go-arounds with the HUD.

The McNemar change test is the appropriate statistical procedure for testing the null hypothesis that pilots were equally likely to (a) land with the HUD and go-around without it, and (b) land without the HUD and go-around with it (Siegel & Castellan, 1988). Because the observed test statistic, calculated from the values given earlier (2 and 6), is 1.125 and is less than the criterion, x² (.05, 1) = 3.84, we cannot reject the null hypothesis. Accordingly we infer that HUD use had no impact on approach success rate.

Touchdown performance. As noted previously, 11 of the 48 pilots conducted one or two go-arounds. The simulator failed to capture the location of the landing footprint for another 7 pilots. As a result the data set for comparing the touchdown footprints across the HUD and no-HUD conditions consists of 30 pairs of approaches. Of these 30, 15 were flown using the HUD in the first approach and 15 using the conventional head-down instruments (no-HUD) in the first approach; 15 were flown in standard RVR (550 m) conditions and 15 in lower than standard RVR conditions (450 m).

Lateral touchdown performance was measured as the absolute lateral deviation from the runway centerline at touchdown. The data for the main effect of HUD use are shown in Figure 7. Landings were closer to the centerline when pilots used the HUD. The two-factors repeated-measures analysis of variance (ANOVA) revealed a strong effect for HUD use on the lateral component of the touchdown footprint, F(1, 28) = 9.05, p < .006,   n² = .12 indicating a power of .80 at α = .05.

The main effects for RVR and order of HUD condition were not significant. There was, however, a marginally significant interaction between HUD use and the order

EXPERIMENT 2

Method

The method, procedure, and design used in the second experiment were identical to those used in the first experiment with the few exceptions discussed here. The different criteria for standard RVR across facility types preclude collapsing and analyzing the data as a single experiment.

Participants. Forty-five pilots from the same major European airline volunteered to participate. None of the volunteers had participated in Experiment 1. All were qualified to fly the B–737–700 aircraft and had completed theirHUDtraining for the operator. Experience on the B–737–700 varied from more than 50 hr to more than 1,000 hr.

Simulated ground facilities. Approaches in Experiment 2 were flown to simulations of a runway with 420mof approach lights. This length falls within the intermediate facilities category of approach lights as defined by European aviation regulations (JAA, 2004b).

 

Results

Approach success rate. Each of the 45 pilots attempted two approaches.

Thirty-two made two successful landings, one with HUD and one without. Four pilots made go-arounds in both conditions. Three pilots landed with the HUD and made go-arounds without the HUD; six pilots landed without the HUD and made go-arounds with the HUD. Once again we used the McNemar change test to test the null hypothesis that pilots were equally likely to (a) land with the HUD and go-around without it, and (b) land without the HUD and go-around with it. Because the observed test statistic, calculated from the values given previously (3 and 6) is 0.44 and is less than the criterion, x² (.05, 1) = 3.84, we infer that HUD use had no impact on approach success rate.

 Touchdown performance. As noted earlier, 13 of the 45 pilots conducted one or two go-arounds. The simulator failed to capture the location of the landing footprint for another 4 pilots. As a result, the data set for comparing the touchdown footprints across the HUD and no-HUD conditions consists of 28 pairs of approaches.

Of these 28 pairs of approaches, 9 were flown using the HUD in the first approach and 19 using the conventional head-down instruments (no-HUD) in the first approach; 14 were flown in standard RVR (700 m) conditions and 14 in lower than standard RVR conditions. The opportunistic nature of data collection precluded balancing the order of HUD use.

The main effect for HUD use, shown in Figure 9, is the only factor in the two-factor repeated-measures ANOVA to achieve statistical significance. As in Experiment 1, the effect for HUD use on the lateral component of the touchdown footprint is strong, F(1, 26) = 14.9, p < .001, n² = .10, indicating a power greater than .70. Once again, landings were closer to the centerline when pilots used the HUD. Because participant order was not fully counterbalanced, it is not possible to assess the potential for asymmetric transfer effects. As in Experiment 1, there was no significant effect for HUD use or RVR on the longitudinal component of the touchdown footprint. Once again, the difference in the observed variances across conditions of HUD use would be significant at  α = .10 if the data sets were independent.

There are three findings. First, HUD use per se did not influence the pilots’ decision to land or go-around at the decision height. The lack of an effect of HUD suggests that the additional information in the HUD did not distract the pilots’ attention or interfere with their decision making during the most critical portion of the approach and landing sequence. Second, HUD use significantly reduced the size of the lateral component of the touchdown footprint for all RVR conditions.

 Arguably it can be said that the difference between the HUD and the no-HUD conditions lay in the presence of a conformal flight-path vector in the pilots’ primary field of view during the landing. Third, in contrast to its effect on the lateral component of the touchdown footprint, it appears that the HUD did not influence the size of the longitudinal footprint. The first two findings conform to our hypotheses. Here we reexamine our hypotheses about the impact of HUD use on the touchdown footprint and offer an explanation for its differential impact on the lateral and longitudinal components.

 The HUD largely eliminates uncertainty about drift. The addition of a conformal flight-path vector projected over the runway provides instantaneous feedback about aircraft drift and actual flight path. The additional information enables precise control of the flight path during approach and landing and reduces the variance in lateral displacement practically to nil.

 Control of the longitudinal component of the touchdown footprint is largely an effect of how pilots handle the aircraft’s energy (operationally manifested as sink rate) in the final seconds before landing. The pilot uses information provided by the optic flow from the looming runway to control the aircraft’s energy (Lee, 1974). It is important to note that pilots of large commercial air transport aircraft are also aided by radio altimeter callouts that count down from 50 ft to 0 ft (runway contact) in 10-ft decrements. The initiation of the landing flare has been shown to be a function of time to contact (Mulder, Pleijsant, van der Vaart, & van Wieringen, 2000). A small change in the timing of a landing flare at the nominal glide slope of 3° results in large longitudinal differences. The HUD mode used in the experiments provided no flare guidance and no additional information that could be used to guide the pilots when to initiate the landing flare. So, if the pilots are relying more on timing of a flare maneuver than on velocity cues from the HUD to initiate the flare, it is easy to understand why we failed to detect any effect of the tested HUD with a flight-path symbol on longitudinal touchdown performance. It remains to be seen whether similar results are found for HUD modes with flare guidance, and which visual representations are actually most effective in prompting pilots to reduce sink rate at the optimal height above the runway.

 

CONCLUSIONS

Data from the experiments reported here show that HUD with a conformal velocity symbol (flight path) improved lateral touchdown performance, likely because the conformal flight-path vector in conjunction with the visual ground segment makes it easier for pilots to determine and correct for aircraft drift. We did not find an effect of HUD use on longitudinal touchdown performance, probably because the pilots flared the aircraft using a time-to-contact strategy, rather than using the flight-path vector available in the HUD modes studied here. The beneficial effects of HUD use on landing performance were seen in both in standard and lower than standard RVR conditions in both experiments, which implies that the minimum RVR for approaches using an HUD could be set lower than for approaches without an HUD.

BACKGROUND

 “Where is the nose of the aircraft?” 

It is shown as a flat vee with wings and is called a boresight.

 “Where is the horizon?”

It is below you, as shown by the synthetically drawn terrain.

The pilot’s primary focus is no longer where the aircraft is pointed, but where it is going. That is represented by the Flight Path Vector (FPV) and is drawn as a circle with small wings and a tail. The white horizontal line can be thought of as a horizon that has been adjusted to consider the altitude of the aircraft, as if the earth’s diameter has been increased. In some HUDs it is called a Zero Pitch Reference Line. You maintain level flight by placing the FPV on the Zero Pitch Reference Line.

The U.S. rules are given in 14 CFR 91.176 and are further explained in Advisory Circular 90-106A. If you meet the requirements of section (b) of that FAR, you can operate using EFVS to 100 feet above the touchdown zone elevation, at which point you must take over what the regulations call “natural vision” to complete the approach and landing. If you are operating under part 91K, 121, 129, or 135, you will need a management or operations specification. If you meet the requirements of section (a) of that FAR, you can operate using EFVS to touchdown and rollout. You will need a letter of authorization, management specification, or operations specification. AC 90-106A lists 1000 RVR as an adequate flight visibility and authorizations are normally written with this as a minimum.

Recent flight experience: EFVS. Except as provided in paragraphs (f) and (h) of this section, no person may manipulate the controls of an aircraft during an EFVS operation or act as pilot in command of an aircraft during an EFVS operation unless, within 6 calendar months preceding the month of the flight, that person performs and logs six instrument approaches as the sole manipulator of the controls using an EFVS under any weather conditions in the category of aircraft for which the person seeks the EFVS privilege. The instrument approaches may be performed in day or night conditions; and

(1) One approach must terminate in a full stop landing; and

(2) For persons authorized to exercise the privileges of § 91.176(a), the full stop landing must be conducted using the EFVS.

Source: 14 CFR 61, ¶61.66 (d)

comparison of flight director symbology

Click on image below to download it for visualization on large TV (magnification 9 times)

UNRESPONSIVE CIVIL AIRCRAFT TO AIR TRAFFIC CONTROL - NOT ALLOWED INTERCEPTING SUPERSONIC SPEED

 3.2.4 PROHIBITED AND RESTRICTED AREAS

3.2.4.1 Aircraft shall not be flown in aa PROHIBITED area, or in a RESTRICTED area the particular of which have been duly published, except in accordance with the conditions of the restrictions or by permission of the State over whose territory the areas are established.

Special Use Airspace (faa.gov)

The CIVIL jet plane did NOT offer any imminent threat to Washington's FRZ. It was flying leveled off on 34,000 feet during two overflight.

NORAD authorization for all F-16 fighter to make supersonic speed passage near the civil aircraft it was unprofessional and exhibitionist and, the supersonic passage produced severe WAKE TURBULENCE, which it resulted in intentional AUTOPILOT DESENGAGEMENT.