Cold Wx and LVP's

Question 1

What manuals/sources might you refer to in cold wx ops?

Answer 1

Docunet Cold Wx Ops Aide Memoire (particularly useful)/OMC Section 4/ibook/OMA 8.8/OMB 0.5.8.Also some useful info available form the Resource dashboard.

Question 2

What do you understand by ‘Snowflake’?

Answer 2

OMC 1.5.2 Teams of aircrew/tech managers controlled by De-ice Control to facilitate a/c on-stand inspections. The teams will be activated according to the Winter Ops colour status of LHR.

Question 3

Can the 777 use JEDI facilities? Where would you find guidance on those facilities?

Answer 3

Yes. OMC Section 4.1 > Ops Info and Aide Memoire. Also a video in the MLA

Question 4

Define icing conditions?

Answer 4

OAT 10c deg (50F) and below and viz moisture or fog in which viz is 1500m (1sm) or less or ice/slush/snow on paved surfaces.

Question 5

What further actions would be required when FZFG was reported or fog with a temp below zero? What if the viz were also below 300m in these conditions?

Answer 5

Both OMA and GOM specify that after landing in freezing fog (or fog with an OAT of less than zero) engineering should be informed. A check should requested for fan blade icing and an entry made in the AML. If FZFG is present AND viz is below 300m then for -RR observe Taxi time restrictions and run-ups. Refer to SP 16. Add comment in AML of taxi IN time (unless a run-up can be accomplished within 5 mins of shutdown) as it is the TOTAL taxi time that is important so it is necessary to account for the time taken to taxiing in ADDED to the taxi out. Take off is not permitted if total taxi time in freezing fog with visibility 300 meters or less exceeds 60 minutes without having accomplished the core ice shed procedure. The engine core must be manually de-iced.

Question 6

When and how would you conduct engine run-ups?

Answer 6

Anytime icing conditions exist and the OAT is 3deg and below. GE 50%/N1/1s/15min -RR 50%N1/1s/60min AND before take-off.

Question 7

You require intake/fan/undercarriage/windscreen de-icing. Who do you call and when?

Answer 7

Engineering. ASAP

Question 8

The a/c wings/tail/fuselage/tail/underwing requires de/ant-icing. Who do you call and when?

Answer 8

De-ice control 131.765 at ETD -20mins

Question 9

How could you ascertain if an aeroplane has been treated at briefing?

Answer 9

FICO > ICE space and last 3 letters of reg. e.g. ICE TBA

Question 10

Where would you find guidance on configuring the a/c for de-icing treatment?

Answer 10

ECL > Supp > Ops Info > De/Anti Icing.

FCOM > SP4 > De/Anti Icing

Question 11

With respect to the de-icing codes where in the AML would you insert it and what info should it contain?

Answer 11

On the out going sector page (the yellow page you are not going to remove!).Type concentration local time and date. Example Type 2/75/0630/01Jan. The time is the start time of the final step and is LOCAL.

Question 12

Do Holdover tables provide info for heavy ppt?

Answer 12

NO. Only light to moderate.

Question 13

What is a ‘slippery runway’?

Answer 13

A slippery runway defined as Mu of 0.05 over full length (highly unlikely). Slippery when wet is issued if 100m or more affected and not necessarily indicative of state of entire rwy.

Dry Runway
A runway whose surface is free of visible moisture and not contaminated within the area intended to be used.

Wet Runway
A runway whose surface is covered by any visible dampness or water up to and including 3 mm deep within the area intended to be used.

Contaminated
A runway of which a significant portion of its surface area (whether in isolated areas or not) within the length and width being used is covered by one or more of: more than 3 mm of water/wet snow/dry snow/slush, compacted snow or ice.

Degraded Braking Action
A runway covered by compacted snow or ice or a runway that is reported to be slippery when wet. A reported braking action is usually given for such runways.

Slippery
A runway having a theoretical aircraft braking coefficient of 0.05 mu.

Question 14

When would a runway be considered contaminated?

Answer 14

Perf Man 4.4 A rwy is considered contaminated when a significant portion of the runway is covered with more than 3mm of water/slush/wet snow or compacted snow. For 3mm or less of any ‘contaminant’ the runway is considered WET.

There is no longer a reference to 10mm of dry snow in the definition. CARD codes have now been provided for greater than 3mm of Dry Snow. In summary ANY contaminant depth greater than 3mm means the runway is contaminated.

Note: Snow is considered to be dry below -5deg.

Question 15

What are the maximum suggested depths of contamination?

Answer 15

Take-off - Dry Snow up to 102mm, Slush 13mm
Landing - Dry Snow 10CM Slush 13mm.

Note: CARD only has performance to 60mm dry snow.

Question 16

What are min oil temps for start and take-off -RR?

Answer 16

-40deg & 50deg

Question 17

What are min fuel temps?

Answer 17

Limitations > RR min tank temp -37 GE -40 or 3 deg above fuel freeze point.

Question 18

Snow banks and minimum cleared width?

Answer 18

Min width 45m (150ft) and min cleared width is 40m (130ft) with snowbanks at this width 45cm (1.5ft).

Question 19

Altimeter over-read in cold weather?

Answer 19

4% per 10deg below ISA

Question 20

When trying to establish braking actions how might you go about ascertaining it?

Answer 20

PIREPS will usually provide the best source of rwy info using the Reported Braking Action Table in QRH. You can try to make a correlation of the braking conditions expected on a landing runway using table at 4.2 in PM. E.g. Consider a rwy with 5mm of wet snow temp below -3 – ICAO code 3 in the table. The corresponding braking action is quoted as medium. From the QRH PI at 200T for GE/RR (no other factors) F30 max Auto = 2055/2075m. This figure has already been factored by 1.15. NOTE: In QRH an advisory of “Good” = wet rwy and “Poor” = wet ice (source Boeing Tech Bulletin ‘Landing on Slippery Runways’).

Question 21

What are the take-off alternate ‘time and distance’ requirements for 777?

Answer 21

120mins/800nm

USA/Canada/Saudi are now the same having previously been 60mins/400nm

Question 22

What are the ‘standard’ take-off alternate minima?

Answer 22

+/- 1hr of ETL normal operating mins.
USA/Canada standard mins are 600ft/2sm PA and 800ft/2sm NPA but under certain conditions this may reduce to 400ft/1sm 8.2.6

Question 23

What is a low viz take-off?

Answer 23

Take-off in 400m (1300ft) or less. (Low Viz landing below 550m).

Question 24

What is the lowest visibility for take-off before ‘facilities’ (essentially combinations of runway lighting/PVD/LVPs etc) are required?

Answer 24

500m BY DAY

Question 25

Where would you find the Take-off minima for a particular runway?

Answer 25

LIDO AOI pages. NB these minima are runway specific and absolute minima. The a/c may not be able to comply with them e.g. PVD u/s.

Question 26

Define the Take-off Ban.

Answer 26

Take-off Ban 8.22.3.d - if any of rqd RVR’s are below stated mins or rwy indistinguishable. Below 200m all three RVR’s rqd and SE is also controlling.

Question 27

To what would you refer if there were NOTAM’d deficiencies in airfield infrastructure?

Answer 27

Table OMA Section 8 > 8.22.3.e/g Note: for partial failures e.g. some of edge lights, 8.22.3.g commander may apply discretion. NB RVR reporting is required for ops below 400m. The TDZ may be replaced by pilot assessment.

Question 28

On a CAT 3 runway with 15m CL lights how many lights do you need to see?

Answer 28

75m - 4 lights
125m - 7 lights
150m - 9 lights

Question 29

In the UK what are the absolute mins for the 777 on take-off and/or landing?

Answer 29

75/75/75

Question 30

In the USA and Canada what are the lowest take-off mins?

Answer 30

USA - 500ft/500ft/500ft

Canada - 600ft/600ft/600ft

Question 31

In USA below what visibility do ALL RVR become controlling for TAKE-OFF (as opposed to Landing)?

Answer 31

​For Ops below 1600ft​ RVR - minimum 2​ RVR reporting​ systems required and​ All​ available RVR reports are controlling.

Question 32

What are AUTOLAND wind limits?

Answer 32

25HWC 25 CWC (15 USA) 15TWC

Question 33

For Autoland what are the runway glideslope limits?

Answer 33

2.5-3.25deg

Question 34

All RVR are below limits. Can you commence an approach?

Answer 34

Yes - May commence an approach regardless of RVR/Vis. It is the RVR at 1000ft (or higher if DA/H is higher than 1000ft aal) that dictates if the approach may be continued.

Question 35

You wish to make an approach to a runway that states on LIDO chart CAT 3 “Company”. Where do you find the mins?

Answer 35

On the CCI pages.

Question 36

In the absence of CCI pages or if ‘Not Auth BA Ops’ are stated therein what are the lowest minima you could use?

Answer 36

Those that are stated on the chart. i.e. if there are published CAT2 mins on the relevant runway (IAC) chart you may use those.

Question 37

You see the annotation ‘ACFT MAX65/7’ against a set of minima. Can you use them?

Answer 37

Yes.

Question 38

You commence an approach in LVO to CAT2 minima and become visual sooner than expected. Can you complete a manual landing?

Answer 38

NO. - 8.22.12 ANY LVO approach to minima below Cat1 must be completed using Autoland.

Question 39

In USA below what visibility do all RVR become controlling for LANDING (as opposed to Take-off).

Answer 39

700ft.

Question 40

What are the visual requirements to complete CAT1, CAT2 and CAT3 approaches?

Answer 40

CAT1 - distinctly visible
CAT2 & LTS CAT1 - x3 CL lights and lateral element.
CAT3A - x3 lights
CAT3B - x1 light.
CAT3b No DH - nothing!

Question 41

What are the visibility requirements for a visual approach?

Answer 41

5Km (3sm USA) unless established on the centreline then 800m

Question 42

When can you NOT use CMV to ascertain an RVR?

Answer 42

May NOT be used for Take-off or if RVR mins are below 800m. Also if the visibility is annotated on the LIDO minima box with an ‘R’ or ‘V’ (e.g. 800R or 1.3V) they may not be factored.