FCOM Chapter 4 - Supplementary
Engine
ECMP limits do not apply for climb in icing when setting charted power
Ensure ECMP limits do not result in Tq being more than 5% below charted power
When using HP bleed, minimise engine ITT by control of compressor / engine speed. Max ITT on ground with HPs is 800°C
Do not use HP bleed on ground when OAT is 0°-20° (excluding de-ice testing requirements)
Engine Trend Monitoring
Daily Trend (EFL) - monitors shifts in engine over long period. Preferably leave for 10 min before conducting, if intake light illuminates retest (OFF then ON) once. If recorded under special conditions (e.g. high DC load 250+, or bleed air off), make note in EFL
Airborne Continuous Monitoring (Delta T) - highlights sudden changes in engine performance as a change in temp. Engineering will produce a baseline temp every 30 days.
| DDT | Action |
|---|---|
| 0 - 29 | No action |
| 30 - 40 | Record 1 (if possible 2) sets of trend data b/w FL120 and FL150. Notify engineering prior to departure. Conduct visual inspection of intake area, particularly IGVs for FOD |
| 40+ | Engineering action must be taken prior to next flight |
Warning
Avoid steady state (5 seconds) engine operation between 80 - 84% and 94 - 98% Ng with DDT of 40+. A bird strike or FOD ingestion are major causes of large shift in the DDT.
Fuel
Come back
Icing
Caution
Saab 340 is not certified to fly in freezing drizzle / rain
Ground De Ice Procedures
Pay special attention to performance degradation, with impact to takeoff distance and climb capability
Must not use aircraft systems to clear ice and snow on ground
Ice may occur when:
- fog / misty weather below freezing point. Rime ice may form, thicker on windward side
- frost may form on surfaces during cold clear nights
- snow
- after landing, skin temp below freezing and wet snow / rain falling, ice may form
The PIC must determine the extent of the contamination before entering the aircraft
Critical areas:
- Aerofoils (wing and tail),
- Props,
- Pitot / static systems,
- Engines,
Rex use Type 1 De-Ice fluid (glycol and water). Mainly provides protection against refreezing. Approx 35 min holdover time
Do not spray in engines, wheels, antennas, windows, probes / ports (consider fitting pitot covers). Ensure flap 0 selected. Must not use windshield wipers to clear de-ice fluid
Post application safety inspection:
- pitot / static
- wheel wells + doors
- windshields
- antenna
- prop + prop rotation
- engine inlets + outlets
- wings, vert + horizontal stab (underside wing hoar frost 3mm allowed. Light rhyme frost on upper allowed provided no obstruction vents)
- control surfaces, full control + trim travel
- Areas of working areas should be payed attention to. E.g. landing gear linkages. Hyd seals could freeze.
Caution
Clear ice could build up on upper wing if vis moisture is present, temp below freezing. Ensure checking via touch
Before Engine Start
Wind and tail must be clear
Light rime / thin hoar frost allowed on upper wing (provided all vents / ports clear)
Thin <3 mm frost allowed on underside of wing in fuel tank area
Working parts should be checked, especially control surface mechanisms, hinges, landing gear assemblies
In extreme cold, pay attention to landing gear and mechanisms (exp hyd seals). Rubber seals may stiffen, allow to thaw before attempting to open
After engine start
- If cold soaked & HP required, wait 5 min b/f HP on. Overtemp ECS
- Flight deck airflow to defog as required (windshields heated via ac systems only)
- F - Cycle flaps a couple of times,
- B - Check de-icing boots,
- B - Check Bottoming Governor engagement (when checking, ensure prop RPM advances normally. If engine RPM increases prior to prop RPM reaching 830 = fail)
- Cold oil makes it possible for BG to not engage
- Retard CL to START -> avoid steady state avoidance range
- Before advancing again, ensure PL isn’t below GI stop and prop oil temp > 25˚
- Engine oil bypass, fuel low temp (until PGB oil temp increase - run at GI until within limits, about 5 min), prop oil pressure may be on
- Warm up brakes
- Pre take-off contamination check (check L/R wing area over fuel tank, if any doubt one pilot must check near overwing emergency exit)
- Take-off – rated power. Apply brakes and FI + 15% for 15s
Weather
Weather Radar
Green - 1-4mm - light to mod turb
Yellow - 4-12mm
Red - 12-50mm - sever turb, lightning
Magenta - greater 50 - severe turb, large hail, lightning, gusts
Ground, 37 m from refuelling, fuel, people, aircraft
Tests
While taxing or when the aircraft is clear of the terminal area and other aircraft, select the shortest range on the radar panel, set the Mode Selector to WX and then adjust tilt downwards until ground echoes appear at the bottom of the display.
Perform the check at 10 000 ft, because at 10,000 ft the line of sight is just 100 nm. Set range 200 nm and the TILT control at minus 1°
Check for ground returns displayed out to a distance of at least 100 nm.
Tilt Procedure
Below 15,000 - bottom of beam on 20 nm arc and note tilt setting
Above 15,000 - bottom of beam on 40 nm arc and note tilt setting
Divide altitude in thousands of feet by 2 (4 above 15,000)
Increase tilt by a number of degrees equal to calc
Terminal Area Weather
- With + 10 tilt - any echo that appears on 20 nm or greater must be avoided regardless of contouring
- With + 10 tilt - any echo giving contours regardless of distance must be avoided no matter how high it is
- With + 10 tilt - and in landing config, if contouring echo is detected within 5 nm and cannot be avoided perform an immediate go-around.
Avoid sharp rainfall intensity changes on the weather radar by:
- Below 10,000ft - 5nm (10nm if OAT below 0)
- Between FL150 & FL200 - 10nm to 15nm
- Above FL200 - 20nm
Caution
Avoid cells containing magenta / red areas by at least 20nm if possible
Hail shafts are usually identified with four different characteristic patterns:
- fingers,
- hooks,
- scalloped edges on the cloud outline, and
- U-shaped cloud edges 3 to 7 miles across.