EMJ 170/175/190/195

[grintavec]

Question for Embraer pilots.

Been flying the EMbraer series for several years and want to compare opinions regarding Abnormals with "Stall Protection Ice Speeds" message latched on Eicas and how different carriers teach/handle abnormals with this message. In particular are the corrections to VREF FULL listed in the QRH (due to an abnormal, like Flap/Slat fail, Engine Failure, HYD fail etc.) to be applied to Vref FULL (no ice) or VREF FULL (ice)

Example 1.

Engine failure, "Stall Protection Ice Speeds" message is latched on Eicas due Ice Accretion in cloud. QRH for "One Engine Inoperative Approach and Landing" says land Flap 5 but set speed Vref FULL plus 20. Would one set VREF FULL plus 20 or VREF FULL ICE plus 20.... ? Usually a 7 knot difference.


Example 2.

You have a flap or slat failure and are landing partial slat or flap. You enter the QRH for your speeds and have a "shaker anticipated" message and use the corresponding table and the correction factor you get for example on a 0 flap 0 slat landing VREF FULL + 60. You also have the "Stall Protection Ice Speed" message latched due to ice accretion in cloud. Would you use VREF FULL + 60 or VREF FULL ICE plus 60?


And does anyone have an email/phone number for Embraer flight operations/performance where one can get an answer directly from Embraer.

Thanks in advance for your input.

[FE Hoppy]

It's in the SOPM 3-35-01 page 7 (revision 15)

NOTE: Anytime the EICAS message STAL PROT ICE SPEEDS
becomes active during approach on normal or abnormal
conditions, the speeds must be adjusted for ICE ACCRETION
table regardless of the icing condition on landing.


And it's either ERJ or EMB not EMJ :)

[grintavec]

Im aware of that line just the interpretation that seems to be at issue.

So out of curiosity what speed would your airline fly for an Embraer 190 at 40000 kgs Lndg Weight when single engine landing flaps 5 with "stall protection ice speeds" dislayed on ECAM? Just want to make sure we are comparing apples to apples. Also what speed would you fly with a E190 at 40000kgs in a flap and slat 0 situation with " stall protection ice speeds" on eicas and "stick shaker anticipated" on Eicas?


Does "stick shaker anticipated" latched message already know that you have "stall protection ice speeds" and therefore its already factored into the correction factor?

[dhc83driver]

you are talking about two different things, All speeds in the QRH are referenced to Flap full as they are based on a factor for those speeds so if you are flying flap 3 with the RAT out or with a elevator fail, or even OEI your Vref and to the same effect VAC for that config are factored performance.

Stall protection ice speed is based on the assumption that there is ice on the tail. This could still be there after an ice encounter on departure due to cold soak in the cruise when landing at a warmer destination. (ice condition will not always trigger Stall Prot ice speed). Vref Full is the same for Vref Full ice and also Vac 4 = Vac 4 ice. Vref 5 and Vref 5 ice are different and need to be applied for ice so Vac 3 also need applying.

All Qrh actions are a factor of VFull so your ice is covered! so for example OEI Vref full +20 at 40000Kgs E190 =140kts. Vref 5 ice would of been 132 extra speed is in for other items and as your Vac is equal to Vref full +20 is also covers Vmca and you are greater than V2 + 10 so no bank limit needed.

[FE Hoppy]

Just a note.

FAA Flap full ice speeds are higher. The correction is still applied so Flaps Full Ice * factor is used which gives a higher speed.

And the assumption isn't ice on the tail but ice on all unprotected surfaces. The speed increase is for drag and weight and also to ensure landing climb performance more than stall margin with flaps full.

Flaps full Vref is limited by landing climb not margin above stall. Which is why in EASA land there is no need for an increase for Ice. Vref flaps 5 is purely based on stall margin as Landing climb is no problem hence the increase for Ice.

The difference between FAA and EASA Vref is due to the AMC used to demonstrate the performance. EASA assumes the engine has already failed at the start of the approach whereas FAA assumes the failure when the Go-around is commenced.

Same aircraft. Same Stall margin and climb requirements but different way of proving the performance leads to different speed schedules.

[the_stranger]

We don't have a different Vref full for ice. So with stall prot ice speeds on EICAS flap full speeds stay the same as without that message. So all ops based on that speed stay the same too.

[FE Hoppy]

The Vref Full speeds are titled With/Without Ice for those certifications that use the same speed. Like the CAT II/III Vref. For the others there are 2 tables.

[grintavec]

This is why I wanted to compare actual numbers that various carriers use, since as noticed from the replies different carriers in different countries use different speeds depending on the regulating authority. Some operators as "The Stranger" above mentioned do not have seperate speeds for ICE and NO ICE and use one set of speeds which already include the ice correction.

[FE Hoppy]

Well I wouldn't normally do this in my own time as 8 hours a day is frankly more than enough but here are the FAA Landing Ref and Unfactored Landing distances for No Ice and Ice. As you can see the speeds are higher and the corresponding distances are longer with Ice Accretion. Thus the basic data used in calculating factored performance for abnormals is higher when the Stall Prot Ice speed message is displayed.

https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-snc6/181033_10200239384400752_252628449_n.jpg
https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-ash3/534114_10200239387760836_1641200581_n.jpg
https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-ash3/522437_10200239384880764_938129434_n.jpg
https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-ash3/579638_10200239386080794_1617167409_n.jpg

Stick shaker anticipated will show if there is either an unknown configuration or for specific ADS failures.(I would have to dig out some tech docs to find the list) It is unrelated to ice accretion. When selecting the "desired" un failed surface position in case of Flap or Slat failure you should refer to the 8 tables in the back of the QRH where all possible combinations of Shaker/Overspeed/wet/dry are listed but also be aware that you may trigger the shaker anticipated message when selecting a more desirable configuration which can add frustration and error if care isn't taken.

[grintavec]

Thanks for all the info FE Hoppy. You are the first person who was ever able to even remotely explain "shaker anticipated" message with slat/flap failures and from what you say it is unrelated to "ice accretion".

Going back to a single engine approach with "stall protection ice speeds" in other words "ice accretion" at 40,000 kgs or 88,000lbs in your case, you would fly VREF FULL ICE "ICE ACCRETION" plus 20kts, so a speed of 126+20=146 kts is that correct? And not VREF FULL "no ice" 119+20=139

Thanks again for the info FE Hoppy.

Cheers

[FE Hoppy]

That is correct.

Everyone will fly Vref full with Ice accretion + xxx but in easa land it just so happens that the speed "With ice" is the same as the speed "without ice".

and you're welcome.

If I get bored this weekend I will find the list of things that can trigger the Shaker anticipated message:-)

not sure if this is the latest info but here is the original explanation for "Shaker anticipated". Take it with a pinch of salt.

The SPS ANTICIPATED condition indicates that the SWPS has identified miscompare or a failure in the sensors. The SWPS shall operate in the normal mode in a single valid sensor condition, except for ADS, which needs two valid sources of data.
The SWPS is set to SHAKER ANTICIPATED condition when:
· Loss or miscompare of all flaps channels
· Loss or miscompare of all slats channels
· Invalid flap/slat configuration
· Loss or miscompare of all IRS channels
· Loss or miscompare of two ADS channels
· Failure of the probes 1 and/or 2 and 4 (includes the electrical emergency case)
In the event that any of the above condition is satisfied, the SWPS shall request a ‘SHAKER ANTICIPATED’ CAS message display. While SHAKER ANTICIPATED
condition is set, the SWPS shall use the default values specified below in all SWPS computations:
· Flap Position = 7
· Mach = 0.8
· IRS Roll Rate = 0.0 deg/sec.
· IRS Yaw Rate = 0.0 deg/sec.
· IRS Pitch Rate = 0.0 deg/sec.
· Sideslip (Beta) = 0.0 deg.
This values effectively allows continued operation of the SWPS with the Stall
Warning and Stall Protection Activation angles set to the most conservative values while SHAKER ANTICIPATED condition is set. Default values of shaker firing angle are also set in the SHAKER ANTICIPATED
condition.