Sign in to follow this  
youngie63

Windshear warning

Recommended Posts

G'day All

 

I recently did simulations with arrivals into Singapore and Penang. On both occasions I ran into some nasty weather on final approach (thunderstorm activity - AS for P3Dv4 real time). Both resulted in Go Arounds due to vis and severe turbulence. My real life experience had me believing that I should have received a 'Windshear' warning given the noticeable RoD on final. Bottom line is that there was no aural or annunciation warning in either case.

Two questions:

1. Does QOTS incorporate a windshear warning into the EGPWS? and

2. If so, how is it setup (can't find anything in the intro manual)?

Any help appreciated.

Cheers Steve  

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

IIRC there is a possibility in AS to check if the windshear warning system of the airplanes works correctly. I cannot tell you off the cut where you find that, but there are several setups for training and testing. And I think I had a windshear warning in the 747 into LEPA... 

Share this post


Link to post
Share on other sites

Thanks mate, I have revised the values in AS. May get to see if it works as I am currently an hour out from Penang with expected thunderstorms on arival

Share this post


Link to post
Share on other sites

Does not the WXR test include windshear as in all other Boeings?  Off the top of my head I think so.  Also, you can have solid TS and still not have a windshear event, or a single TS ruin your day.  Turbulence can be present and get pretty severe but that doesn't define windshear.

Share this post


Link to post
Share on other sites

Windshear does in fact work in the PMDG line and is reflected by AS. I had windshear during a bad weather day going into EWR in the 737 over the summer time while doing the ILS22L Circle to land 29  as I rolled into the left turn off of the ILS 22L and a few weeks ago I had a windshear in the 744 during departure from PANC in the initial climb right after the gear came up. It works. Maybe there is a way to reduce the trigger limit, I don't know but generally if there is known windshear, it is not a flight environment that ATC will put you in even in real world flying. 

Share this post


Link to post
Share on other sites

My parents were on holiday at Madeira... They told me about a very roughly flown go around on arrival into RW 05. I guess that was a W/S (alert). I told them about the windshear escape maneuver and they agreed with it.. There are places you just can't avoid it but you are aware of the risk. Well, Funchal is one of them :D

  • Upvote 1

Share this post


Link to post
Share on other sites
On 12/1/2017 at 5:44 AM, youngie63 said:

1. Does QOTS incorporate a windshear warning into the EGPWS? and

2. If so, how is it setup (can't find anything in the intro manual)?

Any help appreciated.

Cheers Steve  

1 Yes it does.  It will activate automatically provided the appropriate aircraft conditions are met and the weather is bad enough; even if you don't have any addons like AS installed.

2. Consider the system and its warnings as automatically set.  Have a look at the QOTS FCOM Manual, Section 15 for details of the GPWS (immediate) and PWS (predictive) warnings, which also explains when they are enabled. There are two basic types of Windshear Warning on most (but not all) B744s.  The QOTS Windshear system and its warnings are faithfully reproduced for a B744 aircraft fitted with an immediate Enhanced Ground Proximity Warning System (EGPWS) and a Predictive Windshear (PWS). 

(E)GPWS Windshear warnings (Mode 7) are based on either excessive downdraft or tailwind component and are enabled as you rotate.  In the air GPWS Windshear is also enabled whenever the aircraft is below 1,500ft RA, so don't expect to get a Windshear warning above this height.  The PWS (predictive) Windshear warning system uses the WX Radar imaging to look ahead of the aircraft and it is enabled on the ground when the No.2 or No.3 thrust lever is in the takeoff range and approx 12 secs after the radar begins scanning for windshear.  Although it looks ahead up to 3nm and detects microbursts and high levels of moisture it does not detect every type of windshear, so as a pilot you need to be constantly alert for any indications of Windshear.  These are uncontrolled changes in excess of the following (a) +/-15kts IAS or (b) +/-500ft/min V/S or (c) +/-5 deg pitch or (d) 1 dot G/S deviation. Other clues are sudden and large differences between the IAS and G/S, or large pitch and thrust lever movements with the A/P and A/T engaged.

Bertie Goddard 

 

Share this post


Link to post
Share on other sites

Thanks Bertie. As with most simmers l do like a challenge, especially with the Queen. While l have received Too Low Gear and Bank Angle warnings l have never received a Windshear warning. I have read the doco you mentioned and applied the changes as stated but still no warning. Trust me, the weather was such l should have received one (heavy turbulence and high ROD). 

Share this post


Link to post
Share on other sites
13 hours ago, youngie63 said:

Trust me, the weather was such l should have received one (heavy turbulence and high ROD). 

Heavy turbulence is not correlated with wind shear, in fact the air can be calm right up until stuff hits the fan and you are suddenly in a microburst. It is not a frequent event, I have only had one event in almost daily simulator flying for past couple of years.

Share this post


Link to post
Share on other sites
17 hours ago, youngie63 said:

Thanks Bertie. As with most simmers l do like a challenge, especially with the Queen. While l have received Too Low Gear and Bank Angle warnings l have never received a Windshear warning. I have read the doco you mentioned and applied the changes as stated but still no warning. Trust me, the weather was such l should have received one (heavy turbulence and high ROD). 

What was your airspeed indicator doing during these events?

Did you notice any severe losses in airspeed?

Turbulence is just that....turbulence.

What was your descent rate? Just curious...

Share this post


Link to post
Share on other sites

Airspeed was fluctuating - was around 165 at about 7 miles rnav app. Bouncing around due heavy turbulence as was airspeed (+/- 10-15kts) since beginning the final approach (RoD ~700, trying to maintain it anyway!). At about 4 miles airspeed dropped below Vref (145) with a RoD around 2200, could've been more but was busy executing a GA at this point. Estimate it pushed me below minimums <500' before GA kicked in. 

Please note these are only estimates as initial focus was on a difficult approach (sweating bullets) when the aeroplane 'dropped' on me.

Share this post


Link to post
Share on other sites
8 hours ago, youngie63 said:

Airspeed was fluctuating - was around 165 at about 7 miles rnav app. Bouncing around due heavy turbulence as was airspeed (+/- 10-15kts) since beginning the final approach (RoD ~700, trying to maintain it anyway!). At about 4 miles airspeed dropped below Vref (145) with a RoD around 2200, could've been more but was busy executing a GA at this point. Estimate it pushed me below minimums <500' before GA kicked in. 

Please note these are only estimates as initial focus was on a difficult approach (sweating bullets) when the aeroplane 'dropped' on me.

Using Active Sky your turbulence and downdraft siders should all be on the left side around 20%.  Your story sounds like unrealistic turbulence, a wind shear that resulted in IAS dropping would be caused by a rapid increase in tail wind component which would probably not cause the sudden increase in descent rate (you'd sink but not as is being pushed down).  A down draft effect that is thrown at you unrealistically is not the same as windshear.  Also, at 4 nm you should be about 1200 AGL and stabilized at Vref+5 plus your gust allowance.

Share this post


Link to post
Share on other sites
On 12/3/2017 at 6:26 AM, youngie63 said:

Trust me, the weather was such l should have received one (heavy turbulence and high ROD). 

Not necessarily, Steve.  Remember ..... it (i.e. the aircraft's windshear system) does not detect every type of windshear.  Windshear recovery training in a full sized simulator will usually be conducted with something like a 5,000ft/min downdraft and a 70kt horizontal shear programmed into the lesson plan in order to simulate a typical microburst encounter.  Believe me when I say that if you encounter anything like this in an aircraft - or a full motion simulator - you will definitely know about it and probably sweat more than buckets!

Bertie G

 

Share this post


Link to post
Share on other sites
17 hours ago, berts said:

you will definitely know about it and probably sweat more than buckets!

I always wondered how often the seat cushions get replaced in those torture chamb..., I mean simulators.  Do you bring your own Febreze?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this