Ziggy

Any time the leading edges are removed, you need to verify the stall characteristics. The aircraft should stall in a stable condition. If one wing breaks before the other, then the stall strips have to be readjusted. Also you want to verify that shaker and pusher activates at the appropriate times.

Hoof Hearted

Thanks for the replies everyone, it's been helpful. I do have a question regarding how to stall the aircraft when you have a stick pusher. I guess you try and stall the aircraft normally, monitoring where the shaker goes off and the pusher against the graph in the AFM for a given weight and flap setting, I get that. But if you have to go beyond the pusher to the stall... how do you do that when the pusher is pushing the nose down. The only thing I can think of is to inhibit both stall channels but that just doesn't seem right. Could someone explain the process so even I could understand it. Thanks

Ziggy

Hoof: With reference to the AOA installed in the A/C. Shaker should activate when the needle enters the red zone. Pusher should activate just prior to 1.0 on the AOA or the stall. DON'T FIGHT THE PUSHER, just let it take the aircraft and recover. If you didn't receive any wing break, and the shaker, and pusher activated according to the graph you have completed that stall check for that configuration. There is no reason to go beyond the pusher. I unfortunately posted some miss information in my previous posts and I cannot edit it, so sorry about that.

bcaviator

Ziggy is absolutely correct.
Do NOT go past the stick pusher. While the stall may be docile, you are operating outside of manufacturers guidelines and you are not covered if anything happens. The pusher is there to prevent a full stall, if the channels activate together, and on the appropriate speed with minimal buffet and/or roll, the aircraft is flying correctly. Fighting the stick pusher risks a deep stall. Deep stalls are not good in ANY airplane, especially the larger ones.

DSflyer05

When you go to stall the airplane before you ever take off make sure to do your shaker and pusher tests, that goes without saying. You can also test the individual stall channels in flight just prior to executing the maneuver if you want. Make sure you set the AOA to 1.3 on the left of the gauge. The pre stall check is,

Ignition on, engine sync off, no ice on the airframe, no fuel in the ventral tank, radar to standby.

With the gear up slience the horn with the button on the left throttle lever, with gear and flaps down maintain altitude and heading. Keep wings level, keep the AOA gauge in your scan as the A/C slowes. between .8 and .85 the shaker will activate. At .95 to 1.0 the pusher will activate. When the pusher activates the airplane is in an actual stall. The pusher gives 70lbs of forward pressure. Don't fight it. Lower the nose slightly and recover the airplane as normal. The nose should fall forward with no roll tendencies. It really should be a non event. Let me know if you have any other questions.

DSflyer

kalymnos

The AOA guide vane and meter will tell you everything you need to know about what that wing is doing, which allows you to anticipate.. Ive been watching that gauge for years but has become underestimated or not thoroughly explained and involved with pilot training.

Ziggy

While I agree that the AOA is a useful instrument, in the Hawker it doesn't have a calibration schedule like some other aircraft. That's probably one of the reason why pilots aren't trained to use it during say approach and landing or other maneuvers.

Hoof Hearted

Thanks for all your useful information. I really learned quite a bit more than I thought I knew regarding the stall system. There's the old adage, you never stop learning. Once again thanks for all your help.
The stall test went off without a hitch. Just like everyone said, prepare for everything and be ready for anything. It was a nonevent. pusher came on as on cue and pushed nose down. The aircraft went straight ahead which was a relief, but also a testament to the work being done properly.
Thanks Again to all who responded

acftfliehr

Here is the procedure following the Stall Warning testing done on the ground.... One should never take a swept wing jet to Full Stall unless your a "qualified Test Pilot working directly with the factory.... Bac 1-11 and Trident are prime examples of very experienced pilots not recognizing the stall before it was unrecoverable... I think this check is done to first shaker like on a lot of other aircraft I have worked on over the years. The test is usually accomplished with the AOA being watched and referenced to the computed speed/altitude vs weight and balance at the time of check... which the AOA number calculated the 1st shaker is achieved. This requires that one of the Stall Computers say there is an impending stall... to get the secondary shaker you need both computers to agree (which include their AOA probes in agreement - i.e. 737 MAX FUBAR in Design). One should never get to this point as the push comes right beyond that AOA threshold. I worked at AirResearch as a line mechanic on the reengine from Viper to Garretts at LAX and after install this what checked, but only to the st shaker... Probably the first article was tested to the stall, the models from 1A to 700 series had wing fences and this precluded no stick push. the 800 removed the fences and installed the stick push and the stall trigger that is now on the later versions... The fences would have maybe saved their lives.... However, it is tragic and never - never go to full stall with a swept wing jet unless you are one of the young and bold...

Procedure on removal of TKS panels on 800 and later aircraft... We did this on the earlier series and this was not required....

CAUTION: After adjustment, replacement or Removal/installation of two or more wing distributor panels on one side, or either of the one piece titanium leading edge sections or adjustment, replacement or I Removal/installation of either Stall Trigger, the airplane must be test flown, using Flight Manual procedures, by a pilot familiar with the Stall Identification System and stall handling characteristics of the Series 800XP airplane, in order to check the stall characteristics.

The Stall Identification System must be operative at all times.

Stan446

Wow, 13 year old thread revival.