Some Techincal Questions

[FlyChicaga]

I figured I'd post this here, since I'd imagine there is a more wide variety of experienced pilots viewing this forum.

I've been reading the book "Fly The Wing" for the past week pretty religiously. Taking in all the info as best I can. From what I understand, the book was written back in the 70's by an Eastern Airlines pilot, and was updated in the early 90's. It seems there is some GREAT information in this book, which has really opened my eyes a bit to some topics. I'm trying to read a lot since I've transitioned from flying props (turboprops) to a jet, getting information on aerodynamics, jet operation, etc.

There were a few things in the book that I was curious if anyone had heard about, or used. Particularly in the windshear section, there was some "off the record" recommendations to deal with takeoff windshear and approach windshear. One suggestion was rotating about 25 knots after your bugged Vr, then using a lower deck angle in climbout to gain an additional 25 knots above the new rotation speed. Of course considering runway length, obstacle clearance limits, and tire speed. Has anyone heard of this, or used this technique? According to the book, the addition in speed is building your kinetic energy in the form of excess speed, so should you experience a decrease in performance due to windshear, you have all that potential energy to climb through it and not strike ground.

There were some other suggestions, like speed addition on approach to Vref for steady state and gusty wind conditions. We have specific requirements at my own company, but I'm curious what you use at your company. Or do you not have guidance?

I have a million other questions, but I'll spare you for now. I've got a bunch of other books I'm getting into, like "Weather Flying" by Bob Buck, "How Radar Works" CD by Dave Gwinn, "Aerodynamics For Naval Aviators", and "Flying The Big Jets." Any other recommendations for good books, going above the "basics" and getting more in depth into jet flying?

I'm sure it sounds really dorky, but I don't want to just do. I really want to understand. Nowadays there aren't many opportunities to talk, fly, and learn from the guys who were around in the 60's, 70's, and 80's flying the jets when they weren't so automated.

Anything else you could toss in here to help a new guy just starting out, or any book suggestions, places to find info, etc. would really be appreciated!!

Thanks,

Matt

 

[Captain Overs]

I can tell you were never a CFI. If you were, you would have read those books years ago instead of after getting your first jet job. I think there is something to be said about companies hiring CFI's. They usually have more aviation knowledge than any other pilot, excluding military.

 

[Hangin'On]

It's great that you are studying--no matter what people say, you can always learn more.

To answer your question, in my previous and current life we were taught to max perform the airplane to get out of the windshear. Rocks will kill you. Bend the throttles full forward, raise the nose to the "stick shaker" and then relax it ever-so-slightly so you do not stall. Worry about the engines after the rocks Pilot not flying will give you trend info (ie "airspeed increasing, climbing") so you know if you are in the middle of the phenomenon or getting out of it. While it is true that airspeed is your friend, I would not keep it on the deck to build it up in this situation. Windshear, especially if it is associated with thunderstorm/microburst activity is nasty, unpredictable stuff. Best to get away from the ground.

Your company will probably have their own training standards and critical action procedures. You will most likely practice them in the sim (we do periodically).

Hope this helps. Good luck to you!!

 

[TonyC]

I can tell you were never a CFI. If you were, you would have read those books years ago instead of after getting your first jet job. I think there is something to be said about companies hiring CFI's. They usually have more aviation knowledge than any other pilot, excluding military.

Don't you think you might be over-generalizing just a wee bit?



That looks like a good list to start. Once you've finished reading those, you'll be up for the pitch for speed/power for speed argument.



.

 

[FlyChicaga]

I can tell you were never a CFI. If you were, you would have read those books years ago instead of after getting your first jet job. I think there is something to be said about companies hiring CFI's. They usually have more aviation knowledge than any other pilot, excluding military.

Actually, I was/am a CFI/CFII/MEI. While at the same time trying to get a four year degree and working another job. So I apologize I did not have the free time I do now to get into some of these subjects. While in college and CFIing I was focusing on the information that pertained to my level of flying at the time, which was NOT jets.

 

[typhoonpilot]

One suggestion was rotating about 25 knots after your bugged Vr, then using a lower deck angle in climbout to gain an additional 25 knots above the new rotation speed. Of course considering runway length, obstacle clearance limits, and tire speed. Has anyone heard of this, or used this technique?

That is a nice attempt and I'll partly agree with it, but it should be quantified to ensure you meet all takeoff performance obligations. Try it this way:

1) Use maximum takeoff thrust instead of reduced thrust. ( this is a no brainer item )

2) Use the longest suitable runway provided it is clear of areas of known windshear.

3) Consider increasing Vr speed to the performance limited gross weight rotation speed, not to exceed actual gross weight Vr+20 knots. Set V speeds for the actual gross weight and use the adjusted ( higher ) rotation speed. If windshear is encountered at or beyond the actual gross weight Vr, do not attempt to accelerate to the increased Vr, but rotate without hesitation.

In my aircraft if we tried the second part of increasing the initial climb speed by 25 knots we would blow through the flap speed limitation pretty easily so that is not an option. Not to mention that you would almost certainly be violating second segment climb criteria.

Of course avoidance is always the best preventive measure when dealing with windshear.

There were some other suggestions, like speed addition on approach to Vref for steady state and gusty wind conditions. We have specific requirements at my own company, but I'm curious what you use at your company. Or do you not have guidance?

This isn't so much company specific as it is aircraft manufacturer specific. This from the Boeing 777 Flight Crew Training Manual:

" When using autothrottle, position command speed to VREF + 5 knots. Sufficient wind and gust protection is available with autothrottle engaged because the autothrottle adjusts the approach speed upward to account for the wind gusts actually encountered during the approach.

If the A/T is disengaged or planned to be disengaged prior to landing, the recommended speed correction is to add one half of the reported steady headwind component PLUS the full gust increment above the steady wind to the reference speed. One half of the reported headwind component can be estimated by using 50% for a direct headwind, 35% for a 45 degree crosswind, zero for a direct crosswind and interpolation in between. "

From memory the McDonnell Douglas MD-90 had a somewhat similar clause for the autothrottle engaged, but I believe it could only add 5 knots and then you had to do the rest. The difference though was in their wording for manual throttles, it was something like one half of the steady wind OR all the gust, whichever is greater. See the difference ?

In all cases not to exceed Vref + 20 knots.


Typhoonpilot

 

[VVJM265]

A few suggestions on some other books, if you haven’t thought of them yet:

1. Encyclopedia of Technical Aviation, Gary V. Bristow.
2. Airplane Flying Handbook (FAA-H-8083-3A; the 2004 ed.); especially chapter 15 for jet transition.
3. Stick & Rudder, Wolfgang Langewiesche; a classic on the basics.

Good luck!

 

[cheater1239]

typhoonpilot relayed the delayed rotation technique that i know as the "std", in addition, select the least amount of flap for the runway. this is all for inadvertant windshear encounter, not a depart into windshear method. regarding call outs DO NOT include airspeed, it will be abnormal fly the pitch additude specified by airline/manufacurer. the usair(ways) dc9 windsheer accident, among other errors included an airspeed callout by the pnf, followed by a pitch reduction by the pf.
captain overs, why the snide post?

 

[Donsa320]

Quote:
One suggestion was rotating about 25 knots after your bugged Vr, then using a lower deck angle in climbout to gain an additional 25 knots above the new rotation speed. Of course considering runway length, obstacle clearance limits, and tire speed. Has anyone heard of this, or used this technique?



There is an old saying: You can't have a second segment climb if you do not get a first segment climb.
I've seen too many people yank airplanes into the air when a delayed rotation was a better option. If obstacles or runway length preclude a delayed rotation, don't go at all. They don't give out Air Medals for poor judgement.

~DC

 

[FatesPawn]

One suggestion was rotating about 25 knots after your bugged Vr, then using a lower deck angle in climbout to gain an additional 25 knots above the new rotation speed. Of course considering runway length, obstacle clearance limits, and tire speed. Has anyone heard of this, or used this technique? According to the book, the addition in speed is building your kinetic energy in the form of excess speed, so should you experience a decrease in performance due to windshear, you have all that potential energy to climb through it and not strike ground.

$.02

Obstacle clearance limits don't really come into play during a windshear take-off profile. The profile is based on the assumption that you DID NOT lose an engine at V1. As such, even a lower deck angle will give you a better climb gradient than an engine-out-profile.... probably - that is, if you didn't get windshear.

The above mentioned technique is pretty much the procedure used by my company, but common sense must be used if you're just looking for a WAG procedure. For example, you'll hear Boeing people (that's what I'm familiar with...) talk about "in any case, don't delay rotation past 2000ft remaining..."


That's all well and good when you're talking about a nice 2.5-3 degree rotation rate in a 100,000lb+ airliner, but if you are developing a windshear profile for your Citation V and the runway is only 4,000' to begin with this probably isn't good gouge.

If you're developing a procedure for YOURSELF... I'd use the bananna approach. V1, VR, 1 bananna, 2 bananna, 3 bananna ROTATE.

Fate