Tech Q's....

[ASH]

Didn't mean to imply anything by sticking this in the "majors forum" all are welcomed to reply. Would appreciate thoughts on the following questions

#1: What is the specific procedure for re-applying de-icing fluid after a significant delay? I believe you must make a full type 1 and 4 re-app to keep the controls from gumming up. True?

#2: Comments on throat venturi/throat velocity changes...

#3: What would you clasify as the biggest hazard in heavy rain on final approach?

#4: What are the advantages of an MLS or GPS?

#5: What is higher, Vmcg or Vmca on a 747-400? Why?

#6: What things are considered for an airline to be certified for 180 minute ETOPS? What are the various ETOPS categories?

#7: During what phase of flight is lift the greatest...ahhh..be careful they
say..

Techies UNITE!!!

 

[ASH]

Thirty views, and nothing! C'mon guys!:smash:

 

[Mr Proachpoint]

Check out www.pprune.org for all your Cathay interview questions!

Tons of info over there, just search.

 

[lumax]

1. type I to get the ice off then re-apply type 4
2. Bernoulli's principle: as the speed of a fluid increases (within the throat/veturi) its pressure and temp decreases. That's why you get carb ice.
3. Nothing bad, you get a clean windshield!
4.don't even know of an airport that is still using an MLS.
5. who knows!
6. who knows!
7. landing, or is it takeoff, or is it normal flight, or other? but really, I think is landing

Disclaimer: It has been a long time since I studied my private pilot handbook.

 

[FatesPawn]

#4: What are the advantages of an MLS or GPS?

Stabilized approaches are always better than dive and drive non-precision approaches so VNAV GPS approaches offer a better option than an NDB/VOR/LOC approach.

#5: What is higher, Vmcg or Vmca on a 747-400? Why?

I would assume that Vmcg is always lower than Vmca because the friction of the tires would aid in directional control... Would I be wrong? It wouldn't be the first time.... and 16 wheels helping with directional control would be a big aid...

#7: During what phase of flight is lift the greatest...ahhh..be careful they
say..

Steep turns.... otherwise a 1,000,000 lb. aircraft always generates 1,000,000 of lift regardless if it's landing, taking off, or cruising.... The only time an aircraft generates more lift than it weighs is during "accelerated" flight. Private Pilot 101.

Flames?

-Fate

 

[FatesPawn]

Oh, I'll stab at these too....

#1: What is the specific procedure for re-applying de-icing fluid after a significant delay? I believe you must make a full type 1 and 4 re-app to keep the controls from gumming up. True?

It has nothing to do with controls "gumming up." A 2 step process is always a 2 step process... If you have to go back to the gate to get "re-deiced" you have accumulation on your aircraft.... that means either Type I ONLY.... or Type I then Type IV.

#3: What would you clasify as the biggest hazard in heavy rain on final approach?

....relying on windshield wipers that haven't been tested in weeks or even months....

-fate

 

[ASH]

Exceedance of hold over time does not nec. constitute accumulation. I think what the question is stabbing for is the fact that we should clean off the old type 4 with type 1 before re-applying new type 4.

 

[BEECH-SLAPPED]

Steep turns.... otherwise a 1,000,000 lb. aircraft always generates 1,000,000 of lift regardless if it's landing, taking off, or cruising.... The only time an aircraft generates more lift than it weighs is during "accelerated" flight. Private Pilot 101.

Actually, if you want to be "crazy" technical about it, lift RARELY equals weight! Lift is the aerodynamic force which acts perpendicular to the relative wind. Depending on the regime of flight, lift can be less than weight or greater than weight. I'm still talking about unaccelerated flight here! In a constant speed, unaccelerated climb or descent, lift only has to counteract the component of weight perpendicular to the flight path plus the aerodynamic tail-down force. Even in unaccelerated straight and level flight, lift is GREATER than weight because it still has to support the tail-down force plus the weight of the aircraft. There is also a vertical component of thrust that will act upwards (positive AOA) to reduce the lift required but it is normally small in comparison. Now of course in all unaccelerated flight, the "up" forces equal the "down" forces but lift is just one of several of those "up" forces.

 

[Alcatraz]

It has nothing to do with controls "gumming up." A 2 step process is always a 2 step process... If you have to go back to the gate to get "re-deiced" you have accumulation on your aircraft.... that means either Type I ONLY.... or Type I then Type IV. -fate

Actually, some operators are approved to not use the "two step process" when applying Type IV in certain circumstances... such as before morning frost is anticipated (key word before).

However, if you return to the gate for re-deicing, you probably have contamination (or are unable to verify cleanliness, such as with -FZRA), and Type I is the only fluid used by most operators to remove frozen contamination. If you aren't contaminated and freezing precip is not falling, then why would you return for another deice?

So, I agree that the answer is false, since it's not really about a gumming of controls, and removing the old Type IV isn't the problem... it's the frozen crud that mixes in.

 

[Sig]

#3: What would you clasify as the biggest hazard in heavy rain on final approach?

DISCLAIMER: DashTrash input only.

It depends, doesn't it? Is it a locally narrow rain shaft aligned on final that opened up in relatively warm, dry air? The descending column of rapidly cooled air around the rain shaft will give you one HECK of a ride.

At least it did one day in IPT. Crazy day.