View Full Version : General Questions

26th Jul 2001, 08:02
Any ideas

1. What is the danger of flying an approach in heavy rain?

2. What is jet upset?

3. What is spoiler blowback?

4. What is a safety cell battery?

5. What are the general procedures and precautions for flying in areas with volcanic dust?

Dave Incognito
26th Jul 2001, 10:45
A layer of water on the windscreen can cause the illusion of appearing high on approach.

It is then possible for a pilot to fly the aircraft below glide slope on what visually appears to be the correct slope. :eek:

Pete the Pilot
26th Jul 2001, 14:43
Heard somewhere that heavy rain can disrupt the airflow over the wing increasing stall speed.....

Volcanic ash - Oxygen and goggles on, 180 degree turn , idle thrust, start switches flt and run away.

Spoiler blowback-? (sounds like fun)

jet upset-loss of control at high airspeed and high altitude. (Unusual attitudes)

26th Jul 2001, 15:25
Get yourself a copy of "Handling The Big Jets" by DP Davies. You'll find ALL the CORRECT answers to all of your questions there. :D

26th Jul 2001, 19:15
Spoiler blowback - when you deploy the spoilers at tooooo high an airspeed the spoilers will retract (blowback) to prevent damage, same as flap load relief for the same reasons.

27th Jul 2001, 07:03
1. What is the danger of flying an approach in heavy rain?

A. As stated above, rain on the windshield can cause some illusions for visual slope guidance onto the runway. On landing the runway will be wet, a consideration for landing technique. The rain will affect the visibility at the minimum height for either circling, or continuing the visual portion of the approach. Very heavy rain can effect engine operation.

2. What is jet upset?

A. Sometimes referred to as "Airplane unpset", Jet upset usually refers to an aircraft in flight (in this case a jet aircraft) unintentionally exceeding the parameters normally experienced in everyday operations. This could be due to a slow speed stall, high speed stall, turbulence, uncorrected engine or airframe problems etc.

Jet upset training involves teaching pilots how to recover an aircraft from an extreme attitude with the minimum possible damage to the aircraft.

3. What is spoiler blowback?

A. Bit more of a difference there I think spanners!

Flap load relief is a system that detects high speed and then signals a flap retract to a lower setting.

Spoiler blow back involves a spoiler panel that would extend, say 10 at zero airspeed, extending only 5 at high airspeed, as the airload is greater than the hydraulic force on the panel. As spanners said, it is usualy a good thing as it protects the panel against overload.

4. What is a safety cell battery?

A. Hmmmm I would assume that it is a sealed cell, not allowing release of acid if upset, but not sure on this one!

5. What are the general procedures and precautions for flying in areas with volcanic dust?

A. Check the forcast. Don't fly there! :) Companies (and pilots) that fly in volvanic areas keep a very close watch on active volcanoes, and ash forcasts are issued for current eruptions. Airliners are routed well clear of known eruptions. On the very rare occasions that a volcano erupts without warning and an aircraft flys into the ash cloud (this only happens at night, as you can see the cloud easily by day) then you follow the general advice above.

[ 27 July 2001: Message edited by: Checkboard ]