Pitch angle and Climb angle

[raul.jetpilot]

Another one confusing me:

Question ID 1452 Bristol Database
A jet aeroplane is climbing at a constant IAS and maximum climb thrust, how will the climb angle / the pitch angle change?

It seems very obviuos that climb angle will reduce mainly due to the loss of Thrust associated with altitude raise and the need to keep IAS constant...but I can't find a rationale for pich angle...because, it seems that I am not understanding very well the difference between climb angle and pitch angle...

Any help on this one??????

Kind Regards to all helpers

Thanks

[Lord Spandex Masher]

Think of the climb angle as the flight path vector. Angle between the horizon and the flight path of the aircraft.

Pitch angle is the angle between the horizon and the aircraft attitude.

The difference between the two is, for all intents and purposes, aircraft angle of attack.

AoA wil remain constant at constant IAS. Climb angle, as you state, will reduce at higher altitudes.

If that helps you should be able to work it out a bit more easily.

[raul.jetpilot]

But answer says differently

Thanks for your reply...I understand the AoA/IAS relation but, the correct answer to the question states that...both Climb and Pitch angle will REDUCE...

[nzflygirl]

As you climb, the power available is decreasing all the time, hence you would have to pitch down to maintain the constant IAS which will also reduce your climb angle.

[keith williams]

As you climb higher the reducing thrust available causes the climb angle to decrease.

If you maintain a constant pitch angle as the climb angle decreases, your angle of attack will be increasing. This will cause IAS to decrease.

So to maintain a constant angle of attack, in order to maintain a constant IAS, you must reduce pitch angle to compensate for the reducing climb path angle.

WARNING TO PEDANTS....Yes I know that we should really be talking about constant EAS, but this is just another of those exam simplifications!