PPRuNe Forums - View Single Post - Bell 206: JetRanger and LongRanger
View Single Post
Old 15th Sep 2005, 06:10
  #703 (permalink)  
NedRex
 
Join Date: Sep 2003
Location: Melbourne, Australia
Age: 73
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
With that N1, TOT and Torque you appear to have a massive compressor inefficiency.

1. Look to a heavily erroded compressor case half set (been in the dust?). Have you had a history of case half errosion? Remember after about the third set of cases, the rotors are so thin that you will generate an impressive compressor stall as the pressure waves roll between the efficient stators and the inefficient blades of the compressor rotors.

or

2 An air leak from the Bleed valve not closed. Remember at 94%N1 you will still be in Bleed Valve modulation range. Get up to about 5000' PH and try it again. Your N1 should be higher than 95% to be sure that it is closed.

or

3. Look for a split in the armpits of the combustion outer case, a split in the discharge tubes , a popped seal in either of the ends of the discharge tubes or the burner drain valve wide open. If these are the cause you should also experience a significant delay in the acceleration schedule after the first peak in TOT.

or

4. The anti-ice valve or bleed air heater valve is leaking badly.


Good luck

Ned
NedRex is offline