CPRjet
Topic Author
Posts: 64
Joined: Thu Nov 11, 1999 7:04 am

CFM56 Compression Stall

Fri Nov 12, 1999 12:11 am

We had a compression stall of the port engine on a UA 737-300 about 12 minutes out of ORD to ONT. It was a rough turnaround, presumably due to asymmetric thrust, and we waited about 45 minutes to land. What is a compression stall and how common is this type of incident and how much danger were we in?
 
OPNLguy
Posts: 11191
Joined: Tue Jun 15, 1999 11:29 am

RE: CFM56 Compression Stall

Fri Nov 12, 1999 3:47 am

CPRjet wrote:
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We had a compression stall of the port engine on a UA 737-300 about 12 minutes out of ORD to ONT. It was a rough turnaround, presumably due to asymmetric thrust, and we waited about 45 minutes to land. What is a compression stall and how common is this type of incident and how much danger were we in?


It probably was a compressOR stall. The compressor section of a jet engine (as its name implies) compresses the air, and downstream of that, fuel is added and combustion takes place. There is a massive volume of air moving through an engine, and sometimes disruptions can occur. I wasn't there obviously, but it appears the crew shut the engine down, and returned to ORD.

As far as emergencies go, this sounds like more of a "procedural" emergency versus a genuine "oh-my-gawd-get-this-sucker-on-the-ground-or-we're-all-gonna-die" types of emergencies (ex. Valujet afire trying to return to MIAmi.) On *any* twin-engine airliner (737 to 777) shutting down a engine mandates a landing at the nearest suitable airport in point of time.

Certainly wasn't the "routine" flight you expected, but I personally don't think you were in any great peril. My airline flies over 300 aircraft with 3000 flights a day, and we have *maybe* a handful of engine shutowns a year.
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
VC-10
Posts: 3546
Joined: Tue Oct 26, 1999 11:34 am

RE: CFM56 Compression Stall

Fri Nov 12, 1999 8:29 am

A Compressor stall is when the airflow over the engine compressor blades breaks up in a similar way to airflow break up over a wing that results in a stall. There can be many causes for this but you were in no great danger.