Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Stall Warning Tab On PA-44 Piper Seminole  
User currently offlineSkihigh2002 From United States of America, joined Jun 2000, 315 posts, RR: 0
Posted (8 years 8 months 4 days 7 hours ago) and read 6094 times:

If someone could help me figure this question out, I'm a Commercial Multi-Engine pilot and I'm not sure as to the answer:

The PA-44 has two stall warning tabs because of various flap changes. But the stall warning tabs are linked to the squat switch. So, when the aircraft is on the ground they do not engage. Why is that? Other airplanes, such as the PA-32 Piper Arrow have stall warning tabs but they are not linked to the squat switch.

A possible explanation I have is the fact that once the aircraft lands you do not want the stall warning horn blaring because the aircraft is below stalling speed. But why is is different on the Seminole from any other GA aircraft?

Thanks,
Chris

4 replies: All unread, jump to last
 
User currently offlineLeanOfPeak From United States of America, joined Oct 2004, 509 posts, RR: 1
Reply 1, posted (8 years 8 months 4 days 6 hours ago) and read 6087 times:

Not sure about your question, but the Arrow is the PA-28R. The PA-32 is the Cherokee Six/Lance/Saratoga/6X series.

User currently offlineLowrider From United States of America, joined Jun 2004, 3220 posts, RR: 10
Reply 2, posted (8 years 8 months 4 days 5 hours ago) and read 6070 times:

Stall speed will vary greatly. I would guess that Piper found that the stall horn was prone to inadvertent activation on the ground or during TO/lndg roll. Call Piper, I am sure they know the answer.


Proud OOTSK member
User currently offlineKFLLCFII From United States of America, joined Sep 2004, 3288 posts, RR: 31
Reply 3, posted (8 years 8 months 4 days 2 hours ago) and read 6043 times:

Per the PA-44-180 Information Manual:

7.33 Stall Warning (para. 3)

The stall warning horn is activated by two lift detectors on the leading edge of the left wing, outboard of the engine nacelle. The inboard detector activates the horn when the flaps are in the 25 and 40 degree positions, the outboard when the flaps are in positions less than 10 degrees. A squat switch in the stall warning system does not allow the units to be activated on the ground.


My assumption is that since there is a turning prop (when the left engine is running) in close proximity to the switches, there is a good chance that the airflow produced by the prop could inadvertently activate one or both switches on the ground if the circuit wasn't linked to the squat switch. Since the outboard blade on the left engine ascends, there a strong probability that the outflow from that blade could get under the lift detector and lift it up (thereby activating the horn if the circuit was linked to the squat switch).

Why this shouldn't apply to singles? The lift deflector(s) are much further away from the turning prop than on the multis.



"About the only way to look at it, just a pity you are not POTUS KFLLCFII, seems as if we would all be better off."
User currently offlineModesto2 From United States of America, joined Jul 2000, 2770 posts, RR: 6
Reply 4, posted (8 years 8 months 3 days 7 hours ago) and read 5994 times:

Based on explanations from instructors, I agree with KFLLCFII. The airflow off the #1 engine could accidentally activate either stall tab. Any other theories?

Top Of Page
Forum Index

Reply To This Topic Stall Warning Tab On PA-44 Piper Seminole
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Stall Warning / Alert posted Fri Oct 31 2003 22:50:41 by Saintsman
Warning Lights On Top posted Sun Apr 14 2002 10:07:05 by Seb146
Stall Warning! posted Tue Mar 5 2002 20:10:19 by Lehpron
Airliner Stall Warning "Stick Shakers"? posted Mon Sep 10 2001 22:48:45 by Mr Spaceman
"I Just Got A Windshear Warning On The System" posted Fri Dec 2 2005 18:55:23 by Julesmusician
Power-On Stall On 172S posted Wed Oct 20 2004 15:18:10 by Corsair2
Power-On Stall posted Sun Aug 3 2003 00:11:33 by Lehpron
Information On The Piper Aztec III posted Wed Jun 25 2003 06:21:43 by Cosync
Your Views On The PA-28-161. posted Mon Sep 17 2001 23:38:37 by King767
Info On 707 Testing 727 Engines posted Wed Dec 6 2006 16:39:20 by Nosedive
Stall Warning / Stick Pusher Re: Colgan Crash posted Mon Mar 30 2009 17:29:04 by Aviateur
Weird GPS On PA-28.. posted Sat Aug 25 2007 12:50:29 by EGBJ
Stall Warning / Alert posted Fri Oct 31 2003 22:50:41 by Saintsman
Warning Lights On Top posted Sun Apr 14 2002 10:07:05 by Seb146
Stall Warning! posted Tue Mar 5 2002 20:10:19 by Lehpron
Airliner Stall Warning "Stick Shakers"? posted Mon Sep 10 2001 22:48:45 by Mr Spaceman
Adjustment Of PA Volume On A320 Enhanced posted Fri Oct 30 2009 04:05:08 by Lufthansi
Background Noise On The PA On DC-9s posted Thu May 29 2008 12:15:51 by Falstaff
"T" Strip On PC-12 Rudder Trim Tab posted Tue Jul 24 2007 15:34:23 by Vzlet
Background Noise On The PA On DC-9s posted Thu May 29 2008 12:15:51 by Falstaff
"T" Strip On PC-12 Rudder Trim Tab posted Tue Jul 24 2007 15:34:23 by Vzlet

Sponsor Message:
Printer friendly format