If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Alternate static on "big iron"?
Last night on Discovery Channel there was a story of a Peruvian 757 that
went down because the two static ports had been taped over for cleaning and not removed. As you might imagine, the airspeed indicator and altimeter gave erroneous readings and fed the onboard computers erroneous data; after a series of bizarre warning messages (zero airspeed and "over speed warning" from the computer) the pilots attempted to correct for contradictory information and multiple warnings and the plane crashed into the ocean Do modern airliners not have an alternate static source as on my 172? Marc |
#2
|
|||
|
|||
Marc Lattoni wrote:
Last night on Discovery Channel there was a story of a Peruvian 757 that went down because the two static ports had been taped over for cleaning and not removed. As you might imagine, the airspeed indicator and altimeter gave erroneous readings and fed the onboard computers erroneous data; after a series of bizarre warning messages (zero airspeed and "over speed warning" from the computer) the pilots attempted to correct for contradictory information and multiple warnings and the plane crashed into the ocean I do not know the answer to your question, but an important point about this crash is that the aircraft was completely flyable and should never have gone down. What caused the aircraft to crash was the fact that both pilots were so distracted attempting to troubleshoot the problem that neither paid any attention to flying the aircraft. I couldn't tell from your synopsis if you were aware that the availability of alternate air was most likely irrelevant to the outcome of this unfortunate accident. -- Peter |
#3
|
|||
|
|||
Why did they even take off? Isn't airspeed a required call-out and part of
the operating rules for all carriers? "Marc Lattoni" wrote in message news:c3%hc.1386$2q2.192@edtnps84... Last night on Discovery Channel there was a story of a Peruvian 757 that went down because the two static ports had been taped over for cleaning and not removed. As you might imagine, the airspeed indicator and altimeter gave erroneous readings and fed the onboard computers erroneous data; after a series of bizarre warning messages (zero airspeed and "over speed warning" from the computer) the pilots attempted to correct for contradictory information and multiple warnings and the plane crashed into the ocean Do modern airliners not have an alternate static source as on my 172? Marc |
#4
|
|||
|
|||
"Brad Z" wrote in message Why did they even take off? Isn't airspeed a
required call-out and part of the operating rules for all carriers? The pitot tube was NOT taped over, only the static ports. The runway at Puerta Plata is fairly level, not much slope. Would the airspeed operate normally until the altitude changed, which would be after rotation? D. |
#5
|
|||
|
|||
"Marc Lattoni" wrote in message Do modern airliners not have an
alternate static source as on my 172? The MD-80 does have an alternate static source for each side. It is a checklist item. However, the crew was distracted at a busy time. Switching to alternate static probably wouldn't come to mind very quickly. D. |
#6
|
|||
|
|||
Brad Z wrote:
Why did they even take off? Isn't airspeed a required call-out and part of the operating rules for all carriers? ASI works just fine on takeoff is the static ports are blocked. Hilton |
#7
|
|||
|
|||
Woops, I had pitot on my mind!
"Capt.Doug" wrote in message news "Brad Z" wrote in message Why did they even take off? Isn't airspeed a required call-out and part of the operating rules for all carriers? The pitot tube was NOT taped over, only the static ports. The runway at Puerta Plata is fairly level, not much slope. Would the airspeed operate normally until the altitude changed, which would be after rotation? D. |
#8
|
|||
|
|||
On the B727, the Captain's or F/O's static sources are selectable from
Normal to "Alternate", which would provide the static instruments with static air which is used for the Mach Airspeed Warning and Pressurization systems "Marc Lattoni" wrote in message news:c3%hc.1386$2q2.192@edtnps84... Last night on Discovery Channel there was a story of a Peruvian 757 that went down because the two static ports had been taped over for cleaning and not removed. As you might imagine, the airspeed indicator and altimeter gave erroneous readings and fed the onboard computers erroneous data; after a series of bizarre warning messages (zero airspeed and "over speed warning" from the computer) the pilots attempted to correct for contradictory information and multiple warnings and the plane crashed into the ocean Do modern airliners not have an alternate static source as on my 172? Marc |
#9
|
|||
|
|||
Marc,
The Canadair Regional Jet has a three static sources. They are selectable from normal to alternate. This usually cross connects the Captains to the F/O and vice versa. The third one is independent for the Mach speed transducer and the Cabin Pressure Acquisition module. It would be safe to assume that if one or more of the static port was taped over for painting then all of them were taped over. Our Turbo Props do not have a selectable static source. They do have selectable Air Data computers though. Michelle Marc Lattoni wrote: Last night on Discovery Channel there was a story of a Peruvian 757 that went down because the two static ports had been taped over for cleaning and not removed. As you might imagine, the airspeed indicator and altimeter gave erroneous readings and fed the onboard computers erroneous data; after a series of bizarre warning messages (zero airspeed and "over speed warning" from the computer) the pilots attempted to correct for contradictory information and multiple warnings and the plane crashed into the ocean Do modern airliners not have an alternate static source as on my 172? Marc -- Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P "Elisabeth" a Maule M-7-235B (no two are alike) Volunteer Pilot, Angel Flight Mid-Atlantic Volunteer Builder, Habitat for Humanity |
#10
|
|||
|
|||
"Marc Lattoni" wrote in message news:c3%hc.1386$2q2.192@edtnps84... Do modern airliners not have an alternate static source as on my 172? Modern airliners have multiple static ports, but they do not have one like your 172. The alternate static port in your 172 uses cabin air. Airliners are pressurized, so an alternate static port like on the 172 would be worthless. |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Is my static port leaking? | Derrick Early | Instrument Flight Rules | 2 | August 15th 04 01:13 AM |
What caused the VSI and ALT bouce in the IMC? | cpu | Instrument Flight Rules | 38 | May 5th 04 03:45 PM |
Transponder test after static system opened? | Jack I | Owning | 6 | March 14th 04 03:09 PM |
Why a static port? | Paul Mennen | Owning | 11 | August 19th 03 04:58 AM |
Static in KX-165A | Chad Lemmen | Owning | 3 | July 21st 03 09:57 PM |