Mitch Cronin Posted September 19, 2003 Share Posted September 19, 2003 I happened upon a tv show yesterday about a 757 accident, where the poor buggers had to fight long and hard with an airplane that had tape over the static ports... they eventually lost the fight. Anyway, it made me wonder if anyone remembers the old trick, taught in some ground schools, of breaking the glass face on the altimiter, so the instrument will at least get static pressure from the airplane? I know in that case it wouldn't be true static pressure, due to a pressurized hull, but even that would have been something better than the completely false trapped air in the static lines they had.... It seemed, from the info given during the show, that at no time did they understand what was going on... (Those poor guys had just about every warning you can think of blaring in their ears all at once!) So my question is a bit more than the one, I guess.... Has that accident led to any more training regarding that kind of problem?... and is breaking the glass ever mentioned as a possible aid in the event? Link to comment Share on other sites More sharing options...
SkyBlazer Posted September 19, 2003 Share Posted September 19, 2003 Hey Mitch, yeah used to talk about it on the F28, and way back I used to fly the puddle jumpers.... But somehow I dont know I would get the same effect if I smashed a PFD on the glass instrument of the Rj.. cheers SB Link to comment Share on other sites More sharing options...
Mitch Cronin Posted September 19, 2003 Author Share Posted September 19, 2003 LOL.... no silly, not the pfd, but the stand by gizmo. lol... Link to comment Share on other sites More sharing options...
Guest neo Posted September 19, 2003 Share Posted September 19, 2003 Hi Mitch, A sticky wicket, what? If you recognize that the problem is blocked static ports, then presumably you could do that depending on how the system is plumbed. And depressurizing the a/c would give you something close to static pressure. But the trick from the pilots' perspective is recognizing what the problem is. Visually (and as you mention, audibly) you get a barrage of conflicting information. Stick shakers and overspeed horns at the same time, stuff like that. Even reverting to 'needle, ball and airspeed' techniques is no good because of course your airspeed indicator is hooped. Couple all that with a dark night (no visual clues) and you'll need to be one cool customer to pull it off. Having seen it in a simulator would help a lot. In the 757/767 you'd stand a decent chance if you could somehow force yourself to disregard everything but your attitude as displayed on the ADI (and standby indicator) and the groundspeed readout. Those are referenced inertially and should give reliable indications. Hope I never have to try it, though. neo Link to comment Share on other sites More sharing options...
B75/76 Posted September 19, 2003 Share Posted September 19, 2003 I remember the trick. With a pressurized hull I suspect the error would remain, just might appear different. I didn't see the show and only have limited knowledge of the accident, but the '57 QRH has power settings and attitudes to deal with such an event. I think that would be the only real option to get safely through this scenario. A very good reason to have in mind, a general idea of these settings for a given phase of flight. Harkens back to another basic; 'Attitude + Power = Performance'. Easier said than done, however, on a dark night when already tired. Link to comment Share on other sites More sharing options...
Guest qb Posted September 19, 2003 Share Posted September 19, 2003 In the incident you're talking about, wasn't it just the captain's airspeed that was affected and that was why they got the overspeed warnings/stall warnings? Didn't they still have two perfectly good airspeed indicators on board (standby and f/o's)? I never saw the show you're talking about but when I flew the 57 that's what we were told in groundschool; that all they had to do was ignore the affected asi and associated warnings. Just curious, qb Link to comment Share on other sites More sharing options...
Guest AME Posted September 19, 2003 Share Posted September 19, 2003 Cockpit Voice Recorders: Transcripts: Birgenair 301 http://www.airdisaster.com/cvr/birgenair.shtml Link to comment Share on other sites More sharing options...
B75/76 Posted September 19, 2003 Share Posted September 19, 2003 At 80 knots "My airspeed is not working" would have been time for a reject. IMHO. Link to comment Share on other sites More sharing options...
Guest pikachu Posted September 19, 2003 Share Posted September 19, 2003 The VSI's on the 757 are elctrically driven. Although they appear to be steam driven gauges all of their inputs come from IRS's and ADC's; not a pressure line. Breaking the glass would not clear any trapped air. Link to comment Share on other sites More sharing options...
Kip Powick Posted September 19, 2003 Share Posted September 19, 2003 I guess it depends on your experience and training but I have always been of the opinion that the most critical aspects of a complete WALKAROUND were clean wings, panels/doors secured, good brakes, good tires, “no drips or slips”, and MOST IMPORTANT, pitot static ports clear of all debris. TRUE STORY… while stationed at CFB Gimli and while instructing a student on circuits with a T-33 I heard a call on the radio from a Tutor pilot in the local area who advised Twr that he had no airspeed indication and was requesting someone who was already flying to escort him down for a final approach and use the assisting air craft in formation as a speed reference. In other words he would fly formation on the assisting aircraft until just before touchdown and then the “lead” would break away. I volunteered. And we rendezvoused in the circuit but he was adamant that he would only fly on my right wing, even though the traffic pattern would have been easier with him on my left wing. He was, by the way, one of the senior base test pilots doing an air test. The flight to final was normal and at about 200 feet he told me he had it “wired” and I was cleared to break away. I leveled off applied power, cleaned up the T-bird, and was accelerating beside and above him when I had a notion to find out why he was adamant that he fly on my right wing. I did a half barrel roll behind him, and over to his right side and as I passed inverted over, and just ahead of his aircraft I looked down and saw the bright red streamer from the pitot tube cover, still attached to his pitot tube, flailing in the breeze as he touched down!!!!! Now I know why he didn’t want me to see the right side of his aircraft, (on a Tutor the pitot tube is on the Rt wing)…….however….. at beer call there was no argument who was paying !!!! Link to comment Share on other sites More sharing options...
B75/76 Posted September 19, 2003 Share Posted September 19, 2003 I expect that was a rather expensive evening for the red faced beer purchaser?! ( Link to comment Share on other sites More sharing options...
Guest Propellerhead Posted September 19, 2003 Share Posted September 19, 2003 http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/ComAndRep/AeroPeru/aeroperu-news.html Link to comment Share on other sites More sharing options...
Mitch Cronin Posted September 19, 2003 Author Share Posted September 19, 2003 Negative... I haven't read the report posted by Propellerhead below, yet (Thanks for that P), ...but at least according to the show: All static ports were taped, and all airspeed, vsi, and altitude info was lost. Add to that the darkness of night, the conflicting and continuous warnings, and the misconception that the Lima controller was reporting their altitude correctly (in reality he was reading the same incorrect altitude the airplane was sending to the controller)... Anyway, now I'll read the report. Thanks for the comments folks. Cheers, Mitch Link to comment Share on other sites More sharing options...
Vsplat Posted September 19, 2003 Share Posted September 19, 2003 I don't know the Boeing, so I'll defer to a guru on type, but on some aircraft even the data fed to the standby instruments is processed by an ADC or other correction. So, I'm not sure what you'd get if you broke the glass. Maybe nothing. On the other hand, if the instrument is connected to the ADC, I'm not sure what other problems you introduce when you break the seal. Again, depending on the aircraft, all sorts of systems draw from the sensor ports. Bottom line, they were set up by a failure of their safety system by taking off in the state they did. Link to comment Share on other sites More sharing options...
Guest HPT-TOUR Posted September 20, 2003 Share Posted September 20, 2003 Heard about it on the CV-580, the FO left them on. Nothin like a little prop heat to melt your troubles away. Link to comment Share on other sites More sharing options...
Guest flatspin Posted September 20, 2003 Share Posted September 20, 2003 Prop heat ?? Link to comment Share on other sites More sharing options...
Guest Rob Assaf Posted September 20, 2003 Share Posted September 20, 2003 My bother-in-law, an MD83 skipper and I watched the same program the other night as well. Several thoughts crossed our minds. 1. Radar altimeter, the MD83 and my lowly Dash 8 are equipped with radar altimeters that kick in at 2500 ft agl. Doesn't the 757 have radar altimeter? 2. as already discussed, attitude and known power settings equal somewhat stable flight. If the instruments are going from looking normal to 0 indicated, then temp normal and then 0 again, then off the clock high, one would have to wonder whether one could trust them even if they started indicating normal readings? 3. a/c knowledge. the mode c transponder works off the a/c static system. Faulty airspeed and suspect altimeter should lead one to know that the mode c readout that atc is using to relay your altitude is also suspect, again, over the pacific, why not select 2500 feet in the DH on the radar altimeter and at least if one gets down to 2500 above the ocean waves you would get a minimums call? 4. use the weather radar? although this might not be of use in this situation because of the over water attenuation of the signal, over land using the weather radar to get a rough idea of altitude is better than nothing. At least an opportunity to keep the game alive till you can get some help in the form of another a/c to formate on to the ILS. As the AC capt said on TV, it is easy to monday morning quarterback that accident. But I'll bet that all of us that watched that will never be able to do a walkaround again without thinking of that event with a plugged static system. Sincerely, Rob Assaf Link to comment Share on other sites More sharing options...
wrench Posted September 20, 2003 Share Posted September 20, 2003 I remember this one. You have got to ask yourself.........Why did they rotate in the first place. Link to comment Share on other sites More sharing options...
Guest HPT-TOUR Posted September 20, 2003 Share Posted September 20, 2003 Gotme, pitot heat. Link to comment Share on other sites More sharing options...
Guest Sopwith Posted September 20, 2003 Share Posted September 20, 2003 PPL have been discussing the right course of action in this thread for two days now. Those guys had about 5 minutes and no 20/20 hindsight to help them. Link to comment Share on other sites More sharing options...
Mitch Cronin Posted September 20, 2003 Author Share Posted September 20, 2003 When you think about it, on the ground, where the static ports were taped, during takeoff is the only place airspeed could have read correctly. Airspeed is just a comparison of dynamic to static pressure. The pitot probes weren't covered, so dynamic pressure did indeed increase during take-off, ...so they would have been reading airspeed. Only when they started climbing would things have started getting silly. Link to comment Share on other sites More sharing options...
Mitch Cronin Posted September 20, 2003 Author Share Posted September 20, 2003 Absolutely right. And, as I understand it, at no time did they ever understand what was happening to them well enough to formulate a good plan, or course of action. The info the Lima controller gave them, though only repeated transponder info, and therefore just as erroneous as their own instruments, they apparently took for gospel. As posted in my initial query, I still find myself wondering if any training benefits came from this one... Do those who are responsible for flight training have their own say in what gets added to the roster of scenarios to throw at people? Do they recieve direction from manufacturers to add certain elements? Does the loss of a shipload of folks over such a ... preventable, and controlable situation result in enough education to prevent a re-occurance? It's good to hear that some will never forget to look, but I've never seen the "new" covers for static vents... I suppose someone has them. Are crews trained to recognize the bizzare series of clues to their being covered? And now having read the report that Propellerhead posted the link to, It's interesting to read the comments on breaking the glass... Maybe it's not the answer I thought it might be... It also presupposes one knows what's wrong. I don't think those poor guys did. Link to comment Share on other sites More sharing options...
Seeker Posted September 20, 2003 Share Posted September 20, 2003 I don't think anyone has mentioned this yet - the Mighty Dash 8 has two independent static systems with normal and alternate selections available on both. The alternate source draws from the nose wheelwell. In addition, at Jazz, we regularly train in the sim in the recognition of pitot/static failures. seeker Link to comment Share on other sites More sharing options...
Mitch Cronin Posted September 20, 2003 Author Share Posted September 20, 2003 That is cool!.... the "Mighty Dash 8"... That twin-weed-wacker-flying-turtle-machine?... Who was it built that again? Good on 'em! And it's good to hear of that training too. Cheers, Mitch Link to comment Share on other sites More sharing options...
Seeker Posted September 20, 2003 Share Posted September 20, 2003 This thread has reminded me of a another story involing aircraft and tape. Fairchild, in San Antonio, would build and assemble their Metros at one airport and then fly them to another airport nearby for paint. After painting they would be flown back to the first airport for final quality checks before being turned over to the customer. One aircraft departed the paint shop airport with the fuel vent taped over on one wing. The Metro has a wet wing with no fuel cell or bladder - just the upper and lower skin of the wing. In the few moments that the flight took ( just a few miles between airports ) the suction of the high pressure fuel pump collapsed the wing to the point where it had to be removed from the aircraft and scrapped. I can't imagine what it would feel like to look at the window and see that happen!! seeker Link to comment Share on other sites More sharing options...
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