HP Hermes air test after engine change
I am in the throes of writing my Father's aviation career. His last flight (ending in in the crash of Hermes G-ALDV 1/4/58) was for the purposes of an air test. The aircraft was due to fly passengers that afternoon. The take off was normal and there was no hint of trouble until the co-pilot contacted Stanstead ATC informing them that they had jammed controls, 30 seconds later the co-pilot told the ATC that they were about to crash. They did.
From the Inquest witness statements (sometimes grisly, sometimes inaccurate and occasionaly innapropriate) there is 14 minutes during which life after T/O seemed to be normal. My questions are: What would the air test entail? If you were a pilot with jammed elevators (or progressively stiffening elevators) would you turn to Stanstead with its long tempting runway (and Bishops Stortford) or would you head for the farm land in the opposite direction? Google ICAO circular 59-AN/54 David Rayment |
Status:
Date: Tuesday 1 April 1958 Type: Handley Page HP.81 Hermes IVA Operator: Skyways Registration: G-ALDV C/n / msn: HP.81/22 First flight: 1950 Crew: Fatalities: 3 / Occupants: 3 Passengers: Fatalities: 0 / Occupants: 0 Total: Fatalities: 3 / Occupants: 3 Aircraft damage: Damaged beyond repair Location: Phase: Maneuvering (MNV) Nature: Test Departure airport: London-Stansted Airport (STN/EGSS), United Kingdom Destination airport: ? Narrative: The Handley Page Hermes was on a test flight when the controls became jammed. Eyewitnesses saw the plane descending in a series of dives and climbed until it crashed and caught fire. Probable Cause: PROBABLE CAUSE: "The accident was caused by the elevator mechanism becoming jammed. This deprived the pilots of control of the aircraft. The jamming was due to the presence of a small extraneous object which entered the control mechanism." Classification: Elevator issue Loss of control They probably had no choice as to which direction to fly |
HP Hermes air test after engine change
I'm struggling to think what the connection might be, if any, between the engine change and the jammed elevator.
Post hoc ergo propter hoc? |
Ray, if the accident occurred shortly after takeoff i.e in the initial 15-20 minutes of flight I would have expected the engine parameters and performance to have been closely monitored. Had your Dad had the opportunity to continue the air test he would probably have climbed to altitude, closed down the subject engine, checked the feathering and re-started it. I don't know what else would be involved. I did go as a joy-rider on one of our Vikings that was having an air test and that was what I observed. Regards Tom.
|
Somewhere in aviation archives will be a report on an incident on an RAF Hastings which suffered an elevator 'restriction' and which was recovered using trims only. The Hermes was, essentially, a Hastings converted to tricycle (nosewheel) undercarriage. Sadly, control problems of that sort, while rare, are not unique.
|
Hi DaveReidUK - I do not think that there was any direct connection between the jamming and the air test, although the statement "took off and climbed steeply towards the North West" appears in the accident report. Maybe that was sufficient to disturb the jamming object from its resting position. I wonder if the locking mechanism is still resident in the Duxford Hermes? I shall ask them!
|
Tom, thanks for that. Sometime in the 14 minutes of radio quiet they were in the 'Aviate' phase of the emergency. Difficult determine 'when' with few reliabe witnesses!
Regards Ray. |
Originally Posted by DaveReidUK
(Post 10980124)
I'm struggling to think what the connection might be, if any, between the engine change and the jammed elevator.
Post hoc ergo propter hoc? IIRC some years ago there was a UK charter flight out of Tenerife. The crew suffered from control movement being restricted sometime after take off. I believe they could only turn one way. They eventually landed safely, I believe the captain never flew again? Investigators found a spanner fouling the controls. An engineer had left it there during maintenance. Apparently the engineer put a notice in his crew room asking if anyone had seen it. I assume all tools are on a highlighted board, so one can see if anything is missing. I am not suggesting the Hermes accident was similar to this incident, but the report of a extraneous object , reminded me of the incident I have described. This is all from memory, so apologies if my account is wrong. |
rolling20 - the jamming object was probably something like a 3/32" or 1/16" split pin (from the inquest)
|
Originally Posted by rolling20
(Post 10980226)
Investigators found a spanner fouling the controls. An engineer had left it there during maintenance. Apparently the engineer put a notice in his crew room asking if anyone had seen it. I assume all tools are on a highlighted board, so one can see if anything is missing.
|
David,
My home is near Meesden (where the Hermes came down) I've often ridden my bike, or run around the area and wondered if they were trying to make it into Nuthampstead. Though I'm not sure quite where it came down, Meesden is very close. I believe the runways at Nuthampstead weren't broken up unitl the 60's and though I don't think it was operational in 1958, perhaps they were trying to land there. The runway (though shorter than Stansted) would have had the same alignment - 05/23. Good luck with your writing. |
BSD - An interesting theory. The crash site was : 'some 200yds South West of Manor Farm, Meesden' . The A/C crashed on a heading of 040°M, about 1 1/4 miles from Nuthamstead.
Thank You |
Originally Posted by DaveReidUK
(Post 10980280)
That typically only applies to special tools that an engineer wouldn't be expected to possess. Spanners, sockets, etc would typically reside in the individual's own toolbox, as was probably the case here.
|
The Hermes suffered from significant longitudinal instability from the word go - how Handley Page could get there from the aerodynamic refinement of the Halifax is difficult to see. The prototype's maiden flight got out of control on takeoff and crashed after a few miles with the loss of their two principal test pilots, right in front of all the key executives and officials assembled to watch. The production aircraft flew with such a noticeable tail-down attitude that not only did this impact drag but passing aircraft were known to enquire if everything was alright. BOAC junked them within a couple of years, although they had to make a comeback after the loss of the Comet fleet. Independent airlines such as Skyways here were told (straightforwardly, by the Ministry) to buy the aircraft secondhand, to be used on trooping flights - nothing else British made was available and no imports allowed.
|
Originally Posted by WHBM
(Post 10981347)
The Hermes suffered from significant longitudinal instability from the word go - how Handley Page could get there from the aerodynamic refinement of the Halifax is difficult to see. The prototype's maiden flight got out of control on takeoff and crashed after a few miles with the loss of their two principal test pilots, right in front of all the key executives and officials assembled to watch. The production aircraft flew with such a noticeable tail-down attitude that not only did this impact drag but passing aircraft were known to enquire if everything was alright. BOAC junked them within a couple of years, although they had to make a comeback after the loss of the Comet fleet. Independent airlines such as Skyways here were told (straightforwardly, by the Ministry) to buy the aircraft secondhand, to be used on trooping flights - nothing else British made was available and no imports allowed.
I knew a Skyways pilot who flew Hermes' and Connies for Skyways and before that Hastings for the RAF. He never complained about handling on the Hermes or Hastings and they were certified as safe by the ARB and the A&AEE. The reason the Hermes was a disaster for BOAC was appalling payload/range particularly in tropical locations. Hence, they standardised on Argonauts and Connies. The Skyways pilot was Dick Glading. Maybe Davids father encountered him |
Originally Posted by bean
(Post 10981432)
They weren't told to by them, they opted to buy them to try to obtain trooping contracts which were just being introduced
they were certified as safe by the ARB and the A&AEE The reason the Hermes was a disaster for BOAC was appalling payload/range particularly in tropical locations. Commentary on "The Good Old Days" of Airline Travel - Page 2 - PPRuNe Forums |
WHBM.
I think you're being unfair to thr ARB over the Comet they were the first authority in th world to try to certify a jet airliner. You've made assertions about the Hermes pitch attitude in the cruise before. It did"nt stagger along at a noticebly high pitch attitude in level fligh, otherwise, there would have inebitabily have been stalling accidents. Never happened . |
In my researches I talked to at least a dozen pilots and none of them mentioned logitudinal instability. Underpowered yes so the a/c had to be handled carefully. The hosteses had a number of comments about the incline. A small number of engineers commented on the sitting 'backwards', but other aircraft have a similar arangement. On the positive side the comments were that it was quiet, comfortable and handled OK, one pilot even commented that it was quite 'pleasant to fly'. Looking at the accident statistics for the Hasting they seemed to have a prediliction for stalling.
The prototype crashed due to elevator overbalance. The name Dick Gladdings dose not ring any bells - when was he with Skyways? |
There was a significant discussion about the Hermes here some years ago, which may be of interest :
Handley Page Hermes IV - PPRuNe Forums |
You've made assertions about the Hermes pitch attitude in the cruise before. It did"nt stagger along at a noticebly high pitch attitude in level fligh, otherwise, there would have inebitabily have been stalling accidents. Never happened |
All times are GMT. The time now is 05:03. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.